美国贝勒医学院Jeffrey C. Magee等研究人员合作揭示海马CA3区支持记忆的神经元动态机制。2024年10月24日，《细胞》杂志在线发表了这项成果。

通过对行为小鼠进行细胞内膜电位记录和光遗传学操作，研究人员发现CA3区的位置场活动是由CA3锥体神经元间的递归突触的行为时间尺度突触可塑性（BTSP）对称形式产生的，而在齿状回（DG）突触中并不存在。

进一步的操作揭示，从内嗅皮层（EC）而非DG的兴奋性输入是根据动物运动更新位置细胞活动所必需的。这些数据通过一个计算模型得以捕捉，该模型使用BTSP和外部更新输入在在线学习条件下产生吸引子动态。

理论分析进一步强调了此类网络的优越记忆存储能力，特别是在处理相关输入模式时。这些证据阐明了海马中学习和记忆形成的细胞和回路机制。

据了解，海马CA3区在记忆的形成和检索中至关重要。尽管提出了各种网络机制，但缺乏直接证据。

附：英文原文

Title: Mechanisms of memory-supporting neuronal dynamics in hippocampal area CA3

Author: Yiding Li, John J. Briguglio, Sandro Romani, Jeffrey C. Magee

Issue&Volume: 2024-10-24

Abstract: Hippocampal CA3 is central to memory formation and retrieval. Although various network mechanisms have been proposed, direct evidence is lacking. Using intracellular Vm recordings and optogenetic manipulations in behaving mice, we found that CA3 place-field activity is produced by a symmetric form of behavioral timescale synaptic plasticity (BTSP) at recurrent synapses among CA3 pyramidal neurons but not at synapses from the dentate gyrus (DG). Additional manipulations revealed that excitatory input from the entorhinal cortex (EC) but not the DG was required to update place cell activity based on the animal’s movement. These data were captured by a computational model that used BTSP and an external updating input to produce attractor dynamics under online learning conditions. Theoretical analyses further highlight the superior memory storage capacity of such networks, especially when dealing with correlated input patterns. This evidence elucidates the cellular and circuit mechanisms of learning and memory formation in the hippocampus.

DOI: 10.1016/j.cell.2024.09.041

Source: https://www.cell.com/cell/abstract/S0092-8674(24)01141-3