Details of the Researcher

PHOTO

Mitsuyuki Nakao
Section
Unprecedented-scale Data Analytics Center
Job title
President-Appointed Extraordinary Professor
Degree

  • 工学博士（東北大学）

  • 工学修士（東北大学）

Research History 7

  • 2022/04 - Present
    Tohoku University　Unprecedented-scale Data Analytics Center　President Appointed Professor

  • 2003/04 - 2022/03
    Tohoku University　Graduate School of Information Sciences Department of Applied Information Sciences　Professor

  • 1993/04 - 2003/03
    Tohoku University　Graduate School of Information Sciences Department of Applied Information Sciences　Associate Professor

  • 1992/05 - 1993/03
    Tohoku University　Faculty of Engineering Department of Electrical,Information and Physics Engineering　Associate Professor

  • 1987/04 - 1992/04
    Tohoku University　Faculty of Engineering Department of Electrical,Information and Physics Engineering　Research Associate

  • 1985/10 - 1987/03
    東北大学 情報処理教育センター　助手

  • 1984/04 - 1985/09
    Tokyo Metropolitan Institute for Gerontology　Department of General Research　Research Associate

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Committee Memberships 5

  • Sleep and Biological Rhythms (Blackwell Publication)　advisor board member

    2004/04 - Present

  • 計測自動制御学会　ライフエンジニアリング部門長

    2017 - 2018

  • 電子情報通信学会　専門別研究会MEとバイオサイバネティクス研究会長

    2016 - 2017

  • 日本睡眠学会　理事

    2004/07 - 2012/06

  • 日本生体医工学会　専門別研究会会長

    2002/05 - 2012/04

Professional Memberships 7

  • 日本生体医工学会

  • 電子情報通信学会

  • 日本時間生物学会

  • 日本睡眠学会

  • 日本生物物理学会

  • 日本生理学会

  • 国際電気電子学会(IEEE)

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Research Interests 31

  • 包括脳ネットワーク

  • コンパ-トメントモデル

  • 脊髄損傷

  • 転写フィードバックモデル

  • 明暗サイクル

  • 指数関数的成長

  • シナプス入力統合特性

  • 最適制御

  • 制御規範

  • 分子制御ネットワークモデル

  • 休息-活動サイクル

  • DSI

  • 引き込み

  • 視交差上核

  • 樹状突起

  • アトラクタ

  • 準安定性

  • 大域的抑制

  • 逆説睡眠

  • インパルス応答

  • 時差飛行

  • 心臓血管系

  • 再同調

  • シナプスの棲み分け

  • 除波睡眠

  • 夢見

  • 海馬

  • 神経回路網モデル

  • 徐波睡眠

  • fゆらぎ

  • 1

Research Areas 6

  • Humanities & social sciences / Linguistics /

  • Life sciences / Biomaterials /

  • Life sciences / Biomedical engineering /

  • Life sciences / Neuroscience - general /

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Control and systems engineering /

  • Informatics / Biological, health, and medical informatics /

Papers 199

  1. Statistical Modeling of Subjective Sleep Quality

    S. Choilek, A. Karashima, I. Motoike, N. Katayama, K. Kinoshita, M. Nakao

    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference　2023　1-6　2023/07/01

    DOI： 10.1109/EMBC40787.2023.10340638 　

    eISSN： 2694-0604

  2. A computational model to explore how temporal stimulation patterns affect synapse plasticity. International-journal

    Ryota Amano, Mitsuyuki Nakao, Kazumichi Matsumiya, Fumikazu Miwakeichi

    PloS one　17　(9)　e0275059　2022

    DOI： 10.1371/journal.pone.0275059 　

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    Plasticity-related proteins (PRPs), which are synthesized in a synapse activation-dependent manner, are shared by multiple synapses to a limited spatial extent for a specific period. In addition, stimulated synapses can utilize shared PRPs through synaptic tagging and capture (STC). In particular, the phenomenon by which short-lived early long-term potentiation is transformed into long-lived late long-term potentiation using shared PRPs is called "late-associativity," which is the underlying principle of "cluster plasticity." We hypothesized that the competitive capture of PRPs by multiple synapses modulates late-associativity and affects the fate of each synapse in terms of whether it is integrated into a synapse cluster. We tested our hypothesis by developing a computational model to simulate STC, late-associativity, and the competitive capture of PRPs. The experimental results obtained using the model revealed that the number of competing synapses, timing of stimulation to each synapse, and basal PRP level in the dendritic compartment altered the effective temporal window of STC and influenced the conditions under which late-associativity occurs. Furthermore, it is suggested that the competitive capture of PRPs results in the selection of synapses to be integrated into a synapse cluster via late-associativity.

  3. Subjective sleep quality, quantitative sleep features, and their associations dependent on demographic characteristics, habitual sleep–wake patterns, and distinction of weekdays/weekends Peer-reviewed

    Siwalee Choilek, Akihiro Karashima, Ikuko Motoike, Norihiro Katayama, Kengo Kinoshita, Mitsuyuki Nakao

    Sleep and Biological Rhythms　2021/05/09

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s41105-021-00326-9 　

    ISSN： 1446-9235

    eISSN： 1479-8425

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    <title>Abstract</title>Generally applicable qualifications of sleep and principles for achieving better sleep are difficult to design, because sleep quality can depend on individual demographic characteristics and lifestyles. In this study, the static and dynamic features of sleep–wake patterns were analyzed in association with quantitative sleep-related parameters and self-rated sleep quality to serve as a practical selection of sleep–wake patterns fitted to individual conditions. Data obtained over a 2-week period by actigraphy from university students and information technology workers were measured to obtain a daily subjective rating of sleep quality using the Oguri–Shirakawa–Azumi (OSA) sleep inventory. Qualitative sleep quality in terms of OSA score and quantitative sleep-related and chronobiological features were analyzed with regard to their dependency on the demographic characteristics, habitual sleep–wake patterns (HSWP), and distinction of weekdays/weekends. Multi-factor ANOVA was used to further investigate their dependencies regarding multiple ways of interactions between the demographic characteristics, HSWP, and distinction of weekdays/weekends. Subjective sleep quality and quantitative sleep-related parameters depended on the demographic characteristics, and so did their associations. The classification of day-to-day variations in HSWP showed four clusters that were effective factors for understanding their dependencies. Multi-factor analysis revealed demographic characteristics, HSWP, distinction of weekdays/weekends, and their multi-way interactions up to 3rd order as significant effectors of qualitative and quantitative quality of sleep. This study clarified how quantitative sleep-related parameters, subjective sleep quality, and their associations depended on demographic characteristics. Furthermore, their dependency was understood as a combination of multi-way interactions between the demographic characteristics, HSWP, and the distinction of weekdays/weekends. Our findings could provide a basis for the design of individually matched sleep–wake patterns.

  4. Estimation of Retinotopic Map of Awake Mouse Brain Based upon Retino-Cortical Response Model.

    R. Togawa, Mitsuyuki Nakao, Norihiro Katayama

    EMBC　4092-4094　2021

    DOI： 10.1109/EMBC46164.2021.9630950 　

  5. Multimodal Functional Analysis Platform: 3. Spherical Treadmill System for Small Animals. International-journal Peer-reviewed

    Norihiro Katayama, Mitsuyuki Nakao, Tetsu Tanaka, Makoto Osanai, Hajime Mushiake

    Advances in experimental medicine and biology　1293　493-500　2021

    DOI： 10.1007/978-981-15-8763-4_33 　

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    In the application of advanced neuroscience techniques including optogenetics to small awake animals, it is often necessary to restrict the animal's movements. A spherical treadmill is a beneficial option that enables virtual locomotion of body- or head-restrained small animals. Besides, it has a wide application range, including virtual reality experiments. This chapter describes the fundamentals of a spherical treadmill for researchers who want to start experiments with it. First, we describe the physical aspect of a spherical treadmill based on the simple mechanical analysis. Next, we explain the basics of data logging and preprocessing for behavioral analysis. We also provide simple computer programs that work for the purpose.

  6. Consistency index of daily activity pattern and its correlations with subjective ratings of QOL Peer-reviewed

    Ryota Amano, Akihiro Karashima, Ikuko Motoike, Norihiro Katayama, Kengo Kinoshita, Mitsuyuki Nakao

    Sleep and Biological Rhythms　18　(4)　297-304　2020

    DOI： 10.1007/s41105-020-00271-z 　

    ISSN： 1446-9235

    eISSN： 1479-8425

  7. Is Sticking to Highly Regular Sleep/Wake Timing Good for Health? -- A quantitative study of associations between sleep/wake habit, objective sleep-related parameters, and subjective sleep quality --

    Siwalee Choilek, Ikuko N. Motoike, Toshihiro Uchibayashi, Akihiro Karashima, Norihiro Katayama, Mitsuyuki Nakao

    119　(224)　35-36　2019/10

  8. Relationship between Dynamics of Physiological Signals and Subjective Quality of Life and Its Lifestyle Dependency Peer-reviewed

    R. Amano, A. Karashima, I. Motoike, N. Katayama, K. Kinoshita, M. Nakao

    Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS　546-549　2019/07

    DOI： 10.1109/EMBC.2019.8857083 　

    ISSN： 1557-170X

  9. 自己評価による睡眠の質と関連した、睡眠中の手首運動の定量的特性(Quantitative characterization of wrist movements during sleep in relation to self-rating sleep quality)

    Choilek Siwalee, Motoike Ikuko N., Uchibayashi Toshihiro, Karashima Akihiro, Katayama Norihiro, Nakao Mitsuyuki

    Sleep and Biological Rhythms　16　(4)　480-480　2018/10

    Publisher: (一社)日本睡眠学会

    ISSN： 1446-9235

    eISSN： 1479-8425

  10. Behavioral testing and resting-state brain functional connectivity analysis of the methimazole-induced transient hypothyroidism mice

    Yuto Yoshida, Ryusei Uchida, Katsuya Uchida, Keiichi Itoi, Mitsuyuki Nakao, Norihiro Katayama

    IEICE Technical Report　MBE2018-33　31　2018/10

  11. Resting-state functional connectivity analysis of the mouse brain using intrinsic optical signal imaging of cerebral blood volume dynamics Peer-reviewed

    Yuto Yoshida, Mitsuyuki Nakao, Norihiro Katayama

    Physiological Measurement　39　(5)　054003　2018/05/24

    DOI： 10.1088/1361-6579/aac033 　

    ISSN： 1361-6579 0967-3334

  12. State-dependent HRV dynamics and their correlations with subjective sleep quality

    AMANO RYOTA, KARASHIMA AKIHIRO, MOTOIKE IKUKO, KATAYAMA NORIHIRO, KINOSHITA KENGO, NAKAO MITSUYUKI

    Transactions of Japanese Society for Medical and Biological Engineering　Annual56　(Abstract)　S331-S331　2018

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI： 10.11239/jsmbe.annual56.s331 　

    ISSN： 1347-443X

    eISSN： 1881-4379

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    Appropriate characterization of state-dependent Heart Rate Variability Dynamics (HRVD) has been explored.We analyzed the difference between state-dependent HRVD and the HRVD of Slow Wave Sleep (SWS: the deepest sleep), together with subjective sleep evaluation. The results showed that the subjective sleep evaluation differentiates the relationship between the state-dependent HRVD with reference to those in SWS. A future study will be further investigation of sleep quality and dynamics of cardiovascular control system.

  13. Estimation of the Retinotopic Map of an Awake Mouse Brain Based upon Intrinsic Optical Signal Imaging Considering the Ocular Position and Variation in Pupil Diameter Peer-reviewed

    Ryunosuke Togawa, Daigo Okuhata, Yuto Yoshida, Mitsuyuki Nakao, Norihiro Katayama

    56　(4)　157-163　2018

    DOI： 10.11239/jsmbe.56.157 　

  14. 【睡眠科学の新潮流】睡眠時神経活動と睡眠 覚醒制御機構の数理モデル

    辛島 彰洋, 中尾 光之

    医薬ジャーナル　53　(2)　669-675　2017/02

    Publisher: (株)医薬ジャーナル社

    ISSN： 0287-4741

  15. Partial correlation-based functional connectivity analysis of the optical intrinsic signals of the mouse neocortex during resting state Peer-reviewed

    Yuto Yoshida, Mitsuyuki Nakao, Norihiro Katayama

    Proceeding of the 8th International Workshop on Biosignal Interpretation (BSI2016)　53-56　2016/09/02

  16. Evaluation of Multidrug Cancer Chronotherapy Based on Cell Cycle Model under Influences of Circadian Clock Peer-reviewed

    Hiroshi Inokawa, Norihiro Katayama, Mitsuyuki Nakao

    2016 38TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　1439-1442　2016

    DOI： 10.1109/EMBC.2016.7590979 　

    ISSN： 1557-170X

  17. Model-based Evaluation of mutidrug cancer chronotherapy

    Hiroshi Inokawa, Norihiro Katayama, Mitsuyuki Nakao

    XIV European Biological Rhythms Society (EBRS) & IV World Congress of Chronobiology (WCC)　56-56　2015/08

  18. Velocity Response-based Modeling of Photoperiod-dependent Synchronization Patterns of Pacemaker Cells in Suprachiasmatic Nucleus Peer-reviewed

    Mitsuyuki Nakao, Ayumi Yoshioka, Norihiro Katayama

    XIV European Biological Rhythms Society (EBRS) & IV World Congress of Chronobiology (WCC)　65-65　2015/08

  19. Performance evaluation of light source noise reduction algorithm based on independent component analysis for optical intrinsic signal data Peer-reviewed

    Yuto Yoshida, Daiki Nakagawa, Akihiro Karashima, Mitsuyuki Nakao, Norihiro Katayama

    Transactions of Japanese Society for Medical and Biological Engineering　53　(6)　328-335　2015

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI： 10.11239/jsmbe.53.328 　

    ISSN： 1347-443X 1881-4379

  20. Reduction of Light Source Noise from Optical Intrinsic Signals of Mouse Neocortex by using Independent Component Analysis Peer-reviewed

    Yuto Yoshida, Daiki Nakagawa, Akihiro Karashima, Mitsuyuki Nakao, Norihiro Katayama

    2015 37TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　6277-6280　2015

    DOI： 10.1109/EMBC.2015.7319827 　

    ISSN： 1557-170X

  21. Modeling of Feedback Mechanisms in Suprachiasmatic Nucleus. Invited Peer-reviewed

    M. Nakao, M. Suzuki, H. Okayama, A. Karashima, N. Katayama

    "Dynamics of Circadian Oscillation in the Suprachiasmatic Nucleus", Ken-ichi Honma ed., Hokkaido Univ Press　115-128　2014

  22. Entrainability of Cell Cycle Oscillator Models with Exponential Growth of Cell Mass Peer-reviewed

    Mitsuyuki Nakao, Tsog-Erdene Enkhkhudulmur, Norihiro Katayama, Akihiro Karashima

    2014 36TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　6826-6829　2014

    DOI： 10.1109/EMBC.2014.6945196 　

    ISSN： 1557-170X

  23. Correlation between Green Autofluorescence and Spontaneous Electroencephalogram in the Cerebral Cortex of Urethane Anesthetized Mice Peer-reviewed

    N.Katayama, D.Nakagawa, A.Ueno, A.Karashima, M.Nakao

    Trans. The Society of Instrument and Control Engineers　50　(8)　602-607　2014

    DOI： 10.9746/sicetr.50.602 　

  24. Targeted subcortical nerve recruitment by controlling waveform of electrical stimulation for MRI-guided surgical ablation Peer-reviewed

    Ayako Ueno, Norihiro Katayama, Akihiro Karashima, Mitsuyuki Nakao

    Advanced Biomedical Engineering　3　139-146　2014

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI： 10.14326/abe.3.139 　

    ISSN： 2187-5219

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    MRI-guided surgical ablation has been used as a novel technique to achieve minimally invasive glioma resection. In this surgery, low-power thermal energy is supplied via a laser probe, which is inserted into the patients brain to coagulate the tumor region. To position the laser probe precisely, intraoperative MRI is performed. However, MRI images cannot provide sufficient details regarding the fiber tracts. In order for surgeons to know the spatial distribution of subcortical nerve tracts and improve safety during surgery, we propose the use of subcortical mapping to support MRI-guided surgical ablation. Conventional electrical stimulation using biphasic rectangular pulses has poor selectivity in nerve recruitment, and precise spatial distribution of nerve fibers in the subcortical region is difficult to obtain. In this study, we conducted computer simulations to determine which waveform of stimulation results in better spatial selectivity. We used a multi-layer volume conductor model of the human skull and neocortex, in which a mathematical model of a human myelinated nerve fiber was embedded. We numerically calculated the nerve responses to extracellular stimulation provided by an electrode attached to the laser probe inserted into the white matter. We evaluated the distance and diameter selectivity of a solitary test pulse alone and that of conditioning stimuli consisting of a triangular waveform and burst pulses followed by the test pulse. The results showed that the distance and diameter selectivity are markedly improved when using conditioning stimuli prior to the test pulse. A mechanism for improvement of selectivity can be explained based on the nonlinear dynamic properties at the axonal node. These results suggest that the novel conditioning waveform has the potential to provide detailed information of nerve fiber tracts to surgeons during MRI-guided surgical ablation.

  25. Development of Distance-Selective Nerve Recruitment for Subcortical Brain Mapping by Controlling Stimulation Waveforms Peer-reviewed

    Ayako Ueno, Akihiro Karashima, Mitsuyuki Nakao, Norihiro Katayama

    2013 35TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　1879-1882　2013

    DOI： 10.1109/EMBC.2013.6609891 　

    ISSN： 1557-170X

  26. Contribution of Visual Feedback to the Hippocampal Theta Activity in Mice Invited Peer-reviewed

    Norihiro Katayama, Keita Hidaka, Akihiro Karashima, Mitsuyuki Nakao

    2013 INTERNATIONAL JOINT CONFERENCE ON AWARENESS SCIENCE AND TECHNOLOGY & UBI-MEDIA COMPUTING (ICAST-UMEDIA)　306-307　2013

    DOI： 10.1109/ICAwST.2013.6765453 　

  27. Reconstruction of Fetal Vector Electrocardiogram from Maternal Abdominal Signals under Fetus Body Rotations Peer-reviewed

    Yuji Nabeshima, Yoshitaka Kimura, Takuro Ito, Kazunari Ohwada, Akihiro Karashima, Norihiro Katayama, Mitsuyuki Nakao

    2013 35TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　7338-7341　2013

    DOI： 10.1109/EMBC.2013.6611253 　

    ISSN： 1557-170X

  28. Is autonomy working under unconscious state of sleep? Invited Peer-reviewed

    Mitsuyuki Nakao, Akihiro Karashima, Norihiro Katayama

    2013 International Joint Conference on Awareness Science and Technology and Ubi-Media Computing: Can We Realize Awareness via Ubi-Media?, iCAST 2013 and UMEDIA 2013　304-305　2013

    Publisher: IEEE Computer Society

    DOI： 10.1109/ICAwST.2013.6765452 　

  29. Improvement of diameter selectivity in nerve recruitment using multi-cuff electrodes Peer-reviewed

    Ayako Ueno, Norihiro Katayama, Akihiro Karashima, Mitsuyuki Nakao

    Advanced Biomedical Engineering　1　36-42　2012/12

    DOI： 10.14326/abe.1.36 　

  30. Development of an Immersive Virtual Reality System for Mice Peer-reviewed

    Norihiro Katayama, Keita Hidaka, Akihiro Karashima, Mitsuyuki Nakao

    SICE Annual Conference (SICE), 2012 Proceedings of　211-214　2012/08

  31. Suppression of anodal break excitation by electrical stimulation with down-staircase waveform for distance-selective nerve recruitment Peer-reviewed

    Ayako Ueno, Akihiro Karashima, Mitsuyuki Nakao, Norihiro Katayama

    Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS　2012　211-214　2012

    DOI： 10.1109/EMBC.2012.6345907 　

    ISSN： 1557-170X

  32. Spatio-temporal dynamics of a myelinated nerve fiber model in response to staircase-shape extracellular electrical stimulation Peer-reviewed

    上野彩子, 片山統裕, 辛島彰洋, 中尾光之

    生体医工学　2012

    DOI： 10.11239/jsmbe.49.896 　

  33. A spike sorting algorithm based on complex-valued ICA solving spatio-temporal mixture and its evaluation Peer-reviewed

    白石泰士, 片山統裕, 辛島彰洋, 中尾光之

    生体医工学　50　(1)　52-61　2012

    Publisher:

    DOI： 10.11239/jsmbe.50.52 　

    ISSN： 1347-443X

    eISSN： 1881-4379

  34. Pontine-wave associated synchronization between hippocampal and amygdala theta waves: a physiological process for sleep-dependent memory processing Peer-reviewed

    Akihiro Karashima, Norihiro Katayama, Mitsuyuki Nakao

    WorldSleep　2011/10

  35. Towards in silico modeling of suprachiasmatic nucleus Peer-reviewed

    M.Nakao, A.Karashima, N.Katayama

    3rd international conference on cognitive neurodynamics　2011/06/09

  36. Neural modeling for cooperative/competitive regulation of REM sleep with NREM sleep and wakefulness Peer-reviewed

    Akihiro Karashima, Yuichi Tamakawa, Yoshimasa Koyama, Norihiro Katayama, Mitsuyuki Nakao

    Rapid Eye Movement Sleep: Regulation and Function　437-449　2011/01/01

    Publisher: Cambridge University Press

    DOI： 10.1017/CBO9780511921179.045 　

  37. Parameter space analysis of extracellular electrical stimulation having staircase waveform for selective excitation of myelinated axons

    Ayako Ueno, Norihiro Katayama, Akihiro Karashima, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　71　E78-E78　2011

    DOI： 10.1016/j.neures.2011.07.333 　

    ISSN： 0168-0102

  38. Accuracy of position estimation of neuron by using extracellular action potential waveforms recorded with multi-site electrodes Peer-reviewed

    Norihiro Katayama, Hou Son, Yasushi Shiraishi, Ayako Ueno, Akihiro Karashima, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　71　E307-E307　2011

    DOI： 10.1016/j.neures.2011.07.1338 　

    ISSN： 0168-0102

  39. Parameter Exploration of Staircase-shape Extracellular Stimulation for Targeted Stimulation of Myelinated Axon Peer-reviewed

    Ayako Ueno, Akihiro Karashima, Mitsuyuki Nakao, Norihiro Katayama

    2011 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　912-915　2011

    ISSN： 1557-170X

  40. Spatio-temporal dynamics of a myelinated nerve fiber model in response to staircase-shape extracellular electrical stimulation Peer-reviewed

    上野彩子, 片山統裕, 辛島彰洋, 中尾光之

    生体医工学　49　(6)　896-903　2011

    Publisher:

    DOI： 10.11239/jsmbe.49.896 　

    ISSN： 1347-443X

    eISSN： 1881-4379

  41. Separation of Multiunit Signals by Independent Component Analysis in Complex-valued Time-Frequency Domain Peer-reviewed

    Yasushi Shiraishi, Norihiro Katayama, Akihiro Karashima, Mitsuyuki Nakao

    2011 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)　4410-4413　2011

    ISSN： 1557-170X

  42. 学生の研究活動におけるプロジェクトマネジメントの有効性 Peer-reviewed

    宮西洋太郎, 庄子栄光, 樋地正浩, 村上隆生, 岩本正敏, 脇山俊一郎, 富樫敦, 曽根秀昭, 中尾光之

    FIT2010(第９回情報科学技術フォーラム)　139-146　2010/09/07

  43. 理念共有型の地域産学協同IT人材育成体系の形成 Peer-reviewed

    庄子栄光, 宮西洋太郎, 樋地正浩, 岩本正敏, 脇山俊一郎, 富樫敦, 曽根秀昭, 中尾光之

    FIT2010(第９回情報科学技術フォーラム)　133-137　2010/09/07

  44. Enhancement of Synchronization Between Hippocampal and Amygdala Theta Waves Associated With Pontine Wave Density Peer-reviewed

    Akihiro Karashima, Norihiro Katayama, Mitsuyuki Nakao

    JOURNAL OF NEUROPHYSIOLOGY　103　(5)　2318-2325　2010/05

    DOI： 10.1152/jn.00551.2009 　

    ISSN： 0022-3077

    eISSN： 1522-1598

  45. Top-down modeling of hierarchical biological clock mechanisms Invited Peer-reviewed

    Mitsuyuki Nakao, Hiroshi Okayama, Akihiro Karashima, Norihiro Katayama

    SLEEP AND BIOLOGICAL RHYTHMS　8　(2)　106-113　2010/04

    DOI： 10.1111/j.1479-8425.2009.00414.x 　

    ISSN： 1446-9235

    eISSN： 1479-8425

  46. Prediction of sleepiness based on auditory evoked potential Peer-reviewed

    Y. Yasui, A. Karashima, H. Nakatani, H. Okubo, N. Katayama, M. Nakao

    5th Int Sympo Med, Bio-, Nano-Electronics　121-122　2010/02

  47. Analysis of spatiotemporal profile of extracellular action potential of a hippocampal pyramidal neuron: a computer simulation study Peer-reviewed

    H. Son, N. Katayama, A. Karashima, M. Nakao

    5th Int Sympo Med, Bio-, Nano-Electronics　119-120　2010/02

  48. Various defuzzification methods on DNA similarity matching using fuzzy inference system Peer-reviewed

    M.Rahmat Widyanto, Nurtami Soedarsono, Norihiro Katayama, Mitsuyuki Nakao

    Journal of Advanced Computational Intelligence and Intelligent Informatics　14　(3)　247-255　2010

    Publisher: Fuji Technology Press

    DOI： 10.20965/jaciii.2010.p0247 　

    ISSN： 1883-8014 1343-0130

  49. ヒト睡眠・覚醒リズムのユーティリティモデルを作る Invited

    中尾光之, 石浦大樹, 辛島彰洋, 片山統裕

    時間生物学　15　(2)　15-20　2009/11

  50. Role of P wave in amygdala and hippocampal theta synchronization during REM sleep in rats

    A. Karashima, N. Katayama, M. Nakao

    ASRS, JSSR, JSC, joint congress 2009, program & abstracts　2009/10/24

  51. ヒト睡眠・覚醒リズムのユーティリティモデルを作る

    中尾 光之, 石浦 大輔, 辛島 彰洋, 片山 統裕

    時間生物学　15　(2)　40-49　2009/10

    Publisher: 日本時間生物学会

    ISSN： 1348-2025

  52. EFFECT OF SLEEP ON AUDITORY EVOKED POTENTIAL Peer-reviewed

    Akihiro Karashima, Hirofumi Okubo, Norihiro Katayama, Hiroto Nakatani, Mitsuyuki Nakao

    JOURNAL OF PHYSIOLOGICAL SCIENCES　59　521-521　2009

    ISSN： 1880-6546

  53. Multi-neuron Action Potentials Recorded with Tetrode are not Instantaneous Mixtures of Single Neuronal Action Potentials Peer-reviewed

    Yasushi Shiraishi, Norihiro Katayama, Tetsuya Takahashi, Akihiro Karashima, Mitsuyuki Nakao

    2009 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-20　1　4019-4022　2009

    DOI： 10.1109/IEMBS.2009.5333505 　

    ISSN： 1557-170X

  54. Modeling of Segmentation Clock Mechanism in Presomitic Mesoderm Peer-reviewed

    A. Kazama, A. Karashima, N. Katayama, M. Nakao

    2009 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-20　1　3267-3270　2009

    DOI： 10.1109/IEMBS.2009.5333510 　

    ISSN： 1557-170X

  55. Model based estimation method of synaptic weight using cross correlation analysis Peer-reviewed

    O. Kikuchi, N. Katayama, A. Karashima, M, Nakao

    生体医工学　46　(6)　667-674　2008/12

    Publisher:

    DOI： 10.11239/jsmbe.46.667 　

    ISSN： 1347-443X

    eISSN： 1881-4379

  56. Development of 3D neural tissue model for virtual multiunit recording and application to the optimization of parameters of multisite neural electrode Peer-reviewed

    T. Kubo, N. Katayama, A. Karashima, M, Nakao

    生体医工学　46　(6)　675-683　2008/12/01

    Publisher:

    DOI： 10.11239/jsmbe.46.675 　

    ISSN： 1347-443X

    eISSN： 1881-4379

  57. Synchronization of amygdala and hippocampal theta rhythm during REM sleep in rats

    A. Karashima, N. Katayama, M. Nakao

    Ann Meet SFN　2008/11

  58. Auditory brainstem responses during wakefulness and sleep

    H. Okubo, A. Karashima, N. Katayama, H. Nakatani, M. Nakao

    Ann Meet SFN　2008/11

  59. Instantaneous theta and alpha rhythm of EEG is related to impairment of drive performance in humans

    K. Watanabe, H. Nakatani, A. Karashima, N. Katayama, M. Nakao

    Ann Meet SFN　2008/11

  60. Progressive changes in sleep electroencephalogram dynamics in the rat barrel cortex associated with long-term alternation of sensory input activities Peer-reviewed

    Naoko Iwasaki, Akihiro Karashima, Norihiro Katayama, Mitsuyuki Nakao

    SLEEP AND BIOLOGICAL RHYTHMS　6　(4)　208-214　2008/10

    DOI： 10.1111/j.1479-8425.2008.00363.x 　

    ISSN： 1446-9235

  61. Balanced reorganization of hippocampal CA3 neural network in vitro Peer-reviewed

    O. Kikuchi, N. Katayama, A. Karashima, M. Nakao

    Intl Sympo Bio- and Nano-Electronics　2008/03/05

  62. A three-dimensional model of hippocampal tissue for assessment of multisite electrode characteristics Peer-reviewed

    T. Kubo, N. Katayama, O. Kikuchi, A. Karashima, M. Nakao

    Intl Sympo Bio- and Nano-Electronics　2008/03/05

  63. Complex-valuded ICA-based realtime spike sorting system for multisite electrode recordings Peer-reviewed

    Y. Shiraishi, N. Katayama, T. Takahashi, O. Kikuchi, A. Karashima, M. Nakao

    Intl Sympo Bio- and Nano-Electronics　2008/03/05

  64. Robustness of the Blind Source Separation with Reference against Uncertainties of the Reference Signals Peer-reviewed

    Totnoyuki Netabayashi, Yoshitaka Kimura, Shinichi Chida, Takuro Ito, Kazunari Ohwada, Norihiro Katayama, Kunihiro Okamura, Mitsuyuki Nakao

    2008 30TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-8　1875-+　2008

    ISSN： 1557-170X

  65. The 3D Position Estimation of Neurons in the Hippocampus Based on the Multi-site Multi-unit Recordings with Silicon Tetrodes Peer-reviewed

    Takashi Kubo, Norihiro Katayama, Akibiro Karashima, Mitsuyuki Nakao

    2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vols 1-8　5021-5024　2008

    ISSN： 1557-170X

  66. Mathematical model of eukaryotic cell cycle and its respobnse to weel stimulation

    Y. Cheng, A. Karashima, N. Katayama, M. Nakao

    2nd World Congress of Chronobiology, Program and Abstract,　92　2007/11

  67. Phase-locking of spontaneous and tone-elicited pontine waves to hippocampal theta waves during REM sleep in rats Peer-reviewed

    Akihiro Karashima, Norihiro Katayama, Mitsuyuki Nakao

    BRAIN RESEARCH　1182　(4)　73-81　2007/11

    DOI： 10.1016/j.brainres.2007.08.060 　

    ISSN： 0006-8993

  68. Integrated model incorporating circadian phase dynamics and the thermoregulatory mechanism of sleep Peer-reviewed

    Daiki Ishiura, Akihiro Karashima, Norihiro Katayama, Mitsuyuki Nakao

    SLEEP AND BIOLOGICAL RHYTHMS　5　(4)　259-270　2007/10

    DOI： 10.1111/j.1479-8425,2007.00319 　

    ISSN： 1446-9235

    eISSN： 1479-8425

  69. Model and actual neuronal activities during transition from NREM to REM sleep

    A. Karashima, Y. Koyama, N. Katayama, M. Nakao

    Proc. World Cong World Federation of Sleep Research　5　A56　2007/09

  70. Mathematical models of regulatory mechanisms of sleep-wake rhythms Invited Peer-reviewed

    M. Nakao, A. Karashima, N. Katayama

    CELLULAR AND MOLECULAR LIFE SCIENCES　64　(10)　1236-1243　2007/05

    DOI： 10.1007/s00018-007-6534-z 　

    ISSN： 1420-682X

    eISSN： 1420-9071

  71. An attempt of modeling signal transduction system in neurons: Computer simulation of PKC translocation wave along dendrites of cerebellar Purkinje cells Peer-reviewed

    Katayama Norihiro, Bao Jio, Karashima Akihiro, Nakao Mitsuyuki, Tsubokawa Hiroshi

    NEUROSCIENCE RESEARCH　58　S28-S28　2007

    DOI： 10.1016/j.neures.2007.06.166 　

    ISSN： 0168-0102

  72. Modeling of extracellular multiple neuronal activities in the three-dimensional hippocampal tissue based on the fluctuation analysis Peer-reviewed

    Takashi Kubo, Norihiro Katayama, Osamu Kikuchi, Akihiro Karashima, Mitsuyuki Nakao

    AIP Conference Proceedings　922　577-580　2007

    DOI： 10.1063/1.2759745 　

    ISSN： 0094-243X 1551-7616

  73. Reduction and retrospection approach to modeling of hierarchical biological rhythms Peer-reviewed

    Mitsuyuki Nakao, Hiroshi Okayama, Norihiro Katayama, Akihiro Karashima

    IEEJ Transactions on Electronics, Information and Systems　127　(10)　1486-1490　2007

    Publisher: Institute of Electrical Engineers of Japan

    DOI： 10.1541/ieejeiss.127.1486 　

    ISSN： 1348-8155 0385-4221

  74. A novel extraction method of fetal electrocardiogram from the composite abdominal signal Peer-reviewed

    Michiyoshi Sato, Yoshitaka Kimura, Shinichi Chida, Takuya Ito, Norihiro Katayama, Kunihiro Okamura, Mitsuyuki Nakao

    IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING　54　(1)　49-58　2007/01

    DOI： 10.1109/TBME.2006.883791 　

    ISSN： 0018-9294

  75. Recurrent excitation of in vitro hippocampal CA3 neurons in response to local glutamate stimulation

    O. Kikuchi, N. Katayama, A. Karashima, M. Nakao

    Annual Meeting of Society for Neuroscience　796.13　2006/11/11

  76. Measurement method for the fetal electrocardiogram Peer-reviewed

    Yoshitaka Kimura, Takuya Ito, Fumiaki Matuyama, Shinichi Chida, Norihiro Katayama, Mitsuyuki Nakao, Kunihiro Okamura

    MINIMALLY INVASIVE THERAPY & ALLIED TECHNOLOGIES　15　(4)　214-217　2006/08

    DOI： 10.1080/13645700600845654 　

    ISSN： 1364-5706

  77. 心臓血管制御系のモデル化

    伊藤 健太, 片山 統裕, 辛島 彰洋, 中尾 光之

    生体医工学　44　(2)　320-320　2006/06

    Publisher: (公社)日本生体医工学会

    ISSN： 1347-443X

    eISSN： 1881-4379

  78. A quartet neural system model orchestrating sleep and wakefulness mechanisms Peer-reviewed

    Y Tamakawa, A Karashima, Y Koyama, N Katayama, M Nakao

    JOURNAL OF NEUROPHYSIOLOGY　95　(4)　2055-2069　2006/04

    DOI： 10.1152/jn.00575.2005 　

    ISSN： 0022-3077

    eISSN： 1522-1598

  79. Estimation of the local neuronal connectivity in the hippocampus in vitro

    Osamu Kikuchi, Norihiro Katayama, Akihiro Karashima, Mitsuyuki Nakao

    Intl Sympo Bio- and Nano-Electronics　P-34　2006/02/03

  80. Wavelet-based neuronal spike sorting method for tetrode-recording data

    Tetsuya Takahashi, Norihiro Katayama, Osamu Kikuch, Akihiro Karashima, Mitsuyuki Nakao

    Intl Sympo Bio- and Nano-Electronics　P-33　2006/02/03

  81. Characterization of cardiovascular dynamics of spinal injury patients

    Takayasu Sakamoto, Norihiro Katayama, Mitsuyuki Nakao, Masanori Munakata

    Intl Sympo Bio- and Nano-Electronics　P-32　2006/02/03

  82. Modeling of somite segmentation clock

    Akihiro Kazama, Norihiro Katayama, Mitsuyuki Nakao

    Intl Sympo Bio- and Nano-Electronics　P-31　2006/02/03

  83. The developing and learning brain during sleep Peer-reviewed

    Mitsuyuki Nakao

    Sleep and Biological Rhythms　4　(1)　2-3　2006/02

    DOI： 10.1111/j.1479-8425.2006.00200.x 　

    ISSN： 1446-9235 1479-8425

  84. Fluctuations and synchronizations of neural activities during sleep: Neural basis of possible sleep functions? Peer-reviewed

    Mitsuyuki Nakao, Akihiro Karashima, Naoko Iwasaki, Norihiro Katayama, Mitsuaki Yamamoto

    Sleep and Biological Rhythms　4　(1)　44-54　2006/02

    DOI： 10.1111/j.1479-8425.2006.00206.x 　

    ISSN： 1446-9235 1479-8425

  85. Fetal ECG extraction with fast nonlinear state space projections Peer-reviewed

    Y. Kimura, T. Ito, F. Matuyama, S. Chiba, M. Seno, N. Katayama, K. Okamura, M. Nakao

    Int Workshop Biosignal Interpretation (BSI2005)　45-47　2005/09

  86. Temporally correlated neuronal discharges induced by local glutamate application in the recurrent neural network of hippocampus in vitro Peer-reviewed

    O. Kikuchi, N. Katayama, A. Karashima, M. Nakao

    Int Workshop Biosignal Interpretation (BSI2005)　179-182　2005/09

  87. Toward hierarchical modeling of biological clock mechanisms Peer-reviewed

    M. Nakao

    Proc. SICE Ann. Conf.　3531-3536　2005/09

  88. Instantaneous acceleration and amplification of hippocampal theta wave coincident with phasic pontine activities during REM sleep Peer-reviewed

    A Karashima, M Nakao, N Katayama, K Honda

    BRAIN RESEARCH　1051　(1-2)　50-56　2005/07

    DOI： 10.1016/j.brainres.2005.05.055 　

    ISSN： 0006-8993

  89. Sleep EEG dynamics in rat barrel cortex associated with sensory deprivation Peer-reviewed

    N Iwasaki, A Karashima, Y Tarnakawa, N Katayama, M Nakao

    NEUROREPORT　15　(17)　2681-2684　2004/12

    DOI： 10.1097/00001756-200412030-00026 　

    ISSN： 0959-4965

  90. Spatio-temporal dynamics of carbachol-induced rhythmic neural activities in the hippocampus in vitro Peer-reviewed

    Norihiro Katayama, Osamu Kikuchi, Naoki Watanabe, Akihiro Karashima, Mitsuyuki Nakao

    Trans. JSMBE　42　(4)　269-276　2004/12

    DOI： 10.11239/jsmbe2002.42.269 　

  91. Accelerations of hippocampal theta wave associated with pontine wave occurrence during REM sleep in rats Peer-reviewed

    A. Karashima, M. Nakao, K. Honda, N, Iwasaki, N. Katayama

    Ann Meet Soc Neurosci　2004/11

  92. Theta wave amplitude and frequency are differentially correlated with pontine waves and rapid eye movements during REM sleep in rats Peer-reviewed

    A Karashima, M Nakao, K Honda, N Iwasaki, N Katayama, M Yamamoto

    NEUROSCIENCE RESEARCH　50　(3)　283-289　2004/11

    DOI： 10.1016/j.neures.2004.07.007 　

    ISSN： 0168-0102

  93. Noise-induced metastability in the Hodgkin-Huxley neural network Peer-reviewed

    N. Katayama, K. Sakamoto, M. Nakao, M. Yamamoto

    Proc. NOLTA 2004　505-508　2004/11

  94. Metastable dynamics of the Hodgkin-Huxley neural network driven by noise Peer-reviewed

    N. Katayama, K. Sakamoto, M. Nakao, M. Yamamoto

    Proc. Intl. Workshop Biol. Inspired Comput.　126-129　2004/11

  95. Modeling interactions between photic and nonphotic entrainment mechanisms in transmeridian flights Peer-reviewed

    M Nakao, K Yamamoto, K Honma, S Hashimoto, S Honma, N Katayama, M Yamamoto

    BIOLOGICAL CYBERNETICS　91　(3)　138-147　2004/09

    DOI： 10.1007/s00422-004-0502-6 　

    ISSN： 0340-1200

  96. Simulating transmeridian flights Peer-reviewed

    Mitsuyuki Nakao, Keisuke Yamamoto, Ken-Ichi Honma, Satoko Hashimoto, Sato Honma, Norihiro Katayama, Mitsuaki Yamamoto

    Sleep and Biological Rhythms　2　(1)　S54　2004/05

    DOI： 10.1111/j.1479-8425.2004.00113.x 　

    ISSN： 1446-9235

  97. Modeling of the suprachiasmatic nucleus based on reduced molecular clock mechanisms Peer-reviewed

    M Nakao, Y Nishimura, K Aoki, N Katayama

    PROCEEDINGS OF THE 26TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-7　26　2897-2900　2004

    ISSN： 1094-687X

  98. Stability of rhythm trajectory generated by feedback loop models Peer-reviewed

    Y. Nishimura, M. Nakao, N. Katayama, M. Yamamoto

    1st world congress of chronobiology　2003/09

  99. Period and phase adjustments of human circadian rhythms in the real world Peer-reviewed

    K Honma, S Hashimoto, M Nakao, S Honma

    JOURNAL OF BIOLOGICAL RHYTHMS　18　(3)　261-270　2003/06

    DOI： 10.1177/0748730403253394 　

    ISSN： 0748-7304

  100. A real-time rapid eye movement sleep analyzer equipped with a portable wide-band polygraphic recorder Peer-reviewed

    Mitsuaki Yamamoto, Norihiro Katayama, Mitsuyuki Nakao, Ryo Kitahara, Takashi Ueno, Ikuo Takeuchi, Noboru Ohki

    Sleep and Biological Rhythms　1　(2)　175-177　2003/03/01

    Publisher: Springer Tokyo

    DOI： 10.1046/j.1446-9235.2003.00038.x 　

    ISSN： 1479-8425 1446-9235

  101. A facial topographic profile of rapid eye movements anticipatory phasic potentials Peer-reviewed

    Ryo Kitahara, Mitsuaki Yamamoto, Norihiro Katayama, Mitsuyuki Nakao, Masato Hattori, Takashi Ueno

    Sleep and Biological Rhythms　1　(2)　151-152　2003/03/01

    Publisher: Springer Tokyo

    DOI： 10.1046/j.1446-9235.2003.00028.x 　

    ISSN： 1479-8425 1446-9235

  102. Changes in the dynamics of sleep electroencephalogram in rat barrel cortex associated with long-term sensory deprivation Peer-reviewed

    Naoko Iwasaki, Akihiro Karashima, Mitsuyuki Nakao, Norihiro Katayama, Mitsuaki Yamamoto

    Sleep and Biological Rhythms　1　(2)　155-157　2003/03/01

    Publisher: Springer Tokyo

    DOI： 10.1046/j.1446-9235.2003.00030.x 　

    ISSN： 1479-8425 1446-9235

  103. Characterization of Baroreflex Response under Head-up Tilting

    M. Nakao, F. Ito, M. Munakata, N. Katayama, M. Yamamoto

    Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings　1　256-259　2003

    ISSN： 0589-1019

  104. Characterization of baroreflex response under head-up tilting Peer-reviewed

    M Nakao, F Ito, M Munakata, N Katayama, M Yamamoto

    PROCEEDINGS OF THE 25TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-4　25　256-259　2003

    ISSN： 1094-687X

  105. Modeling feedbacks from behavior to pacemakers in non-photic entrainment of human circadian system Invited Peer-reviewed

    Mitsuyuki Nakao

    Proc. 9th Sapporo Symposium on Biological Rhythm　219-231　2003

  106. Phase-locking of spontaneous and elicited ponto-geniculo-occipital waves is associated with acceleration of hippocampal theta waves during rapid eye movement sleep in cats Peer-reviewed

    A Karashima, K Nakamura, N Sato, M Nakao, N Katayama, M Yamamoto

    BRAIN RESEARCH　958　(2)　347-358　2002/12

    DOI： 10.1016/S0006-8993(02)03673-9 　

    ISSN： 0006-8993

  107. A phase dynamics model of human circadian rhythms Peer-reviewed

    M Nakao, K Yamamoto, KI Honma, S Hashimoto, S Honma, N Katayama, M Yamamoto

    JOURNAL OF BIOLOGICAL RHYTHMS　17　(5)　476-489　2002/10

    DOI： 10.1177/074873002237141 　

    ISSN： 0748-7304

  108. Elicited ponto-geniculo-occipital waves by auditory stimuli are synchronized with hippocampal theta-waves Peer-reviewed

    A Karashima, K Nakamura, M Horiuchi, M Nakao, N Katayama, M Yamamoto

    PSYCHIATRY AND CLINICAL NEUROSCIENCES　56　(3)　343-344　2002/06

    ISSN： 1323-1316

  109. Under-estimation of baroreflex sensitivity through a closed loop model due to non-gaussian property of blood pressure distribution

    M. Nakao, F. Ito, N. Katayama, M. Yamamoto

    Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings　2　1613-1614　2002

    ISSN： 0589-1019

  110. Under-estimation of baroreflex sensitivity through a closed loop model due to non-Gaussian property of blood pressure distribution Peer-reviewed

    M Nakao, F Ito, N Katayama, M Yamamoto

    SECOND JOINT EMBS-BMES CONFERENCE 2002, VOLS 1-3, CONFERENCE PROCEEDINGS　1613-1614　2002

    ISSN： 1094-687X

  111. Error measures of the back-propagation learning algorithm Peer-reviewed

    S.Fujiki, M.Nakao, N.M. Fujiki

    J. Korean Physical Society　40　(6)　1091-1095　2002/01

  112. Phase shift of coupled oscillator model with feedbacks in response to multiple bright light exposure Peer-reviewed

    Mitsuyuki Nakao, Keisuke Yamamoto, Norihiro Katayama, Mitsuaki Yamamoto

    Psychiatry and Clinical Neurosciences　56　(3)　215-216　2002

    DOI： 10.1046/j.1440-1819.2002.00981.x 　

    ISSN： 1323-1316

  113. Mutual entrainment in a brain slice-artificial oscillator hybrid Peer-reviewed

    N. Katayama, D. Hyakutake, M. Nakao, M. Yamamoto

    Proc. NOLTA　2　375-378　2001/11

  114. Quantitative characteristics of alpha and theta EEG activities during sensory deprivation Peer-reviewed

    K Iwata, M Nakao, M Yamamoto, M Kimura

    PSYCHIATRY AND CLINICAL NEUROSCIENCES　55　(3)　191-192　2001/06

    ISSN： 1323-1316

  115. Synchronization between hippocampal theta waves and PGO waves during REM sleep Peer-reviewed

    A Karashima, K Nakamura, M Watanabe, N Sato, M Nakao, N Katayama, M Yamamoto

    PSYCHIATRY AND CLINICAL NEUROSCIENCES　55　(3)　189-190　2001/06

    DOI： 10.1046/j.1440-1819.2001.00820.x 　

    ISSN： 1323-1316

  116. A circadian system model with feedback of cross-correlation between sleep-wake rhythm and oscillator Peer-reviewed

    M Nakao, K Yamamoto, K Nakamura, N Katayama, M Yamamoto

    PSYCHIATRY AND CLINICAL NEUROSCIENCES　55　(3)　295-297　2001/06

    DOI： 10.1046/j.1440-1819.2001.00865.x 　

    ISSN： 1323-1316

  117. An optimal control model of 1/f fluctuations in heart rate variability Peer-reviewed

    M Nakao, T Takizawa, K Nakamura, N Katayama, M Yamamoto

    IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE　20　(2)　77-87　2001/03

    DOI： 10.1109/51.917727 　

    ISSN： 0739-5175

  118. A model-based interpretation of phantom pain: Conservative body schema and flexible somatotopy Peer-reviewed

    M.Nakao, M.Kawai, Y.Mizutani, N.Katayama, M.Yamamoto

    Interdisciplinary Information Sciences　7　(2)　247-258　2001/01

  119. Dynamics of a hybrid system of a brain neural network and an artificial nonlinear oscillator Peer-reviewed

    N Katayama, M Nakao, H Saitoh, M Yamamoto

    BIOSYSTEMS　58　(1-3)　249-257　2000/10

    DOI： 10.1016/S0303-2647(00)00129-5 　

    ISSN： 0303-2647

  120. High frequency polygraphic observations during rapid eye movement sleep

    M. Yamamoto, K. Suzuki, K. Nakamura, M. Nakao, N. Katayama, T. Ueno

    Sleep　23　(Suppl.2)　A140-A141　2000/06

  121. Consistency in slow dynamics of single neuronal activities, in lateral geniculate nucleus region

    K. Nakamura, M. Yamamoto, K. Takahashi, M. Nakao, Y. Mizutani, N. Katayama, T. Kodama

    Sleep　23　(Suppl.2)　A141　2000/06

  122. Differentiation of physiological states under sensory deprivation Peer-reviewed

    K Iwata, M Nakao, M Yamamoto, M Kimura

    METHODS OF INFORMATION IN MEDICINE　39　(2)　168-170　2000/06

    ISSN： 0026-1270

  123. Relative power contributions of unit discharges simultaneously recorded in the mesencephalic reticular formation Peer-reviewed

    T Kodama, Y Honda, M Nakao, S Sato, M Yamamoto

    PSYCHIATRY AND CLINICAL NEUROSCIENCES　54　(3)　265-267　2000/06

    DOI： 10.1046/j.1440-1819.2000.00671.x 　

    ISSN： 1323-1316

  124. A control strategy underling 1/f flutuations int heart rate variability Peer-reviewed

    M Nakao, A Ito, N Katayama, M Yamamoto

    IEEE-EMBS ASIA PACIFIC CONFERENCE ON BIOMEDICAL ENGINEERING - PROCEEDINGS, PTS 1 & 2　340-341　2000

  125. Nonlinear dynamics of a brain slice-computer hybrid Peer-reviewed

    N.Katayama, M.Nakao, H.Saitoh, M.Yamamoto

    Proc. Symp. Dynamical Aspects of Complex Systems (DACS2000)　2000/01

  126. A Loose Control Mechanism Underlying 1/f Fluctuations in Heart Rate Variability Peer-reviewed

    M.Nakao, A.Ito, K.Nakamura, N.Katayama, M.Yamamoto

    Proc. World Congress on Medical Physics and Biomedical Engineering　2000/01

  127. State-dependency of neuronal slow dynamics during sleep observed in cat lateral geniculate nucleus Peer-reviewed

    Kazuhiro Nakamura, Mitsuaki Yamamoto, Kazumi Takahashi, Mitsuyuki Nakao, Yoshinari Mizutani, Norihiro Katayama, Tohru Kodama

    Sleep Research Online　3　(4)　147-154　2000

    ISSN： 1096-214X

  128. Thermoregulatory model of sleep control: Losing the heat memory Peer-reviewed

    M Nakao, D McGinty, R Szymusiak, M Yamamoto

    JOURNAL OF BIOLOGICAL RHYTHMS　14　(6)　547-556　1999/12

    DOI： 10.1177/074873099129000885 　

    ISSN： 0748-7304

  129. A model-based interpretation of the biphasic daily pattern of sleepiness Peer-reviewed

    M Nakao, H Nishiyama, D McGinty, R Szymusiak, M Yamamoto

    BIOLOGICAL CYBERNETICS　81　(5-6)　403-414　1999/11

    ISSN： 0340-1200

  130. Investigation of the time delay between variations in heart rate and blood pressure Peer-reviewed

    Y Zhao, M Yamamoto, M Munakata, M Nakao, N Katayama

    MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING　37　(3)　344-347　1999/05

    ISSN： 0140-0118

  131. Modeling neuronal dynamics-transition during sleep - A possible framework for investigating the function of dreaming in higher-order brain function Peer-reviewed

    M Nakao, M Yamamoto

    IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE　18　(3)　99-107　1999/05

    DOI： 10.1109/51.765195 　

    ISSN： 0739-5175

  132. A study on polysomnographic observations and subjective experiences under sensory deprivation Peer-reviewed

    K Iwata, M Yamamoto, M Nakao, M Kimura

    PSYCHIATRY AND CLINICAL NEUROSCIENCES　53　(2)　129-131　1999/04

    DOI： 10.1046/j.1440-1819.1999.00517.x 　

    ISSN： 1323-1316

  133. Night-day-night sleep-wakefulness monitoring by ambulatory integrated circuit memories Peer-reviewed

    M Yamamoto, M Nakao, N Katayama, M Waku, K Suzuki, K Irokawa, M Abe, T Ueno

    PSYCHIATRY AND CLINICAL NEUROSCIENCES　53　(2)　171-173　1999/04

    DOI： 10.1046/j.1440-1819.1999.00526.x 　

    ISSN： 1323-1316

  134. Differentiation of Physiological States under Sensory Deprivation Based on Distance Measure of Biosignal Dynamics Peer-reviewed

    K.Iwata, M.Nakao, M.Yamamoto, M.Kimura

    Proc. 3rd Int'l Workshop on Biosignal Interpretaion　96-99　1999/01

  135. Dynamics of Coupled Systems of Brain Neural Network and Artificial Nonlinear Oscillator Peer-reviewed

    N.Katayama, M.Nakao, H.Saitoh, M.Yamamoto

    Proc. Int'l Workshop Neuro. Coding　203-206　1999/01

  136. A Circle Map Model of Human Circadian Systems Peer-reviewed

    H.Sakai, M.Nakao, M.Yamamoto

    Frontiers of Medical and Biological Engineering　9　75-92　1999/01

  137. An Optimal Control Model of 1/f Fluctuations in Heart Rate Variabilities Peer-reviewed

    M.Nakao, T.Takizawa, N.Katayama, M.Yamamoto

    Proc. 15th Int'l Conf. Noise in Physical Systems and 1/f Fluct.　187-190　1999/01

  138. 1/f Fluctuations of Cat's Inter-heartbeat Intervals in Extremely Low Frequency Range Peer-reviewed

    M.Yamamoto, M.Nakao, K.Nakamura, T.Takizawa, Y.Igarashi, N.Katayama, Y.Mizutani, N.Ikuta, E.Chiba, R.Ando

    Proc. 15th Int'l Conf. Noise in Physical Systems and 1/f Fluct　191-194　1999/01

  139. 心臓血管系信号ダイナミクスの多変量多状態解析. Peer-reviewed

    中尾光之, 広川 賢, 片山統裕, 山本光璋, 宗像正徳

    電子情報通信学会論文誌　J82-D-II　(11)　2132-2142　1999/01

  140. Novel Polygraphic Observations in High Frequency Range during Rapid Eye Movement Sleep Peer-reviewed

    M.Yamamoto, K.Suzuki, K.Nakamura, M.Nakao, N.Katayama T.Ueno

    Interdisciplinary Information Sciences　5　(2)　99-108　1999/01

    Publisher: Tohoku University

    DOI： 10.4036/iis.1999.99 　

    ISSN： 1340-9050

    More details Close

    EEG activities in the higher frequency range rather than the conventionally used was hypothesized to be more directly related to neurogenic activities which are expected to construct EEG activities. According to this hypothesis, EEG activities up to 90 Hz were measured and analyzed during REM sleep. REM sleep is considered to be only a physiological state which allows one to measure the high frequency EEG activities without contamination of EMG due to muscle atonia except for twitches. The study found that the rhythmic activities with different frequencies randomly appeared one after another in the frequency range up to at least 90 Hz. This result suggests that the rivalry among small neural assemblies activated synchronously is realized during REM sleep, which might be understood within our hypothesized framework of disinhibition and activation associated with REM sleep. In addition, the extremely wide bandwidth of 500 Hz analyzed here disclosed the phasic potentials related to the rapid eye movements which had the consistent topographic pattern, i.e., frontal positive and occipital negative, which suggests the dipole located deep in the brain. This phasic event may be related to a neurogenic potential generating ponto-geniculo-occipital (PGO) wave observed in cats during REM sleep. Therefore, our finding potentially discloses novel aspects of human neurophysiology.

  141. Neuronal dynamics-transition during sleep Invited

    M. Yamamoto, K. Nakamura, K. Takahashi, M. Nakao, T. Kodama, N. Katayama

    Proc. 2nd RIEC Int'l Symposium DAIPS　91-96　1998/11

  142. A Formal Neuron Model with Active Dendrites Invited Peer-reviewed

    N. Katayama, M. Nakao, M. Yamamoto

    Methodologies for the Conception, Design and Application of Soft Computing　105-108　1998/11

  143. Bifurcation properties of the two process model Peer-reviewed

    M Nakao, M Yamamoto

    PSYCHIATRY AND CLINICAL NEUROSCIENCES　52　(2)　131-133　1998/04

    ISSN： 1323-1316

  144. Dynamics of active neuronal dendrites and their functional significance Peer-reviewed

    N Katayama, M Nakao, M Yamamoto

    1998 SECOND INTERNATIONAL CONFERENCE ON KNOWLEDGE-BASED INTELLIGENT ELECTRONIC SYSTEMS, KES '98, PROCEEDINGS, VOL, 3　240-245　1998

  145. A cardiovascular control model of l/f fluctuations in heart rate variability Peer-reviewed

    M Nakao, T Takizawa, K Nakamura, N Katayama, M Yamamoto

    PROCEEDINGS OF THE 20TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 20, PTS 1-6　20　279-282　1998

    ISSN： 1094-687X

  146. Higher-Order Spectra of Cluster Point Processes Generating 1/f Fluctuations Peer-reviewed

    T.Takahashi, M.Nakao, F.Gruneis, Y.Mizutani, M.Yamamoto

    Interdisciplinary Information Sciences　4　(1)　51-64　1998/01

    Publisher: Tohoku University

    DOI： 10.4036/iis.1998.51 　

    ISSN： 1340-9050

    More details Close

    1/f fluctuations have been extensively observed in various fields including both biology and physics. Recently, a cluster point process has been successfully applied to modeling the physically and the physiologically observed series of events which exhibit 1/f fluctuations. In this paper, the higher-order spectra up to the 3rd order are derived for the general cluster point processes whose primary and secondary processes are renewal according to the heuristic shot noise approach. As far as the cluster point process whose primary process is Poissonian, the results coincide with those obtaind by the probability generating functional. In the context of 1/f fluctuations, the power spectral densities (PSD) and the bispectra are given for varied parameters, especially for the power law distribution of cluster size. In addition to the rising landscape in the lower frequency range, these 2nd- and 3rd-order spectra are shown to have undulating structures that reflect the periodicity of event occurrence within the clusters, which indicates that there are quadratic correlations between the dominant frequency components that construct the 1/f profile in the PSD. Although several point process models that can produce the 1/f PSD have been proposed, the bispectra could be a possible measure for selecting an appropriate model from these candidates and may contribute to identifying the generation mechanism of the 1/f fluctuation.

  147. Current-source Density Analysis of Back-propagation of Somatic Excitation Into Hippocampal Pyramidal Cell Dendrites Peer-reviewed

    N.Katayama, R.Nakayama, M.Nakao, M.Yamamoto

    Proc. 2nd RIEC Intl Sympo. (DAIPS)　153-156　1998/01

  148. Structural Analyses of 1/f Fluctuations in Heart Rate Variability Based on their Spectrograms Peer-reviewed

    M.Nakao, N.Katayama, M.Yamamoto, M.Munakata

    Jpn J Med Electron and Biol Eng　36　(4)　370-381　1998/01

    DOI： 10.11239/jsmbe1963.36.370 　

  149. An interpretation of the internal desynchronizations based on dynamics of the two-process model Peer-reviewed

    M Nakao, H Sakai, M Yamamoto

    METHODS OF INFORMATION IN MEDICINE　36　(4-5)　282-285　1997/12

    ISSN： 0026-1270

  150. Metastable associative network models of dream sleep Peer-reviewed

    M Nakao, Honda, I, M Musila, M Yamamoto

    NEURAL NETWORKS　10　(7)　1289-1302　1997/10

    DOI： 10.1016/S0893-6080(97)00061-0 　

    ISSN： 0893-6080

  151. GABAergic control of backpropagating dendritic potentials in guinea pig hippocampal neurons

    Norihiro Katayama, Ryo Nakayama, Mitsuyuki Nakao, Mitsuaki Yamamoto

    20th annual meet. Japan Neurosci Society　131　1997/09

  152. A model-based prediction of circadian system responses to a heat load pulse Peer-reviewed

    M Nakao, T Ichikawa, D McGinty, R Szymusiak, M Yamamoto

    PROCEEDINGS OF THE 18TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 18, PTS 1-5　18　1729-1730　1997

  153. Characterization of multivariate cardiovascular dynamics during head-up tilting based on Kullback-Leibler divergence Peer-reviewed

    M Nakao, M Sawada, Y Matsushita, N Katayama, M Yamamoto, M Munakata

    PROCEEDINGS OF THE 19TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 19, PTS 1-6　19　2180-2183　1997

    ISSN： 1094-687X

  154. State-dependent responsiveness of cardiovascular system during sleep and wakefulness Peer-reviewed

    M Sawada, M Nakao, M Yamamoto, M Munakata, Y Imai, K Abe

    PROCEEDINGS OF THE 18TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 18, PTS 1-5　18　1800-1801　1997

  155. Model-based Study on Activeness of Neuronal Dendrites and its Functional Significance Peer-reviewed

    中尾光之, 片山統裕, 山本光璋

    Jpn J. Medical Electronics and Biological Engineering　35　(3)　6-16　1997/01

    DOI： 10.11239/jsmbe1963.35.254 　

  156. Thickness controls spatial cooperation of calcium-activated dynamics in neuronal dendrite system Peer-reviewed

    N Katayama, M Nakao, Y Mizutani, M Yamamoto

    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES　E80A　(1)　197-205　1997/01

    ISSN： 0916-8508

    eISSN： 1745-1337

  157. Measurement of burning sensation and change of blood flow elicited by contact heat stimulation at forearm and lower leg in human Peer-reviewed

    Y Mizutani, K Karita, K Takashima, E Gobo, M Nakao, M Yamamoto

    PROCEEDINGS OF THE 8TH WORLD CONGRESS ON PAIN　8　427-433　1997

  158. Spectral distortion properties of the integral pulse frequency modulation model Peer-reviewed

    Mitsuyuki Nakao, Masashi Norimatsu, Yoshinari Mizutani, Mitsuaki Yamamoto

    IEEE Transactions on Biomedical Engineering　44　(5)　419-426　1997

    Publisher: IEEE Computer Society

    DOI： 10.1109/10.568918 　

    ISSN： 0018-9294

  159. Effect of spatial facilitation on neural network excitability Peer-reviewed

    Miroslav Musila, Mitsuyuki Nakao, Alan Fine, Mitsuaki Yamamoto

    Cybernetics and Systems　27　(4)　367-383　1996

    DOI： 10.1080/019697296126471 　

    ISSN： 1087-6553 0196-9722

  160. An Interpretation of the Internal Desynchronizations Based on Dynamics of the Two Process Model Peer-reviewed

    M.Nakao, H.Sakai, M.Yamamoto

    Proc. IMIA-IFMBE Int'l Workshop on Biosignal Interpret.　91-94　1996/01

  161. NORMAL SYMPATHETIC VASOMOTOR AND CARDIAC PARASYMPATHETIC ACTIVITIES IN PATIENTS WITH PRIMARY ALDOSTERONISM - ASSESSMENT BY SPECTRAL-ANALYSIS Peer-reviewed

    M MUNAKATA, Y IMAI, J HASHIMOTO, K OMATA, M NAKAO, M YAMAMOTO, K ABE

    JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM　52　(2-3)　213-223　1995/04

    ISSN： 0165-1838

  162. Trajectory analyses of time-varying multivariate cardiovascular dynamics based on a distance measure

    Mitsuyuki Nakao, Ken Hirokawa, Naoyuki Kawachi, Mitsuaki Yamamoto, Masanori Munakata, Yutaka Imai, Keishi Abe

    Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings　17　(1)　117-118　1995

    ISSN： 0589-1019

  163. DYNAMICAL FEATURES OF THERMOREGULATORY MODEL OF SLEEP CONTROL Peer-reviewed

    M NAKAO, D MCGINTY, R SZYMUSIAK, M YAMAMOTO

    JAPANESE JOURNAL OF PHYSIOLOGY　45　(2)　311-326　1995

    DOI： 10.2170/jjphysiol.45.311 　

    ISSN： 0021-521X

  164. Dynamic Properties in Time Series of Single Neuronal Activity during Sleep Peer-reviewed

    M.Yamamoto, M.Nakao, Y.Mizutani, T.Kodama

    Adv. Neurol. Sci.　39　(1)　29-40　1995/01

    DOI： 10.11477/mf.1431900616 　

  165. A THERMOREGULATORY MODEL OF SLEEP CONTROL Peer-reviewed

    M NAKAO, D MCGINTY, R SZYMUSIAK, M YAMAMOTO

    JAPANESE JOURNAL OF PHYSIOLOGY　45　(2)　291-309　1995

    DOI： 10.2170/jjphysiol.45.291 　

    ISSN： 0021-521X

  166. A Further Study on 1/f Fluctuations in Cat's Inter-Heartbeat Intervals Peer-reviewed

    M.Yamamoto, M.Nakao, Y.Koshikawa, K.Nakamura, N.Ikuta, T.Hondou, Y.Mizutani, R.Ando, S.Nitta, T.Yambe, H.Sei

    Proc. 13th Int'l Con. Noise in Physical Systems and 1/f fluctuations　651-654　1995/01

  167. Dynamics Transition of Cortical Neuronal Activity between REM Sleep and Slow Wave Sleep Peer-reviewed

    M.Yamamoto, M.Nakao, T.Kodama, A.Hanzawa, K.Nakamura, N.Katayama

    4th IBRO Congress of Neurosci.　404-404　1995/01

  168. ALTERED FREQUENCY-DEPENDENT CHARACTERISTICS OF THE CARDIAC BAROREFLEX IN ESSENTIAL-HYPERTENSION Peer-reviewed

    M MUNAKATA, Y IMAI, H TAKAGI, M NAKAO, M YAMAMOTO, K ABE

    JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM　49　(1)　33-45　1994/09

    ISSN： 0165-1838

  169. PHARMACOLOGICAL AND MODEL-BASED INTERPRETATION OF NEURONAL DYNAMICS TRANSITIONS DURING SLEEP-WAKING CYCLE Peer-reviewed

    M YAMAMOTO, M NAKAO, Y MIZUTANI, T TAKAHASHI, K WATANABE, H ARAI, N SASAKI

    METHODS OF INFORMATION IN MEDICINE　33　(1)　125-128　1994/03

    ISSN： 0026-1270

  170. Capability of intensity discrimination in multiple receptor model of insect taste Peer-reviewed

    Mitsuyuki Nakao, Yoshiyuki Kawazoe, Ichiro Shimada

    Chemical Senses　19　(4)　317-329　1994

    DOI： 10.1093/chemse/19.4.317 　

    ISSN： 0379-864X

  171. Simulation of Interneuronal Control of Dendritic Action Potential Propagation in Hippocampal CA1 Pyramidal Neurons Peer-reviewed

    N.Katayama, M.Nakao, Y.Mizutani, M.Yamamoto

    [Proc. Int'l Conf. Neural Inform. Processing　1277-1282　1994/01

  172. Measurement and Analysis of Single Neuronal Activities from an Unrestrained Cat in Natural Outdoor Conditions Peer-reviewed

    M.Nakao, I.Honda, M.Musila, M.Yamamoto

    Proc. ICONIP　30　(1)　1692-1697　1994/01

    Publisher:

    ISSN： 0453-4654

  173. 自然環境下における無拘束ネコの脳単一ニューロン活動の計測と解析 Peer-reviewed

    水谷好成, 尾形義徳, 高橋利光, 斉藤聰, 中尾光之, 松本伍良

    計測自動制御学会論文集　30　(1)　1-8　1994/01

    Publisher:

    DOI： 10.9746/sicetr1965.30.1 　

    ISSN： 0453-4654

  174. Simulation study on oscillatory dynamics of thalamic relay neuron with delayed recurrent input Peer-reviewed

    Nobuya Hidaka, Norihiro Katayama, Mitsuyuki Nakao, Yoshinari Mizutani, Mitsuaki Yamamoto

    Int. Conf. Cellular Consequences of Sleep　432　1993/08

  175. FURTHER STUDY ON 1/F FLUCTUATIONS OBSERVED IN CENTRAL SINGLE NEURONS DURING REM-SLEEP Peer-reviewed

    F GRUNEIS, M NAKAO, Y MIZUTANI, M YAMAMOTO, M MEESMANN, T MUSHA

    BIOLOGICAL CYBERNETICS　68　(3)　193-198　1993/01

    DOI： 10.1007/BF00224851 　

    ISSN： 0340-1200

  176. Simulation Study on Calcium-activated Dynamics of Compartment Dendrite Model Peer-reviewed

    N.Katayama, M.Nakao, Y.Mizutani, M.Yamamoto

    Proc. Internat. Conf. Artificial Neural Net.　205-205　1993/01

  177. Characterization of Cardiovascular Dynamics on the Basis of Slow Wave Sleep Peer-reviewed

    M.Nakao, H.Takagi, Y.Mizutani, M.Yamamoto, M.Munakata, Y.Imai, K.Abe

    Proc. 15th Ann. Intl Conf. IEEE Eng. Med. Biol.　15　566-567　1993/01

  178. Metastability of Network Attractor and Dream Sleep Peer-reviewed

    M.Nakao, K.Watanabe, Y.Mizutani, M.Yamamoto

    Proc. Int'l Conf. Art. Neural Net.　27-30　1993/01

  179. SIMULATION STUDY ON HIERARCHICAL INFORMATION-PROCESSING ON THE ACTIVE NEURONAL DENDRITES Peer-reviewed

    N KATAYAMA, M NAKAO, Y MIZUTANI, M YAMAMOTO

    IJCNN '93-NAGOYA : PROCEEDINGS OF 1993 INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOLS 1-3　123-126　1993

  180. ROBUSTNESS OF 1/F FLUCTUATIONS IN P-P INTERVALS OF CATS ELECTROCARDIOGRAM Peer-reviewed

    M YAMAMOTO, M NAKAO, Y MIZUTANI, T TAKAHASHI, H ARAI, Y NAKAMURA, M NORIMATSU, N IKUTA, R ANDO, S NITTA, T YAMBE

    NOISE IN PHYSICAL SYSTEMS AND 1/F FLUCTUATIONS　(285)　687-692　1993

    ISSN： 0094-243X

  181. Bispectrum of Single Neuronal Activity in Cat's Brain Interpreted as Clustering Poisson Process Peer-reviewed

    T.Takahashi, M.Nakao, Y.Mizutani, M.Yamamoto

    Trans. IEICE-A　J76-A　(8)　1018-1026　1993/01

  182. Modeling Study on Calcium-activated Dynamics of Neuronal Dendrites Peer-reviewed

    N.Katayama, M.Nakao, Y.Mizutani, M.Yamamoto

    Proc. Int'l Joint Conf. Neural Net.　III　(3)　523-528　1992/01

  183. A Rise of Pricking Pain Threshold by Repetitive Radiant Heat Stimulations Peer-reviewed

    Y.Mizutani, N.Ogihara, W.Onodera, S.Ikeda M.Nakao, M.Yamamoto, Y.Yamauchi

    Pain Research　7　(2)　115-122　1992/01

    DOI： 10.11154/pain.7.115 　

  184. GEOMETRIC ANALYSIS OF CARDIOVASCULAR DYNAMICS DURING SLEEP AND WAKEFULNESS Peer-reviewed

    M NAKAO, H TAKAGI, S YOKOTE, Y MIZUTANI, M YAMAMOTO, M MUNAKATA, Y IMAI, K ABE

    PROCEEDINGS OF THE ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 14, PTS 1-7　14　471-472　1992

  185. The Physiological Significance of Spectral Profiles of Central Single Unit Activities during Sleep-Wakefulness Peer-reviewed

    M.Yamamoto, M.Nakao, Y.Mizutani, T.Kodama, Y.Takahashi

    Proc.2nd Congress Asian & Ocean Physiol.Societies　544-547　1992/01

  186. Structural Properties of Network Attractor Associated with Neuronal Dynamics Transition Peer-reviewed

    M.Nakao, K.Watanabe, T.Takahashi, Y.Mizutani, M.Yamamoto

    Int'l Joint Conf. Neural Net.　3　529-534　1992/01

  187. A Thermoregulatory Model of the Ultradian Rhythm of Human Sleep Peer-reviewed

    M.Nakao, D.McGinty, R.Szymusiak, T.Ichikawa, M.Yamamoto

    Sleep Research　20A　554-554　1991/01

  188. 1/f Fluctuations in Stochastic Point Processes:New Tools for Characterizing Neuronal Outputs Peer-reviewed

    F.Gruneis, M.Nakao, M.Yamamoto, T.Musha

    Int'l Noise and 1/f Fluct.　583-586　1991/01

  189. Simulation Study on White-1/f Dynamics Transition in Neural Network Model Peer-reviewed

    M.Nakao, K.Watanabe, T.Takahashi, Y.Mizutani, M.Yamamoto

    Int'l Noise and 1/f Fluct.　651-654　1991/01

  190. A Telemetry System for Recording Cat's Neuronal Spike Trains during Sleep-waking States Peer-reviewed

    Y.Mizutani, M.Nakao, M.Yamamoto, G.Matsumoto

    Biotelemetry　XI　287-290　1991/01

  191. ふく射熱刺激による刺痛いき値測定システム Peer-reviewed

    山本光璋, 水谷好成, 中尾光之, 山内祐一, 中浜 博

    電子情報通信学会論文誌　J-73-DII　470-477　1990/01

  192. SIMULATION STUDY ON DYNAMICS TRANSITION IN NEURONAL-ACTIVITY DURING SLEEP CYCLE BY USING ASYNCHRONOUS AND SYMMETRY NEURAL NETWORK MODEL Peer-reviewed

    M NAKAO, T TAKAHASHI, Y MIZUTANI, M YAMAMOTO

    BIOLOGICAL CYBERNETICS　63　(4)　243-250　1990

    ISSN： 0340-1200

  193. COUNTING STATISTICS OF 1/F FLUCTUATIONS IN NEURONAL SPIKE TRAINS Peer-reviewed

    F GRUNEIS, M NAKAO, M YAMAMOTO

    BIOLOGICAL CYBERNETICS　62　(5)　407-413　1990

    ISSN： 0340-1200

  194. AN INTERPRETATION OF 1/F FLUCTUATIONS IN NEURONAL SPIKE TRAINS DURING DREAM SLEEP Peer-reviewed

    F GRUNEIS, M NAKAO, M YAMAMOTO, T MUSHA, H NAKAHAMA

    BIOLOGICAL CYBERNETICS　60　(3)　161-169　1989

    ISSN： 0340-1200

  195. Hardware-based adaptive system for discrimination of neuronal spikes Peer-reviewed

    M. Nakao, K. Ohmura, R. Sato

    Medical &amp; Biological Engineering &amp; Computing　26　(4)　360-366　1988/07

    Publisher: Kluwer Academic Publishers

    DOI： 10.1007/BF02442292 　

    ISSN： 0140-0118 1741-0444

  196. Acute differential sensitivity and role of the central nervous system in the feeding behavior of Drosophila melanogaster. Peer-reviewed

    I.Shimada, M.Nakao, Y.Kawazoe

    Chemical Senses　12　481-490　1987/01

    DOI： 10.1093/chemse/12.3.481 　

  197. IDENTIFICATION AND ESTIMATION ALGORITHM FOR STOCHASTIC NEURAL SYSTEM .2. Peer-reviewed

    M NAKAO, K HARA, M KIMURA, R SATO

    BIOLOGICAL CYBERNETICS　52　(2)　71-78　1985

    ISSN： 0340-1200

  198. IDENTIFICATION AND ESTIMATION ALGORITHM FOR STOCHASTIC NEURAL SYSTEM Peer-reviewed

    M NAKAO, K HARA, M KIMURA, R SATO

    BIOLOGICAL CYBERNETICS　50　(4)　241-249　1984

    ISSN： 0340-1200

  199. PARAMETER-ESTIMATION OF THE THRESHOLD TIME FUNCTION IN THE NEURAL SYSTEM Peer-reviewed

    M NAKAO, K HARA, M KIMURA, R SATO

    BIOLOGICAL CYBERNETICS　48　(2)　131-137　1983

    ISSN： 0340-1200

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    廣谷 唯, 田中 健也, 吉田 侑冬, 辛島 彰洋, 中尾 光之, 片山 統裕

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    町田 祉永, 片山 統裕, 中澤 邑支朗, 和田 みなみ, 中尾 光之

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    Katayama Norihiro, Nakazawa Yushiro, Machida Yoshihisa, Nakao Mitsuyuki

    Transactions of Japanese Society for Medical and Biological Engineering　55　(3)　139-139　2017

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI： 10.11239/jsmbe.55Annual.139 　

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    &lt;p&gt;In the hippocampus of rodents during locomotion, 5-12 Hz oscillatory EEG (theta activity) is observed. The hippocampal theta activity plays important role in encoding the animal&#039;s position during spatial navigation. It has been reported that frequency and amplitude of the theta activity correlate with the locomotion speed. However, the precise temporal relationship has not been elucidated. To investigate the relationship, we recorded the hippocampal EEG from mice during voluntary locomotion in a virtual corridor. It was confirmed that the hippocampal theta activity occurred during locomotion and its frequency and amplitude positively correlated with the locomotion speed. Time-shift cross-correlation analysis revealed that the change in theta activity was approximately 200 ms ahead to that of locomotion speed. Impact of manipulation of visual feedback to the theta activity was not strong. These results suggest that the hippocampal theta activity is forecasting or attracting instantaneous behavior of the animal.&lt;/p&gt;

  9. Development of an auditory stimulator synchronized with cortical EEG slow oscillation

    Tanaka Kenya, Sato Anri, Yoshida Yuto, Nakao Mitsuyuki, Katayama Norihiro

    Transactions of Japanese Society for Medical and Biological Engineering　55　(3)　185-185　2017

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI： 10.11239/jsmbe.55Annual.185 　

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    &lt;p&gt;The slow oscillation (SO) of cortical EEG during deep sleep is involved in memory consolidation. Recently, it has been reported that auditory stimulation synchronized with spontaneous SO during sleep enhanced the SO and elevated performance of declarative memory in humans. However, detail properties including stimulus timing-dependency have not been clarified. In this study, to elucidate these properties, we developed an experimental system for mice that can generate auditory stimulus at arbitrary phase of SO. This system consists of two components; a microcomputer for real-time waveform analysis based on template matching and a DSP for auditory stimulus generation. Evaluation test using EEG signals recorded from the mouse neocortex during sleep demonstrated that the developed system works as designed. We will investigate phase-response characteristics of SOs and possible contribution to memory consolidation by animal experiments.&lt;/p&gt;

  10. Spatio-temporal dynamics of slow wave activities measured by transcranial flavin autofluorescence imaging in the mouse neocortex

    佐藤 杏莉, 吉田 侑冬, 中尾 光之, 片山 統裕

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報　116　(312)　1-4　2016/11/18

    Publisher: 電子情報通信学会

    ISSN： 0913-5685

  11. Modeling and analysis of visual aliasing phenomena in a virtual reality system

    中澤 邑支朗, 片山 統裕, 町田 祉永, 中尾 光之

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報　116　(312)　21-24　2016/11/18

    Publisher: 電子情報通信学会

    ISSN： 0913-5685

  12. A Pacemaker Network Model of Photoperiod-dependent Synchronization Dynamics in Suprachiasmatic Nucleus

    吉岡 亜由美, 中尾 光之, 片山 統裕

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報　116　(312)　25-28　2016/11/18

    Publisher: 電子情報通信学会

    ISSN： 0913-5685

  13. Sleep-wake dependent changes in synaptic AMPA receptor plasticity in rat cortex

    A. Karashima, A. Nakamura, N. Katayama, M. Nakao

    JOURNAL OF SLEEP RESEARCH　25　207-207　2016/09

    ISSN： 0962-1105

    eISSN： 1365-2869

  14. Analysis of resting-state network of the mouse neocortex by using optical intrinsic signal imaging

    Yoshida Yuto, Nakao Mitsuyuki, Katayama Norihiro

    Transactions of Japanese Society for Medical and Biological Engineering　54　(28)　S296-S296　2016

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI： 10.11239/jsmbe.54Annual.S296 　

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    &lt;p&gt;Recent studies suggest that the resting-state network (RSN) of human brain has close relationship with neurological and psychiatric diseases. So far, mouse has been used to study the mechanism and treatment of these diseases because of applicability of various experimental methods including genetic engineering. Since the fMRI, which has been mainly used to estimate the human RSN, is not suitable for mouse due to insufficient spatial resolution, optical intrinsic signal imaging (OISI) method is being tested on behalf of fMRI. However, it remains many problems including the cost and complexity of experimental system and analytical methods. To solve the problems, we developed a method to analyze RSN of the mouse neocortex by using single-wavelength transcranial OISI method. By using the method, we found that the structure of RSN of mice during REM sleep is significantly different from that during quiescent awake and non-REM sleep.&lt;/p&gt;

  15. Simulations of Chronotherapeutic Effects on Cancer Cell Population under Circadian Regulation

    井ノ川 広, 片山 統裕, 中尾 光之

    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報　115　(317)　43-48　2015/11/20

    Publisher: 電子情報通信学会

    ISSN： 0913-5685

  16. Intrinsic optical imaging of cortical spontaneous activity of unanesthetized mice

    YOSHIDA YUTO, KATAYAMA NORIHIRO, NAKAGAWA DAIKI, KARASHIMA AKIHIRO, NAKAO MITSUYUKI

    Transactions of Japanese Society for Medical and Biological Engineering　53　(0)　S245_01-S245_01　2015

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI： 10.11239/jsmbe.53.S245_01 　

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    So far, many behavioral and pharmacological experiments on genetically modified mice have been conducted to study the molecular mechanism of the psychiatric or neurological diseases. On the other hand, recent functional MRI studies have revealed close relationship between the psychiatric or neurological diseases and the structure of functional connectivity in the resting-state of the human brain. To make linkage between the human and mouse studies, it is necessary to establish the method to analyze brain-wide spontaneous activity in the mouse. In this study, we simultaneously measured spontaneous cortical EEG and transcranial green-reflected-light (GRL, wavelength of 530 nm) signal to monitor cortical hemodynamics at high-spatial resolution in unanesthetized mice during natural sleep-wake cycle. It is shown that GRF decreases at 3% during theta-dominant period (REM sleep) compared to the delta-dominant periods, suggesting the increase in the blood volume of the cerebral cortex during REM sleep.

  17. Simulations of cancer chronotherapeutic effects on cell proliferation dynamics under circadian regulation

    INOKAWA HIROSHI, KARASHIMA AKIHIRO, KATAYAMA NORIHIRO, NAKAO MITSUYUKI

    Transactions of Japanese Society for Medical and Biological Engineering　53　(0)　S133_01-S133_01　2015

    Publisher: Japanese Society for Medical and Biological Engineering

    DOI： 10.11239/jsmbe.53.S133_01 　

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    It has been reported that therapeutic value of cancer chemotherapy depends on a period of treatment time of the day. This effect, circadian time-dependency of treatment, has been considered to come from interactions between cell cycle and circadian rhythm. In this study, we aimed to clarify a biological background of this effect by means of simulating therapeutic effect based on a model of cell cycle controlled by circadian rhythms. Here we constructed a cell proliferation model using a framework of stochastic automaton. During the cell cycle process, a cell is subject to DNA damage with a certain probability. Then the damaged cell dies or returns to the cell cycle, causing a phase response to the cellular circadian clock system. In the simulations, a cancer cell is characterized by prolonged or shortened duration of G1 phase of the cell cycle. We simulated proliferation of 10,000 cells population treated by a drug that increases death rate of cells in S phase. As a result, we found that morning treatment is most effective to maximize the damage to the cancer cells and minimize the normal cell&#039;s death.

  18. Effects of Skilled Training on the Dynamics of Sleep Electroencephalogram in Rat Motor cortex

    ANZAI Yuka, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　114　(325)　1-4　2014/11/21

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Recently, many sleep researchers are interested in the relationship between sleep and synaptic plasticity. In this study, we trained rats in skilled reaching, and measured sleep EEG in the motor cortex after the training. We found that i) slow wave EEG, whose frequency is 0.5-4.5Hz, was increased for 4h after the training in both sides of the motor cortex, ii) the progressive increment of the delta power of the trained side relative to the untrained side was found, but this asymmetry was no longer present after 4h of sleep. These results suggest that the training of skilled reaching, which presumably induces synaptic potentiation, results in slow wave EEG increases during subsequent sleep, and sleep returns the synaptic weight to a baseline level.

  19. Development of somatosensory feedback function for virtual behavioral testing system for mouse

    ARAYA Toshio, KATAYAMA Norihiro, YOSHIDA Yuto, TAKAHASHI Yuto, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　114　(325)　17-22　2014/11/21

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    We have been developing a virtual reality (VR) system that is applicable to behavioral testing of mouse. Because it is expected to improve efficiency and reproducibility of the behavioral testing. However it has been a problem that a mouse sometimes shows unnatural behaviors probably due to imperfect recognition of virtual environment (VE). To ensure recognition of VE, we develop an equipment providing somatosensory feedback to the mouse, i.e. a mouse is applied an air-puff stimulation from an appropriate direction when the mouse is touching a virtual wall. When the somatosensory feedback is activated, the mouse tends to avoid touching virtual walls. As a result, trajectory of movement in the VE becomes similar to that in the real world. Therefore it is suggested that the developed somatosensory feedback would improve the sense of reality of the VR system for mice.

  20. Development of somatosensory feedback function for virtual behavioral testing system for mouse

    ARAYA Toshio, KATAYAMA Norihiro, YOSHIDA Yuto, TAKAHASHI Yuto, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. Neurocomputing　114　(326)　33-38　2014/11/21

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

    More details Close

    We have been developing a virtual reality (VR) system that is applicable to behavioral testing of mouse. Because it is expected to improve efficiency and reproducibility of the behavioral testing. However it has been a problem that a mouse sometimes shows unnatural behaviors probably due to imperfect recognition of virtual environment (VE). To ensure recognition of VE, we develop an equipment providing somatosensory feedback to the mouse, i.e. a mouse is applied an air-puff stimulation from an appropriate direction when the mouse is touching a virtual wall. When the somatosensory feedback is activated, the mouse tends to avoid touching virtual walls. As a result, trajectory of movement in the VE becomes similar to that in the real world. Therefore it is suggested that the developed somatosensory feedback would improve the sense of reality of the VR system for mice.

  21. State-dependencies of auditory evoked potentials during NREM sleep disclose their neurophysiological origins

    A. Karashima, M. Nakao, N. Katayama

    JOURNAL OF SLEEP RESEARCH　23　257-257　2014/09

    ISSN： 0962-1105

    eISSN： 1365-2869

  22. Effect of sleepiness on frequency characteristics of auditory response

    Akihiro Karashima, Hiromi Mukoda, Norihiro Katayama, Mitsuyuki Nakao

    Transactions of Japanese Society for Medical and Biological Engineering　52　(0)　369-O-370　2014/08/17

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI： 10.11239/jsmbe.52.O-369 　

    ISSN： 1347-443X 1881-4379

  23. A basic study on the somatosensory display equipment for the virtual reality system for mice

    Yuto Yoshida, Norihiro Katayama, Toshio Araya, Akihiro Karashima, Mitsuyuki Nakao

    Transactions of Japanese Society for Medical and Biological Engineering　52　(0)　381-O-382　2014/08/17

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI： 10.11239/jsmbe.52.O-381 　

    ISSN： 1347-443X 1881-4379

  24. Functional imaging of spontaneous activity of the brain using green-autofluorescence of flavoprotein

    Norihiro Katayama, Daiki Nakagawa, Ayako Ueno, Akihiro Karashima, Mitsuyuki Nakao

    Transactions of Japanese Society for Medical and Biological Engineering　52　(0)　69-OS-70　2014/08/17

    Publisher: Japan Soc. of Med. Electronics and Biol. Engineering

    DOI： 10.11239/jsmbe.52.OS-69 　

    ISSN： 1347-443X 1881-4379

  25. Oscillators and Neurology

    M.Nakao, N.Katayama, A.Karashima

    Clinical Neuroscience　32　(7)　738-742　2014

    Publisher: 中外医学社

  26. Sleep-Wake Dependent Change in the Excitatory Cortical Networks

    NAKAMURA Aritaka, KARASHIMA Akihiro, TSUBOKAWA Hiroshi, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　113　(314)　1-6　2013/11/22

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Recently, many sleep researchers are interested in the relationship between sleep-wake rhythm and synaptic plasticity. In this study, we performed whole-cell patch-clamp recordings from layer II/III pyramidal neurons of somatosensory cortex in acute slices of the rats that had been awake or asleep to investigate the effect of wake on excitatory synaptic transmission. We found that i) current-voltage relationship of EPSCs showed inward rectification, and ii) eEPSCs were depressed by Philanthotoxin 74, which is antagonist of Ca^&lt;2+&gt; -permeable AMPA receptors, in slices of waking animals. Both results show that Ca^&lt;2+&gt; permeable AMPA receptors levels are high during wakefulness and periods of wakefulness are associated with an increase in cortical synaptic strength.

  27. Measurement and analysis of head acceleration and hippocampal EEG of mice during passive movement

    ISHIKAWA Hiroaki, KATAYAMA Norihiro, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　113　(314)　7-11　2013/11/22

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    When a rodent is running, learning and having REM sleep, a rhythmic EEG activity at 6-9 Hz, called the hippocampal theta rhythm, is observed in the hippocampus of the rodent. It is well known that the frequency and the amplitude of the theta rhythm are modulated by the several types of modality of sensation including the vestibular sensation, which is one of the most effective to the rhythm. In this study, we simultaneously recorded the head acceleration and the hippocampal EEG of mice during a passive periodic movement to analyze the effect of frequency and power of the passive movement on the hippocampal EEG. When a periodic movement at 1-4 Hz is loaded to the mouse, the power of hippocampal theta EEG (6-9 Hz) increased with an increase of the frequency. In addition, the power of the hippocampal EEG at the moving frequency also increase during the passive movement. These results suggest the strong influence of the vestibular sensation to the hippocampal EEG activity.

  28. Visualization of spatial distribution of cerebral local field potential measured by a linear multi-electrode array

    WATANABE Shumpei, KATAYAMA Norihiro, KARASHIMA Akihiro, TANAKA Tetsu, MUSHIAKE Hajime, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　113　(314)　13-18　2013/11/15

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    We propose a visualization method (LFP brain mapping) to capture the spatial organization and the state-transition of the brain by integrating multi-site extracellular potentials and the position of the electrode for recording the potentials. In this method, the extracellular potentials are recorded with a linear multi-site electrode which is precisely positioned by a computer-controlled electrically-operated micromanipulator. Timing signal to reconstruct the position of the electrode and the extracellular signals are simultaneously stored in a computer. The extracellular potentials are frequency-analyzed and are composited according to the position of the recording site into a single map representing the neural spatio-temporal dynamics in the brain. We apply this method to visualize a wide-range spatial organization and dynamics of the cerebral cortex of mice under urethane anesthesia.

  29. Sleep dependent synaptic plasticity in rat barrel cortex Peer-reviewed

    Nakamura Aritaka, Karashima Akihiro, Harada Shingo, Tsubokawa Hiroshi, Katayama Norihiro, Nakao Mitsuyuki

    JOURNAL OF PHYSIOLOGICAL SCIENCES　63　S256-S256　2013

    ISSN： 1880-6546

  30. The Hippocampus and Brainstem were Activated during REM Sleep in Fear-Conditioned Rats Peer-reviewed

    Akihiro Karashima, Takehiro Kuroishi, Norihiro Katayama, Mitsuyuki Nakao

    JOURNAL OF PHYSIOLOGICAL SCIENCES　63　S257-S257　2013

    ISSN： 1880-6546

  31. Dependence of amplitude-modulation following response on sleepiness

    MUKODA Hiromi, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　112　(297)　47-52　2012/11/09

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    We investigated the relationship between sleepiness and amplitude of amplitude-modulation following response (AMFR) to find the best tone to raise awareness of sleepy drivers. In this study, auditory responses which were evoked by amplitude modulated tones whose carrier frequencies were 500, 1000, 4000, and 8000Hz were recorded in 16 subjects. Performance level was divided into three stages by using reaction time of psychomotor vigilance test, and the amplitude of AMFR was found to be decreased as the decrement of the performance in all frequency range. The high performance stages were further divided into two stages, those with alpha wave and without alpha wave. We found that auditory responses evoked by 500Hz AM tone in alpha wave state were smaller those in no-alpha state, but those evoked by the other AM tone were consistent. These results suggest that the high frequency tone could make drivers aware of their sleepiness.

  32. Measurement and analysis of brain activities during sleep after fear learning

    KUROISHI Takehiro, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　112　(297)　53-57　2012/11/09

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    There is a large number of studies showing that REM sleep contributes memory consolidation. The mechanism of the memory consolidation during REM sleep is not clear, but hippocampal theta waves and PGO waves are suggested to be involved in the memory processes. In this study, we have recorded the theta waves and PGO waves during REM sleep in fear-conditioned rats to clarify the mechanism. We found that frequency of hippocampal theta waves and PGO wave densities were increased just after the fear learning. These results suggest that PGO and theta waves contribute cooperatively to the REM sleep dependent memory consolidation.

  33. Modeling of non-homogeneous synchronization patterns of population oscillators in suprachiasmatic nucleus

    SUZUKI Masataka, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　112　(297)　59-60　2012/11/09

    Publisher: The Institute of Electronics, Information and Communication Engineers

  34. Analysis of locomotion and hippocampal EEG of mice in virtual environment

    HIDAKA Keita, KATAYAMA Norihiro, ISHIKAWA Hiroaki, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. Neurocomputing　112　(298)　27-32　2012/11/09

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    We have developed an immersive virtual reality system for mice. By using this system, we recorded locomotion activity of free-moving mice in an infinite wide virtual world. It was found that shape of trajectory of locomotion was strongly dependent on the kinematic parameters of a spherical treadmill that was used to measure the locomotion activity. After adjusting the kinematic parameters of the treadmill properly, locomotion and hippocampal EEG were simultaneously recorded. It was confirmed that the power spectral density of EEG changed strongly dependent on behavior of the mice which was similar to that observed in mice freely behaving in real world. In addition, we found that the frequency of hippocampal theta EEG was correlated with the locomotion speed in the virtual world.

  35. 細胞外電極による神経軸索の直径選択的刺激のシミュレーション解析

    上野彩子, 片山統裕, 辛島彰洋, 中尾光之

    日本生体医工学会大会プログラム・論文集(CD−ROM)　51st　ROMBUNNO.O2-12-5　2012

  36. Numerical simulation of response of nerve fibers to electrical stimulation with staircase waveforms

    UENO Ayako, KATAYAMA Norihiro, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　111　(314)　1-6　2011/11/24

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    It has been suggested that the electrode-to-axonal distance selective recruitment of relatively thick myelinated axons can be achieved by the down staircase-shape electrical nerve stimulation delivered from an extracellular electrode. However, the response of thin axons such as stimulus pulse duration dependency has not clarified. In this research, we investigated the pulse duration-dependency of the response of a thin myelinated axon model to square pulse stimulation by the numerical simulation. It was shown that short pulse stimulus (duration = 50 μs) activated only axons close to the electrode. In contrast, the stimulus with longer duration (e.g. 200 μs) activated more distant axons without activating near axons. However, stimulus with much longer duration (e.g. 500 μs) did not show distance-selective recruitment of axons due to occurrence of anodal break excitation of axons in the neighborhood of the electrode. In addition, thin axons (&amp;lne;1 μm) at more than 300 μm far from the electrode could not be activated by the square pulse stimulation.

  37. Multi-channel neuronal impulse and local field potential recording system using multiplexers

    TAKASHO Koichi, KATAYAMA Norihiro, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　111　(314)　7-11　2011/11/24

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    We developed a system for recording of multi-channel neural activity and local field potential in freely moving rats. This system is composed of four 8-wire electrodes (octrodes), four microdrives, 32-channel high impedance DC amplifiers, band-pass filters (0.8 Hz-5000 Hz), 32:1 multiplexer, single channel A/D converter and custom-made data acquisition software.

  38. Estimation of fetal vector electrocardiography through blind source separation

    NABESHIMA Yuji, KIMURA Yoshitaka, ITO Takuya, SATO Naoaki, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　111　(314)　13-17　2011/11/24

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Electrocardiograph (ECG) could be modeled as a rotating vector (heartvector) representing spatio-temporal electrical activity of myocardial muscle to some precision. In this case, ECG is a projection of the heart vector on some subspace spanned by recording electrodes. Independent component analysis (ICA) has recently been employed to extract the fetal ECG from maternal abdominal composite signals. When ICA is applied to a vector source, it should separate the vector source into mutually uncorrelated signals up to an order of the spatial dimension. However, due to non-stationary factors including movements of maternal abdominal surface and fetus and contamination of noise and electromyogram, only a single component might be extracted. Here, we propose a method for re-constructing vector ECG even in this situation. Through simulations and application to actual data, the validity of our method is examined. It is suggested that our method could detect alternation of ECG waveform caused by pathological factors.

  39. 産学連携PBLによる人材育成のためのスーパーコンピュータ利用の報告

    曽根秀昭, 中尾光之, 林優一, 庄子栄光, 村上隆生

    SENAC　44　(4)　55-60　2011/10

  40. パーキンソン病の脳深部刺激療法とその数理モデル

    片山統裕, 上野彩子, 辛島彰洋, 中尾光之

    システム制御情報学会研究発表講演会講演論文集(CD−ROM)　55th　ROMBUNNO.H25-6　2011/05/17

  41. 細胞外活動電位によるニューロンの位置推定アルゴリズムの性能評価

    片山統裕, SON Hou, 白石泰志, 上野彩子, 辛島彰洋, 中尾光之

    日本生体医工学会大会プログラム・論文集(CD−ROM)　50th　ROMBUNNO.O1-14-1　2011

  42. 睡眠中の情報処理機構と神経回路網の再編成

    辛島彰洋, 片山統裕, 中尾光之

    睡眠医療　4　(4)　469-475　2010/12

    Publisher: ライフ・サイエンス

    ISSN： 1882-2096

  43. Relation of sleepiness to auditory evoked response in human

    YASUI Yosuke, KARASHIMA Akihiro, NAKATANI Hiroto, OKUBO Hirofumi, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report　110　(294)　1-4　2010/11/11

    Publisher: 一般社団法人電子情報通信学会

    ISSN： 0913-5685

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    We recorded Auditory Brainstem Responses (ABR) in humans and investigated the relationship of sleepiness to ABR amplitude to know whether the ABR can measure sleepiness or not. Objective sleepiness is measured by reaction time, which is defined as a reaction latency on button-press action, and facial expression scale. The amplitude of ABR, especially wave IV-V complex, was found to be significantly increased with an increase in sleepiness measured by both reaction time and facial expression scale (p&lt;0.05), suggesting that sleepiness could be measured by ABR amplitude.

  44. Evaluation of neuronal position estimation based on multisite extracellular action potentials by the computer simulation

    SON Hou, KATAYAMA Norihiro, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report　110　(294)　5-10　2010/11/11

    Publisher: 一般社団法人電子情報通信学会

    ISSN： 0913-5685

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    In extracellular action potential (spike) recording of neurons, information about the location of neuron is useful for neuronal spike sorting, optimization of position of the recording electrode and so on. In this study, the accuracy of position estimation methods of neuron based on the multi-site neuronal spike recording is compared by using the computer simulation of extracellular action potential generated from a compartmental model of neuron. In addition, performance characteristics of multi-site electrodes with different shape and layout of recording sites are evaluated in terms of the accuracy of position estimation of neuron.

  45. Role of acetylcholine on change of auditory brainstem responses during sleep

    FUKASAWA Takahiro, OKUBO Hirofumi, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report　110　(294)　11-14　2010/11/11

    Publisher: 一般社団法人電子情報通信学会

    ISSN： 0913-5685

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    Although auditory evoked response (ABR) was considered to be insensitive to physiological sleep, we found that amplitude of the ABR increases during NREM sleep. In this study, effect of carbachol, which activates muscarinic receptor, on amplitude of the ABR was examined to show the role of acetylcholine in the sleep-wake state dependency of ABR amplitude. Amplitude of ABR wave IV was found to decrease just after the injection of carbachol into the lateral ventricle. Because acetylcholine concentration is high during wakefulness, these results suggest that acetylcholine plays a crucial role in the attenuation of ABR during wakefulness.

  46. 脳深部刺激のコンピュータシミュレーション

    片山統裕, 上野彩子, 辛島彰洋, 中尾光之

    生体・生理工学シンポジウム論文集　25th　459-460　2010/09/23

  47. Effect of NREM and REM sleep on somatosensory evoked potentials in rat Peer-reviewed

    Akihiro Karashima, Hiroyuki Inada, Norihiro Katayama, Mitsuyuki Nakao

    JOURNAL OF PHYSIOLOGICAL SCIENCES　60　S181-S181　2010

    ISSN： 1880-6546

  48. Performance evaluation of ICA-based spike sorting methods to multi-unit data recorded by a multi-site electrode in the rat hippocampus in vivo Peer-reviewed

    Yasushi Shiraishi, Norihiro Katayama, Koichi Takasho, Akihiro Karashima, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　68　E440-E440　2010

    DOI： 10.1016/j.neures.2010.07.1950 　

    ISSN： 0168-0102

  49. A Topographic Analysis of Human Scalp Alpha EEG by the Complex-valued ICA

    ZHANG Zhan, KATAYAMA Norihiro, WATANABE Kazuma, NAKATANI Hiroto, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　109　(279)　41-46　2009/11/05

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Sleepiness at the wheel is one of the causes of fatal crashes and highway accidents by car drivers. Since the EEG alpha activity occurs in association with the subjective sleepiness, and the alpha activities are observed in a mixed signal, aureate decomposition method has been required. In this study, we propose a method to decompose the time-delayed mixture of alpha source signals by using the time-frequency domain analysis and complex-valued independent component analysis. The method is applied to the human scalp EEG data to decompose the alpha activities occur associated with the subjective sleepiness during a driving simulation task. It is shown that this method provide information about not only the spatial distribution of alpha power (power map) generated by each source but also the phase difference among the recording site (phase map). The alpha power map and the phase map would be useful for the investigation of the mechanism of cortical alpha rhythms such as dipole estimation in the brain

  50. Multi-site recordings of synaptic responses in mouse thalamocortical slices

    ARAI Kaori, KATAYAMA Norihiro, SHIRAISHI Yasushi, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　109　(279)　3-6　2009/11/05

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    The rodent's whisker sensory information is transmitted to barrel cortex via ventral posteromedian nucleus (VPM) and posterior medial nucleus (POm) of thalamus. It is suggested that POm transmit whiskering sensation, and VPM transmit both whiskering and steady sensation. In this study, we investigate the spatio-temporal dynamics of barrel cortex in response to VPM stimulation using thalamocortical slice preparation of mice, in which thalamus, neocortex and thalamocortecal synaptic connections are kept alive. It is found that the successive two electical stimulation (paired pulse stimulation) to VPM with interval of less than 300-ms showed paired-pulse depression (PPD) of the response in the barrel cortex. The current source-density analysis suggests that the PPD occurrs at the synaptic transmission from VPM to layer 4 neuron in the barrel cortex.

  51. Somatosensory evoked potentials during NREM and REM sleep

    INADA Hiroyuki, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　109　(279)　7-12　2009/11/05

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    There is a hypothesis that the thalamus is the primary structure involved in closing the sensory gate during sleep. Recent findings which shows amplitude of auditory evoked potential during NREM sleep tends to be larger than that during wakefulness conflicts with the hypothesis. In this study, somatosensory evoked potential in the somatosensory cortex was recorded during different sleep-wake state to examine whether there is a common tendency in the other sensory modality. We found that the somatosensory evoked potentials during NREM sleep were larger than those during wakefulness. On the other hand, the evoked potentials during REM sleep were low amplitude as well as those during wakefulness. Taken together, these results suggest that there is a common mechanism involved in state dependency of sensory evoked potentials and the sensory input is not disrupted at the thalamus level during NREM sleep.

  52. A Simulation Study of Single-BSS with References

    HATAYA Toshiaki, KIMURA Yoshitaka, ITO Takuya, KARASHIMA Akihiro, KATAYAMA Norihiro, YAEGASHI Nobuo, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　109　(279)　37-40　2009/11/05

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Single-ICA can be very useful method to extract independent components from signal observed by single channel. But there is still a problem in the accuracy of separation and a lot to work on. We propose a simple single-ICA algorithm using blind source separation with references, and investigate the changes in the accuracy of separation and time gap between extracted signal and source signal, by altering the dimension and the lag time of the multi-dimensional embedded matrix. Then the result is that each extracted signal shows different change characteristics for the increase of dimension and lag time. Considering the property that causes these change characteristics, we are expecting these results to be helpful for optimal design of dimension and lag time.

  53. A Hard Real-Time Neuronal Spike Sorting System by Using Complex-Valued ICA

    SHIRAISHI Yasushi, KATAYAMA Norihiro, TAKAHASHI Tetsuya, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. Neurocomputing　109　(280)　1-6　2009/11/05

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Multi-unit recording methods with multi-channel electrodes have been widely used for brain-machine interface system. For sorting neuronal spikes recorded by this method, the independent component analysis (ICA) is very useful because this analysis can separate neuronal spikes even if the spikes are overlapped. However the accuracy of the spike sorting was insufficient. We have proposed an efficient spike sorting method combined with continuous wavelet transform and complex-valued ICA (WICA method). In this study, we developed a real-time system composed of a DOS PC and a Windows PC. It was confirmed that this system is capable of hard real-time detection and sorting of neuronal spikes within 1.5-milli-seconds.

  54. Rhythmic neural activities during sleep and their possible functions

    A. Karashima, N. Iwasaki, N. Katayama, M, Nakao

    生体の科学　60　(4)　295-302　2009/08

    DOI： 10.11477/mf.2425100857 　

  55. Sleep EEG Dynamics Change and Reorganization of Cortical Neural Networks under Long-term Alternation of Sensory Activations

    A. Karashima, N. Iwasaki, N. Katayama, M, Nakao

    感性福祉研究所年報　10　(10)　15-20　2009/03

    Publisher: 東北福祉大学感性福祉研究所

    ISSN： 1344-9966

  56. 睡眠-覚醒の個人モデルによる日常的活動パターンの評価と設計 (第2期(平成16年度〜20年度)学術フロンティア推進事業 五感を介する刺激測定に基づく健康向上のための人間環境システムの構築 平成20年度の総括) -- (全体総括)

    中尾光之, 片山統裕, 白川修一郎

    感性福祉研究所年報　(10)　131-135　2009/03

    Publisher: 東北福祉大学感性福祉研究所

    ISSN： 1344-9966

  57. Auditory brainstem response dependency on rapid eye movement sleep in rat Peer-reviewed

    Akihiro Karashima, Hirofumi Okubo, Norihiro Katayama, Hiroto Nakatani, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　65　S231-S231　2009

    DOI： 10.1016/j.neures.2009.09.1297 　

    ISSN： 0168-0102

  58. Self-organization process of network structure in a STDP neural network model Peer-reviewed

    Norihiro Katayama, Shohei Yamada, Akihiro Karashima, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　65　S235-S235　2009

    DOI： 10.1016/j.neures.2009.09.1321 　

    ISSN： 0168-0102

  59. CONTRIBUTION OF CALCIUM-INDUCED CALCIUM RELEASE FOR PROPAGATION OF YPKC TRANSLOCATION ALONG THE DENDRITES OF CEREBELLAR PURKINJE CELL Peer-reviewed

    Norihiro Katayama, Norio Sakai, Naoaki Saito, Mitsuyuki Nakao, Hiroshi Tsubokawa

    JOURNAL OF PHYSIOLOGICAL SCIENCES　59　151-151　2009

    ISSN： 1880-6546

  60. 複数ニューロン記録用多重電極の設計支援を志向した3次元神経組織モデルの構築(<特集>生体医工学シンポジウム2008)

    久保貴嗣, 片山統裕, 辛島彰洋, 中尾光之

    生体医工学 : 日本エム・イー学会誌　46　(6)　675-683　2008/12/10

    Publisher: 社団法人日本生体医工学会

    DOI： 10.11239/jsmbe.46.675 　

    ISSN： 1347-443X 1881-4379

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    In multiunit recording with multisite neural electrodes in the brain, an adjustment of electrode parameters such as the spatial arrangement of the recording sites to the target brain region is essential to obtain good signal-to-noise ratio data. However, in the most case, the parameters have been decided according to the experience of experimenter due to the cost of animal experiments. In this study, we propose a framework to optimize the electrode parameters by the virtual experiment of multiunit recording and data analysis including spike detection and sorting of the simulated multiunit d...

  61. 神経スパイクの相互相関解析を利用したシナプス結合強度のモデルベース推定法(<特集>生体医工学シンポジウム2008)

    菊池修, 片山統裕, 辛島彰洋, 中尾光之

    生体医工学 : 日本エム・イー学会誌　46　(6)　667-674　2008/12/10

    Publisher: 社団法人日本生体医工学会

    DOI： 10.11239/jsmbe.46.667 　

    ISSN： 1347-443X 1881-4379

    eISSN： 1881-4379

  62. Estimation of the 3D Neuronal Position by using Multiple-site Recording of Extracellular Action Potential

    KUBO Takashi, KATAYAMA Norihiro, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report　108　(314)　21-24　2008/11/14

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    The mechanical distortion of neural tissue caused by the implant of neuronal electrodes is an important factor affecting the performance of neuronal spike recording in the brain because the mechanical distortion could kill or inactivate the neurons. In this study, we propose a method to obtain the information about the mechanical distortion near the electrode based on the extracellular potential waveforms recorded by the multiple-site electrode. First, the three-dimensional position of each neuron is estimated making use of the spatial profile of action potential. Second, the shift of the neuron in the neural tissue with a movement of the electrode is estimated to visualize the effect of mechanical strain induced by the electrode. Our method will provide useful information for the assessment of the implant of neural electrode in the brain.

  63. Neuronal Spike Sorting Method Using Frequency-domain ICA for Multi-site Multi-unit Recording Data

    SHIRAISHI Yasushi, KATAYAMA Norihiro, KIKUCHI Osamu, KUBO Takashi, KARASHIMA Akihiro, NAKAO Mitsuyuki

    電気学会研究会資料. MBE, 医用・生体工学研究会　2008　(49)　47-52　2008/10/24

  64. Neuronal Spike Sorting Method Using Frequency-domain ICA for Multi-site Multi-unit Recording Data

    SHIRAISHI Yasushi, KATAYAMA Norihiro, KIKUCHI Osamu, KUBO Takashi, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report　108　(264)　101-106　2008/10/16

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Multi-unit recordings with multi-site electrodes have been widely used in the field of neuroscience and neuroengineering, for such as brain-machine interface. This method requires sorting of neuronal spikes according to the pattern of spike waveforms. For this purpose, the independent component analysis (ICA) is known to be useful. However the accuracy of the sorting result is not sufficient in many cases. We have proposed an efficient spike sorting method combined with the wavelet transform and the complex-valued ICA (WICA method) which achieves higher sorting accuracy than the conventional ones. In this study, we explore the parameter dependency of the WICA method on the accuracy of sorting results by using the simulated multi-unit data. In addition, we propose three methods to automatically determine the threshold level for neuronal spike detection from the unmixed signals obtained by the WICA method..

  65. Long-term sensory deprivation causes local change in slow wave activity during NREM sleep Peer-reviewed

    Akihiro Karashima, Naoko Iwasaki, Norihiro Katayama, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　61　S112-S112　2008

    ISSN： 0168-0102

  66. A real-time spike sorting system based on complex-valued ICA for multiunit recording Peer-reviewed

    Norihiro Katayama, Yasushi Shiraishi, Tetsuya Takahashi, Osamu Kikuchi, Takashi Kubo, Akihiro Karashima, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　61　S252-S252　2008

    ISSN： 0168-0102

  67. A three-dimensional neural tissue model of hippocampal CA3 field for simulation of multiunit recording with multi-site electrodes Peer-reviewed

    Takashi Kubo, Norihiro Katayama, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　61　S252-S252　2008

    ISSN： 0168-0102

  68. Coupling circadian rhythm and cell cycle

    CHENG Yan, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report　107　(351)　5-8　2007/11/15

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Circadian and cell cycles are suggested to be linked at molecular level. In order to elucidate the mechanism of interactions, we first established a model for cell cycle in eukaryotes, which involves Cyclin: CDK, CDC25, Wee1, Cyclin: CDK: CKI, SKP2, APC and CDC20. Because Wee1 is suggested to be a candidate to establish the link, phase responsiveness was investigated by applying a perturbation on Wee1 transcription in the model. We found that the growth curve of cell mass has a critical role in the responsiveness. The model with a power law growth curve exhibited a PRC with only a delay response, which will be used to study circadian regulations on cell cycle.

  69. Optimization of Reference Signals in Blind Source Separation of Fetal Electrocardiogram

    NETABAYASHI Tomoyuki, KIMURA Yoshitaka, CHIDA Shin-ichi, ITO Takuya, OWADA Kazunari, KARASHIMA Akihiro, KATAYAMA Norihiro, OKAMURA Kunihiro, NAKAO Mitsuyuki

    IEICE technical report　107　(351)　1-4　2007/11/15

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Blind source separation using reference signals (BSSR) is very useful especially when target signals have distinctive features, where the performance of separation is known to have robustness against uncertainties of the reference signals. Here, detail properties of the robustness were investigated by diluting spike waves composed of the reference signal, widening the spikes, and altering the order of evaluation function. Increased dilution rate and wider spikes were found to deteriorate the performance of BSSR; the 4th order of correlation evaluation was shown to be optimal. These results are expected to be helpful for optimal design of reference signals.

  70. Multiunit recording of neuronal activity in the brainstem to investigate the mechanism of sleep-wake regulation

    SHIMAZAKI Motohiko, KARASHIMA Akihiro, KUBO Takashi, KIKUCHI Osamu, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report　107　(351)　9-12　2007/11/15

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Multi-neuronal activity was recorded by using multi-electrode in the raphe and the tegmental nuclei. In these nuclei, there are "sleep regulating neurons" that are believed to be involved in regulation of sleep-wake rhythm. Cross-correlation analysis of spike trains suggested that (i) there are the functional connections between the adjacent neurons; (ii) there are the connections not only between sleep-regulating neurons, but between state-unrelated neurons and sleep-regulating neurons. These will provide a novel framework for the understanding of the mechanisms regulating sleep and wakefulness.

  71. Hierarchical Modeling of Biological Rhythm Mechanism

    OKAYAMA Hiroshi, NAKAO Mitsuyuki, TOKUMARU Nobuko, HONMA Sato, HONMA Ken-Ichi

    IEICE technical report　107　(351)　13-16　2007/11/15

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Circadian rhythms are biological rhythmic phenomena with about 24 hour period, and generated by the intrinsic mechanisms including the suprachiasmatic nucleus (SCN). The circadian rhythm is generated at a molecular level in the SCN cell, and, through some hierarchies, appears at a behavioral level as overt rhythms such as sleep-wake rhythm, temperature rhythm, and melatonin rhythm. In this research, we first analyzed the dynamics of the two-oscillator models which consist of the SCN oscillator originated from the SCN and the non-SCN oscillator from the clock mechanisms outside of the SCN. In addition, we performed a three-dimensional reconstruction of the clock gene expression rhythms in the SCN. Both results suggested that the SCN is not a single oscillator, but has a non-uniform spatio-temporal oscillation dynamics.

  72. A Real-time Neuronal Spike Sorting System Using Complex-valued ICA for Multi-site Multi-unit Recording Data

    SHIRAISHI Yasushi, KATAYAMA Norihiro, TAKAHASHI Tetsuya, KIKUCHI Osamu, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report　107　(263)　75-80　2007/10/11

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Multi-site multi-unit recording method using multi-channel electrodes have been widely used for brain-machine interface system. Independent component analysis (ICA) is useful for sorting neuronal spikes recorded by this method because this analysis can separate neuronal spikes even if the spikes are overlapped. However the sufficient result would not be obtained if only this analysis was simply applied to the experimental data. We have proposed an efficient spike sorting method combined with continuous wavelet transform and complex-valued ICA. In this study, we show that our method has a better efficiency for sorting noisy data than the conventional method. In addition, we implement this method in a digital signal processor system. This system can process neuronal spike sorting within 2-milli-seconds in real-time.

  73. Simulation of extracellular multi-unit recordings in the three-dimensional neural tissue for characterization of multi-channel electrodes

    KUBO Takashi, KATAYAMA Norihiro, KIKUCHI Osamu, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report　107　(263)　81-86　2007/10/11

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    In order to obtain good signal-to-noise ratio recording of neuronal activities in the brain, adjustments of parameters of neural electrode such as the shape of electrode, number of recording channel and arrangement of recording points are essential. However these parameters have been empirically decided so far because of the high cost to test the electrode by using experiment animals. In this study, we develop a simulation system, which is composed of three-dimensional model neural tissue of the hippocampal CA3 region and the model of extracellular action potential recording system. By combining experimental data and simulation results, we characterize the extracellular electrodes. This system would be useful for the design and test of the neural electrode..

  74. Mathematical models of regulatory mechanisms of sleep-wake rhythms

    M. Nakao, A. Karashima, N. Katayama

    Cellular and Molecular Life Sciences　64　(10)　1236-1243　2007/05

    DOI： 10.1007/s00018-007-6534-z 　

    ISSN： 1420-682X 1569-1632

  75. An integrated model of Sleep-Wake Rhythms

    M. Nakao, A. Karashima, N. Katayama

    感性福祉研究所年報　8　(8)　27-32　2007/03

    Publisher: 東北福祉大学感性福祉研究所

    ISSN： 1344-9966

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    Sleep-wake rhythms are considered to be controlled by the mutually interacting two oscillators, one for suprachiasmatic (SCN) oscillator, and the other for non-SCN oscillator. We have developed two different mathematical models of human sleep-wake rhythms: one is the phase dynamics model of human circadian rhythms, and the other is the thermoregulatory model of sleep control. A phase dynamics model and thermoregulatory model are mutually complementary. The former cannot provide amplitude information such as temperature and sleepiness, and the latter can work only under the externally entrained conditions. We try to integrate them by mapping the phase dynamics onto the oscillators of the thermoregulatory model. The other integration is implementation of regulatory mechanisms of skin temperature in the thermoregulatory model. This integration enables the model to provide a general framework for simulating possible interactions between thermal environments and sleep-wake rhythm. The behavior of integrated models is shown in this paper.

  76. An Oscillator Model of Human Circadian Rhythms

    Nakao Mitsuyuki, Yamamoto Keisuke, Okayama Hiroshi, Katayama Norihiro

    87　(4)　564-569　2007/01/20

    Publisher: 物性研究刊行会

    ISSN： 0525-2997

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    We developed a phase dynamics model of human circadian rhythms that allows non-photic entrainment. Characteristically, our model can simulate the interaction between the melatonin and the sleep-wake rhythms, which owes mainly to the discontinuity in couplings between oscillators in the model. On the other hand, we studied the bifurcation structure of the two process model based on a constructed circle map of the model. This circle map was characterized by its discontinuity. Here, the same circle map was constructed for our model, which was shown to have similar discontinuity to the two process model. Considering the discontinuity shared by the different models, this property may be an essential property in the human circadian rhythms.

  77. Physiology-based model of sleep-wake regulation

    A. Karashima, M. Nakao

    医学のあゆみ,医歯薬出版　220　(4)　303-307　2007

  78. Activity-dependent organization of associative neuronal dynamics of the hippocampal CA3 network in vitro Peer-reviewed

    Kikuchi Osamu, Katayama Norihiro, Karashima Akihiro, Nakao Mitsuyuki

    NEUROSCIENCE RESEARCH　58　S110-S110　2007

    DOI： 10.1016/j.neures.2007.06.1210 　

    ISSN： 0168-0102

  79. Synchronization of theta activity in hippocampus and amygdala during REM sleep Peer-reviewed

    Karashima Akihiro, Hayashi Mio, Shimazaki Motohiko, Katayama Norihiro, Nakao Mitsuyuki

    NEUROSCIENCE RESEARCH　58　S33-S33　2007

    DOI： 10.1016/j.neures.2007.06.189 　

    ISSN： 0168-0102

  80. Calcium-dependent mechanisms underlying propagation of gamma PKC translocation along the dendrites of cerebellar Purkinje cell Peer-reviewed

    Tsubokawa Hiroshi, Kashiwagi Kaori, Saito Naoaki, Nakao Mitsuyuki, Katayama Norihiro

    NEUROSCIENCE RESEARCH　58　S138　2007

    DOI： 10.1016/j.neures.2007.06.1380 　

    ISSN： 0168-0102

  81. Modeling of extracellular multiple neuronal activities based on the multi-unit recording Peer-reviewed

    Kubo Takashi, Katayama Norihiro, Mushiake Hajime, Kikuchi Osamu, Karashima Akihiro, Nakao Mitsuyuki

    NEUROSCIENCE RESEARCH　58　S161-S161　2007

    DOI： 10.1016/j.neures.2007.06.667 　

    ISSN： 0168-0102

  82. Temporal relationship between phasic activity in the brainstem and theta rhythmic activity in the amygdala and hippocampus during REM sleep in rats

    Karashima Akihiro, Hayashi Mio, Iwasaki Naoko, Shimazaki Motohiko, Katayama Norihiro, Nakao Mitsuyuki

    Proceedings of Annual Meeting of the Physiological Society of Japan　2007　(0)　137-137　2007

    Publisher: 日本生理学会

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    We simultaneously recorded hippocampal and amygdaloid field activity during REM sleep in rats. In the amygdala, intermittent rhythmic activity, whose frequency was about 8 Hz, was recorded during REM sleep. This activity was found to be synchronized with hippocampal theta activity. We also recorded pontine phasic potential, which is called P wave. This potential is known to relate to the cholinergic neuronal activity in the brainstem. We found that i) the frequency of theta wave in both the amygdala and hippocampus increased associated with increase in the P wave density, ii) duration of theta in the amygdala increased as P wave density increases iii) synchronization between theta wave in the amygdala and hippocampus became stronger with the increase in the P wave density. Because cholinergic neurons in the brainstem send projections to the amygdala and hippocampus, these results suggest that the brainstem cholinergic neurons activate theta activity both in the amygdala and hippocampus. &lt;b&gt;[J Physiol Sci. 2007;57 Suppl:S137]&lt;/b&gt;

  83. A study to determine the robustness of reference signals for BSSR signal extraction method

    Y. Kimura, T. Netabayashi, T. Ito, S. Jafar, S. Chida, N. Katayama, K. Owada, K. Okamura, M. Nakao

    AIP Conference Proceedings　922　705-708　2007

    DOI： 10.1063/1.2759773 　

    ISSN： 0094-243X 1551-7616

  84. 睡眠-覚醒制御機構の生理学的モデル

    辛島彰洋, 中尾光之

    医学のあゆみ　220　(4)　303-307　2007/01

    Publisher: 医歯薬出版(株)

    ISSN： 0039-2359

  85. Reduction and retrospection approach to modeling of hierarchical biological rhythms

    Mitsuyuki Nakao, Hiroshi Okayama, Norihiro Katayama, Akihiro Karashima

    IEEJ Transactions on Electronics, Information and Systems　127　(10)　1486-1490　2007

    Publisher: Institute of Electrical Engineers of Japan

    DOI： 10.1541/ieejeiss.127.1486 　

    ISSN： 1348-8155 0385-4221

  86. A quartet neural system model orchestrating sleep and wakefulness mechanisms (vol 95, pg 2055, 2006)

    Y. Tamakawa, A. Karashima, Y. Koyama, N. Katayama, M. Nakao

    JOURNAL OF NEUROPHYSIOLOGY　96　(6)　3558-3558　2006/12

    DOI： 10.1152/jn.z9k-7840-corr.2006 　

    ISSN： 0022-3077

  87. Wavelet Transform-based Neuronal Spike Sorting Method for Multi-channel Multi-unit Recording Data

    TAKAHASHI Tetsuya, KATAYAMA Norihiro, KIKUCI Osamu, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report　106　(370)　65-68　2006/11/15

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Multi-site multi-unit recording using a multi-channel electrode is an powerful method for investigating cooperative activity of numerous neurons that interact with each other in the network. In this method, each spike waveform should be sorted into spike-generating neuron by means of pattern matching. However the conventional spike-sorting methods can not correctly resolve overlapping spikes that are caused by synchronized firing of neurons. Recently several methods utilizing the independent component analysis (ICA) have been proposed to overcome this problem, but their performance is insufficient. In this study, an improved spike-sorting method combining continuous wavelet transform and complex-valued ICA is proposed. Computer simulation shows that the new method more accurately resolves overlapping spikes than the conventional ICA-based method.

  88. Modeling of Segmentation Dynamics

    KAZAMA Akihiro, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report　106　(370)　69-72　2006/11/15

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    In the somite, the segmental unit for the metametric structure such as skeletal muscles, vertebrate, and ribs, are sequentially generated in a head-to-tail order by segmentation of the mesenchymal tissue called presomitic mesoderm (PSM). The segmentation occurs periodically at the anterior end of the PSM, and this periodic segmentation has been suggested to be regulated by a molecular clock. In mouse PSM, Notch signaling molecules such as Hes and Lfng alternate their expression every 120 minutes, and this cyclic expression is essential for regular somite segmentation. In this paper, according to recently accumulated knowledge, a molecular network model of segmentation clock mechanisms is constructed. Through simulations, it is clarified how the dynamics of gene expressions are regulated by interactions between molecules.

  89. 22.心臓血管制御系のモデル化(平成17年度東北支部大会抄録)

    伊藤健太, 片山統裕, 辛島彰洋, 中尾光之

    生体医工学 : 日本エム・イー学会誌　44　(2)　2006/06/10

    Publisher: 社団法人日本生体医工学会

    ISSN： 1347-443X

  90. Statistical Testing of Neuronal Connectivity Based on Spike Correlation Analysis

    KATAYAMA Norihiro, KIKUCHI Osamu, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report　106　(79)　1-6　2006/05/19

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Cross-correlation histogram (CCH) of simultaneously recorded multiple neuronal activities has widely been used to decide whether a synaptic connection between two neurons exists or not. In this report, we point out problems in accuracy of statistical testing using conventional shuffling-corrected CCH method when the contribution of shared inputs for the neurons on the CCH is strongly dependent on the lag-time of the correlation function. We propose an improved testing method utilizing the characteristics of shuffling CCH, which has only been used to cancel the effect of the shared input to the raw CCH so far. In addition, we develop a method to evaluate the intensity of the neuronal connectivity utilizing the CCH based on a simple input-output relationship of a neuron and characteristics of common driver.

  91. Mathematical model of the network responsible for sleep-wake regulation

    KARASHIMA Akihiro, TAMAKAWA Yuichi, KOYAMA Yoshimasa, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report　106　(79)　19-24　2006/05/19

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Recent neuroscience research has revealed that sleep is controlled by complicated interactions among many "sleep regulating neurons"' in the hypothalamus and brainstem. Here, we propose a neural network model consisting of these neurons on the basis of the new physiological findings. As a result, this model reproduces many physiological phenomena, such as 90-minute (NREM-REM) ultradian cycles as well as 24-hour sleep-wake cycles. Furthermore, activities of the model neurons mimic rough profiles of the actual neuronal discharge across sleep stage transition. This model will provide a novel framework for the quantitative understanding of the mechanisms regulating sleep and wakefulness.

  92. レム睡眠中の海馬の機能

    辛島彰洋, 片山統裕, 中尾光之

    Brain Medical　18　(1)　80-86　2006/03

    Publisher: (株)メディカルレビュー社

    ISSN： 0915-5759

  93. Transient dynamics of in vitro hippocampal CA3 network in response to single- or multi-site stimulation Peer-reviewed

    Osamu Kikuchi, Norihiro Katayama, Akihiro Karashima, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　55　S164-S164　2006

    ISSN： 0168-0102

  94. Brainstem control of the EEG during REM Peer-reviewed

    Akihiro Karashima, Yoshimasa Koyama, Naoko Iwasaki, Osamu Kikuchi, Motohiko Shimazaki, Norihiro Katayama, Mitsuyuki Nakao

    NEUROSCIENCE RESEARCH　55　S43-S43　2006

    ISSN： 0168-0102

  95. 体節形成分子時計のモデル化

    風間 章寛, 片山 統裕, 中尾 光之

    電気関係学会東北支部連合大会講演論文集　2006　(0)　278-278　2006

    Publisher: 電気関係学会東北支部連合大会実行委員会

  96. 多点記録多ニューロン活動信号のウェーヴレット変換に基づくスパイク弁別

    高橋 哲也, 片山 統裕, 菊池 修, 辛島 彰洋, 中尾 光之

    電気関係学会東北支部連合大会講演論文集　2006　(0)　112-112　2006

    Publisher: 電気関係学会東北支部連合大会実行委員会

  97. An integrated model of human sleep-waking rhythms

    ISHIURA Daiki, KARASHIMA Akihiro, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report　105　(402)　17-20　2005/11/10

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Sleep-wake rhythms are considered to be controlled by the mutually interacting two oscillators, one for suprachiasmatic(SCN) oscillator, and the other for non SCN oscillator. We have developed two different mathematical model of human sleep-wake rhythms : one is the phase dynamics model of human circadian rhythms, and the other is the thermoregulatory model of sleep control. A phase dynamics model and thermoregulatory model are mutually complementary. The former cannot provide amplitude information such as temperature and sleepiness, and the latter can work only under the externally entrained conditions. We try to integrate them by mapping the phase dynamics onto the oscillators of the thermoregulatory model. The behavior of integrated model is shown in this paper.

  98. Extraction of fetal ECG from mother's abdominal electrical signals

    MATSUYAMA Fumiaki, KIMURA Yoshitaka, CHIDA Shinichi, ITO Takuya, KARASHIMA Akihiro, KATAYAMA Norihiro, OKAMURA Kunihiro, NAKAO Mitsuyuki

    IEICE technical report　105　(402)　25-28　2005/11/10

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Fetal electrocardiogram (fECG) has been expected to play an important role in monitoring condition of fetal heart. A blind source separation (BSS) has been employed to extract the fECG. However, extracted fECG is not so reliable for clinical application. Distortion or nonlinearity of the fECG signal is one of the main reasons of this difficulty. We have developed a new filtering method to extract nonlinear signals from the noisy mixed observation. In this paper, the result of extraction is shown together with the filtering method.

  99. Modeling of the suprachiasmatic nucleus based on the reduced cellular clock mechanisms

    AOKI Kazufumi, NAKAO Mitsuyuki, KATAYAMA Norihiro

    IEICE technical report　105　(335)　37-40　2005/10/07

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    It is believed that the suprachiasmatic nucleus (SCN) plays an important role in circadian regulation of biological systems. We construct the mathematical model of the cellular clock mechanisms in the SCN by reducing the detailed model and including the intracelluar signaling pathways. The reduced models are spatially coupled by diffusions of molecule and cellular activity, and synaptic connections so as to construct the whole SCN model. Various phase relationships between activities of cellular subpopulations are observed dependent on the diffusion rate, some of which mimic those of the ventrolateral and dorsomedial parts of the SCN. This result suggests that the model reduction and the construction whole SCN model are appropriately done.

  100. Process of network self-organization in a spike-timing-dependent plasticity neural circuit

    YAMADA Shohei, KATAYAMA Norihiro, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report　105　(335)　41-44　2005/10/07

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    The synaptic plasticity dependent on the order and time interval of pre- and postsynaptic spikes (spike timing-dependent-plasticity, STDP) is observed in the hippocampus and cerebral cortex. STDP is believed to play an important role in self-organization of network structure in the brain. In this study, we explored self-organizing process of network in a model of neural circuit incorporating STDP rule and time delay for signal transmission among neurons, which is an extended version of a model proposed by Kitano et al. It is shown that the self-organizing process and resultant network structure are strongly dependent on the time delay.

  101. モデリングによる生体システムダイナミクスの特徴づけと制御規範推定

    NAKAO Mitsuyuki, KATAYAMA Norihiro, KARASHIMA Akihiro

    Journal of the Japan Society of Applied Electromagnetics　13　(3)　221-229　2005/09/10

    Publisher: 日本AEM学会

    ISSN： 0919-4452

  102. Topological conditions for coherent gamma oscillation in an interneuron network model

    KATAYAMA Norihiro, SASAKI Shinya, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. Neurocomputing　105　(82)　13-17　2005/05/19

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Gamma frequency (20-80Hz) oscillation of electroencephalogram observed in the hippocampus and cerebral cortex is expected to be used as neural clock for parallel distributed information processing. Recently, it has been shown that the gamma oscillation is mainly generated by the synchronous activities of the interneuron network. In this study, we explore topological conditions for generation of spatially coherent gamma oscillation by the computer simulations. It reveals that the boundary line for coherent gamma oscillation in the parameter space agree well with isogram of the product of average number of synaptic contacts par neuron and clustering coefficient of the network, which measures the cliquishness of neighborhood.

  103. 体温調節機能に着目した睡眠-覚醒リズムのモデル化とその応用 (健康スケールに関するセミナー解説論文集)

    中尾光之, 片山統裕, 山本光璋

    感性福祉研究所年報　(6)　115-120　2005/03

    Publisher: 東北福祉大学感性福祉研究所

    ISSN： 1344-9966

  104. Model-based characterization of biological system dynamics and estimation of their regulatory criteria

    M. Nakao, N. Katayama, A. Karashi

    日本AEM学会誌　13　21-29　2005

  105. 参照信号系を持つ独立成分分析法による胎児心電図の解析

    松山文昭, 木村芳孝, 佐藤道由, 伊藤拓哉, 千田新一, 妹尾匡人, 中尾光之

    日本生体医工学会誌　43　567　2005

  106. カルバコールにより賦活される海馬神経回路の時空間ダイナミクス

    片山統裕, 菊池修, 渡邉直樹, 辛島彰洋, 中尾光之

    生体医工学 : 日本エム・イー学会誌　42　(4)　269-276　2004/12/10

    Publisher: 社団法人日本生体医工学会

    DOI： 10.11239/jsmbe2002.42.269 　

    ISSN： 1347-443X

    eISSN： 1881-4379

  107. Network structure-dependent dynamics of a biological neural network model

    SASAKI Shinya, KATAYAMA Norihiro, KARASHIMA Akihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　104　(429)　5-8　2004/11/08

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Gamma frequency (20-80Hz) oscillation observed in the cerebral cortex and hippocampus thought to be supported by the synchronous activities in the interneuron network. In this study, a model of interneuron network proposed by Wang & Buzsaki is extended to study the effect of spatial network structure and time delay for synaptic interaction on the γ-range synchronous neural activities. It is shown that 'Small-World'-like structure is useful for generation of synchronous activities. In addition synaptic delay also gives increase of γ-range synchronization.

  108. Extraction of Fetal Electrocardiogram by Blind Source Separation

    SATO Michiyoshi, KIMURA Yoshitaka, NAKAO Mitsuyuki, KATAYAMA Norihiro

    IEICE technical report. ME and bio cybernetics　104　(429)　45-48　2004/11/08

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    In this paper, we propose a new blind source separation (BSS) algorithm to extract a fetal electrocardiogram (ECG) from the ECG recording with multiple electrodes placed on mother's abdomen. After removing the mother's ECG based on its vector cardiogram, the different BSSs were applied. The BSS referring to a signal mimicking ultrasonic Doppler signals could extract more fetal ECG precisely.

  109. Relationship between EEG Dynamics and Neuronal Activities during Transition of Sleep Stages

    TAMAKAWA Yuuichi, KARASHIMA Akihiro, KOYAMA Yoshimasa, KATAYAMA Norihiro, NAKAO Mitsuyuki

    IEICE technical report. ME and bio cybernetics　104　(429)　9-12　2004/11/08

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    We have examined EEG power spectra during transition of sleep stages in rats, which discloses characteristic EEG dynamics associated with the transitions. In this study, we analyzed a relationship between EEG dynamics and neuronal activities in the hypothalamus and the brainstem. These neurons are known to have something to do with sleep-wake regulation. As a result, we found these neuronal activities were correlated with EEG theta (5-10Hz) and alpha (10-16Hz) band power spectra. Additionally, neuronal activities started to change at or prior to the transition. These results suggest that these neurons play different roles in switching and maintaining sleep stages.

  110. 生体医工学における研究の最前線

    南谷晴之, 井出徹, 土居伸二, E. Bagarinao, 中尾光之, 佐藤俊輔

    電子情報通信学会 情報・システムソサイエティ誌　9　(2)　4-11　2004/08

  111. Instantaneous acceleration of hippocampal theta wave associated with pontine phasic activity during REM sleep in rats

    A. Karashima, M. Nakao, K. Honda, N. Iwasaki, N. Katayama, M. Yamamoto

    Neuroscience Research　2004

  112. Models of Molecular Mechanisms of Biological Rhythm

    NISHIMURA Yoshinari, NAKAO Mitsuyuki, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　103　(470)　17-22　2003/11/20

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    There are two different ideas for possible molecular mechanisms of biological clock: one is that the multiple transcription-translation feedback loops involving clock genes generate a limit cycle, and the other is that such feedback loops are not substrate of biological clock. Here, the models based on the former idea are tentatively called Goodwin type, and the latter oscillator-feedback type. Firstly, this study shows that an increase in the feedback gain reduces the stability of periodic trajectory in the Goodwin type models. In addition, phase response and entrainment properties to the light stimuli differentiate the dynamics of the Goodwin type and oscillator-feedback type models. The results here provide a framework for experimentally assessing reality of the ideas of molecular mechanism of biological clock.

  113. Changes of Sleep EEG Dynamics in Rat Barrel Cortex Associated with Long-term Sensory Deprivation

    IWASAKI Naoko, KARASHIMA Akihiro, TAMAKAWA Yuichi, NAKAO Mitsuyuki, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　103　(470)　23-28　2003/11/20

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Sensory deprivation is known to alter the neural organizations involved for processing the deprived neural information especially in developmental process. However, long-term effects of the sensory deprivation have not yet been well-understood. In order to investigate this effect on the post-mature neural organizations and possible contribution of sleep to them, cortical EEG dynamics during sleep in adult rats were measured during up to a month, while somatosensory inputs were constantly deprived by cutting whiskers unilaterally. Keeping rat's whiskers cut unilaterally, the resulting change in balance between EEG spectral powers in the intact and the sense-deprived barrel cortices was traced. Spectral powers of EEG in the sense-deprived barrel cortex decreased in terms of their ratio to the intact during initial 10 days. Subsequently, the ratio was gradually restored to the control level. The resulting change in EEG dynamics is expected to be caused by a certain re-organization of neural circuits associated with the long-term sensory deprivation. The results here suggest the possibility of alternation in neural circuit even after maturation.

  114. Formal similarity between the two process model and a coupled oscillator model

    M Nakao, K Yamamoto, N Katayama, M Yamamoto

    SLEEP　26　A98-A99　2003/05

    ISSN： 0161-8105

  115. Pontine phasic activity is phase-locked to hippocampal theta wave during REM sleep in rats

    A Karashima, M Nakao, K Honda, K Nakamura, N Katayama, M Yamamoto

    SLEEP　26　A3-A3　2003/05

    ISSN： 0161-8105

  116. Non-monotonic changes of sleep EEG dynamics in rat barrel cortex associated with long-term sensory deprivations

    N Iwasaki, H Karashima, M Nakao, N Katayama, M Yamamoto

    SLEEP　26　A30-A30　2003/05

    ISSN： 0161-8105

  117. 12.状態依存性の固有周期を持つ振動子ネットワークのダイナミクス(平成14年度東北支部大会抄録)

    堀内正裕, 中尾光之, 片山統裕, 山本光璋

    生体医工学 : 日本エム・イー学会誌　41　(1)　67-67　2003/03/10

    Publisher: 社団法人日本生体医工学会

    ISSN： 1347-443X

  118. 13.培養心筋細胞の興奮リズムに対するoctanolの効果(平成14年度東北支部大会抄録)

    諸橋裕, 片山統裕, 中尾光之, 山本光璋

    生体医工学 : 日本エム・イー学会誌　41　(1)　67-67　2003/03/10

    Publisher: 社団法人日本生体医工学会

    ISSN： 1347-443X

  119. Temporal- relationship between hippocampal theta wave and spontaneous and elicited PGO-like wave during REM sleep in rats

    A.Karashima, M.Nakao, K.Honda, K.Nakamura, N.Katayama, M.Yamamoto

    Neuroscience Research　46　(Suppl. 1)　S107-S107　2003

  120. An Analysis of Cardiovascular Dynamics under Head-up Tilting

    ITO Fuminori, NAKAO Mitsuyuki, KATAYAMA Norihiro, YAMAMOTO Mitsuaki, MUNAKATA Masanori

    IEICE technical report. ME and bio cybernetics　102　(481)　29-32　2002/11/21

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    In order to investigate the responsiveness of cardiovascular system to gravity, tilting angle-dependency of the cardiovascular dynamics is characterized by closed-loop impulse responses and barorefiex sensitivity (BRS) estimated by the sequence method. Actually, the cardiovascular signals are measured under the supine, 10, 20, 30, and the standing. Obtained time series of instantaneous heart rate (HR), systolic blood pressure (BP), and respiration rhythm (RP) are subject to the analysis. The closed-loop impulse responses are estimated by the fitted ARX model. As a result, BRS is shown to decrease as the tilting angle increases. The closed-loop impulse responses BP→HR and BP→BP are shown to be more accelerated as the tilting angle increases. Naturally, blood pressure regulation is expected to be enhanced as the tilting angle increases. Therefore, the angle-dependencies shown above might indicate the validity of the closed-loop modeling.

  121. Measurement and analysis of spike-like potentials precending rapid eye movements in human

    KITAHARA Ryo, YAMAMOTO Mitsuaki, KATAYAMA Norihiro, NAKAO Mitsuyuki, HATTORI Masato, UENO Takashi

    IEICE technical report. ME and bio cybernetics　102　(481)　33-36　2002/11/21

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Rapid eye movements (REMs) anticipatory phasic potentials (RAPPs) are spike-like scalp potentials with duration of approximately 20ms appeared prior to REMs during REM sleep. RAPPs are known to similar to presaccadic spike potentials (PsSPs) observed prior to saccades during wakefulness in terms of their occurrence time and topographic profiles. In this study, we measured and compared them quantitatively. We used amplitude of bipolar-leaded electrooculogram reflecting the size of eye movements preceding the spike potentials for studying the relationship of their amplitudes, because the measurement of electrooculogram was much easier than the direct measurement of the eye movement during sleeping state. It was confirmed that the amplitude of PsSPs was strongly dependent on the eye movement size. In contrast, the amplitude of RAPPs was found to be almost constant against the size of eye movements. These results suggest the physiological difference in the brain state between wakefulness and REM sleep during which the spike potentials were activated.

  122. 生体リズム機構のモデリング

    中尾光之, 山本啓介, 片山統裕, 山本光璋

    計測と制御　41　(10)　733-739　2002/10/10

    Publisher: 2

    DOI： 10.11499/sicejl1962.41.733 　

    ISSN： 0453-4662

  123. Phase Dynamics Model of Biological Rhythms and Its Properties

    NAKAO Mitsuyuki, YAMAMOTO Keisuke, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    17　367-368　2002/09/09

  124. ブラインド信号分離とその生体信号処理への応用

    中尾光之

    BME : bio medical engineering　16　(5)　1-1　2002/05/10

    DOI： 10.11239/jsmbe1987.16.5_2 　

    ISSN： 0913-7556

  125. ブラインド信号分離技術のてんかん脳波解析への応用

    中尾光之, 佐藤大輔, 大槻泰介, 片山統裕, 山本光璋

    日本エム・イー学会誌　16　(5)　38-45　2002/05/10

    Publisher: 2

    DOI： 10.11239/jsmbe1987.16.5_38 　

    ISSN： 0913-7556 2185-5382

  126. 聴覚刺激により誘起されるPGO波と海馬θ波との同期的関係

    辛島彰洋, 中尾光之, 中村和浩, 片山統裕, 山本光あき

    日本神経科学大会プログラム・抄録集　25th　2002

    ISSN： 1347-8583

  127. Temporal relationships between hippocampal theta waves and isolated and cluster PGO waves

    A. Karashima, M. Nakao, K. Nakamura, N. Katayama, M. Yamamoto

    Neuroscience Research　25　S117-S117　2002

  128. Phase-locking between elicited PGO waves by tone stimuli and hippocampal theta waves during REMs sleep

    A. Karashima, M. Nakao, K. Nakamura, N. Katayama, M. Yamamoto

    Neuroscience Research　26　S125-S125　2002

  129. ヒトのサーカディアン・システムのモデル化とその応用

    中尾光之

    Pharma Medica　20(Suppl.)　39-44　2002/01

    Publisher: 2

  130. A Multi-oscillator Model of Methamphetamine-induced Circadian Rhythms

    TOKUMARU Nobuko, NAKAO Mitsuyuki, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　101　(478)　17-22　2001/11/22

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Administration of methamphetamine(MAP)is known to induce behavioral rhythm in rats independent of suprachiasmatic nucleus(MAP-induced rhythm), which is regarded as a possible candidate of circadian oscillator driving an overt activity rhythm. Here, in order to investigate underlying mechanism of rhythm generation and its dynamics, a model consisting of mutually coupled multiple Bonhoeffer-Van del Pol(BVP)oscillators was constructed. As a result, both of limit cycle and damping oscillator models reproduced MAP concentration-dependency of oscillation parameters such as α/ρ ratio. Haloperidol, non-selective antagonist of dopamine, induced phase shift of the MAP-induced rhythm was qualitatively reproduced only by the damping oscillator-coupled model. Therefore, coupled-multiple damping oscillator is suggested to be plausible as a generation mechanism of MAP-induced rhythm/

  131. Modeling Circadian System with Feedback Mechanisms

    YAMAMOTO Keisuke, NAKAO Mitsuyuki, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　101　(478)　23-30　2001/11/22

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    On the human circadian system, there exist the reports that non-photic time-cues work on the sleep-wake rhythm as well as the circadian pacemaker. Since sleep-wake pattern is under control of circadian pacemaker while non-photic time-cues affect circadian pacemaker through sleep-wake schedule, there exist feedback mechanisms in the circadian system. In this study, the phase dynamic model with feedback mechanisms was constructed. On the base of two oscillator model, Osc I and Osc II drives melatonin rhythm and sleep-wake rhythm, respectively. In addition, the overt sleep-wake rhythm is introduced, which behaves like an oscillator. Three oscillators are mutually coupled, where the cumulative feedback mechanisms are implemented by modulating the coupling strength. The model constructed here gave us the behavior and the interpretation of circadian system.

  132. Dynamics of Polygraphic Signals during Sleep Stage Transition

    IKENO Miki, NAKAO Mitsuyuki, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　101　(478)　31-38　2001/11/22

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Conventional criteria for scoring sleep stages have empirically been designed, which has been noticed that they do not reflect actual state-dependent changes in dynamics of polygraphic signals. In this study, in order to see interaction between neural mechanisms underlying polygraphic events characterizing the respective sleep stages, we investigated the dynamics of polygraphic signals during transitions between rapid eye movement sleep(REM)and non-REM sleep(NREM). As a result, we found that order of changes in dynamics of polygraphic signals during the transition from REM to NREM was almost reversed for that from NREM to REM. In addition, occurrence of rapid eye movements was shown to be anti-correlated with β-band EEG activity. These findings suggest hierarchical relationship between the neural mechanisms underlying change in sleep states.

  133. Source estimation of the brain stem spike potential preceding rapid eye movements

    HATTORI Masato, YAMAMOTO Mitsuaki, NAKAO Mitsuyuki, KATAYAMA Norihiro, KARASHIMA Akihiro, IKENO Miki, KITAHARA Ryo, UENO Takashi

    IEICE technical report. ME and bio cybernetics　101　(478)　39-46　2001/11/22

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    The spike potentials called rapid eye movements anticipatory phasic potentials(RAPPs), discovered in our laboratory, have been suggested that its source is located in the brain stem. In order to verify the hypothesis, a human head model consisting of an actual human skull was constructed. In addition, the potential distribution produced by the artificial current dipole located at the sites corresponding to the brain stem was measured on the surface of the head model. The potential distribution fairly mimicked the RAPPs. This result suggests that the RAPPs would correspond to the potential electronically spread from the brain stem through the optic canal and the superior orbital fissure.

  134. Application of an integrated bio-signal measurement system to dental medicine

    NAKAMURA Kazuhiro, YAMAMOTO Mitsuaki, NAKAO Mitsuyuki, KATAYAMA Norihiro, SASAKI Hideo, WATANABE Makoto, SATOH Chiaki, TAKESHIMA Hidetoshi, UENO Takashi, HIDA Wataru

    IEICE technical report. ME and bio cybernetics　101　(478)　47-53　2001/11/22

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    In the field of dentistry, it is clinically known that quality of sleep improves by occlusal treatment. Using an integrated bio-signal measurement system, we tried to evaluate change in quality of sleep associated with dental treatment. As a result, although we studied only one patient, we confirmed improvement in quality of sleep after the treatment.

  135. A Measurement System of Pricking-Pain Reaction Time by Using Thin-Film Thermode

    FUJIBE Tasuku, YAMAMOTO Mitsuaki, MURATA Tetsuya, MIZUTANI Yoshinari, NAKAO Mitsuyuki, KATAYAMA Norihiro, KUDO Haruo, YAMAUCHI Yuichi

    IEICE technical report. ME and bio cybernetics　101　(478)　55-62　2001/11/22

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    We have developed a new integrated measurement system of pricking-pain reaction time for repetitive stimuli with thin-film thermode. The system evokes a clear pricking-pain sensation as much as radiant-heat stimulation system used so far. Since the system involves Windows-based software with graphical user interface, no special experience is needed for the measurements. In addition, the system includes interface to cooperate with external relational database management system(RDBMS)and WWW server. By using this system, we measured pricking-pain reaction time of control and painful subjects. The result suggests difference between those subjects.

  136. Multi-channel recording and analysis of neuronal activities in hippocampal slice preparations

    HYAKUTAKE Daisuke, KATAYAMA Norihiro, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　101　(478)　79-86　2001/11/22

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    A tetrode recording system was constructed for multi-channel multi-unit recording of neuronal activities in hippocampal slices. In sorting the neuronal spikes, new spike-feature parameters that reflect shape of the spikes were developed. in addition, Hierarchical cluster analysis and discriminant analysis were adopted for clustering spikes. By the system, CA3 neuronal activities were recorded in hippocampal slices in response to single pulses and θ-burst stimulation to mossy fiber(mf). Stimulus-to-response characteristics and the cross-correlation statistics were analyzed. The results suggest that the hippocampal CA3 network could be reconstructed by the θ-burst stimulation to the mf.

  137. SPATIO-TEMPORAL DYNAMICS OF ICTAL ACTIVITIES OF EPILEPSY

    Nakao Mitsuyuki, Sato Daisuke, Ohtsuki Taisuke, Katayama Norihiro, Yamamoto Mitsuaki

    Proceedings of the IEICE General Conference　2001　(1)　272-272　2001/03/07

    Publisher: The Institute of Electronics, Information and Communication Engineers

  138. Hypothalamic sleep-promoting mechanisms: Coupling to thermoregulation

    D McGinty, MN Alam, R Szymusiak, M Nakao, M Yamamoto

    ARCHIVES ITALIENNES DE BIOLOGIE　139　(1-2)　63-75　2001/02

    ISSN： 0003-9829

  139. 海馬θ波リズムと孤立および群発PGO波との時間関係

    辛島彰洋, 中尾光之, 中村和浩, 片山統裕, 山本光しょう

    神経化学　40　(2/3)　2001

    ISSN： 0037-3796

  140. ヒーター測温抵抗体を用いた熱絶縁型痛覚閾値センサ

    中村和浩, 江刺正喜, 山本光璋, 中尾光之, 藤部亮, 水谷好成, 工藤治夫, 今井正三, 寿田一男

    センサ・マイクロマシンと応用システムシンポジウム講演概要集　18th　2001

  141. バイオインフォマティクスと生理学 : 生体情報の計測,解析,解釈の視点から

    山本光璋, 中尾光之

    日本生理学雜誌　63　(1)　13-16　2001/01/01

    Publisher: 日本生理学会

    ISSN： 0031-9341

  142. Dynamics of a spiking neural network model driven by noise

    SAKAMOTO Kazuhisa, KATAYAMA Norihiro, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　100　(478)　45-52　2000/11/23

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    We constructed a symmetry neural network model driven by while noise, which consists of Hodgkin-Huxley-type model neurons with a global inhibition. Dynamics of the network model were studies by the computer simulation. In the network model, many neurons showed oscillatory activities approximately at 40Hz. The single neuronal dynamics in the low frequency range changed from a white noise-like spectral profile to an 1/f noise-like one as the global inhibition decreased. The network models involving the 1/f noise-like neuronal dynamics showed intermittent state transitions between metastable firing patterns, which were emerged under the random perturbations.

  143. An analysis of the dynamics of epileptic EEG

    SATO Daisuke, NAKAO Mitsuyuki, OTUKI Taisuke, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　100　(478)　61-67　2000/11/23

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    We aimed to estimate epileptic foci and spreading processes of excitation. We assumed that the observed epileptic electroencephalogram(EEG)is a mixture of mutually uncorrelated signals, and analyzed it by applying a blind source separation(BBS). BBS was performed by the method using the covariance matrices with some time-lags. We showed spatial contribution of the separated sources by topogaph, and traced the time-evolution of source dynamics by connecting correlated sources in the adjacent data segments. As a result, it was found that the features of the time-evolution was shared by the epileptic activities studied. In addition, in the beginning of the epileptic activity there was a source showing the focus-related topograph. These findings provide important information to understand the nerual mechanism underlying epileptic activities.

  144. Long-term potentiation of synaptically activated increases in calcium concentration in hippocampal dentate dyrus cells

    OZAWA Masato, KATAYAMA Norihiro, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　100　(478)　69-75　2000/11/23

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

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    Intracellular Ca^2+ is known to play important role for regulation and control of many cellular chemical processes. In this study, increase in intracellular Ca^2+ concentration(△[Ca^2+])evoked by a burst stimulation (20Hz, 5pulses)to perforant path(PP)synapses were measured in dentate granule cells of rat hippocampal slices by means of laser scanning microscope. After a tetanic stimulation(100Hz, 100pulses)to the PP-synapses, some cells showed increase in △[Ca^2+]evoked by PP-synaptic inputs for 1 hour. Since the △[Ca^2+]is known to associated with the firing of granule cells, the result is expected to reflect the increase of firing probabirily of the cells in response to the synaptic inputs caused by the long-term potentiation at the synapses.

  145. Temporal-realtionship between Hippocampal Theta Waves and LGN Ponto-geniculo-occpital Waves during REM Sleep in Cats.

    辛島彰洋, 中尾光之, 片山統裕, 佐藤直樹, 中村和浩, 山本光あき

    電子情報通信学会技術研究報告　100　(478)　93-100　2000/11/23

    Publisher: 社団法人電子情報通信学会

    ISSN： 0913-5685

  146. Dynamics of Cerebellar Cortex Neuron Activities during Non-REM and REM Sleep.

    佐藤直樹, 山本光あき, 中尾光之, 片山統裕, 中村和浩, 辛島彰洋, 高橋和己, 児玉亨

    電子情報通信学会技術研究報告　100　(478)　101-108　2000/11/23

    Publisher: 社団法人電子情報通信学会

    ISSN： 0913-5685

  147. A multivariate and multistate analysis of dynamics of cardiovascular signals

    M.Nakao, K.Hirokawa, N.Katayama, M.Yamamoto

    Systems and Computers in Japan　31　(10)　2132-2142　2000/01

    Publisher: 2

  148. A Multivariate and Multistate Analysis on Dynamics of Cardiovascular Signals

    NAKAO Mitsuyuki, HIROKAWA Ken, KATAYAMA Norihiro, YAMAMOTO Mitsuaki, MUNAKATA Masanori

    The Transactions of the Institute of Electronics,Information and Communication Engineers.　82　(11)　2132-2142　1999/11/25

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0915-1923

  149. Application of ambulatory digital polygraph

    IROKAWA Kazutaka, WAKU Mitsuru, NAKAMURA Kazuhiro, KATAYAMA Norihiro, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki, UENO Takashi, ABE Masato, OKABE Shin-ichi, HIDA Wataru, SHIRATO Kunio, HORI Tadao, HAYASHI Mitsuo

    IEICE technical report. ME and bio cybernetics　99　(458)　37-44　1999/11/19

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

  150. A Neural Network Model of Sleep-Wake Cycle

    FUJIMORI Hisashi, NAKAO Mitsuyuki, KATAYAMA Norihiro, NAKAMURA Kazuhiro, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　99　(458)　53-60　1999/11/19

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

  151. Nonlinear synaptic integration in pyramidal neuron of hippocampal CA1 region

    SHIMAKATA Katsuyoshi, KATAYAMA Norihiro, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　99　(458)　61-68　1999/11/19

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5685

  152. Modeling Neuronal Dynamics-Transition during Sleep

    M.Nakao, M.Yamamoto

    IEEE Eng. Med. & Biol. Magazine　17　99-107　1999/01

    Publisher: 2

    DOI： 10.1109/51.765195 　

  153. Structural Analyses of 1/f Fluctuations in Heart Rate Variability Based on Their Spectrograms

    NAKAO Mitsuyuki, KATAYAMA Norihiro, YAMAMOTO Mitsuaki, MUNAKATA Masanori

    Japanese journal of medical electronics and biological engineering　36　(4)　370-381　1998/12/10

    Publisher: 日本エム・イー学会

    DOI： 10.11239/jsmbe1963.36.370 　

    ISSN： 0021-3292 2185-5498

  154. Nonlinear oscillation and mutual entrainment of the neural network in hippocampal slices

    SAITO Hiroaki, KATAYAMA Norihiro, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. Neurocomputing　98　(401)　35-42　1998/11/17

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    We studied mutual entrainment of neural network in area CA3 of the hippocampal slice, which showed epileptic activity by the pharmacological treatment, and artificial nonlinear oscillator(Radial Isochron Clock). That is, the firing of CA3 network perturbates RIC to shift the phase, in turn, the RIC determines the timing of the stimulation to CA3 according to the phase. We analyzed time series of firing intervals and "phase" which is defined by the interval between the stimulus to the firing, and the dependency of the strength of entrainment on the intensity of the perturbation.

  155. Nonlinear synaptic integration in hippocampal neurons

    SHIMAKATA Katsuyoshi, KATAYAMA Norihiro, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. Neurocomputing　98　(401)　43-49　1998/11/17

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    Recently, neuronal dendrites have been proved to have active properties and been expected to have special function in signal integration making use of the property. In this study, synaptic integration in neurons of hippocampal slice preparations is investigated by applying paired-pulse stimulation with interval of 100ms to multiple-site. It will be shown that synaptic inputs to the basal and the apical dendrites evoked by the first stimulation of PPS are integrated in an AND-logic manner, in contrast, the inputs by the second one are in an OR-logic manner. Inputs to the proximal and the distal apical dendrites by both the pair are integrated in an OR-login manner.

  156. 睡眠時脳単一ニューロン活動の低周波ダイナミクス

    中村和浩, 高橋和巳, 片山統裕, 中尾光之, 児玉亨, 山本光璋

    電子情報通信学会技術研究報告. NC, ニューロコンピューティング　98　(401)　105-112　1998/11/17

    Publisher: 社団法人電子情報通信学会

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    睡眠中の脳単一ニューロン活動をネコの外側膝状体領域から記録し、その発火頻度時系列のパワースペクトル解析を行った。その結果、徐波睡眠中は、0.04Hzから1.0Hzの帯域で白色雑音様のスペクトルを示したのに対し、レム睡眠中は1/f様のスペクトルを示した。この2状態間の低周波ダイナミクスの遷移現象は、視床腹側基底核、中脳網様体、海馬錐体細胞、大脳皮質一次体性感覚野、6野、18野で今迄調べてきた結果と一致する。このことから、この遷移現象が実行系ニューロン群の一般的性質であり、レム睡眠と徐波睡眠の指標となり得ることを示している。本論ではこの遷移現象を生じる原因について、睡眠中のアミン系/コリン系による調節の観点から議論する。

  157. A System for Measuremet of Direct and Axon-Reflex Vasodilatatioin Induced by Heat Stimulation

    MIZUTANI Yoshinari, YONEDA Tohru, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　98　(400)　1-6　1998/11/17

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    We have developed a system for measurement of change of blood flow elicited by heat stimulation using a contact foil-thermode on skin for pain measurements. The system can simultaneously measure direct and axon reflex vasodilatation induced by heating. The blood flow increases due to those vasodilatation were clearly observed by laser Doppler flowmeters. As for axon reflex response, the latency was longer and the magnitude of increase was smaller than those of the direct response.

  158. Measurement of Event-related Potentials to Novel Electrical Stimuli with Painful Sensation

    YONEDA Tohru, MIZUTANI Yoshinari, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　98　(400)　7-12　1998/11/17

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    To investigate the process of pain cognition, event-related potentials to electrical painful and non-painful stimuli have been measured. An oddball task with the 3rd novel stimulation was used. Standard(80%)and target(12%)stimulation were non-painful stimulation. They were delivered to forefinger and radial site of palm, respectively. The novel stimulation(8%)was given to little finger, and evoked painful or non-painful sensation. P300 components evoked by novel painful stimuli were larger and faster than those evoked novel non-painful stimuli.

  159. On the slow-dynamics in spontaneous activity of central single neurons during sleep

    NAKAMURA K., TAKAHASHI K., KATAYAMA N., NAKAO M., KODAMA T., YAMAMOTO M.

    IEICE technical report. ME and bio cybernetics　98　(400)　103-110　1998/11/17

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    Spontaneous single-unit activity during sleep was recorded from neurons in the region of the cat's lateral geniculate nucleus. The results showed a white noise-like spectrum in the low frequency range, 0.04-1.0 Hz, during steady-state non-REM sleep(slow-wave sleep), and a 1/f-noise, during REM sleep. These results are consistent with our previous reports regarding the thalamic ventrobasal complex neurons, as well as the hippocampal theta and pyramidal neurons, the neurons of the mesencephalic reticular formation, the primary somatosensory cortex, and areas 6 and 18. Possible mechanisms underlying the transition in slow-dynamics between non-REM and REM sleep are discussed in view of an alteration in neuronal interactions due to changes in the effects of aminergic/cholinegic modulations of the brain during sleep.

  160. An Optimal Control Model of 1/f Fluctuations in Heart Rate Variability

    NAKAO Mitsuyuki, TAKIZAWA Tomokazu, KATAYAMA Norihiro, NAKAMURA Kazuhiro, YAMAMOTO Mitsuaki

    13　315-318　1998/09/09

  161. Fluctuations of Physiological Signals in Circulation Systems and their Analyses

    中尾光之, 山本光璋

    人工臓器　27　(3)　620-629　1998/08/15

    Publisher: 2

    DOI： 10.11392/jsao1972.27.620 　

    ISSN： 0300-0818 1883-6097

  162. Modeling of Sleep-Wake Rhythms

    M.Nakao, M.Yamamoto

    日本臨床　56　(2)　499-503　1998/01

    Publisher: 2

  163. 睡眠・覚醒サイクルのモデル化とコンピュータ

    中尾光之

    脳波と筋電図　25　(6)　442-446　1997/12/01

    Publisher: 1

    ISSN： 0389-6153

  164. A Self-organizing Model of Neural Networks in Somatosensory Cortex

    KAWAI Masayoshi, NAKAO Mitsuyuki, MIZUTANI Yoshinari, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　97　(371)　51-58　1997/11/07

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    Although it is important for us to understand physiological mechanisms underlying pain sensation; there are still many problems remain unsolved. Here, in order to examine the possibility of our hypothesis on the phantom pain which was proposed based on the physiological knowledge concerning somatosensory system and pain sensation, simulations were performed by making use of the neural network model. The model implemented the corticofugal connections and lateral inhibitions at thalamic level. As a result, the boundary of the somatotopic representation was self-organized, and the reorganization of the somatosensory map was realized. These results here could provide all essential cue for understanding the cognitive system of pain.

  165. 1/f fluctuations in heart rate variability and modeling of cardiovascular regulatory system

    TAKIZAWA Tomokazu, NAKAO Mitsuyuki, IGARASHI Yosuke, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　97　(371)　97-104　1997/11/07

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    Recently, the 1/f fluctuations in heart rate variabilities (HRV) of human and animals have been empirically established. They reflect various regulatory mechanisms such as the autonomic nervous system, hormonal systems, and variations in physiological states. So far, researches studying the dynamics of HRV have not directly reached the regulatory rationale of the cardiovascular system, which have been done rather for assessing the above regulatory system functions. Here, the longterm recordings of HRV were performed to confirm the 1/f spectral structure down to very low frequency range. Additionally, they were shown to have properties of a stationary incremental process. In order to study their regulatory rationale, the relationship between the regulatory rules and the resulting dynamics was investigated by applying an optimal control on the newly proposed cardiovascular model. The 1/f fluctuations in HRV was suggested to be generated under the loose regulatory rule on the deviations in blood pressure from its working point. In addition, the simulated HRV Was shown to be a stationary incremental process similar to the actual data.

  166. Measurements and Analyses on Heart Rate Variability Associated with States of Consciousness : An Application of Ambulatory Digital Polygraph

    WAKU Mituru, ABE Masato, KATAYAMA Norihiro, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　97　(371)　105-112　1997/11/07

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    Measurements and Analyses on heart rate variability associated with states of subject's consciousness have not been established. We have developed an ambulatory digital polygraph by which signals, such as electrocardiogram, electromyogram, electroencephalogram, electrooculogram and body activities can be recorded durin9 30 hours. We have shown that RR intervals fluctuates during REM sleep with 1/f power spectral densities (PSD) in the frequency range, 0.01〜0:1Hz, and during slow wave sleep with white PSD, as shown in a cat.

  167. Choice of an Error Meaure of a Multilayer Neural Network and an Efficiency of Learning Processes

    FUJIKI Sumiyoshi, FUJIKI Nahomi M., NAKAO Mitsuyuki

    8　196-197　1997/11/05

  168. Learning Processes of Neural Networks and Error Meaures

    FUJIKI Sumiyoshi, FUJIKI Nahomi M., NAKAO Mitsuyuki

    IEICE technical report. Neurocomputing　97　(332)　57-64　1997/10/20

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    In the learning process by the conventional back-propagation algorithm, the trapping problem in metastable states occurs using the quadratic error measure. By using the Kullback divergence as an error measure, it is shown by numerical simulations that the learning efficiency is improved significantly no matter how large the number of internal nurons, and the optimal network size is achieved automatically. The Kullback divergence is a superior error measure in the two sence of the scalability: one for the complexity of the problem, and another for the excess network size.

  169. Model-Based Study on Activeness of Neuronal Dendrites and Its Functional Significance

    NAKAO Mitsuyuki, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    Japanese journal of medical electronics and biological engineering　35　(3)　254-264　1997/09/10

    Publisher: 日本エム・イー学会

    DOI： 10.11239/jsmbe1963.35.254 　

    ISSN： 0021-3292 2185-5498

  170. 睡眠とゆらぎ

    中尾光之, 山本光璋

    現代のエスプリ　357　(357)　171-182　1997/04

    Publisher: 2

    ISSN： 0435-2165

  171. Analysis of time varying spectrum of hippocampus local brain wave in sleeping ane waked cnditions of cat.

    斉藤洋明, 片山統裕, 中村和浩, 高橋和巳, 中尾光之, 山本光あき

    電気関係学会東北支部連合大会講演論文集　1997　1997

  172. Estimation of hot face temperature on a contact foil-thermode

    GOBO Eiichi, MIZUTANI Yoshinari, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki, IMAI Syozo, SUDA Kazuo

    IEICE technical report. ME and bio cybernetics　96　(429)　1-7　1996/12/14

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    We have developed a contact heat-stimulator using a film foil-thermode to measure threshold of heat pain. There are thermal resistances between the heater in the thermode and the hot face on the device, so that the temperature of the hot face is lower than that of the heater. We have examined the model of thermal resistances including capacitances to estimate the hot face temperature on the thermode. The face temperature estimated by the model agreed with experimental values measured using thermo-couple on the hot face of thermode.

  173. Measurement of event-related potentials to painful and non-painful stimulation

    NOHARA Takeshi, MIZUTANI Yoshinari, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　96　(429)　47-54　1996/12/14

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    We measured evoked potentials and event-related potentials for electrical painful and non-painful stimulation to fingers and radial site of palm. In case of oddball task with 2 kinds of stimulation (standard and target stimulation), less difference was observed between P300 components for painful and non-painful stimulation. Oddball task with 3 kinds of stimuli, including painful and non-painful stimulation, elicited larger P300 components for rare and novel stimulation than the oddball task with non-painful novel stimulation.

  174. Mutual Information Analysis of Cardiovascular Signal

    ZHAO Yujei, YAMAMOTO Mitsuaki, NAKAO Mitsuyuki, MUNAKATA Masanori

    IEICE technical report. ME and bio cybernetics　96　(379)　59-66　1996/11/21

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    Recently, the cardiovascular control system such as the baroreflex has been studied based on linear system theoretical tools including transfer function and coherence analyses. Here, we investigated the correlation properties between a systolic blood pressure (BP) and an inter-R wave interval of ECG (RR) based on the information theory. By assuming BP and RR as an input and an output of the information channel, the transition probabilities and the averaged mutual information (AMI) were obtained for the normal subjects and chronic renal failure patients. As a result, the AMI for the patients tended to be reduced in comparison with the normal irrespective of postures, and it was almost posture-independent, which suggests that the control mechanism mediated by the baroreflex is ineffective in the patients.

  175. Heart Beat Analysis based on Spectral Indices of Autonomic Nervous Activities

    SHIGA Satoshi, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　96　(379)　67-74　1996/11/21

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    The dynamics of heart rate variability, which is regulated by sympathetic, parasympathetic nervous activities, and hormones, changes associated with physiological states such as wakefulness and sleep. It has been established that the long-term power spectrum of heart rate variability shows a 1/f shape. In the paper, R-R intervals of human ECG were recorded for about 24 hours, and were subjected to the time-variant power spectral analysis. The power spectrum was devided into 3 frequency bands, LF(<0.05Hz), MF(0.05-0.15Hz), and HF(0.15-0.45Hz), as indices of autonomic nervous activities which regulated the rhythm of the heart rate variability. As the result, the power balance among those of the three frequency bands showed the different distribution between wakefulness and sleep. During wakefulness, LF and HF contributions were dominant. In contrast during sleep, the balance between HF and LF/MF alternatively changed.

  176. Measurement and analysis on single neuronal activities in the cat’s lateral geniculate nucleus during sleep.

    高橋和巳, 中村和浩, 遠藤久美, 片山統裕, 中尾光之, 児玉亨, 山本光あき

    電子情報通信学会技術研究報告　96　(379)　75-82　1996/11/21

    Publisher: 社団法人電子情報通信学会

    ISSN： 0913-5685

  177. 1/f Fluctuations in Biological Signals and their Possible Mechanisms -Model-Based Interpretations-

    M.Nakao, M.Yamamoto

    電子情報通信学会論文誌　79　(1)　62-64　1996/01/25

    Publisher: 2

    ISSN： 0913-5693

  178. 脳・ゆらぎ・ニューラルネットワーク

    山本光璋, 中尾光之, 水谷好成

    応用物理　64　(12)　1216-1220　1995/12/10

    Publisher: 2

    DOI： 10.11470/oubutsu1932.64.1216 　

    ISSN： 0369-8009

  179. Synaptic Interactions and Their Integration in the Active Neuronal Dendrite Model

    KATAYAMA Norihiro, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. Neurocomputing　95　(389)　53-60　1995/11/24

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    By the computer simulations, we studied the synaptic interactions in the compartment model of a hippocampal pyramidal neuron which is known to have active dendrites. The spatial interactions among the excitatory and the inhibitory synaptic inputs in the active dendrites of the neuron model are characterized quantitatively. The interactions and the hierarchical integration of synaptic inputs in the active dendrite system were investigated On the basis of the results; the input-output relationship of the compartment neuron model with active dendrites is modeled formally. This newly constructed neuron model has a tractable structure like a multilayerd neural network, and is suitable for constructing a large scale neural network.

  180. Simulation Study on Dynamics of Hippocampal CA1 Pyramidal Neuron

    IWASAKI M., KATAYAMA N., NAKAO M., YAMAMOTO M.

    IEICE technical report. ME and bio cybernetics　95　(356)　51-58　1995/11/16

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    Recent neurophysiological studies revealed that dendrites have various voltage-gated ion channels and therefore show active properties such as action potential generation. In order to understand its functional significance, we carried out computer simulations, using a compartment neuron model. Results:(1)An inhibitory synaptic inputs call spatially modify the spike initiation and its propagation.(2)Amplitude damping phenomena of repetitively firing spikes call be reproduced by including Ca^<2+> current and Ca^<2+> dependent K.^+ current in the model.

  181. On the low frequency characteristic of 1/f fluctuations in P-P intervals of a cat

    KOSHIKAWA Y., YAMAMOTO M., NAKAO M., MIZUTANI Y., NAKAMURA K., IKUTA N., HONDOU T., ANDO R., NITTA S., YAMBE T., SEI H.

    IEICE technical report. ME and bio cybernetics　95　(356)　59-64　1995/11/16

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    The power spectral density(PSD) of cat's P-P intervals recorded during over 100 hrs was compared between 2 experimental conditions: adaptation to free running in an isolated room and daily life in an animal's room. Both conditions produced a plateau in PSD in the frequency range of 10^<-5>-10^<-4>Hz and 1/f profile in the higher frequency range over 10^<-4>Hz where the robustness of the 1/f spectral characteristic was shown.

  182. On the Fluctuations in Electroencephalogram during Pain Sensation

    AOKI Hideki, MIZUTANI Yoshinari, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki

    IEICE technical report. ME and bio cybernetics　95　(356)　71-78　1995/11/16

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    We measured electroencephalogram(EEG) for more than :30 min, under the condition with pain sensation evoked by l024 electric current stimuli with an every 2sec interval and the condition without stimulation. Variations in the electrically evoked potentials were observed when they were averaged with a small number of trials. Fluctuations in the sequential distributions of the EEG amplitude calculated with every 500msec were also observed. From the distributions, mean, variance, skewness and kurtosis were calculated, then new time series of these parameters were obtained. Slow fluctuations were observed in the time series of variance; which was shown by power spectral analysis on the series.

  183. 1/f Fluctuations of Single Neuronal Activities in the Brain and Metastability of Neural Network Model

    中尾光之, 山本光璋

    数理科学　33　(3)　p31-35　1995/03

    Publisher: 2

    ISSN： 0386-2240 0386-8257

  184. A Microdialysis Probe with Metal Microelectrodes. An Application to Neuropharmacological Studies on a Single Neuronal Activity.

    中村和浩, 山本光あき, 中尾光之, 児玉亨, 片山統裕, 高橋和巳, 遠藤久美

    生体・生理工学シンポジウム論文集　10th　1995

  185. 睡眠時ニューロン活動の時系列特性

    山本光璋, 中尾光之, 水谷好成, 児玉 亨

    神経研究の進歩　39　(1)　29-40　1995/01

    Publisher: 2

    DOI： 10.11477/mf.1431900616 　

  186. 脳におけるゆらぎ

    中尾光之, 山本光璋

    Jap. J. Sports. Sci.　14　(5)　497-502　1995/01

    Publisher: 2

  187. Dynamics of Cortical Neuronal Activities During non-REM and REM Sleep.

    半沢淳, 中村和浩, 遠藤久美, 片山統裕, 水谷好成, 中尾光之, 山本光あき

    電子情報通信学会技術研究報告　94　(350)　65-72　1994/11/18

    Publisher: 社団法人電子情報通信学会

    ISSN： 0913-5685

  188. A Study on Dynamics of Human Circadian System Model

    Sakai Hideki, Nakao Mitsuyuki, Hondou Tsuyoshi, Yamamoto Mitsuaki

    IEICE technical report. ME and bio cybernetics　94　(350)　73-80　1994/11/18

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    During externally synchronized states as well as free-run which is free from zeitgebers,the consistent relationships between temperature and sleep-wake rhythms have been observed.In this paper,a new circadian system model is developed in order to systematically understand the mechanism underlying them.Our model consists of two cascaded phase maps,one determines sleep onset phase and the other wake onset phase.The model dynamics is controlled by a single bifurcation parameter.The diverse behavior of sleep-wake rhythm associated with the synchronized and desynchronized states is suggested to be understood as bifurcation phenomena of the cascaded maps.

  189. A Study on Dynamics of Self-similar Neural Network Model

    Sato Akihiro, Honda Iwao, Nakao Mitsuyuki, Yamamoto Mitsuaki, Sato Risaburo

    IEICE technical report. ME and bio cybernetics　94　(350)　81-88　1994/11/18

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    We have simulated the neuronal dynamics transition during sleep cycle by using the fully connected neural network model which is inhibited globally and perturbed by the random noise.In this paper, dynamics of a self-similar neural network is studied as a natural realization of sparsely connected network.Computer simulations show that the metastability of the network attractor is weakened into a monotonous structure,as the connectedness becomes sparse. Along with this structural change of the attractor,PSD of a single neuronal activity is modified from the 1, f to the flat.This result newly suggests the possibility that change in the network structure itself could contribute to the neuronal dynamics transition.

  190. Multivariate and Multistate Analysis of Cardiovascular Dynamics During Sleep and Wakefulness

    Hirokawa Ken, Nakao Mitsuyuki, Yamamoto Mitsuaki, Munakata Masanori, Imai Yutaka, Abe Keishi

    IEICE technical report. ME and bio cybernetics　94　(350)　97-104　1994/11/18

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    We have invewtigated the cardiovascular dynamics during physiological states such as sleep and wakefulness.Their dynamics are modeled as a multivariate autoregressive process.Mutual geometric relationships among state-dependent dynamics are obtained by means of Kullback-Leibler(K-L)Divergence.The results show that,concerning identical variables,the geometrical relation among their dynamics except for REM is consistent through subjects, and that,concerning different variables,the relation among their dynamics is varied dependent of subject.In addition,the cardiovascular dynamics during the transient phase from wakefulness to SWS are tracked by the time-varying multivariate AR model,which shows the geometrical properties of the orbit of the transient dynamics change.

  191. Neural Network Dynamics under Random Perturbations

    Honda Iwao, Nakao Mitsuyuki, Hondou Tsuyoshi, Yamamoto Mitsuaki

    IEICE technical report. Neurocomputing　94　(272)　71-78　1994/10/13

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    We investigated the neural network dynamics using the Hopfield- type neural network model under the correlated random perturbations and the global inhibition,which were supposed to mimic the cholinergic system and the serotonergic system in the brain stem,respectively.In the simulation,the perturbation was generated as the autoregressive process.The computer simulations showed that the correlation of the noise prolonged the maintained period of neuronal activities,and shifted the distributions of the staying time in the equilibrium states as well as the escape time from them to the longer-tailed profiles.Those results could provide the framework for studying the possible role of the cholinergic system in the brain functions through the neuronal dynamics transition during sleep cycle.

  192. Measurement and Analysis of Single Neuronal Activities from an Unrestrained Cat in Natural Outdoor Conditions

    MIZUTANI Yoshinari, OGATA Yoshinori, TAKAHASHI Toshimitsu, SAITO Satoshi, NAKAO Mitsuyuki, YAMAMOTO Mitsuaki, MATSUMOTO Goro

    30　(1)　1-8　1994/01/31

    Publisher: 計測自動制御学会

    DOI： 10.9746/sicetr1965.30.1 　

    ISSN： 0453-4654

  193. 意識とゆらぎ

    山本光璋, 中尾光之, 水谷好成, 児玉亨

    数理科学　37　(7)　40-46　1994/01

    Publisher: 2

  194. Fluctuations in Central Signal Unit Activity

    M.Yamamoto, M.Nakao, Y.Mizutani, T.Kodama

    Jpn. J. Clinical Monitoring　5　(4)　295-303　1994/01

    Publisher: 2

  195. Sleep and 1/f Fluctuations of Neuronal Activities

    山本光璋, 中尾光之, 水谷好成

    Jpn. J. Med. Elec. & Biol. Eng.　8　(10)　49-57　1994/01

    Publisher: 2

    DOI： 10.11239/jsmbe1987.8.10_49 　

  196. Modeling of Circadian System Based on Interaction between Substances and Rhythms

    中尾光之, 山本光璋

    Chemical Industry　44　(12)　p1003-1007　1993/12

    Publisher: 2

    ISSN： 0451-2014

  197. Simulation study on dynamics of thalamocortical system

    Hidaka Nobuya, Nakao Mitsuyuki, Katayama Norihiro, Mizutani Yoshinari, Yamamoto Mitsuaki

    IEICE technical report. ME and bio cybernetics　93　(356)　15-20　1993/11/26

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    Both thalamic relay and reticular neurons are modeled by Hodgkin- Huxley-type differentioal equations in order to investigate the oscillatory mechanism of thalamocortical system.A network model of the thalamocortical system is also constructed with these neuron models.The network model shows that (1) the cooperation between thalamic relay and reticular neurons is essential to generate the bursting oscillation,and that (2) the dc input current to the relay neuron can control the firing mode from tonic to bursting oscillation.These simulations suggest that the thalamocortical circuit and the dc input play an essential role for the dynamics transition in the thalamic neurons during sleep-waking cycle.

  198. Analysis of dynamics of single central neuron and its application to neuropharmacology

    Arai Hideki, Nakao Mitsuyuki, Takahashi Toshimitsu, Ikuta Nobuyuki, Mizutani Yoshinari, Yamamoto Mitsuaki

    IEICE technical report. ME and bio cybernetics　93　(356)　21-28　1993/11/26

    Publisher: The Institute of Electronics, Information and Communication Engineers

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    A long term recording of a single mesencephalic reticular formation(MRF) neuron was successfully carried out both during natural sleep-wakefulness and after the administrations of nicotinic antagonist,mecamylamine(0.6mg, kg),and muscarinic antagonist,atropine sulfate(1.0mg/kg).Although mecamylamine did abolish PGO-waves,no substantial change in the 1/f spectral characteristic of the single MRF neuronal activity during REM sleep was observed.Atropine sulfate completely eliminnated the 1/f fluctuations in the activity during initial 2 hrs after the administration.The restoration of the 1/f fluctuations was observed during REM-sleep-like states which appeared 2 hrs after the administration,although the mean discharge rate was deeply suppressed.These results support the idea that 1/f fluctuation in the single MRF neuronal activity during REM sleep depends on a muscarinic effect of acetylcholine.

  199. Bispectrom of Single Neuronal Activity in Cat's Brain Interpreted as Clustering Poisson Prosess

    TAKAHASHI Toshimitsu, NAKAO Mitsuyuki, MIZUTANI Yoshinari, YAMAMOTO Mitsuaki

    The Transactions of the Institute of Electronics,Information and Communication Engineers. A　76　(8)　1018-1026　1993/08/25

    Publisher: The Institute of Electronics, Information and Communication Engineers

    ISSN： 0913-5707

  200. Biological Rhythms and 1/f Fluctuations

    Mitsuaki Yamamomto, Mistuyuki Nakao, Yoshinari Mizutani

    nonoGIGA　2　(6)　1071-1076　1993/01

    Publisher: 2

  201. A Technological Model of Human Sleep-Waking Rhythms

    中尾光之, 山本光璋

    Brain Science and Mental Disorders　4　(1)　101-105　1993/01

    Publisher: 2

  202. Modeling of Human Circadian System Based on Thermoregulatory Function of Sleep

    中尾光之, 山本光璋

    Biophysiology　32　(3)　141-146　1992/05/25

    Publisher: 2

    DOI： 10.2142/biophys.32.141 　

    ISSN： 0582-4052 1347-4219

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    Mathematical models have contributed toward understanding the mechanisms of human circadian system. Results given by those models could qualitatively simulate some of features of the circadian system, but were difficult to be interpreted at physiological level. We have developed a quantitative model of human sleep-waking behavior based on a hypothesis that NREMS (Non Rapid Eye Movement Sleep) is controlled by thermoregulatory mechanisms of the preoptic/anterior hypothalamus, which is supported by recent observations. Circadian and homeostatic thermoregulatory processes may be integrated in this brain area. Simulations under entrained conditions show that the model closely mimics typical features of human sleep-wake rhythms. Simultaneously, the model couuld predict the possible underlying mechanisms for those features. These results suggest that the control of sleep-waking cycle can be understood within the framework of thermoregulation.

  203. 味覚の高識別感度とそのメカニズム

    中尾光之

    生物物理学会誌　28　(6)　305-308　1992/01

    Publisher: 1

    DOI： 10.2142/biophys.28.305 　

    ISSN： 0582-4052

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    The model of the acute differential sensitivity in taste of insect is introduced here. Modeling study shows that this can be realized through the central mechanism which CNS taste neuron integrates inputs from peripheral receptors. Such the mechanism is expected to contribute to the enhancement of the peripheral sensitivity in biological sensory system.

  204. 熱刺激と臨床痛の定量化

    山本光璋, 水谷好成, 中尾光之, 山内祐一

    下顎運動機能とEMG論文集　11　1-2　1992

    Publisher: 日本顎口腔機能学会

    DOI： 10.7144/sgf1982.11.1 　

    ISSN： 0911-8721

  205. 睡眠-覚醒サイクルにおけるネコ中脳網様体単一ニューロン活動とそのモデル化

    中尾光之

    信学技報　MBE88-69　1988

  206. 東北大学情報処理教育センター利用の手引

    奈良 久, 川添良幸, 金井 浩, 中尾光之, 他

    1986/10

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    その他の教育的著書・記事など<br /> 第1 版(October 1986),<br /> 第2 版(April 1987),<br /> 第3 版(April 1988),<br /> 第4 版(April 1989)

  207. マイクロコンピュータを用いた生体インパルス情報計測システム

    香田政彦, 中尾光之, 古賀和利, 三池秀敏, 蛯名良雄

    山口大学工学部研究報告　30　(1)　45-53　1979/10

    Publisher: 山口大学

    ISSN： 0372-7661

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    To compute the statistical characteristics of impulses recorded externally in nerve fibers, a microcomputer system was made up by utilizing two computer kits (MOTOROLA MEK-6800 DII). Two computers were connected with the stimulator, A/D converter, pulse counter, peak discriminator, and some additional electronic circuits. The combined system could measure the interval of impulses with different heights. The one microcomputer controlled the input gate of another microcomputer, and could give rise to the adjusted stimulus waveform, i.e. the train of sinusoidal waveform with several time inter...

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Books and Other Publications 19

  1. Mishima ed. "Sleep Science"

    M.Nakao

    Kagaku Dojin　2016

    ISBN: 9784759817270

  2. "Sleep Medicine: A comprehensive guide to its development, clinical milestones and advances in treatment", S. Chokroverty and M. Billiard eds.

    M. Nakao, A. Karashima, N. Katayama

    Springer　2015

    ISBN: 9781493920884

  3. Neural modeling for cooperative/competitive regulation of REM sleep with NREM sleep and wakefulness

    A. Karashima, Y. Tamakawa, Y. Koyama, N. Katayama, M. Nakao

    Cambridge University Press　2011/07

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    Rapid Eye Movement Sleep : Regulation and Function, Eds. B.N. Mallick, S.R. Pandi-Perumal, R.W. McCarley, A. Morrison

  4. 睡眠学

    中尾光之ら

    朝倉書店　2009/01/30

  5. 時間生物学事典

    中尾光之ら

    Asakura Publishing Co., Ldt.　2008/05/10

    ISBN: 9784254171303

  6. Trends in Chronobiology Research

    M. Nakao, K. Yamamoto, K. Honma, S. Hashimoto, S. Honma, N. Katayama

    Nova Science Publishers, Inc.　2006/02

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    ISBN-10: 1594544824 ISBN-13: 978-1594544828

  7. 生体リズムとゆらぎ

    中尾光之, 山本光璋

    コロナ社　2004/11

  8. スペクトル解析ハンドブック

    中尾光之, 山本光璋

    朝倉書店　2004/01

  9. Handbook of Computational Methods in Biomaterials, Biotechnology, and Biomedical Systems

    M.Nakao, F.Grüneis, M.Yamamoto

    Kluwer Academic Publishers　2003/01

  10. 快眠の科学

    中尾光之, 山本光璋

    朝倉書店　2002/01

  11. Brainware: Bio-Inspired Architecture and its Hardware Implementation

    N.Katayama, M.Nakao, M.Yamamoto

    2001

  12. Brainware – Bio-inspired Architecture and Its Hardware Implementation

    N.Katayama, M.Nakao, M.Yamamoto

    World Scientific　2001/01

  13. Nonlinear Biomedical Signal Processing I

    M.Nakao, M.Yamamoto

    IEEE　2000/01

  14. Nonlinear Biomedical Signal Processing I

    M.Nakao, M.Yamamoto

    2000

  15. Rapid Eye Movement Sleep

    M.Nakao, M.Yamamoto

    Narosa Publishing House　1999/01

  16. Rapid Eye Movement Sleep

    M.Nakao, M.Yamamoto

    1999

  17. ME用語辞典

    中尾光之

    コロナ社　1999/01

  18. Computer Analysis of Cardiovascular Signals

    M.Nakao, H.Takagi, Y.Mizutani, M.Yamamoto, M.Munakata, Y.Imai, K.Abe

    IOS Press　1995/01

  19. 睡眠学ハンドブック

    山本光璋, 中尾光之

    朝倉書店　1994/01

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Presentations 2

  1. Mathematical modeling as a tool for exploring sleep-wake control mechanisms International-presentation

    WorldSleep2011　2011/10/16

  2. 神経計算論2 (Neural Computation 2)

    第３４回日本神経科学大会　2011/09/14

Research Projects 25

  1. Design of chronotheraputic strategy against tumorgenesis based on modeling of cell cycle interacting with circadian clock

    Nakao Mitsuyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2015/04/01 - 2019/03/31

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    It has been reported that tumorigenesis and progression increase significantly when the circadian rhythms are impaired. Therefore, the chronotherapy of cancer has naturally been conducted. In this study, we constructed an automaton model of normal and cancer cell proliferation under the control of the circadian clock, and simulated their metabolic selection and proliferation. This indicates that the growth of cancer can be suppressed through metabolic modification. Furthermore, we focused on the transition mechanism from bile acid (BA) concentration abnormality to liver tumorigenesis, and modeling of the control mechanism of BA recycling and production under circadian rhythm control. The modeling indicates that changes in temporal order of BA production/uptake and degradation/excretion could cause an abnormal increase in the hepatic BA concentration, which leads to tumorigenesis.

  2. Multiscale models of biological clock mechanisms

    Nakao Mitsuyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2012/04/01 - 2016/03/31

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    In order to design a practical strategy for human to adapt against the unnatural environment, modeling is done for dynamics of pacemaker cells (mesoscopic scale) in the suprachiasmatic nucleus (SCN), the center of circadian clock mechanism, where local synchronization clusters appear. Experimentally in the slice culture of SCN, synchronizing clusters of pacemaker cells are observed in the photo-period dependent manner. This result is reproduced by the discrete and continuous models with the photo-responsive period-modulation mechanisms. As a result, it is clarified that (1)distribution of intrinsic periods of pacemakers, (2)coupling strength between the pacemakers, and (3)deadzone length of photo-responsive function cooperatively determine synchronization properties of the pacemaker population. This knowledge should be a convergent node connecting between the macroscopic (behavioral level) and microscopic (intracellular signaling) processes in the circadian clock mechanisms.

  3. The Role of Sleep in the Reorganization of the Cerebral Cortex

    KARASHIMA Akihiro, NAKAO Mitsuyuki, KATAYAMA Norihiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Young Scientists (B)

    Institution: Tohoku University

    2011 - 2013

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    Recently, the relationship between sleep-wake rhythm and synaptic plasticity is investigated by many sleep researchers. They suggest that the synaptic connection became stronger during wakefulness and became weaker during sleep. In order to confirm this suggestion, we performed whole-cell patch-clamp recordings from layer II/III pyramidal neurons of somatosensory cortex in acute slices of the rats that had been awake or asleep. We found that i) current-voltage relationship of EPSCs showed inward rectification, and ii) eEPSCs were depressed by Philanthotoxin 74, which is antagonist of Ca2+-permeable AMPA receptors, in slices of spontaneously waking and sleep-deprived animals. Both results show that amount of Ca2+permeable AMPA receptors, which plays crucial role in synaptic plasticity, are high during wakefulness. These strongly suggest that synapses become widely potentiated during wakefulness and were downscaled during sleep.

  4. Self-organization mechanisms of topology of local neural circuit

    KATAYAMA Norihiro, KARASHIMA Akihiro, NAKAO Mitsuyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2007 - 2010

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    In this study, we investigated the dynamics and self-organization of cortical local neural network by electrophysiological experiments on acute brain slices, mathematical modeling and computer simulations of realistic neural network. It was found that autonomous change of functional neural connections occurred associated with metastable dynamics of ensemble neuronal activities in the local neural circuit. In addition, it is suggested that a certain degree of robustness of the distribution of efficacy of functional neuronal connections against the self-organization of the network.

  5. 細胞周期とそのサーカディアン制御モデル

    中尾 光之

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 挑戦的萌芽研究

    Institution: 東北大学

    2008 - 2009

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    最新の知見を基に哺乳動物細胞の細胞周期の分子制御ネットワークのモデルを構築した。その基本構造はCyclin, CDK, CKI, CDC, Cyclin-CDK(MPF : M期促進因子),weel, APC, SKP2、およびそれらの分解、リン酸化過程からなる。これは基本的にG2/M期のモデルである。細胞サイズの成長曲線が、細胞周期と概日リズムとの相互引き込み特性への影響について調べ、線形成長やべき成長などの場合に細胞分裂サイクルと細胞周期の相互引き込み特性を調べた。その結果、指数成長と線形成長の場合にBMAL1とCyclin-CDKの頂点位相が一致し、生物学的なリアリティが高いことが分かった。また、未分化中胚葉(PSM)の分節時計の分子メカニズムのモデル化を行い、自律振動するWntシグナル系に減衰振動するDelta-Notch系が駆動されて分節化の2時間リズムが作られていることが明らかになった。さらに、Wnt系の分岐特性がAxinの産生率に依存しており、特にSuper-critical Hopf分岐を与える条件下で、PSMにおける分節遺伝子発現波の尾側から吻側への伝播が再現されることが分かった。また、分節化領域とPSM領域がWntの空間的な濃度勾配によって分離することを示した。分節化の従来モデルとしてClock and Wavefrontモデルがあるがこれでは分節化領域でのLfngとHesの空間的な棲み分けが説明できず、我々のモデル化からLfngの活性化レベルを低下させるメカニズムが予定分節領域において必須であることが示唆された。本研究を通じて、細胞周期と分節時計といういずれも発生過程を支配する分子時計メカニズムをモデル化したが、これらと日周リズムの同期関係をさらに調べることにより、時間薬理学的なガン治療のヒントが得られるかもしれない。

  6. 樹状突起活動電位の生理学的役割に関する研究

    中尾 光之, 坪川 宏

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特定領域研究

    Institution: 東北大学

    2008 - 2009

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    我々は、樹状突起活動電位の生理学的役割の候補の一つとしては、内因性カナビノイドを介した抑制性シナプスにおける逆行性情報伝達、いわゆるDSIが、生理的にはNa^+スパイクの樹状突起への逆伝播によって誘発されるという仮説を立てた。DSI自体のメカニズムに関するこれまでの研究からポストシナプスより放出される内因性カナビノイドは、2-アラキドノイルグリセロール(2-AG)であると考えられている。そこで、プレシナプスの機能修飾のメカニズムを調べるために、本年度はCOX-2の活性変化の影響や代謝産物の投与効果について調べた。 2-4週齢のマウスより海馬スライス標本を作成し、CAI野錐体細胞における単シナプス性IPSCをボルテージクランプ・モードで経時的に記録した。COX-2の抑制剤であるCAY10404を細胞外投与すると、IPSCの振幅は減少した。この効果はCBI受容体のアンタゴニストであるSR141716の追加投与により阻害されたことから、内因性カナビノイドである2-AGの働き、すなわちDSIと同等の伝達物質放出抑制によると考えられる。一方、COX-2による2-AGの代謝産物であるPGE2-Gを細胞外へ投与すると、IPSC振幅には一過性の増強が観察された。これらの結果は、(1)海馬スライス標本においてはプロスタグランジンとカナビノイドのある程度の放出・滲出が常にあること、(2)COX-2活性の程度により両者の放出・滲出のバランスが変化し、結果としてプレシナプスにおけるGABAの放出が促進・抑制の両方向に調節され得ること、(3)樹状突起活動電位によるポストシナプスの脱分極は2-AGの産生を促進することで両者のバランスを変化させ、GABAの放出抑制を引き起こしていること、を示唆している。樹状突起活動電位がCOX-2活性に影響を与えるか否かなどが今後の重要な課題である。

  7. Role of Stress-related Peptide CRH in Brain-Gut Interactions

    FUKUDO Shin, AOKI Masashi, KANAZAWA Motoyori

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2003 - 2006

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    Brain-gut interactions are functional and reciprocal connection between the brain and the gut. Brain-gut interactions are the developmentally old phenomena but are not fully investigated. There are two major directions in these phenomena. One is changing the gut function by stress-induced excitation of the brain via autonomic and/or endocrine pathways. The other is changing the brain function by the perception signal from the gut via visceral afferent pathways. We hypothesized that corticotropin-releasing hormone (CRH) and related neurotransmitters may be released in the specific regions of the brain by psychosocial stress or visceral stimulation and that these phenomena may be augmented in patients with irritable bowel syndrome (IBS). The main objective of this research is to test our hypotheses by animal experiments and clinical brain-gut examination including positron emission tomography (PET) and quantitative analysis of electroencephalography (EEG). Using this grant (2003-2006), we successfully developed rats mimicking pathophysiology of IBS. Administration of specific CRH-Rl antagonist reversed the IBS-like pathophysiology of rats. Visceral stimulation in humans induced abdominal pain and increase in regional cerebral blood flow. The specific regions activated by visceral stimulation were thalamus and the limbic cortices. EEG power spectra and topogram were also changed by visceral stimulation. The visceral stimulation also changed visceral sensation, anxiety, and gastrointestinal motility. These phenomena were exaggerated in IBS patients and administration of CRH antagonist reversed the IBS pathophysiology. These findings suggest that released CRH in the specific brain or in the other organs may play a major role of IBS and animals mimicking IBS. Thus using this grant (2003-2006), we succeeded to clarify some fundamental roles of CRH in brain-gut interactions. Further investigation on this paradigm is highly expected by our research group.

  8. Control of Circadian Rhythms Based on The Oscillator Model.

    NAKAO Mitsuyuki, KATAYAMA Norihiro, KARASHIMA Akihiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2003 - 2004

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    In this research, we planned to propose the strategy for minimizing the adaptation failure to the shiftwork and time zone flights by controlling the entrainment mechanisms of biological rhythms. The results are summarized as follows. (1)The model of the human circadian clock mechanisms was constructed, which consists of the oscillators I, II, and SW. In addition, the photo-responsiveness was introduced to the model (2)The behavior of biological rhythms under the time-zone flights was simulated by the model The simulations showed the plausible mechanisms underlying the diverse reentrainment patterns such as the orthodrimic, antidromic, and those by partition. That is, the magnitude of photic phase response and its sign when the subject is exposed to light, and the value of the interaction function from the oscillator I to II just after the exposure to light were shown to determine the reentrainment direction. (3)Exercise during waking time in the destination could prevent the circadian pacemakers from its reentrainment by partition In addition to the conditions (2), the value of the interaction function from the oscillator SW to II just after the exposure to light modifies the reentrainment direction. According to these knowledge, the favorable flight schedule from Tokyo to New York was proposed to accelerate the reentrainments and reduce the expected jet lag. (4)The phase oscillator does not have the amplitude. On the other hand, the thermoregulatory model of sleep control which we previously proposed has a merit to predict the behavior of alertness under the various circumstances. However, the model application was confined to the steady state where the phase relation between the pacemakers is not expected to significantly change. In other words, it is not applicable to the environments where light-dark and sleep-waking cycles dynamically change. Here, the integrated model was constructed by combining the phase oscillator model and the thermoregulatory model of sleep control This was realized by mapping the phases of the oscillators I and II to those of the oscillators X and Y. This integrated model provides the framework for predicting the behavior of alertness and biological rhythms under the diverse light-dark cycles and working schedules.

  9. 階層的集合振動体としての生物時計機構のモデル化

    中尾 光之, 片山 統裕, 山本 光璋

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特定領域研究

    Institution: 東北大学

    2003 - 2003

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    脳の視交叉上核(SCN)に存在するニューロン群は日周振動子の生理学的実体と考えられる。(1)時計遺伝子を含む哺乳類の振動機構をモデル化した。これは、Per,Clock,Cry,Bmal1,Decからなる転写・翻訳フィードバックループの酵素反応系からなっている。このモデルは、Per,Cry,DecとBmal1とが逆位相関係を保ちながら振動しており、また、、Per,Clock,Cry,Bmal1のノックアウト実験の結果を再現した。また、Decをノックアウトした場合について振舞いを予測した。さらにCREBのリン酸化レベルの日周変動を転写・翻訳ループの外部に結合し、光変換機構のモデル化を行った。これにより、位相反応曲線に不感領域が現れ、実際の位相反応性を再現するものとなった。(2)分子レベルからSCN全体をモデル化するために、分子レベルの振動モデルを15変数から4変数へ縮約し、その振動解の振舞いや位相反応性について調べた。その結果、この縮約は詳細な記述によるモデルの力学的な性質を定性的には保存していることが明らかになった。さらに縮約モデルを拡散で結合した系についてそのダイナミクスを調べた。その結果、Perあるいはそれと同相で動いている変数に関連した拡散が系全体での同期性に支配的な役割を担っていることが明らかになった。(3)行動レベルから振動子への適応的なフィードバックを有する位相振動子モデルに新たに光応答性を導入し、時差飛行時の日周振動子の振舞いをシミュレーションした。それにより、順行性、逆行性、分離再同調が生じる条件を明らかにした。また、運動によって分離再同調が防止されることが明らかになった。以上は階層的集合振動体としてのSCNの生体リズム機構から、行動レベルまでを見通した統合的なモデル化による独自の成果である。

  10. Constructions of Wearable Digital Recorder Equipped with Widehand Amplifier and Its Application Softwares

    YAMAMOTO Mitsuaki, KATAYAMA Norihiro, NAKAO Mitsuyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    2001 - 2003

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    In cognitive and behavioral neurosciences, it is important to measure biological information in diverse environments including natural daily life. In order to realize this, constructing a multichannel wearable digital polygraph with wideband amplifiers and confirming its usefulness are our purpose. Its specification is described as follows. Maximum sampling frequency : 1kHz, Flash memory with large capacity, Noise level : p-p2μV (up to 300Hz), Channel number : 24ch, Weight : 300g, Maximum recording time : 24hr or longer, Bandwidth & Gain : programmable, Stimulus/Measurement/Sampling Parameters : adaptively set. All the circuits are made by CMOS technology. The system construction was ordered to Digitecs Co. Ltd. In addition, application softwares such as waveform viewer and transformer of data format were made. Thus constructed system was subject to applications to human and animal studies so as to verify its applicability The results are summaried as follows. (1)Measurements were performed for the dental patients suffering from sleep disorder. Quantitative examination was done whether or not the disorder was relaxed by the dental treatment. It was confirmed that the quality of sleep in terms of the polysomnograph was improved by the treatment. (2)Spike-like rapid eye movement anticipatory pre-potentials (RAPPS) were measured together with human electroencephalogram, which is owing to the specification that the system was equipped with the wider bandwidth and many channels. Pre-saccade spike potentials (PsSP) were also measured. Through elaborate analysis of measured RAPPS and PsSP, possible physiological origins were inferred. (3)Simultaneous multi-channel recording of electroocculogram, and hippocampal and brainstem EEGs were measured in rats under free-moving situations. Steady and instantaneous correlations between hippocampal θ wave and PGO wave/REMs was found during rapid eye movement (REM) sleep. These novel findings thank to the specification of constructed system such as the wide bandwidth, multiple channels, and a large amount of storage, which verifies the usefulness in the medical and biological applications.

  11. 階層的集合振動体としての生物時計機構のモデル化

    中尾 光之, 片山 統裕, 山本 光璋

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特定領域研究

    Institution: 東北大学

    2002 - 2002

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    脳の視交叉上核(SCN)のニューロンにおいて一群の遺伝子(時計遺伝子)が約24時間周期で発現の増減を繰り返していることが明らかになってきた。一方で、時計遺伝子は脳内の他の組織や体内の多くの組織にも発現している。SCNに存在するニューロン群は日周振動子の生理学的実体と考えられる。SCNの腹外側と背内側では、含有されるペプタイド、光感受性、入出力関係などが異なっていることから、少なくとも二つの異なる振動体が存在していると考えられる。SCN外や末梢に存在する振動機構はSCNとは独立した振動子を構成するものと考えられる。今年度は(1)時計遺伝子を含む振動機構をモデル化する基礎として、代表的なモデル化の枠組み、非線形転写制御フィードバックモデル(以下、Goodwin型モデルと呼ぶ)と振動子フィードバック型モデル、についてその外部入力に対する分岐特性を調べた。これより、Goodwin型モデルは1:1の引き込み領域が狭く、外力の強度が増した場合には他の周期比の引き込みに移行するか、引き込まれなくなった。振動子フィードバックモデルは広い1:1の引き込み領域を持ち、振動子自身の固有周期と外力の周波数がかけ離れていても外力が強ければ1:1で引き込んだ。このようなモデルの力学的な構造に依存した本質的な分岐構造の違いは、前提されることが多いが依然として仮説でしかない非線形転写フィードバックが日周リズムを作り出しているとする考えの妥当性を実験的に検証する手がかりを与えている。(2)SCNの大規模シミュレーションに向けて16ノードからなるクラスター計算機を構成した。現在数百程度のHodgkin-Huxley方程式を基幹としたネットワークをシミュレーションした結果、大規模シミュレーションに堪え得るものであることが示された。(3)行動レベルから振動子への適応的なフィードバックを有する位相振動子モデルを構成し、その妥当性をシミュレーションによって示した。フィードバックの必然性が示されたことで、生体リズムでは行動パターンが階層を越えて時計遺伝子を含む分子レベルの時計機構やその集合体における協同性に影響を与えていることが示唆された。これは階層的集合振動体として生体リズム機構を考えていく上での指針を与える。

  12. Control Criteria of Cardiovascular System Generating 1/f Fluctuations

    NAKAO Mitsuyuki, KATAYAMA Norihiro, YAMAMOTO Mitsuaki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2001 - 2002

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    In this study, we explored the control criteria of the cardiovascular system generating 1/f fluctuations. Through estimating the baroreflex gain (BRG), state-dependency of the regulatory system was studied. BRG was estimated by the sequence method constructed under an open-loop assumption from blood pressure (BP) to heart rate (HR). As a result, the estimated BRSs were lower in order standing, non rapid eye movement (nonREM) sleep, REM sleep, supine. In addition, under the head-up tilting posing orthostatic stress, it was paradoxically found that BRS becomes reduced as the tilt angle (gravity) increases. As a novel technique estimating BRS based on the closed-loop assumption, a new method was proposed that the sequence method is applied to a time series generated by the identified multivariate autoregressive (MAR) model driven by the innovation process, tentatively called "innovation method". Comparison between the estimates obtained by the sequence and the innovation methods did not show large disparity, which clears the difference in the absolute value of BRS estimated by the open- and closed-loop techniques. In addition, the closed-loop impulse response from BP to BP was found to be accelerated as the orthostatic stress became heavier. Similar analyses were applied to the data of spinal injury patients. As a result, the cardiovascular system showed unstable responses for the patients of upper level injury. In contrast, the patients of lower level injury were found to have similar characteristics to the healthy subjects. Besides, the patients showed the distinct 0.05Hz oscillation, which could provide novel information concerning generation mechanism of Mayer wave. From the analysis of inter-dependency between BP and HR, the cardiovascular system is considered to be unstabilized by the disconnection between them due to the injury. Because the response to the orthostatic stress reflects control of peripheral resistance and behavior of venous return, the control criteria of the cardiovascular system could be explored by modeling them. Additionally, we constructed the cardiovascular model which consists of HR and sympathetic activity as control variables and BP as a variable to be controlled. Simulation of optimal control on the model suggests that the criteria for generating 1/f fluctuation in HR are loose ones allowing deviations to some extent rather than rigid one not allowing fluctuations.

  13. 能動的樹状突起を有する形式ニューロン回路網のダイナミクス

    片山 統裕, 山本 光璋, 中尾 光之

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特定領域研究(A)

    Institution: 東北大学

    1999 - 1999

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    我々は,ニューロン樹状突起の能動的特性とシナプスの棲み分けに基づいたモデルである階層型形式ニューロンを提案してきた.本研究では,階層型形式ニューロンにより,海馬CA3領域のシナプスの投射パターン,シナプス可塑性の性質に基づいた相互結合回路モデルを構築し,そのダイナミクスを計算機シミュレーションにより研究した. CA3領域の錐体ニューロンは歯状回顆粒細胞から出力される苔状線維によるシナプス入力を尖頭樹状突起の基部に,またCA3錐体ニューロンの出力線維の側枝(シェーファー側枝)が作る回帰性シナプスは,尖頭樹状突起の先端部に作られる.回帰性シナプスの可塑性がそれ自身の活動とシナプス後細胞(CA3錐体ニューロン)の活動の連合によって伝達効率が変化するHebb型であるのに対し,苔状線維シナプスはシナプス前ニューロンの活動のみに依存する非連合型である.そこで本研究では,苔状線維シナプスについてはシナプス荷重を固定し,先端部の回帰性シナプスの結合を錐体ニューロンの出力と連合して変化させた.これは「教師なし学習」の一種であるHebb学習法に相当するものである. 苔状線維に複数のランダムなバイナリパターンを繰り返し与えると,そのパターンが相関マトリクスとして神経回路モデルに埋め込まれ,自己連想できるようになることがシミュレーションにより示された. 従来の神経回路モデルにおいては,自己連想メモリは相関学習などの「教師あり学習」により実現されてきたが,これには教師信号を生成する別の神経回路を仮定する必要があった.本研究により,樹状突起の能動性によってもたらされるシナプス統合の階層性,入力系統に依存したシナプスの棲み分けパターン,及び「教師なし学習」の一種であるHebb学習という,生理学的・解剖学的にみて自然なメカニズムのみによって,海馬CA3領域が原理的には単独で自己相関メモリ機能を実現できることが示された.

  14. Proposals and simulations from brain science for regulating large-scale and wide-spread information systems

    YAMAMOTO Mitsuaki, NEMOTO Yoshiaki, SHIRATORI Norio, ITO Takayasu, NAKAO Mitsuyuki, INOUE Shojiro

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: TOHOKU UNIVERSITY

    1998 - 1999

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    This study explores the way of coexistence of human being and information system by investigating biological information systems such as brain and biosystems. Simulations were performed using interconnected neural network models consisting of spiking neurons, where neuronal spikes could be regarded as an information carrier in the brain (packets in a computer network). Resulting cluster patterns of neuronal activities are similar to those of packet flow in the computer network. In addition, enhancing mutual connections between neurons augments the clustering. This result indicates that enhancing inter-node connections could result in localizing highly activated nodes in the computer network. Possible control strategy employed in cardiovascular system is explored through modeling, which underlies 1/f fluctuations in heart rate and blood pressure. The results clarified that the control strategy is not a rigid one prohibiting deviations of control variables from an operational point, but that it is a loose one allowing the variations to some extent. Simultaneously, the hierarchical control strategy is shown to be essential that switches global activation level of the control variable. Resulting dynamics of hybrid system coupling an actual hippocampal neural network and nonlinear oscillator is investigated for varied coupling mode. This study suggests that a system of essentially high degree of freedom happens to exhibit behavior of lower degree of freedom dependent on control strategy. Brain is considered to realize such a diverse dynamics in the neural network by varying controls. Thus clarified control strategies employed in the brain and biosystem could provide a novel framework for network control and information access control in the internet.

  15. 能動的な樹状突起におけるシナプスの棲み分けと情報表現

    中尾 光之, 片山 統裕, 山本 光璋

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特定領域研究(A)

    Institution: 東北大学

    1998 - 1998

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    我々はアクティブな樹状突起をもつニューロンのコンパートメントモデルの入出力特性に基づいた形式ニューロンを定式化した。形式ニューロンの基となった海馬CA1錐体ニューロンのコンパートメントモデルは、等価円柱で近似した細胞体、基底樹状突起と尖頭樹状突起、および軸索小丘が電気的に結合されたものである。各コンパートメントの膜電位ダイナミクスはHodgkin-Huxley方程式を拡張した微分方程式で記述されている。樹状突起の能動性を表現するモデルパラメータは、最新の生理学的知見に基づいて設定した。また、ニューロンは多種の興奮性および抑制性シナプス入力を受容するが、これらはその入力系統に応じて細胞体や樹状突起の上を整然と「棲み分け」ていることが知られている。そこで「シナプスの棲み分け」を考慮して形式ニューロンを構築した。具体的には、興奮性(x)および抑制性(y)シナプス入力をそれぞれ尖頭樹状突起の中央に配置されたものをx_m,y_m,末端に置されたものをX_d,y_d,および基底樹状突起に配置されたものをX_b,y_b)と記す。同時に与えられる1組のシナプス入力(X_b,y_b,X_m,y_m,X_d,y_d)に対するニューロンの出力ζ(1または0の値をとり、ニューロンの興奮をζ=1で表す)が次の様に定式化できるものと仮定した。ζ=θ[I_<dendrite>(x_b,y_b,x_m,y_m,X_d,y_d)-h]。ここにI_<dendrite>は樹状突起によるシナプス入力の統合特性を表すスカラー関数(シナプス入力統合関数),hはニューロンの発火閾値、またθ=[z]はヘビサイドステップ関数(z【less than or equal】0でθ=1、z<0でθ=0)である。シナプス入力統合の局所性と階層性を考慮し、コンパートメントモデルのシミュレーション結果に基づいて、I_<dendrite>の構造を同定した。構築された形式ニューロンは、古典ニューロンで構成された多層神経回路網と相似な構造を有していた。ここでは以上のように、シナプス入力間の相互作用の特性に基づき、アクティブな樹状突起を有するニューロンモデルの入出力特性を定量的に近似する形式ニューロンを開発した。この形式ニューロンは多層神経回路網と相似な見通しのよい構造をしており、大規模なネットワークモデルの構築に適するものである。また、このモデルは生物学的に知られている樹状突起のアクティブな性質とシナプスの棲み分けの機能的意義を理解する上でも有用である。さらにモデルを改良して行くとともに、回路網を構成しそのダイナミクスを調べることにより樹状突起の能動性の機能的意義を明らかにして行く。

  16. Construction of Programmable Long-Term Measurement and Recording System for Biological Signals

    YAMAMOTO Mitsuaki, ABE Masato, DENDO Isao, NITTA Shinichi, ESASHI Masaki, NAKAO Mitsuyuki

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (A)

    Institution: Tohoku University

    1995 - 1997

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    In order to investigate fluctuations in the cardiovascular signals and to predict occurrences of pathological events, a system is essential which realizes stable measurement and recording for a long period beyond the day length. In this study, such a system is constructed. The results are summarized as follows. 1.The constructed portable long-term recording system for biological signals has the following merits including a large scale memory up to 192MB,low power consumption realized by CMOS-based circuits, programmable measurement modes. The 2nd system is additionally developed based on the experiences of the 1st one, where the interface for data transfer is enhanced and the indicators for monitoring the internal states of the system is newly equipped. 2.The multiple digital notch filter is composed for excluding slow fluctuations of the baseline contained in ECG,and the special-purpose algorithms for extracting R and T waves are also developed. 3.For further analyzes of EGG data, a novel method is developed to clarify a transition rule of the balance between the autonomic activities based on the nonstationary spectral analysis. The bispectral analysis is also implemented. Impulse responses between cardiovascular variables are estimated for chracterizing the state-dependency of the cardiovascular system. The distance measure between cardiovascular dynamics are newly proposed to quantitatively differentiate the state-dependent properties. 4.Under the free-moving environment, faithful measurement and recording are confirmed to be maintained up to 32 hours including sleep and waking states. The subjects claim no uncomfortable feelings while wearing the system. The system is applied to the sleep apnea patient under allowed to move freely, where a condenser microphone is equipped instead of the acceleration sensor for monitoring tracheal sounds. This application shows satisfactory availability of the system for patients as well.

  17. Biological and Physiological Engineering Study on Global Regulatory Mechanisms of The Brain as A Complex System

    YAMAMOTO Mitsuaki, NAKAO Mitsuyuki, AKAIKE Norio

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for Scientific Research (B)

    Institution: Tohoku University

    1995 - 1997

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    As a representative of a complex system, global regulatory mechanisms of the brain are investigated from the biological and physiological engineering point of view. The research results are summarizedas follows. 1.Dynamics tratnsitions of neuronal activities during sleep cycles are studied in the lateral geniculate nucleus (LGN) and the cortical areas 18 and 6. The LGN neurons characteristically show bursting activities, which are confirmed to exhibit the neuronal dynamics transition from the white power spectral density (PSD) (slow wave sleep : SWS) to the 1/f PSD (rapid eye movement sleep : REM). The cortical neurons also exhibit the same dynamics transition as the neurons studied so far. These results support our hypothesis that neurons in the processing systems of the brain commonly exhibit the concerned dynamics transitions during sleep cycles. 2.The length of the column, the compositions of medium, and the oxidation-reduction potential of the high precision liquid chromatography are optimized to carry out a microdialysis of serotonin concentration, a neurotransmitter of the regulatory system in the brain, which enables us to study the relationship between the serotonin concentration and the neuronal dynamics. As a result, concentration can be measured down to an order of fmol. By this novel method, sleep-wake-dependent variations of the serotonin concentration are measured in LGN (wake>SWS>REM). 3.Mechanisms underlying the neuronal dynamics transition are investigated based on the neural network model, which shows that the balance between the inputs from the neurons within the network and those from the external neurons is essential for this phenomenon. That is, for the 1/f fluctuations the internal inputs are required to dominate the external, and the opposite relation should be satisfied for the random activities exhibiting the white PSD.This suggests that the regulatory system exerts diverse effects on the concerned dynamics transition. In addition, the metastability of the neural network relates to REM sleep might be a physiological substrate of dreaming, which provides a novel information for understanding the relationship between dreaming and higher-order brain functions.

  18. Experimental and Modeling Study on the Stabilization Mechanism of Neuronal Network by Aminergic System

    YAMAMOTO Mitsuaki, MIZUTANI Yoshinari, NAKAO Mitsuyuki, WATANABE Tatehiko

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for General Scientific Research (C)

    Institution: Tohoku University

    1993 - 1994

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    We fabricated a probe of microdialysis with stainless steel microelectrodes which was inserted into the lateral geniculate nucleus of a cat. A single neuronal activity was recorded for more than several hours stably during sleep-waking states, during which 10^<-2>M serotonin was perfused. Following results were obtained : (1) During slow wave sleep of control state, the neuronal activity was characterized by a burst and silence type of firing with a low mean discharge rate, and had white noise like dynamics, whereas it showed a tonic and higher firing rate with 1/* fluctuations for serotonin perfusion. (2) During REM sleep the firing rate was tonically increased due to serotonin perfusion. The 1/* fluctuations were constantly observed for both control and drug supply. (3) The tonic membrane depolarization was observed during serotonin perfusion. After all, so far, it is the following three states when 1/* fluctuations have been observed in a single neuronal activity of the central nervous system : (1) REM sleep (2) the state in which the brain serotonin is depleted. (3) slow wave sleep during which serotonin of high concentration was diffused through a microdialysis probe On the other hand, the white noise like dynamics has been observed both during slow wave sleep and during arousal state in which an animal is highly attended to the environment. Therefore, imbalance of neuromodulatory substances such as serotonin, noradrenaline, acetylcholine, etc.would produce 1/* fluctuations in a neuronal activity of the central nervous subsystem we call "executive system".

  19. 夢見と神経回路網の準安定性に関する研究

    中尾 光之, 水谷 好成, 山本 光璋

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 重点領域研究

    Institution: 東北大学

    1993 - 1993

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    我々はネコの脳内単一ニューロン活動が睡眠サイクルの各意識状態において異なったダイナミクスを示すことを明らかにした。即ち、徐波睡眠(SWS)時には単一ニューロン活動が0.01-1.0Hzの低周波帯域において平坦なパワースペクトル密度(PSD)を呈し、夢見の睡眠である逆説睡眠時(PS)にはニューロン活動のPSDは同帯域で周波数に逆比例する様な(1/f様と呼ばれる)構造を示す。本研究では、この生理学的現象の生成メカニズムの解明のために、状態空間における神経回路網の振舞いを解析した。我々が用いた神経回路網モデルはHopfield型の回路網に大域的な抑制と正規白色ノイズを加えたものである。シミュレーション結果から、弱抑制時に顕在化していた準安定な平衡点が抑制入力の増大によって不安定化すると同時に、"0"状態が大域的なアトラクタとして顕在化するような回路網アトラクタの幾何学的な構造の変化が単一ニューロン活動の遷移現象を引き起こしている可能性が示唆された。また、各準安定平衡点の滞在時間の分布は指数分布となった。理論的な知見から、分布の指数は、各準安定状態を囲む最も低いポテンシャルの壁の高さに対応するものであることが示唆される。従って、滞在時間の分布は準安定な性質が顕在化する弱抑制時の回路網アトラクタの幾何学的な構造を間接的に表していると考えられる。以上の結果から、PS時に対応する弱抑制状態においては、神経回路網は準安定平衡点を想起しながら状態遷移し続けることになる。これは「夢見」と類似した現象であるとも考えられる。このようなネットワークの準安定性が何らかのかたちで脳の高次機能に関わっているとすると興味深い。 結果の一部は"A network attractor-based interpretation of neuronal dynamics transition during sleep cycle"としてBiological Cyberneticsに投稿中である。

  20. 夢見とその神経機構に関する神経回路網モデル

    中尾 光之, 水谷 好成, 山本 光璋

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 重点領域研究

    Institution: 東北大学

    1992 - 1992

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    本研究では、逆説睡眠時の単一ニューロン活動l/fゆらぎや睡眠サイクルにおけるダイナミクス遷移現象の生成メカニズムに関するより詳しい解析のために、モデルにおける単一ニューロン活動の時系列のスペクトル解析に加えて、状態空間における神経回路網の振舞いを解析した。我々が用いた神経回路網モデルはHopfield型の回路網に大域的な抑制と正規白色ノイズを加えたものである。回路網のアトラクタの構造を記憶パターン数によってパラメトリックに制御するためにシナプス荷重を相関記憶の場合と同様なやり方で与えた。またニューロンの属性でシナプスの作用を一荷に決定されるような非対称な結合を有する回路網についても同様なシミュレーションを行った。シミュレーション結果を纏めると以下のようになる。逆説睡眠時に対応する弱抑制状態においては、回路網はノイズの摂動を受ながら、いくつかの局所的な平衡点の間を間欠的に移動している、即ち、神経回路は準安定平衡点を相起しながら状態遷移し続けていることが分かった。一方、除波睡眠に対応する強抑制時には、回路網は大域的なアトラクタであると考えられる"0"状態の近傍を摂動を受けながら状態遷移していることが示された。このことは、弱抑制所に顕在していた局所的な平衡点が大域点な抑制性入力によって不安定化すると同時に、"0"状態が大域的なアトラクタとして顕在化するような回路網アトラクタの幾何学的な構造の変化が単一ニューロン活動の遷移現象を引き起こしている可能性を示唆している。これらの平衡状態は必ずしも過去に記憶されたパターンとは限らずその記憶とは全く関係がないものも含まれている。つまり、相起される過去の記憶やそれとは無関係な記憶パターン間の遷移であり、これは「夢見」と類似した現象であるとも考えられる。このようなネットワークの準安定性が何らかのかたちで脳の高次機能に関わっているとすると興味深い。これまでの成果は、9月にアムステルダムで行われるICANN'93に"Metastability of network attractor and dream sleep"として投稿された。

  21. 最新の生理学的知見に基づく神経系数理モデルの構築とその情報処理機能に関する研究

    中尾 光之

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1987 - 1987

  22. Research on a Thinking Scheme of the Brain-Structured Computer Research on a Thinking Scheme of the Brain-Structured Computer

    NAKAMURA Tadao, YOSHIOKA Yoshio, HORIGUCHI Susumu, SHIGEI Yoshiharu

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for General Scientific Research (B)

    Institution: TOHOKU UNIVERSITY

    1986 - 1987

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    We have studied a real intelligent computer "The Brain-Structured Computer" stemmed from the functions of the human brain. In order to realize functions of the human brain on computers, we usually provides computers with programs associated with the algorithms. However, the computer built by us is based on the general-purpose pipeline which is in multiple instruction stream-single data stream fashion. We use this machine as FP graph reduction machine, where FP is the functional program proposed by J. Backus. The reason for using the FP language is because this language is familiar with mathematical thinking. The computer is composed of a structure memory, a reduction engine, and a reduction controller. If we apply the FP language to the computer, the language should be translated into FFP language to be interpreted by the machine. The FFP has a capability to make the pipelined reduction machine understand the meaning of programs written in FP. To realize such processes, we have introduced the notions associated with the activities of the human brain. Firstly We have mabe the model of thinking scheme on the computer considering the above. And then we designed the hardware of the brain-structures computer and built it. Software's design and production and its installation were completed. Finally we have built the brain-structured computer. To improve this machine, we evaluated the performance through several applications programs. The above is rather to realize arithmetic-logic part of the human brain. The image processing in the human brain is ambiguous but interesting to research. We have build high speed computer graphics by a ray-tracing method in parallel processing. This serves analyses of each stage of image processing.

  23. 合成音声を使った日本語教授法の研究

    原土 洋, 金井 浩, 中尾 光之, 川添 良幸, 安倍 正人, 堀口 進, 城戸 健一, 大坪 一夫

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 一般研究(B)

    Institution: 東北大学

    1985 - 1987

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    前年度の成果に従い, 留学生の音声解析システムの抜本的な改善を行なった. その具体的内容は, A/D変換部を本学応用情報学研究センターの開発したシステムを利用し, 精度の向上を図ったこと, およびデータ解析にIBM3081-KX6汎用大型計算機を用いたことである. この変更により, フォルマント抽出, ピッチ抽出等の信頼度が飛躍的に向上した. また, 標準音声としてNHKのアナウンサーによる発声データを利用し, "正しい日本語"の音声データをコンピュータ上に蓄積した. この標準データを用いることにより, 留学生の発声に対する評価関数の作成を可能とした. このデータは60分テープ1巻にまとめられたものであるが, 数多くの短い文章により構成され, その各々が日本語の特徴的な部分を表わすように作られている. 汎用大型計算機上の解析プログラムは, 留学生の発声に対する正しい評価を行うために, DPマッチング法を用いて各要素音を対応させている. このシステムを用い, 中国人留学生, 男女各1名の発声データを上記NHKアナウンサーの発声データと比較検討した. この結果, 日本人には見られなに発声上の違いが得られた. 今後, 国による違い等についての詳細な調査を行なう必要がある. また, 数多くの留学生に対して本システムを試用し, 効率的なコースウエアの確立を行わねばならない.

  24. 神経化学的過程を考慮した神経系数理モデルの情報処理機能

    中尾 光之

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 奨励研究(A)

    Institution: 東北大学

    1986 - 1986

  25. 高性能化学センサとしての昆虫味覚システム

    嶋田 一郎, 中尾 光之

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特定研究

    Institution: 東北大学

    1986 - 1986

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    ハエの味覚システムの情報処理過程の解明を通して、新しい高性能化学センサシステムの原理を開発する。本年度においては、ハエの糖受容器をRサイトにおける光学異性体の高選択性のメカニズムを解明し、さらにショ糖濃度の高感度識別機構を多チャネル情報システムとして解明した。 1.ハエ糖受容器のRサイトのキラル特性 Rサイトには、脂肪族アミノ酸とならんで、ジペプチド類が反応する。D型のアミノ酸は全く刺激性がないが、N-Ac-D-Valが明瞭な刺激性を有し、かつN-Ac-L-Valより刺激性が高く、アセチル化によるD型,L型の刺激性の逆転が見いだされた。各種のN-アシル-D-Valの刺激性の解析から、Rサイトに、新たに疎水性のサブサイトの存在が示唆され、これとアシル基の結合によってN-アシル-D-Valの刺激性が出現すると考えられる。D-Valは、その遊離のアミノ基が親水のためにこのサブサイトとは結合できずに、刺激性を有しないのである。このように、Rサイトにおける光学異性体の識別は絶対的なものではないが、厳格な構造特異性は保持されている。 2.ショ糖濃度高感度識別と多チャネル情報処理 20時間絶食したショウジョウバエは、10.0mMショ糖液に対し10.25mMを選択的に摂取し、その差は統計学的に有意であった。この識別感度をWeder比で表すと0.025となり、これは今までの味覚の最高の識別感度である。そこで報告者は、ハエの味覚器を多チャネル情報処理系として捉え、nコの糖受容器における相互情報量をSmithら(1983)のデータに基ずいてコンピュータによる数値計算を行った。結果は、nをさらに大きくすれば、さらに細かい濃度段階を識別し得ることを示している。従って、ショウジョウバエの高いショ糖濃度識別力は、多数の糖受容器からの情報の統合によって十分可能である。

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  1. 先端材料等に関する学術指導

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    先端材料等に関する学術指導

  2. 短時間睡眠が認知機能や夜間睡眠に及ぼす影響に関する基礎的研究

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    短時間仮眠が認知機能や夜間睡眠に及ぼす影響に関する基礎的研究

  3. 眠気の脳内メカニズムと眠気時の脳機能モニター手法の研究

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    自動車運転中、眠気を感じている時に、脳波どのような働きをしてるのかを解明し、その時の脳機能モニタ手法を構築する

  4. 眠気予測シミュレーター・システムによる事故防止と防止対策

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    「眠気予測シミュレーター・システムによる事故防止と防止対策」に関する研究

  5. フォイルサーモード型痛覚測定システムに関する痛覚計測の研究開発

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    「フォイルサーモード型痛覚測定システムを用いた痛覚計測の開発」

  6. 睡眠・覚醒発現機構のモデル化による事故予測システムに関する研究

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    「睡眠・覚醒発現機構のモデル化による事故予測システム」に関する研究

  7. 心臓血管系の多状態多変量解析と臨床応用

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    「心臓血管系の多状態多変量解析と臨床応用」に関する研究

  8. 神経回路網ダイナミクスの階層的モデリングとその計算論的研究

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    「神経回路網ダイナミクスの階層的モデリングとその計算論的研究」

  9. ボルツマンマシンによる通信路容量の計算

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    「ボルツマンマシンによる通信路容量の計算」に関する研究

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