Theta rhythm of navigation:: Link between path integration and landmark navigation, episodic and semantic memory
Theta rhythm of navigation:: Link between path integration and landmark navigation, episodic and semantic memory
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DOI：
10.1002/hipo.20113
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发表时间：
2005-01-01
期刊：
影响因子：
3.5
通讯作者：
Buzsáki, G
中科院分区：
文献类型：
--
作者：
Buzsáki, G
在过去的五十年中，海马 - 进入皮层（EC）研究中的五个关键主题一直在回荡：情节和语义记忆，路径集成（'Dead receconin''）和地标（“ MAP”）导航和Theta Oscillation 。我们建议，单细胞放电与在局部场振荡中反映的神经元集合活性之间的系统关系为这些术语之间的关系提供了有用的见解。在受过方向引导（一维）任务奔跑的大鼠中，海马细胞组件顺序排出，不同的组件在相反的运行中活跃，即位置单元是单向的。这样的任务不需要地图表示，并且与情节中的学习依次出现的项目正式相同。 Hebbian可塑性作用在Theta循环的时间窗口内，将行进距离转换为依次激活和单向连接的组件之间的突触强度。相反，在二维环境中，海马神经元的位置表示通常是全向图，是地图的特征。地图的产生需要探索，本质上是死去的估算行为。我们建议在探索过程中通过相同位置（连接）的全向导航产生全向位置单元，因此，映射没有时间环境。类似地，情节的常见连接的多个交叉将公共连接转换为无上下文或语义记忆。因此，可以将theta振荡视为通过物理和助记符空间的导航节奏，从而促进地图和情节/语义记忆的形成。 （c）2005 Wiley-Liss，Inc。
Five key topics have been reverberating in hippocampal-entorhinal cortex (EC) research over the past five decades: episodic and semantic memory, path integration (''dead reckonin'') and landmark (''map'') navigation, and theta oscillation. We suggest that the systematic relations between single cell discharge and the activity of neuronal ensembles reflected in local field theta oscillations provide a useful insight into the relationship among these terms. In rats trained to run in direction-guided (1-dimensional) tasks, hippocampal cell assemblies discharge sequentially, with different assemblies active on opposite runs, i.e., place cells are unidirectional. Such tasks do not require map representation and are formally identical with learning sequentially occurring items in an episode. Hebbian plasticity, acting within the temporal window of the theta cycle, converts the travel distances into synaptic strengths between the sequentially activated and unidirectionally connected assemblies. In contrast, place representations by hippocampal neurons in 2-dimensional environments are typically omnidirectional, characteristic of a map. Generation of a map requires exploration, essentially a dead reckoning behavior. We suggest that omnidirectional navigation through the same places (junctions) during exploration gives rise to omnidirectional place cells and, consequently, maps free of temporal context. Analogously, multiple crossings of common junction(s) of episodes convert the common junction(s) into context-free or semantic memory. Theta oscillation can hence be conceived as the navigation rhythm through both physical and mnemonic space, facilitating the formation of maps and episodic/semantic memories. (c) 2005 Wiley-Liss, Inc.