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林映晞组揭示记忆印迹中功能不同的神经元群体
作者:小柯机器人 发布时间:2020/3/24 12:44:05

近日,美国麻省理工学院林映晞(Yingxi Lin)及其课题组揭示记忆印迹中功能不同的神经元群体。2020年3月17日,《细胞》杂志在线发表了这项成果。

研究人员发现,小鼠齿状回中的情景恐惧记忆印记包含功能上不同的神经元群体,这些基因在遗传上由Fos或Npas4依赖性转录途径定义。依赖Fos的群体可促进记忆泛化,并从内侧内嗅皮层接收增强的兴奋性突触输入,研究人员发现其自身也介导泛化。Npas4依赖的群体促进记忆辨别,并从表达局部胆囊收缩素的中间神经元获得增强的抑制驱动力,并且辨别需要其活性。这项研究为记忆印记内的功能异质性提供了因果证据,并揭示了每个群体用来调节记忆辨别与泛化平衡的突触和回路机制。
 
据介绍,记忆被认为是由大脑中零散的神经元群体所编码的。然而,尚不清楚单个记忆体中是否存在功能异质性,即单独的神经元亚群是否编码记忆的不同方面并以不同的方式驱动记忆表达。
 
附:英文原文

Title: Functionally Distinct Neuronal Ensembles within the Memory Engram

Author: Xiaochen Sun, Max J. Bernstein, Meizhen Meng, Siyuan Rao, Andreas T. Srensen, Li Yao, Xiaohui Zhang, Polina O. Anikeeva, Yingxi Lin

Issue&Volume: 2020-03-17

Abstract: Memories are believed to be encoded by sparse ensembles of neurons in the brain. However,it remains unclear whether there is functional heterogeneity within individual memoryengrams, i.e., if separate neuronal subpopulations encode distinct aspects of thememory and drive memory expression differently. Here, we show that contextual fearmemory engrams in the mouse dentate gyrus contain functionally distinct neuronal ensembles,genetically defined by the Fos- or Npas4-dependent transcriptional pathways. The Fos-dependent ensemble promotes memory generalization and receives enhanced excitatorysynaptic inputs from the medial entorhinal cortex, which we find itself also mediatesgeneralization. The Npas4-dependent ensemble promotes memory discrimination and receives enhanced inhibitorydrive from local cholecystokinin-expressing interneurons, the activity of which isrequired for discrimination. Our study provides causal evidence for functional heterogeneitywithin the memory engram and reveals synaptic and circuit mechanisms used by eachensemble to regulate the memory discrimination-generalization balance.

DOI: 10.1016/j.cell.2020.02.055

Source: https://www.cell.com/cell/fulltext/S0092-8674(20)30232-4

期刊信息
Cell:《细胞》,创刊于1974年。隶属于细胞出版社,最新IF:36.216
官方网址:https://www.cell.com/