Sakurai Y
Primate Research Institute, Kyoto University, Kanrin, 484-8506, Japan.
Neurobiol Learn Mem. 1998 Jul-Sep;70(1-2):212-25. doi: 10.1006/nlme.1998.3849.
The present paper discusses why the cell assembly, i.e., an ensemble population of neurons with flexible functional connections, is a tenable view of the basic code for information processes in the brain. The main properties indicating the reality of cell-assembly coding are neurons overlaps among different assemblies and connection dynamics within and among the assemblies. The former can be detected as multiple functions of individual neurons in processing different kinds of information. Individual neurons appear to be involved in multiple information processes. The latter can be detected as changes of functional synaptic connections in processing different kinds of information. Correlations of activity among some of the recorded neurons appear to change in multiple information processes. Recent experiments have compared several different memory processes (tasks) and detected these two main properties, indicating cell-assembly coding of memory in the working brain. The first experiment compared different types of processing of identical stimuli, i.e., working memory and reference memory of auditory stimuli. The second experiment compared identical processes of different types of stimuli, i.e., discriminations of simple auditory, simple visual, and configural auditory-visual stimuli. The third experiment compared identical processes of different types of stimuli with or without temporal processing of stimuli, i.e., discriminations of elemental auditory, configural auditory-visual, and sequential auditory-visual stimuli. Some possible features of the cell-assembly coding, especially "dual coding" by individual neurons and cell assemblies, are discussed for future experimental approaches.
本文讨论了为何细胞集合体，即具有灵活功能连接的神经元群体，是大脑信息处理基本编码的一种合理观点。表明细胞集合体编码真实性的主要特性是不同集合体之间的神经元重叠以及集合体内和集合体之间的连接动态变化。前者可通过单个神经元在处理不同类型信息时的多种功能检测到。单个神经元似乎参与多种信息处理过程。后者可通过处理不同类型信息时功能性突触连接的变化检测到。一些记录神经元之间的活动相关性似乎在多种信息处理过程中发生变化。最近的实验比较了几种不同的记忆过程（任务）并检测到了这两个主要特性，表明工作大脑中记忆的细胞集合体编码。第一个实验比较了相同刺激的不同类型处理，即听觉刺激的工作记忆和参考记忆。第二个实验比较了不同类型刺激的相同过程，即简单听觉、简单视觉和构型听觉 - 视觉刺激的辨别。第三个实验比较了不同类型刺激在有无刺激时间处理情况下的相同过程，即基本听觉、构型听觉 - 视觉和序列听觉 - 视觉刺激的辨别。针对未来的实验方法，讨论了细胞集合体编码的一些可能特征，特别是单个神经元和细胞集合体的“双重编码”。
