Analysis of dynamic neuronal assemblies for memory processes of stimulus and temporal events

本研究调查了细胞组装，即，具有灵活功能连接的神经元的集合群体是大脑中记忆信息处理的基本神经元代码。表明细胞组装编码真实性的主要特性是不同组装体之间的神经元重叠以及组装体内部和之间的连接动力学。前者可以被检测为单个神经元在处理不同类型的信息时的多种功能。单个神经元似乎参与多种信息处理。后者可以被检测为功能性突触连接在处理不同类型的信息时的变化。一些记录的神经元之间的活动相关性似乎在多个信息过程中发生变化。本实验比较了几种不同的记忆过程（任务），包括刺激和时间事件的加工，并寻找两个主要的属性。第一次实验 ...更多信息 以大鼠为被试，比较了刺激的记忆过程（刺激辨别）及其呈现持续时间（持续时间辨别）。记录并分析大鼠在完成这两种任务时海马区的多神经元活动。第二个实验以猴子为被试，比较了刺激（延迟匹配到样本的颜色）和其呈现持续时间（延迟匹配到样本的持续时间）的短期记忆保持过程。记录并分析了猴子在执行这两种任务时前额叶皮层的多神经元活动。通过分析单个神经元的活动以及它们之间的活动相关性，这些实验都证明了细胞组装编码在刺激和时间事件处理中的两个主要特性。同时，这些实验也揭示了刺激和时间事件加工过程中细胞组装编码的一些不同特点。少

The present research investigated if the cell assembly, i.e., an ensemble population of neurons with flexible functional connections, is the basic neuronal code for information processes of memory in the brain. The main properties indicating the reality of cell-assembly coding are neurons overlapping 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. The present experiments compared several different memory processes (tasks), including processings of stimulus and temporal events and searched for the two main properties. The first experim … More ent used rats as subjects and compared memory processes of stimulus (stimulus discrimination) and its presented duration (duration discrimination). Multineuronal activities from the hippocampal areas were recorded and analyzed when the rats were performing the both tasks. The second experiment used monkeys as subjects and compared short-term retention processes of memory for stimulus (delayed matching-to-sample of color) and its presented duration (delayed matching-to-sample of duration). Multineuronal activities from the prefrontal cortical areas were recorded and analyzed when the monkeys were performing the both tasks. By analyzing the individual neuronal activities and their activity correlations with each others, all theses experiments are demonstrating the two main properties of cell-assembly coding in processings of stimulus and temporal events. Also, the experiments are suggesting some different features of cell-assembly coding between the processings of stimulus and temporal events. Less