Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France.
Science. 2018 Nov 9;362(6415):675-679. doi: 10.1126/science.aat2952.
Consolidation of spatial and episodic memories is thought to rely on replay of neuronal activity sequences during sleep. However, the network dynamics underlying the initial storage of memories during wakefulness have never been tested. Although slow, behavioral time scale sequences have been claimed to sustain sequential memory formation, fast ("theta") time scale sequences, nested within slow sequences, could be instrumental. We found that in rats traveling passively on a model train, place cells formed behavioral time scale sequences but theta sequences were degraded, resulting in impaired subsequent sleep replay. In contrast, when the rats actively ran on a treadmill while being transported on the train, place cells generated clear theta sequences and accurate trajectory replay during sleep. Our results support the view that nested sequences underlie the initial formation of memory traces subsequently consolidated during sleep.
巩固空间和情景记忆被认为依赖于睡眠期间神经元活动序列的重放。然而，在清醒状态下初始存储记忆的网络动力学从未被测试过。尽管缓慢，但据称行为时间尺度序列可以维持序列记忆的形成，而嵌套在慢序列中的快速（“theta”）时间尺度序列可能是至关重要的。我们发现，在被动地在模型火车上行驶的大鼠中，位置细胞形成行为时间尺度序列，但 theta 序列被降解，导致随后的睡眠重放受损。相比之下，当大鼠在火车上被运输时主动在跑步机上跑步时，位置细胞在睡眠中产生清晰的 theta 序列和准确的轨迹重放。我们的结果支持这样一种观点，即嵌套序列是随后在睡眠中巩固的记忆痕迹的初始形成的基础。
