Robinson Heath L, Todorova Ralitsa, Nagy Gergo A, Gruzdeva Anna, Paudel Praveen, Oliva Azahara, Fernandez-Ruiz Antonio
bioRxiv. 2025 Jun 29:2025.06.27.662061. doi: 10.1101/2025.06.27.662061.
During sleep, ensemble activity patterns encoding recent experiences are reactivated in the hippocampus and cortex. This reactivation is coordinated by hippocampal sharp-wave ripples (SWRs) and is believed to support the early stages of memory consolidation. However, only a minority of sleep SWRs are associated with memory reactivation in the hippocampus and its downstream areas. Whether that subset of SWRs have specific physiological characteristics and directly contribute to memory performance is not known. We identified a specific subset of large SWRs linked to memory reactivation in both the hippocampus and prefrontal cortex (PFC) of mice, and found that their occurrence selectively increased during sleep following new learning. Closed-loop optogenetic SWR boosting during sleep was sufficient to enhance ensemble memory reactivation in hippocampus and PFC. This manipulation also improved subsequent memory retrieval and hippocampal-PFC coordination, causally linking both phenomena to SWR-associated ensemble reactivation during sleep.
在睡眠期间，编码近期经历的神经元集群活动模式会在海马体和皮层中重新激活。这种重新激活由海马体的尖波涟漪（SWRs）协调，并且被认为支持记忆巩固的早期阶段。然而，只有少数睡眠中的SWRs与海马体及其下游区域的记忆重新激活相关。尚不清楚该SWRs子集是否具有特定的生理特征并直接影响记忆表现。我们在小鼠的海马体和前额叶皮层（PFC）中鉴定出与记忆重新激活相关的大型SWRs的一个特定子集，并发现它们的出现会在新学习后的睡眠期间选择性增加。睡眠期间闭环光遗传学增强SWRs足以增强海马体和PFC中的神经元集群记忆重新激活。这种操作还改善了随后的记忆检索以及海马体 - PFC协调，将这两种现象与睡眠期间与SWR相关的神经元集群重新激活建立了因果联系。
