Dynamics of memory state of the brain

大脑记忆状态的动态变化

• 批准号: 11837016
• 负责人: HAYASHI Hatsuo
• 金额: $ 2.18万
• 依托单位: Kyushu Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11837016/
• 关键词: Hippocampus; CA3 and CA1 regions; Periodic stimulation; Field potential responses; Synaptic plasticity; Multi-recording; Chaos; Dynamics; CA3領野の周期刺激; CA1領野の電場電位応答; 時空応答; CA3領野の自発リズム

In this research project, long-term potentiation (LTP) at synapses in the rat hippocampus followed by spontaneous bursting discharges was induced and dynamical features of the responses of the hippocampal CA3 and CA1 regions to periodic stimulation were investigated, (l) LTP at afferent synapses to CA3 did not contribute to generate the spontaneous activity of CA3 but LTP at recurrent excitatory synapses in CA3 did. (2) The CA3 region where LTP was induced in recurrent excitatory circuits caused phase-locked and chaotic responses to periodic mossy fiber stimulation. (3) LTP can be induced in a local area of the CA3 region. The local area was maintained even if LTP was enhanced and resulted in spontaneous epileptiform bursts. The local area might correspond to a memory state. (4) The excitatory pathway from contralateral CA3 to CA1 via ipsilateral CA3 was augmented by tetanic stimulation of the contralateral CA3, while the direct pathway from the contralateral CA3 to CA1 was not. (5) Field potential responses of CA1 to periodic stimulation of ipsilateral CA3 depend on the stimulus frequency; the feature of the responses to 20 40 Hz stimulation changes dramatically with time. The negative field potential after an initial transient especially caused phase-locked and chaotic responses. This results from the dynamical features of CA3.The above results conclude that the CA3 region, which has rich recurrent excitatory connections, causes phase-locked and chaotic responses to periodic stimulation when LTP is induced in CA3, and those activities are projected to CA1 excitatory through Schaffer collaterals and inhibitory through interneurons.

本研究通过诱发大鼠海马突触长时程增强（LTP）和自发爆发放电，研究了海马CA 3区和CA 1区对周期性刺激反应的动力学特征。（1）CA 3区传入突触LTP不参与CA 3区自发放电的产生，而CA 3区兴奋性突触LTP参与CA 3区自发放电的产生。(2)在CA 3区，LTP诱导的周期性兴奋回路引起锁相和混沌响应周期苔藓纤维刺激。(3)LTP可以在CA 3区域的局部区域中诱导。即使LTP增强并导致自发性癫痫样发作，局部区域仍得以维持。局部区域可以对应于存储器状态。(4)强直刺激对侧CA 3可增强对侧CA 3经同侧CA 3至CA 1的兴奋性通路，而对侧CA 3至CA 1的直接通路则无增强作用。(5)场电位反应的CA 1周期性刺激同侧CA 3依赖于刺激频率，20 - 40 Hz刺激的响应的功能随时间的变化显着。初始瞬态后的负场电位尤其会导致锁相和混乱响应。上述结果表明，CA 3区具有丰富的反复兴奋性联系，在LTP诱导时，CA 3区对周期性刺激产生锁相和混沌反应，这些活动通过Schaffer侧支兴奋性投射到CA 1区，通过中间神经元抑制性投射到CA 1区。

项目成果

Koushi Nakashima 他: "Spontaneous epileptiform bursts induced in different regions of rat longitudinal CA3 slices by mossy fiber stimulation at different sites"Proceedings of a the 3rd International Workshop on Neural Coding. 79-82 (1999)

Koushi Nakashima 等人：“通过不同部位的苔藓纤维刺激，在大鼠纵向 CA3 切片的不同区域诱发自发性癫痫样爆发”，第三届国际神经编码研讨会论文集 79-82 (1999)。

K.Nakashima, H.Hayashi, S.Ishizuka: "LTP-induced synchronous activity of CA3 is stably localized by feed-forward and recurrent inhibition ---"Proceedings of the 7th International Conference on Neural In formation Processing. 1. 55-58 (2000)

K.Nakashima、H.Hayashi、S.Ishizuka：“LTP 诱导的 CA3 同步活性通过前馈和循环抑制稳定定位 ---”第七届国际神经信息处理会议论文集。

Y. Hinayasumi, H. Shiraishi, K. Nakashima, H. Hayashi and S. Ishizuka: "Temporal change of the spatial distribution of the hippocampal CA1 response to periodic hippocampal CA3 stimulation"Proceedings of the 3rd International Workshop on Neural Coding. 147

Y. Hinayasumi、H. Shiraishi、K. Nakashima、H. Hayashi 和 S. Ishizuka：“海马 CA1 响应周期性海马 CA3 刺激的空间分布的时间变化”第三届国际神经编码研讨会论文集。

日南休 泰明 他: "ラットの海馬CA3領域の周期刺激に対する海馬CA1領域の応答の空間分布とその時間変化"日本神経回路学会講演論文集. 132-133 (1999)

Yasuaki Hinankyu 等人：“海马 CA1 区域对大鼠海马 CA3 区域周期性刺激的反应的空间分布和时间变化”日本神经网络学会论文集 132-133 (1999)。

中島 孔志 他: "CA3錐体細胞相間の興奮性シナプスのLTPと自発性のてんかん様バースト"日本生物物理学会講演予稿集. s56-s56 (1999)

Koushi Nakajima 等人：“LTP 和 CA3 锥体细胞期之间兴奋性突触的自发性癫痫样爆发”，日本生物物理学会论文集 s56-s56 (1999)。