小柯机器人

英国帝国理工学院Claudia Clopath等研究人员合作揭示记忆巩固过程中出现的动态和选择性印迹。该研究于2024年1月19日在线发表于国际一流学术期刊《自然—神经科学》。

研究人员采用了计算和实验方法来研究记忆片段的神经组成，和选择性是如何随着记忆的巩固而变化的。脉冲神经网络模型得出了可检验的预测：随着神经元退出和进入记忆片段，记忆从无选择性过渡到有选择性；回忆过程中的抑制性活动对记忆的选择性至关重要；记忆巩固过程中的抑制性突触可塑性对记忆片段的选择性至关重要。

研究人员在小鼠齿状回中使用活动依赖性标记、纵向钙成像以及光遗传学和化学遗传学相结合的方法，进行了情境恐惧条件反射实验，结果支持了研究人员的模型预测。这些研究结果表明，记忆片段是动态的，由抑制可塑性介导的记忆片段组成的变化对于记忆选择性的出现至关重要。

研究人员表示，情景记忆是由经验激活的神经元组合编码的，这些神经元组合对于回忆仍是必要且充分的。然而，记忆印迹在初始编码后的时间演变尚不清楚。

附：英文原文

Title: Dynamic and selective engrams emerge with memory consolidation

Author: Tom, Douglas Feitosa, Zhang, Ying, Aida, Tomomi, Mosto, Olivia, Lu, Yifeng, Chen, Mandy, Sadeh, Sadra, Roy, Dheeraj S., Clopath, Claudia

Issue&Volume: 2024-01-19

Abstract: Episodic memories are encoded by experience-activated neuronal ensembles that remain necessary and sufficient for recall. However, the temporal evolution of memory engrams after initial encoding is unclear. In this study, we employed computational and experimental approaches to examine how the neural composition and selectivity of engrams change with memory consolidation. Our spiking neural network model yielded testable predictions: memories transition from unselective to selective as neurons drop out of and drop into engrams; inhibitory activity during recall is essential for memory selectivity; and inhibitory synaptic plasticity during memory consolidation is critical for engrams to become selective. Using activity-dependent labeling, longitudinal calcium imaging and a combination of optogenetic and chemogenetic manipulations in mouse dentate gyrus, we conducted contextual fear conditioning experiments that supported our model’s predictions. Our results reveal that memory engrams are dynamic and that changes in engram composition mediated by inhibitory plasticity are crucial for the emergence of memory selectivity.

DOI: 10.1038/s41593-023-01551-w

Source: https://www.nature.com/articles/s41593-023-01551-w

Nature Neuroscience：《自然—神经科学》，创刊于1998年。隶属于施普林格·自然出版集团，最新IF：28.771
官方网址：https://www.nature.com/neuro/
投稿链接：https://mts-nn.nature.com/cgi-bin/main.plex