美国西奈山伊坎医学院Denise J. Cai小组最新研究发现，离线集成记忆协同再激活将跨天记忆联系起来。相关论文发表在2024年11月6日出版的《自然》杂志上。

据介绍，在学习过程中记忆被编码到神经集合中，并通过学习后的重新激活而稳定存在。将最近的经验整合到现有记忆中，可确保记忆包含最近可用的信息，但仍不清楚大脑如何完成这一关键过程。

研究人员发现在小鼠中，强烈的厌恶体验不仅会促使最近的离线厌恶记忆重新激活，而且还会促使两天前形成的离线中性记忆重新激活，从而将对最近厌恶记忆的恐惧与之前的中性记忆联系起来。恐惧与跨天中性记忆的联系是回顾性的，而不是前瞻性的。与之前的研究一致，研究人员发现，最近的厌恶记忆组合在学习后的离线期被重新激活。

然而，强烈的厌恶体验也会增加离线期间厌恶记忆和中性记忆组合的共同再激活。在清醒状态下，记忆组的共同激活比在睡眠状态时发生得多。最后，在中性情境中表达恐惧与重新激活厌恶记忆，和中性记忆之间的共享记忆集合有关。总之，这些结果表明，离线集合共同激活是一种神经机制，通过这种机制可以实现记忆跨天整合。

附：英文原文

Title: Offline ensemble co-reactivation links memories across days

Author: Zaki, Yosif, Pennington, Zachary T., Morales-Rodriguez, Denisse, Bacon, Madeline E., Ko, BumJin, Francisco, Taylor R., LaBanca, Alexa R., Sompolpong, Patlapa, Dong, Zhe, Lamsifer, Sophia, Chen, Hung-Tu, Carrillo Segura, Simn, Christenson Wick, Zo, Silva, Alcino J., Rajan, Kanaka, van der Meer, Matthijs, Fenton, Andr, Shuman, Tristan, Cai, Denise J.

Issue&Volume: 2024-11-06

Abstract: Memories are encoded in neural ensembles during learning1,2,3,4,5,6 and are stabilized by post-learning reactivation7,8,9,10,11,12,13,14,15,16,17. Integrating recent experiences into existing memories ensures that memories contain the most recently available information, but how the brain accomplishes this critical process remains unclear. Here we show that in mice, a strong aversive experience drives offline ensemble reactivation of not only the recent aversive memory but also a neutral memory formed 2 days before, linking fear of the recent aversive memory to the previous neutral memory. Fear specifically links retrospectively, but not prospectively, to neutral memories across days. Consistent with previous studies, we find that the recent aversive memory ensemble is reactivated during the offline period after learning. However, a strong aversive experience also increases co-reactivation of the aversive and neutral memory ensembles during the offline period. Ensemble co-reactivation occurs more during wake than during sleep. Finally, the expression of fear in the neutral context is associated with reactivation of the shared ensemble between the aversive and neutral memories. Collectively, these results demonstrate that offline ensemble co-reactivation is a neural mechanism by which memories are integrated across days.

DOI: 10.1038/s41586-024-08168-4

Source: https://www.nature.com/articles/s41586-024-08168-4