近日，美国加州大学洛杉矶分校Mayank R. Mehta、Jason J. Moore等研究人员合作揭示海马多重功能之间的联系。这一研究成果于2021年10月20日在线发表在国际学术期刊《自然》上。
通过大鼠只使用远端视觉线索进行虚拟导航任务（类似于空间记忆的标准水迷宫测试）时，研究人员揭示了背侧CA1神经元的多重选择性。神经反应主要是编码距离起点的路径和大鼠的头部角度，具有类似于灵长类动物弱分配中心的空间成分，但大大弱于现实世界中的啮齿动物。通常情况下，相同的细胞在一个序列中对路径距离、角度和分配中心位置进行复用和编码，从而对一个旅程的特定情节进行编码。神经活动和调谐的强度与表现密切相关，其时间关系表明神经反应影响着行为，反之亦然。
与关联和因果Hebbian学习的计算模型一致，神经反应显示出越来越多的聚类，并成为行为相关变量的更好预测者，平均神经计量曲线超过并趋向于心理计量曲线。因此，海马神经元复用并表现出高度的可塑性、任务和经验依赖性，对以路径为中心和以分配为中心的变量进行调谐，从而形成支持导航的情景序列。
据悉，海马功能的三个主要支柱是空间导航、Hebbian突触可塑性和空间选择性。海马还牵涉到情景记忆，但这四种功能之间的确切联系还没有找到。
附：英文原文
Title: Linking hippocampal multiplexed tuning, Hebbian plasticity and navigation
Author: Moore, Jason J., Cushman, Jesse D., Acharya, Lavanya, Popeney, Briana, Mehta, Mayank R.
Issue&Volume: 2021-10-20
Abstract: Three major pillars of hippocampal function are spatial navigation1, Hebbian synaptic plasticity2 and spatial selectivity3. The hippocampus is also implicated in episodic memory4, but the precise link between these four functions is missing. Here we report the multiplexed selectivity of dorsal CA1 neurons while rats performed a virtual navigation task using only distal visual cues5, similar to the standard water maze test of spatial memory1. Neural responses primarily encoded path distance from the start point and the head angle of rats, with a weak allocentric spatial component similar to that in primates but substantially weaker than in rodents in the real world. Often, the same cells multiplexed and encoded path distance, angle and allocentric position in a sequence, thus encoding a journey-specific episode. The strength of neural activity and tuning strongly correlated with performance, with a temporal relationship indicating neural responses influencing behaviour and vice versa. Consistent with computational models of associative and causal Hebbian learning6,7, neural responses showed increasing clustering8 and became better predictors of behaviourally relevant variables, with the average neurometric curves exceeding and converging to psychometric curves. Thus, hippocampal neurons multiplex and exhibit highly plastic, task- and experience-dependent tuning to path-centric and allocentric variables to form episodic sequences supporting navigation.
DOI: 10.1038/s41586-021-03989-z
Source: https://www.nature.com/articles/s41586-021-03989-z
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
