研究人员发现了一个由CA2锥体细胞与表达胆囊收缩素（CCK+）的篮状细胞形成的海马内回路事件，该事件在非快速眼动睡眠期间生成了一个动作电位爆发（“BARR”）。
CA1神经元和在学习期间活跃的神经元群体在尖波-振荡波（SWR）期间被重新激活，但在BARR期间受到抑制。SWR期间的初始再激活增加通过睡眠回到基线。这一趋势在BARR期间通过静默CCK+篮状细胞被消除，导致CA1神经元群体的同步性增强和记忆巩固受损。
研究人员表示，记忆巩固涉及在睡眠的SWR期间海马细胞的同步再激活。如何在学习后增加的放电率和同步性得到平衡以保持网络稳定尚不清楚。
附：英文原文
Title: A hippocampal circuit mechanism to balance memory reactivation during sleep
Author: Lindsay A. Karaba, Heath L. Robinson, Ryan E. Harvey, Weiwei Chen, Antonio Fernandez-Ruiz, Azahara Oliva
Issue&Volume: 2024-08-16
Abstract: Memory consolidation involves the synchronous reactivation of hippocampal cells active during recent experience in sleep sharp-wave ripples (SWRs). How this increase in firing rates and synchrony after learning is counterbalanced to preserve network stability is not understood. We discovered a network event generated by an intrahippocampal circuit formed by a subset of CA2 pyramidal cells to cholecystokinin-expressing (CCK+) basket cells, which fire a barrage of action potentials (“BARR”) during non–rapid eye movement sleep. CA1 neurons and assemblies that increased their activity during learning were reactivated during SWRs but inhibited during BARRs. The initial increase in reactivation during SWRs returned to baseline through sleep. This trend was abolished by silencing CCK+ basket cells during BARRs, resulting in higher synchrony of CA1 assemblies and impaired memory consolidation.
DOI: ado5708
Source: https://www.science.org/doi/10.1126/science.ado5708