美国麻省理工学院的Susumu Tonegawa和Chen Sun研究组合作探明了海马神经元可将事件表示为经验的可转移单元。相关论文发表在2020年4月6日出版的《自然-神经科学》杂志上。

他们为小鼠设计了一个迷宫，该迷宫由四个基本无法区分的单圈事件组成，并鉴定了海马CA1神经元，其活动不仅受空间位置而且还受单圈数量调控。即使在试验中迷宫长度发生不可预测的变化，这些“事件特定速率重新映射”（ESR）细胞仍会保持单圈特异性，这表明ESR细胞将单圈事件视为基本单位。

当迷宫的几何形状从正方形变为圆形时，ESR细胞的活动模式可重复用于表示单圈事件，这表明它有助于在经验之间传递认知。ESR活动可以与空间活动分开进行，因此可以构成一个独立的海马代码：“事件代码”，用于将事件的经验组织为离散的和可移动的单元。

研究人员表示，大脑在日常经验中编码连续的空间、时间和感觉变化。最近的研究表明，大脑还以分段（事件）的形式追踪经验，但是编码事件的神经基础仍然不清楚。

附：英文原文

Title: Hippocampal neurons represent events as transferable units of experience

Author: Chen Sun, Wannan Yang, Jared Martin, Susumu Tonegawa

Issue&Volume: 2020-04-06

Abstract: The brain codes continuous spatial, temporal and sensory changes in daily experience. Recent studies suggest that the brain also tracks experience as segmented subdivisions (events), but the neural basis for encoding events remains unclear. Here, we designed a maze for mice, composed of four materially indistinguishable lap events, and identify hippocampal CA1 neurons whose activity are modulated not only by spatial location but also lap number. These ‘event-specific rate remapping’ (ESR) cells remain lap-specific even when the maze length is unpredictably altered within trials, which suggests that ESR cells treat lap events as fundamental units. The activity pattern of ESR cells is reused to represent lap events when the maze geometry is altered from square to circle, which suggests that it helps transfer knowledge between experiences. ESR activity is separately manipulable from spatial activity, and may therefore constitute an independent hippocampal code: an ‘event code’ dedicated to organizing experience by events as discrete and transferable units.

DOI: 10.1038/s41593-020-0614-x

Source: https://www.nature.com/articles/s41593-020-0614-x