Okada Ken-ichi
| Faculty of Medicine Physiological Science Physiology | Lecturer |
Last Updated :2025/06/07
■Researcher basic information
Researchmap personal page
Researcher number
- 80790956
J-Global ID
Educational Organization
- Bachelor's degree program, Departments of Medicine, School of Medicine
- Master's degree program, Graduate School of Medicine
- Doctoral (PhD) degree program, Graduate School of Medicine
■Career
Career
- Apr. 2024 - Present
Hokkaido University, 医学研究院 神経生理学教室, 講師 - Oct. 2020 - Mar. 2024
Hokkaido University, 医学研究院 神経生理学教室, 助教 - Apr. 2019 - Sep. 2020
Osaka University, 生命機能研究科, 助教 - Apr. 2016 - Mar. 2019
Osaka University, 生命機能研究科, 特任研究員（常勤） - Oct. 2009 - Mar. 2016
Osaka University, Graduate School of Frontier Biosciences, 特任研究員
Educational Background
■Research activity information
Awards
Papers
- Cross-species Convergence of Functional Connectivity Changes in Thalamic Pain across Human Patients and Model Macaques.
Dong Dong, Koichi Hosomi, Takeshi Shimizu, Ken-Ichi Okada, Yoshinori Kadono, Nobuhiko Mori, Yuki Hori, Noriaki Yahata, Toshiyuki Hirabayashi, Haruhiko Kishima, Youichi Saitoh
The journal of pain, 104661, 104661, 23 Aug. 2024, [Peer-reviewed], [International Magazine]
English, Scientific journal, Thalamic pain can be understood as a network reorganization disorder. This study aimed to investigate functional connectivity (FC) in human patients and a macaque model of thalamic pain. In humans, functional brain activity was compared between patients with thalamic pain and healthy individuals. Furthermore, functional brain activity was compared in macaques, before and after the induction of thalamic pain in the same individuals. FCs between the amygdala of the unaffected hemisphere and the brainstem was significantly higher in patients with thalamic pain. More specifically, a significant FC higher was observed between the basolateral amygdala (BLA) and the ventral tegmental area, which also significantly predicted the value of a visual analog scale of pain intensity in individual patients. The macaque model of thalamic pain also exhibited a significant FC higher between the amygdala of the unaffected hemisphere and the brainstem, particularly between the BLA and the midbrain. Furthermore, the previously reported significant FC higher between the amygdala and the mediodorsal nucleus of the thalamus in macaques with thalamic pain was also reproduced in the human patients. Therefore, the present results suggest that the FC changes in the regions associated with emotion, memory, motivation, and reward are part of the underlying mechanisms of thalamic pain onset present in both human patients and model macaques. This cross-species convergence provides new insights into the neurological mechanisms underlying thalamic pain, paving the way for further studies and the development of therapeutic strategies. PERSPECTIVE: This article presents that the functional connectivity changes in the regions associated with emotion, motivation, and reward are part of the underlying mechanisms of thalamic pain in humans and macaques. - An easy-to-implement, non-invasive head restraint method for monkey fMRI.
Reiji Tanaka, Kei Watanabe, Takafumi Suzuki, Kae Nakamura, Masaharu Yasuda, Hiroshi Ban, Ken-Ichi Okada, Shigeru Kitazawa
NeuroImage, 120479, 120479, 29 Nov. 2023, [Peer-reviewed], [International Magazine]
English, Scientific journal, Functional magnetic resonance imaging (fMRI) in behaving monkeys has a strong potential to bridge the gap between human neuroimaging and primate neurophysiology. In monkey fMRI, to restrain head movements, researchers usually surgically implant a plastic head-post on the skull. Although time-proven to be effective, this technique could create burdens for animals, including a risk of infection and discomfort. Furthermore, the presence of extraneous objects on the skull, such as bone screws and dental cement, adversely affects signals near the cortical surface. These side effects are undesirable in terms of both the practical aspect of efficient data collection and the spirit of "refinement" from the 3R's. Here, we demonstrate that a completely non-invasive fMRI scan in awake monkeys is possible by using a plastic head mask made to fit the skull of individual animals. In all of the three monkeys tested, longitudinal, quantitative assessment of head movements showed that the plastic mask has effectively suppressed head movements, and we were able to obtain reliable retinotopic BOLD signals in a standard retinotopic mapping task. The present, easy-to-make plastic mask has a strong potential to simplify fMRI experiments in awake monkeys, while giving data that is as good as or even better quality than that obtained with the conventional head-post method. - Neural signals regulating motor synchronization in the primate deep cerebellar nuclei
Ken-ichi Okada, Ryuji Takeya, Masaki Tanaka
Nature Communications, 13, 1, Springer Science and Business Media LLC, May 2022, [Peer-reviewed], [Lead author]
Scientific journal, Abstract
Movements synchronized with external rhythms are ubiquitous in our daily lives. Despite the involvement of the cerebellum, the underlying mechanism remains unclear. In monkeys performing synchronized saccades to periodically alternating visual stimuli, we found that neuronal activity in the cerebellar dentate nucleus correlated with the timing of the next saccade and the current temporal error. One-third of the neurons were active regardless of saccade direction and showed greater activity for synchronized than for reactive saccades. During the transition from reactive to predictive saccades in each trial, the activity of these neurons coincided with target onset, representing an internal model of rhythmic structure rather than a specific motor command. The behavioural changes induced by electrical stimulation were explained by activating different groups of neurons at various strengths, suggesting that the lateral cerebellum contains multiple functional modules for the acquisition of internal rhythms, predictive motor control, and error detection during synchronized movements. - Repetitive transcranial magnetic stimulation restores altered functional connectivity of central poststroke pain model monkeys
Yoshinori Kadono, Keigo Koguchi, Ken-ichi Okada, Koichi Hosomi, Motoki Hiraishi, Takashi Ueguchi, Ikuhiro Kida, Adnan Shah, Guoxiang Liu, Youichi Saitoh
Scientific Reports, 11, 1, 6126, 6126, Springer Science and Business Media LLC, Dec. 2021, [Peer-reviewed], [Corresponding author], [International Magazine]
English, Scientific journal,Abstract Central poststroke pain (CPSP) develops after a stroke around the somatosensory pathway. CPSP is hypothesized to be caused by maladaptive reorganization between various brain regions. The treatment for CPSP has not been established; however, repetitive transcranial magnetic stimulation (rTMS) to the primary motor cortex has a clinical effect. To verify the functional reorganization hypothesis for CPSP development and rTMS therapeutic mechanism, we longitudinally pursued the structural and functional changes of the brain by using two male CPSP model monkeys (Macaca fuscata ) developed by unilateral hemorrhage in the ventral posterolateral nucleus of the thalamus. Application of rTMS to the ipsilesional primary motor cortex relieved the induced pain of the model monkeys. A tractography analysis revealed a decrease in the structural connectivity in the ipsilesional thalamocortical tract, and rTMS had no effect on the structural connectivity. A region of interest analysis using resting-state functional magnetic resonance imaging revealed inappropriately strengthened functional connectivity between the ipsilesional mediodorsal nucleus of the thalamus and the amygdala, which are regions associated with emotion and memory, suggesting that this may be the cause of CPSP development. Moreover, rTMS normalizes this strengthened connectivity, which may be a possible therapeutic mechanism of rTMS for CPSP. - Impaired inhibition of return during free-viewing behaviour in patients with schizophrenia.
Ken-Ichi Okada, Kenichiro Miura, Michiko Fujimoto, Kentaro Morita, Masatoshi Yoshida, Hidenaga Yamamori, Yuka Yasuda, Masao Iwase, Mikio Inagaki, Takashi Shinozaki, Ichiro Fujita, Ryota Hashimoto
Scientific reports, 11, 1, 3237, 3237, 05 Feb. 2021, [Peer-reviewed], [Lead author], [International Magazine]
English, Scientific journal, Schizophrenia affects various aspects of cognitive and behavioural functioning. Eye movement abnormalities are commonly observed in patients with schizophrenia (SZs). Here we examined whether such abnormalities reflect an anomaly in inhibition of return (IOR), the mechanism that inhibits orienting to previously fixated or attended locations. We analyzed spatiotemporal patterns of eye movement during free-viewing of visual images including natural scenes, geometrical patterns, and pseudorandom noise in SZs and healthy control participants (HCs). SZs made saccades to previously fixated locations more frequently than HCs. The time lapse from the preceding saccade was longer for return saccades than for forward saccades in both SZs and HCs, but the difference was smaller in SZs. SZs explored a smaller area than HCs. Generalized linear mixed-effect model analysis indicated that the frequent return saccades served to confine SZs' visual exploration to localized regions. The higher probability of return saccades in SZs was related to cognitive decline after disease onset but not to the dose of prescribed antipsychotics. We conclude that SZs exhibited attenuated IOR under free-viewing conditions, which led to restricted scene scanning. IOR attenuation will be a useful clue for detecting impairment in attention/orienting control and accompanying cognitive decline in schizophrenia. - Concomitant improvement in anti-saccade success rate and postural instability gait difficulty after rTMS treatment for Parkinson's disease.
Ken-Ichi Okada, Mizuki Takahira, Tomoo Mano, Taichi Uga, Kuni Konaka, Koichi Hosomi, Youichi Saitoh
Scientific reports, 11, 1, 2472, 2472, 28 Jan. 2021, [Peer-reviewed], [Lead author], [International Magazine]
English, Scientific journal, Parkinson's disease (PD) is a progressive neurological disorder characterised by motor and non-motor deficits. Repetitive transcranial magnetic stimulation (rTMS) over the bilateral primary motor cortex at a high frequency (5 Hz or higher) is reported to be a potential treatment of PD. We aimed to assess the effect of rTMS on eye movement control in patients with PD in their 'on' state. We enrolled 14 patients with PD and assessed motor symptoms (Movement Disorder Society-Sponsored Unified Parkinson's Disease Rating Scale; MDS-UPDRS) and eye movement performances (visually guided saccades, volitional anti-saccades, and small involuntary saccades during fixation) at baseline and after administering bilateral 10 Hz rTMS on leg region of the motor cortex. We confirmed that rTMS improved the MDS-UPDRS motor scores and found that rTMS improved the anti-saccade success rate, which requires adequate inhibition of the reflexive response. The improvement in anti-saccade success rate was correlated with that of the postural instability gait difficulty (PIGD) sub-scores of MDS-UPDRS and lower baseline Japanese version of the Montreal Cognitive Assessment scores. This result is consistent with previous findings that PIGD and inhibitory control deficits share common brain dysfunctions in PD. rTMS may alleviate dysfunctions of that circuit and have a clinical effect. - Ocular drift reflects volitional action preparation.
Watanabe M, Okada KI, Hamasaki Y, Funamoto M, Kobayashi Y, MacAskill M, Anderson T
The European journal of neuroscience, Feb. 2019, [Peer-reviewed], ［Internationally co-authored］
English, Scientific journal - Reward and behavioral factors contributing to the tonic activity of monkey pedunculopontine tegmental nucleus neurons during saccade tasks
Ken-Ichi Okada, Yasushi Kobayashi
Frontiers in Systems Neuroscience, 10, 94, Frontiers Research Foundation, 11 Nov. 2016, [Peer-reviewed], [Lead author]
English, Scientific journal - The Pedunculopontine Tegmental Nucleus as a Motor and Cognitive Interface between the Cerebellum and Basal Ganglia
Fumika Mori, Ken-ichi Okada, Taishin Nomura, Yasushi Kobayashi
FRONTIERS IN NEUROANATOMY, 10, 109, Nov. 2016, [Peer-reviewed]
English, Scientific journal - Rhythmic Firing of Pedunculopontine Tegmental Nucleus Neurons in Monkeys during Eye Movement Task
Ken-ichi Okada, Yasushi Kobayashi
PLOS ONE, 10, 6, e0128147, Jun. 2015, [Peer-reviewed], [Lead author]
English, Scientific journal - Fixational saccade-related activity of pedunculopontine tegmental nucleus neurons in behaving monkeys
Ken-ichi Okada, Yasushi Kobayashi
EUROPEAN JOURNAL OF NEUROSCIENCE, 40, 4, 2641, 2651, Aug. 2014, [Peer-reviewed], [Lead author]
English, Scientific journal - Reward prediction-related increases and decreases in tonic neuronal activity of the pedunculopontine tegmental nucleus.
Okada K, Kobayashi Y
Frontiers in integrative neuroscience, 7, 36, 2013, [Peer-reviewed], [Lead author]
English, Scientific journal - A neural correlate of predicted and actual reward-value information in monkey pedunculopontine tegmental and dorsal raphe nucleus during saccade tasks
Ken-Ichi Okada, Kae Nakamura, Yasushi Kobayashi
Neural Plasticity, 2011, 579840, 2011, [Peer-reviewed], [Lead author]
English - Characterization of oculomotor and visual activities in the primate pedunculopontine tegmental nucleus during visually guided saccade tasks
Ken-Ichi Okada, Yasushi Kobayashi
EUROPEAN JOURNAL OF NEUROSCIENCE, 30, 11, 2211, 2223, Dec. 2009, [Peer-reviewed], [Lead author]
English, Scientific journal - Different Pedunculopontine Tegmental Neurons Signal Predicted and Actual Task Rewards
Ken-ichi Okada, Keisuke Toyama, Yuka Inoue, Tadashi Isa, Yasushi Kobayashi
JOURNAL OF NEUROSCIENCE, 29, 15, 4858, 4870, Apr. 2009, [Peer-reviewed], [Lead author]
English, Scientific journal - Reward Prediction Error Computation in the Pedunculopontine Tegmental Nucleus Neurons
Y. KOBAYASHI, K.-I. OKADA
Annals of the New York Academy of Sciences, 1104, 1, 310, 323, 13 Apr. 2007, [Peer-reviewed]
English, Scientific journal
Other Activities and Achievements
- 視床痛における機能結合変化 異種間神経画像研究
董 冬, 細見 晃一, 清水 豪士, 岡田 研一, 角野 喜則, 森 信彦, 堀 祐樹, 八幡 憲明, 平林 敏行, 貴島 晴彦, 齋藤 洋一, 臨床神経生理学, 51, 5, 547, 547, Oct. 2023
(一社)日本臨床神経生理学会, Japanese - 時間の神経科学-時を生み出すこころと脳の仕組み C 時間の心理学と神経科学 同期運動とリズム知覚の神経機構
田中真樹, 岡田研一, 亀田将史, Clinical Neuroscience, 41, 8, 2023 - rTMSを用いたパーキンソン病の脳内メカニズムの解明研究
眞野 智生, 岡田 研一, 細見 晃一, 後藤 雄子, 小林 康, 貴島 晴彦, 齋藤 洋一, 機能的脳神経外科, 57, 30, 34, Dec. 2018, [Invited]
(一社)日本定位・機能神経外科学会, Japanese - The pedunculopontine tegmental nucleus neurons encode predicted reward signal by tonic regular firing and given reward signal phasically
Yasushi Kobayashi, Ken-ichi Okada, NEUROSCIENCE RESEARCH, 71, E72, E73, 2011
English, Summary international conference - Neuronal coding of rewarding and aversive stimuli in the primate dorsal raphe nucleus
Kazuko Hayashi, Kazuko Nakao, Ken-ichi Okada, Yasushi Kobayashi, Kae Nakamura, NEUROSCIENCE RESEARCH, 68, E404, E404, 2010
English, Summary international conference - The pedunculopontine tegmental nucleus neurons relay predicted and actual reward and context dependent visuomotor information
Yasushi Kobayashi, Ken-ichi Okada, NEUROSCIENCE RESEARCH, 68, E72, E72, 2010
English, Summary international conference - Rhythmic firing of pedunculopontine tegmental nucleus neurons in behaving monkeys
Ken-ichi Okada, Yasushi Kobayashi, NEUROSCIENCE RESEARCH, 68, E104, E104, 2010, [Peer-reviewed]
English, Summary international conference - Reward coding by the primate dorsal raphe neurons is context dependent
Kazuko Nakao, Ryuichi Matsuzaki, Ken-ichi Okada, Yasushi Kobayashi, Kae Nakamura, NEUROSCIENCE RESEARCH, 65, S113, S114, 2009
English, Summary international conference - Computational mechanism of reward prediction error by the Pedunculopontine tegmental nucleus neurons
Yasushi Kobayashi, Ken-ichi Okada, NEUROSCIENCE RESEARCH, 65, S48, S48, 2009, [Peer-reviewed]
English, Summary international conference - Relation of pedunculopontine tegmental nucleus neurons in monkeys to reward prediction and behavior
Ken-Ichi Okada, Yasushi Kobayashi, NEUROSCIENCE RESEARCH, 65, S114, S114, 2009, [Peer-reviewed]
English, Summary international conference - Neural correlates of task performance in the primate pedunculopontine tegmental nucleus
Ken-ichi Okada, Yasushi Kobayashi, NEUROSCIENCE RESEARCH, 61, S60, S60, 2008
English, Summary international conference - Using eye-movements as a research tool in children with autistic spectrum disorders
Yuri Kitamura, Koshiro Maruyama, Ken-ichi Okada, Yasushi Kobayashi, Yuji Yahata, Syoji Kobashi, Ikuko Mohri, Masako Taniike, NEUROSCIENCE RESEARCH, 61, S131, S131, 2008, [Peer-reviewed]
English, Summary international conference - Phasic responses of the pedunculopontine tegmental nucleus in primates
Ken-Ichi Okada, Yuka Inoue, Tadashi Isa, Yasushi Kobayashi, NEUROSCIENCE RESEARCH, 58, S45, S45, 2007, [Peer-reviewed]
English, Summary international conference - Different groups of pedunculopontine tegmental nucleus neurons signal the expected and actual task reward
Yasushi Kobayashi, Ken-ichi Okada, NEUROSCIENCE RESEARCH, 58, S45, S45, 2007, [Peer-reviewed]
English, Summary international conference - Context-Dependent Property of Visuomotor Activities of the Pedunculopontine Tegmental Nucleus in Primates
Okada Ken-Ichi, Inoue Yuka, Isa Tadashi, Kobayashi Yasushi, Proceedings of Annual Meeting of the Physiological Society of Japan, 2007, 0, 161, 161, 2007
The cholinergic pedunculopontine tegmental nucleus (PPTN) in the brainstem is thought to associated with reward-related behaviors by integrating polymodal signals related to the motivational state of animal, sensory information, motor control and reward. Here, we examined the effect of behavioral and reward context on neuronal activity of the pedunculopontine tegmental nucleus (PPTN) in primates during visually guided saccade tasks. About half of movement-related activities occurred for only the saccades to the saccade target in the task, but they did not occur for the saccades outside the task. On the other hand, for the other half of neurons, movement-related activities occurred for every saccade regardless of the task condition. For visual responses, some neurons responded either the initial fixation point or saccade target, and others responded equally to both stimuli. We further analyzed mutual relationship among modulation timing, preferred direction, effect of reward expectation and this context dependency of the activities, and discussed the visuo-motor processing of PPTN. [J Physiol Sci. 2007;57 Suppl:S161], PHYSIOLOGICAL SOCIETY OF JAPAN - Reward Prediction Error Computation in the Pedunculopontine Tegmental Nucleus Neurons
Kobayashi Yasushi, Okada Kenichi, Proceedings of Annual Meeting of the Physiological Society of Japan, 2007, 0, 56, 56, 2007
We address the neuronal activity in pathways of brainstem-midbrain circuit that provides advantages over previous reinforcement learning theory. Several lines of evidence lead the reward based learning theory that midbrain dopamine (DA) neurons send a teaching signal (the reward prediction error signal) to control synaptic plasticity of the projection area. However, the underling mechanism of where and how to compute reward prediction error signal still remains unclear. Since the pedunculopontine tegmental nucleus (PPTN) in the brainstem is one of the strongest excitatory input sources to DA neurons, we hypothesized that the PPTN may play an important role in activating DA neurons and reinforcement learning by relaying necessary signals for reward prediction error computation on DA neurons. To investigate the involvement of the PPTN neurons in computation of reward prediction error, we used visually guided saccade task during recording of neuronal activity in monkeys. Here, we predict that PPTN neurons may relay excitatory component of tonic reward prediction and phasic primary reward signals, allowing new computational theory of reward prediction error in DA neurons. [J Physiol Sci. 2007;57 Suppl:S56], PHYSIOLOGICAL SOCIETY OF JAPAN - Context dependent property of visuomotor activities of pedunculopontine tegmental nucleus in primates
Ken-ichi Okada, Yuka Inoue, Tadashi Isa, Yasushi Kobayashi, NEUROSCIENCE RESEARCH, 55, S59, S59, 2006
English, Summary international conference
Books and other publications
- 【神経疾患における時間認知障害】時間知覚と予測の神経機構
田中 真樹, 岡田 研一, 亀田 将史
(有)科学評論社, Jun. 2024, Japanese - Temporal Information Processing in the Cerebellum and Basal Ganglia.
Masaki Tanaka, Masashi Kameda, Ken-Ichi Okada
2024, English, Temporal information processing in the range of a few hundred milliseconds to seconds involves the cerebellum and basal ganglia. In this chapter, we present recent studies on nonhuman primates. In the studies presented in the first half of the chapter, monkeys were trained to make eye movements when a certain amount of time had elapsed since the onset of the visual cue (time production task). The animals had to report time lapses ranging from several hundred milliseconds to a few seconds based on the color of the fixation point. In this task, the saccade latency varied with the time length to be measured and showed stochastic variability from one trial to the other. Trial-to-trial variability under the same conditions correlated well with pupil diameter and the preparatory activity in the deep cerebellar nuclei and the motor thalamus. Inactivation of these brain regions delayed saccades when asked to report subsecond intervals. These results suggest that the internal state, which changes with each trial, may cause fluctuations in cerebellar neuronal activity, thereby producing variations in self-timing. When measuring different time intervals, the preparatory activity in the cerebellum always begins approximately 500 ms before movements, regardless of the length of the time interval being measured. However, the preparatory activity in the striatum persists throughout the mandatory delay period, which can be up to 2 s, with different rate of increasing activity. Furthermore, in the striatum, the visual response and low-frequency oscillatory activity immediately before time measurement were altered by the length of the intended time interval. These results indicate that the state of the network, including the striatum, changes with the intended timing, which lead to different time courses of preparatory activity. Thus, the basal ganglia appear to be responsible for measuring time in the range of several hundred milliseconds to seconds, whereas the cerebellum is responsible for regulating self-timing variability in the subsecond range. The second half of this chapter presents studies related to periodic timing. During eye movements synchronized with alternating targets at regular intervals, different neurons in the cerebellar nuclei exhibit activity related to movement timing, predicted stimulus timing, and the temporal error of synchronization. Among these, the activity associated with target appearance is particularly enhanced during synchronized movements and may represent an internal model of the temporal structure of stimulus sequence. We also considered neural mechanism underlying the perception of periodic timing in the absence of movement. During perception of rhythm, we predict the timing of the next stimulus and focus our attention on that moment. In the missing oddball paradigm, the subjects had to detect the omission of a regularly repeated stimulus. When employed in humans, the results show that the fastest temporal limit for predicting each stimulus timing is about 0.25 s (4 Hz). In monkeys performing this task, neurons in the cerebellar nuclei, striatum, and motor thalamus exhibit periodic activity, with different time courses depending on the brain region. Since electrical stimulation or inactivation of recording sites changes the reaction time to stimulus omission, these neuronal activities must be involved in periodic temporal processing. Future research is needed to elucidate the mechanism of rhythm perception, which appears to be processed by both cortico-cerebellar and cortico-basal ganglia pathways. - 【時間の神経科学-時を生み出すこころと脳の仕組み】時間の心理学と神経科学 同期運動とリズム知覚の神経機構
田中 真樹, 岡田 研一, 亀田 将史
(株)中外医学社, Aug. 2023, Japanese - Computation of reward prediction error in the midbrain circuit
小林康, 岡田研一
金原一郎記念医学医療振興財団 ; 1949-, Jul. 2013, Japanese - Advances in Reinforcement Learning
Yasushi Kobayashi, Ken-ichi Okada, Reward prediction error computation in the pedunculopontine tegmental nucleus neurons
INTECH, Jan. 2011, [Contributor] - Reward processing of the basal ganglia: reward function of pedunculopontine tegmental nucleus
小林康, 岡田研一
医学書院, Apr. 2009, Japanese - [Reward processing of the basal ganglia--reward function of pedunculopontine tegmental nucleus].
Kobayashi- Y, Okada K
4, Apr. 2009, [Peer-reviewed]
Lectures, oral presentations, etc.
- Dynamic changes in cortico-striatal transmission associated with striatal beta oscillations in monkeys
K. OKADA, M. TANAKA
Neuroscience 2024, 07 Oct. 2024 - Cerebellar learning underlies neural entrainment to rhythmic visual stimuli in monkeys
M. TANAKA, K. OKADA
Neuroscience 2024, 07 Oct. 2024 - サル皮質−線条体経路の信号伝達は線条体のβ律動に伴い動的に変化する
岡田 研一, 田中 真樹
第47回日本神経科学大会, 25 Jul. 2024 - 視床痛における機能結合変化：異種間神経画像研究
董 冬, 細見 晃一, 清水 豪士, 岡田 研一, 角野 喜則, 森 信彦, 堀 祐樹, 八幡 憲明, 平林 敏行, 貴島 晴彦, 齋藤 洋一
第53回日本臨床神経生理学会学術大会, Nov. 2023 - 視床痛における機能結合変化 異種間神経画像研究
董 冬, 細見 晃一, 清水 豪士, 岡田 研一, 角野 喜則, 森 信彦, 堀 祐樹, 八幡 憲明, 平林 敏行, 貴島 晴彦, 齋藤 洋一
臨床神経生理学, Oct. 2023, (一社)日本臨床神経生理学会, Japanese
Oct. 2023 - Oct. 2023 - 皮質−線条体経路の信号伝達はサルの適応行動に伴い柔軟に変化する
岡田 研一, 田中 真樹
第46回日本神経科学大会, 02 Aug. 2023 - リズミカルな視覚刺激の時間予測に関わる小脳プルキンエ細胞の活動
リ リ, 岡田 研一, 田中 真樹
第46回日本神経科学大会, 02 Aug. 2023 - 小脳は行動エラーに関連した信号を内側前頭葉に送る
安部 楓, 岡田 研一, 田中 真樹
第46回日本神経科学大会, 01 Aug. 2023 - 聴覚オドボール課題中にみられた視覚誘発電位の周期的変化
杉尾 凌虎, 岡田 研一, 田中 真樹
第46回日本神経科学大会, 01 Aug. 2023 - Rapid changes in cortico-striatal signal transmission during adaptive behavior in monkeys
岡田研一, 田中真樹
Gordon Research Conference, Eye Movements, 2023, 12 Jul. 2023 - 行動上のエラー検出における小脳と内側前頭葉の機能連関
安部 楓, 岡田 研一, 田中 真樹
第100回日本生理学会大会, 14 Mar. 2023 - Rapid changes in cortico-striatal signal transmission during adaptive behavior in monkeys
岡田 研一, 田中 真樹
第100回日本生理学会大会, 14 Mar. 2023 - Efficacy of corticostriatal signaling changes rapidly during adaptive behavior in monkeys
岡田研一, 田中真樹
International Symposium on Chronogenesis: How the Mind Generates Time, 23 Nov. 2022 - Rapid changes in the efficacy of corticostriatal signal transmission during adaptive behavior in monkeys
岡田研一, 田中真樹
Japan and Norway United in Brain, Educations and Therapeutics (JANUBET) Symposium 2022 "Tools and the Study of Brain Systems: New Vistas!", 22 Sep. 2022 - 覚醒サルfMRIのための完全非侵襲な頭部固定法
渡邉 慶, 田中 澪士, 番 浩志, 岡田 研一, 北澤 茂
第44回日本神経科学大会, 28 Jul. 2021 - 同期眼球運動の実行における小脳歯状核の役割
岡田 研一, 竹谷 隆司, 田中 真樹
第44回日本神経科学大会, 28 Jul. 2021 - パーキンソン病患者の眼球運動制御に反復経頭蓋磁気刺激が与える影響
岡田 研一, 高比良 みずき, 眞野 智生, 細見 晃一, 齋藤 洋一
第43回日本神経科学大会, 31 Jul. 2020 - Spatiotemporal characteristics of eye movement during a free-viewing task suggests failure of inhibition of return in schizophrenia
岡田 研一, 三浦 健一郎, 藤本 美智子, 森田 健太郎, 山森 英長, 安田 由華, 稲垣 未来男, 篠崎 隆志, 藤田 一郎, 橋本 亮太
第41回日本神経科学大会, 28 Jul. 2018 - Effect of reprtitive transcranial magnetic stimulation on neuronal network for central post-stroke pain model monkeys
角野 喜則, 細見 晃一, 岡田 研一, 平石 幹, 高口 圭吾, 劉 国相, 黄田 育宏, 上口 貴志, 齋藤 洋一, 小林 康
第41回日本神経科学大会, 27 Jul. 2018 - An evaluation of the effectiveness of multifocal repetitive transcranial magnetic stimulation on cardinal and eye movement control of patients with Parkinsoisease
眞野 智生, 岡田 研一, 細見 晃一, 小林 康, 齋藤 洋一
第41回日本神経科学大会, 26 Jul. 2018 - An evaluation of repetitive transcranial magnetic stimulation effectiveness on cardinal and eye movement control of patients with Parkinson's disease
眞野 智生, 岡田 研一, 細見 晃一, 後藤 雄子, 小林 康, 貴島 晴彦, 齋藤 洋一
機能的脳神経外科 : 日本定位・機能神経外科学会機関誌 = Functional neurosurgery : official journal of the Japan Society for Stereotactic and Functional Neurosurgery, 2018, 日本定位・機能神経外科学会事務局, Japanese
2018 - 2018 - Effect of repetitive transcranial magnetic stimulation treatment on eye movement of Parkinson´s disease patients
宇賀 太一, 船本万里, 森風美加, 平石幹, 岡田研一, 小林康, 眞野智生, 齋藤 洋一
第40回日本神経科学大会, 20 Jul. 2017 - Analysis of local field potential and spike activity in monkey pedunculopontine tegmental nucleus during eye movement task
岡田 研一, 小林 康
第40回日本神経科学大会, 20 Jul. 2017 - Effect of M1 repetitive transcranial magnetic stimulation on neuronal activity in monkey pedunculopontine tegmental nucleus.
小林 康, 岡田 研一
第39回日本神経科学大会, 22 Jul. 2016 - An integrated system for the quantitative measure of motivation and emotion in monkeys.
安田 正治, 中村 晋也, 岡田 研一, 飯島 敏夫, 小林 康, 筒井 健一郎, 中村 加枝
第38回日本神経科学大会, 29 Jul. 2015 - Microsaccades during pro- and antisaccade tasks in patients with Parkinson´s disease
浜咲 雄太, 船本 万里, 浅原 舜平, 田中 文哲, 岡田 研一, 小林 康, Michael MacAskill, Leslie Livingston, Tim Anderson, 渡邊 雅之
第38回日本神経科学大会, 28 Jul. 2015 - Microsaccades during pro- and antisaccade tasks in patients with multiple sclerosis
船本 万里, 浜咲 雄太, 浅原 舜平, 田中 文哲, 岡田研一, 小林 康, Sridhar Alla, Michael MacAskill, Deborah Mason, Tim Anderson, 渡邊 雅之
第38回日本神経科学大会, 28 Jul. 2015 - Impact of repetitive transcranial magnetic stimulation on eye movements in monkeys
小林 康, 岡田 研一
第38回日本神経科学大会, 28 Jul. 2015 - Analysis of eye movements after repetitive transcranial magnetic stimulation on behaving monkeys.
Okada K, Kobayashi Y
The 45th Annual Meeting of the Society for Neuroscience, 2015 - Periodic discharge of pedunculopontine tegmental nucleus neurons in behaving monkeys
岡田 研一, 小林 康
第37回日本神経科学大会, 12 Sep. 2014 - Analysis of eye blink and eye movement around voluntary and involuntary eye blink
田中 文哲, 浜咲 雄太, 浅原 舜平, 岡田 研一, 喜多村 祐里, 渡邊 雅之, 小林 康
第37回日本神経科学大会, 11 Sep. 2014 - Microsaccade rate reflects mental fatigue
浅原 舜平, 田中 文哲, 浜咲 雄太, 岡田 研一, 喜多村 祐里, 渡邊 雅之, 小林 康
第37回日本神経科学大会, 11 Sep. 2014 - Fixational-saccade related activity of pedunculopontine tegmental nucleus neurons in monkeys
小林 康, 岡田 研一
第37回日本神経科学大会, 11 Sep. 2014 - Fixational-saccade related and periodic activity of the pedunculopontine tegmental nucleus neurons in behaving monkeys
Y. KOBAYASHI, K. OKADA
The 44th Annual Meeting of the Society for Neuroscience, 2014 - Interactions between microsaccades and the preparation of repetitive volitional blinks
浅原 舜平, 田中 文哲, 松尾 有華, 査 凌, 岡田 研一, 渡邊 雅之, 小林 康
第36回日本神経科学大会・第56回日本神経化会大会・第23回日本神経回路学会大会合同大会, 22 Jun. 2013 - Reward prediction related increases or decreases in neuronal activity of the monkey pedunculopontine tegmental nucleus
岡田 研一, 小林 康
第36回日本神経科学大会・第56回日本神経化会大会・第23回日本神経回路学会大会合同大会, 21 Jun. 2013 - Microsaccade-related activity of pedunculopontine tegmental nucleus neurons in behaving monkeys.
Okada K, Kobayashi Y
The 43rd Annual Meeting of the Society for Neuroscience, 2013 - Saccade-related pause and rebound of activity on pedunculopontine tegmental nucleus neurons in behaving monkeys
岡田 研一, 小林 康
第35回日本神経科学大会, 18 Sep. 2012 - Sustained tonic excitation and suppression of activity on pedunculopontine tegmental nucleus neurons in behaving monkeys.
Okada K, Kobayashi Y
The 42nd Annual Meeting of the Society for Neuroscience, 2012 - Saccade-related modulation of rhythmic firing pattern on pedunculopontine tegmental nucleus neurons in behaving monkeys.
Okada K, Kobayashi Y
The 41st annual meeting of the society for neuroscience, 2011 - The pedunculopontine tegmental nucleus neurons encode predicted reward signal by tonic regular firing and given reward signal phasically
Kobayashi Yasushi, Okada Ken-ichi
NEUROSCIENCE RESEARCH, 2011 - Context-dependent firing regularity of pedunculopontine tegmental nucleus neurons in behaving monkeys.
Okada K, Kobayashi Y
The 40th Annual Meeting of the Society for Neuroscience, 2010 - The pedunculopontine tegmental nucleus neurons relay predicted and actual reward and context dependent visuomotor information
Kobayashi Yasushi, Okada Ken-ichi
NEUROSCIENCE RESEARCH, 2010 - Rhythmic firing of pedunculopontine tegmental nucleus neurons in behaving monkeys
Okada Ken-ichi, Kobayashi Yasushi
NEUROSCIENCE RESEARCH, 2010 - Analyses of the time course of neuronal activity of the pedunculopontine tegmental nucleus in monkeys for reward conditioned saccade task.
Okada K, Kobayashi Y
The 39th Annual Meeting of the Society for Neuroscience,, 2009 - Computational mechanism of reward prediction error by the Pedunculopontine tegmental nucleus neurons
Kobayashi Yasushi, Okada Ken-ichi
NEUROSCIENCE RESEARCH, 2009 - Relation of pedunculopontine tegmental nucleus neurons in monkeys to reward prediction and behavior
Okada Ken-Ichi, Kobayashi Yasushi
NEUROSCIENCE RESEARCH, 2009 - Neural correlates of task performance of the visually guided saccade tasks in the primate pedunculopontine tegmental nucleus.
Okada K, Kobayashi Y
The 38th Annual Meeting of the Society for Neuroscience, 2008 - Neural correlates of task performance in the primate pedunculopontine tegmental nucleus
Okada Ken-ichi, Kobayashi Yasushi
NEUROSCIENCE RESEARCH, 2008 - Different groups of pedunculopontine tegmental nucleus neurons signal the expected and actual task reward
Y. KOBAYASHI, K. OKADA, K. TOYAMA, T. ISA
The 37th Annual Meeting of the Society for Neuroscience, 2007 - Phasic responses of the pedunculopontine tegmental nucleus in primates
Okada Ken-Ichi, Inoue Yuka, Isa Tadashi, Kobayashi Yasushi
NEUROSCIENCE RESEARCH, 2007 - Different groups of pedunculopontine tegmental nucleus neurons signal the expected and actual task reward
Kobayashi Yasushi, Okada Ken-ichi
NEUROSCIENCE RESEARCH, 2007 - Context-Dependent Property of Visuomotor Activities of the Pedunculopontine Tegmental Nucleus in Primates
Okada Ken-Ichi, Inoue Yuka, Isa Tadashi, Kobayashi Yasushi
Proc Annu Meet PSJ, 2007
The cholinergic pedunculopontine tegmental nucleus (PPTN) in the brainstem is thought to associated with reward-related behaviors by integrating polymodal signals related to the motivational state of animal, sensory information, motor control and reward. Here, we examined the effect of behavioral and reward context on neuronal activity of the pedunculopontine tegmental nucleus (PPTN) in primates during visually guided saccade tasks. About half of movement-related activities occurred for only the saccades to the saccade target in the task, but they did not occur for the saccades outside the task. On the other hand, for the other half of neurons, movement-related activities occurred for every saccade regardless of the task condition. For visual responses, some neurons responded either the initial fixation point or saccade target, and others responded equally to both stimuli. We further analyzed mutual relationship among modulation timing, preferred direction, effect of reward expectation and this context dependency of the activities, and discussed the visuo-motor processing of PPTN. [J Physiol Sci. 2007;57 Suppl:S161] - Influences of reward prediction on neuronal activity of the pedunculopontine tegmental nucleus during visually guided saccade tasks in monkeys.
Okada K, Inoue Y, Isa T, Kobayashi Y
The 36th Annual Meeting of the Society for Neuroscience, 2006 - Context dependent property of visuomotor activities of pedunculopontine tegmental nucleus in primates
Okada Ken-ichi, Inoue Yuka, Isa Tadashi, Kobayashi Yasushi
NEUROSCIENCE RESEARCH, 2006 - Neuronal activities sufficient for reward prediction error computation in the pedunculopontine tegmental nucleus during visually guided saccade tasks in monkeys
Kobayashi Yasushi, Okada Kenich, Isa Tadashi, Inoue Yuka
NEUROSCIENCE RESEARCH, 2006
Research Themes
- 線条体の柔軟な神経活動を制御するメカニズムの解明
科学研究費助成事業 基盤研究(C)
01 Apr. 2021 - 31 Mar. 2024
岡田 研一
状況に合わせた行動の選択・抑制に大脳基底核の線条体が重要な役割を果たしており、大脳皮質－基底核ネットワークの状態変化によって、線条体の神経活動が動的に制御されていると考えられる。試行毎のルールに応じて行動を切り替えるような短い時間スケールでの行動選択における大脳皮質－基底核ネットワークの状態変化の役割を明らかにすべく、研究を行った。
短い時間スケールでの状況適応的な行動の制御機構を調べるために、試行毎に示される指示（CUE）に従って、（i）突然現れる視覚刺激にそのままサッカードするか、（ii）視覚刺激への反射的なサッカードを抑制し反対方向にサッカードするかを選択するアンチサッカード課題を２頭のサルに習得させた。それぞれのサルにおいて、MRI画像と機能マッピングにより線条体と大脳皮質の補足眼野を同定した。試行毎の大脳皮質－基底核ネットワークのダイナミックな状態変化を調べるためにアンチサッカード課題中のLFPを単一電極により記録し、CUEの呈示から視覚刺激の呈示までの期間において試行毎のルールに応じてLFPのβ成分が減弱することを確認した。
更に当初の予定を上回った成果として、皮質線条体経路の機能結合の変化を調べるために、補足眼野への微小電流刺激に対する線条体での短潜時応答を記録した。補足眼野への刺激は、新たに開発した複数本の単一電極を短期間埋め込む手法と、同心円型双極電極を用いて局所的に刺激する手法で行った。線条体に刺入した単一電極を用いて、同側・対側の補足眼野への微小電流刺激に対する応答を記録したところ、線条体LFPの刺激誘発応答のみならず、線条体ニューロンの短潜時の刺激誘発スパイクの計測に成功した。これらのLFP・スパイク応答が、課題のルールや刺激前のLFPのβ成分の強さや位相に応じてどのように変化するか、解析を進めている。
日本学術振興会, 基盤研究(C), 北海道大学, 21K06418 - Non-invasive brain imaging to study mechanisms of pain relief after motor cortex stimulation
Grants-in-Aid for Scientific Research
01 Apr. 2018 - 31 Mar. 2021
Hosomi Koichi
We investigated brain activity changes in the sensorimotor area after motor cortex stimulation in thalamic pain model macaques and patients with central neuropathic pain. The thalamic pain macaques showed that increased functional connectivity between amygdala and mediodorsal nucleus of the thalamus normalized after motor cortex stimulation by transcranial magnetic stimulation. Patients with central neuropathic pain showed that pain relief after motor cortex stimulation by transcranial magnetic stimulation related to changes in functional connectivity of anterior cingulate gyrus. The findings of this study suggested that motor cortex stimulation acted on the medial pain system related to affective component.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Osaka University, 18K08993 - Analysis of the mechanism of central pain in thalamic pain model of non-human primate
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
01 Apr. 2017 - 31 Mar. 2020
Saitoh Youichi
With the assist of Dr. Higo, we made a lesion in VPL nucleus of hemi-thalamus in Macaque monkey, and the monkey showed allodynia. The change of behavior (temperature and touch stimulation) of two monkeys were analysed. Few weeks after the lesioning of hemi-VPL nucleus, the monkeys developed allodynia on the contralateral side of lesion. For few months, the allodynia was tended to be improved. Structual MRI imaging showed that the lesion became smaller for a month. DWI imaging showed that the density of the nerve bundle was decreased between VPL nucleus and primary sensory.
The analysis of serial rs-FMRI showed that the functional connectivity was increased between amygdala and MD/Pf nucleus of thalamus after the appearance of allodynia, and rTMS treatment decreased that connectivity.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Osaka University, 17K10893 - Animal model study for mechanisms of central poststroke pain and pain relieving effect with neurostimulation
Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)
01 Apr. 2015 - 31 Mar. 2018
Hosomi Koichi, SAITOH Youichi, OKADA Kenichi, KADONO Yoshinori
We created a macaque model of central poststroke pain (CPSP), and investigated its behavior and brain function using a high magnetic field MRI. Functional connectivities between pain related brain regions increased after pain development. Primary motor cortex stimulation using repetitive transcranial magnetic stimulation (rTMS) alleviated hyperesthesia, and decreased functional connectivities between pain related brain regions. The findings from this study have suggested that the functional connectivity between pain related brain regions is involved in mechanisms of CPSP development and pain relief after rTMS.
Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Osaka University, 15K21142
