Department of Neurosurgery, University of California, Los Angeles, Los Angeles, CA, USA.
Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
Nat Neurosci. 2023 Jun;26(6):1100-1110. doi: 10.1038/s41593-023-01324-5. Epub 2023 Jun 1.
Memory consolidation during sleep is thought to depend on the coordinated interplay between cortical slow waves, thalamocortical sleep spindles and hippocampal ripples, but direct evidence is lacking. Here, we implemented real-time closed-loop deep brain stimulation in human prefrontal cortex during sleep and tested its effects on sleep electrophysiology and on overnight consolidation of declarative memory. Synchronizing the stimulation to the active phases of endogenous slow waves in the medial temporal lobe (MTL) enhanced sleep spindles, boosted locking of brain-wide neural spiking activity to MTL slow waves, and improved coupling between MTL ripples and thalamocortical oscillations. Furthermore, synchronized stimulation enhanced the accuracy of recognition memory. By contrast, identical stimulation without this precise time-locking was not associated with, and sometimes even degraded, these electrophysiological and behavioral effects. Notably, individual changes in memory accuracy were highly correlated with electrophysiological effects. Our results indicate that hippocampo-thalamocortical synchronization during sleep causally supports human memory consolidation.
睡眠期间的记忆巩固被认为依赖于皮质慢波、丘脑皮质睡眠纺锤波和海马回波之间的协调相互作用，但缺乏直接证据。在这里，我们在人类前额叶皮层的睡眠期间实施了实时闭环深部脑刺激，并测试了它对睡眠电生理学和陈述性记忆的夜间巩固的影响。将刺激与内侧颞叶（MTL）中内源性慢波的活动阶段同步，可以增强睡眠纺锤波，增强全脑神经放电活动与 MTL 慢波的锁定，并改善 MTL 回波与丘脑皮质振荡之间的耦合。此外，同步刺激提高了识别记忆的准确性。相比之下，没有这种精确时间锁定的相同刺激与这些电生理和行为效应无关，有时甚至会降低这些效应。值得注意的是，记忆准确性的个体变化与电生理效应高度相关。我们的结果表明，海马-丘脑-皮质在睡眠期间的同步化会导致人类记忆巩固。
