2024-01-19 バッファロー大学(UB)
◆研究はエングラム(脳の神経細胞で記憶情報を保存するもの)に焦点を当て、記憶が形成され、固定化され、再生される過程を解明しました。エングラムの数が時間の経過とともに動的であり、これが異なる記憶の識別が向上する理由である可能性があります。これらの発見はアルツハイマー病などの記憶障害の原因を理解する上で鍵となり、早い段階の治療法開発に寄与する見込みです。
<関連情報>
- https://www.buffalo.edu/news/releases/2024/01/How-memory-cells-engrams-stabilize.html
- https://www.nature.com/articles/s41593-023-01551-w
記憶の統合に伴い、動的かつ選択的なエングラムが出現する Dynamic and selective engrams emerge with memory consolidation
Douglas Feitosa Tomé,Ying Zhang,Tomomi Aida,Olivia Mosto,Yifeng Lu,Mandy Chen,Sadra Sadeh,Dheeraj S. Roy & Claudia Clopath
Nature Neuroscience Published:19 January 2024
DO:Ihttps://doi.org/10.1038/s41593-023-01551-w
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.
