Sleep Unit, University of Ottawa Institute of Mental Health Research at The Royal, Ottawa, ON, Canada.
School of Psychology, University of Ottawa, Ottawa, ON, Canada.
Commun Biol. 2024 Nov 12;7(1):1492. doi: 10.1038/s42003-024-07197-z.
Sleep is essential for the optimal consolidation of newly acquired memories. This study examines the neurophysiological processes underlying memory consolidation during sleep, via reactivation. Here, we investigated the impact of slow wave - spindle (SW-SP) coupling on regionally-task-specific brain reactivations following motor sequence learning. Utilizing simultaneous EEG-fMRI during sleep, our findings revealed that memory reactivation occured time-locked to coupled SW-SP complexes, and specifically in areas critical for motor sequence learning. Notably, these reactivations were confined to the hemisphere actively involved in learning the task. This regional specificity highlights a precise and targeted neural mechanism, underscoring the crucial role of SW-SP coupling. In addition, we observed double-dissociation whereby primary sensory areas were recruited time-locked to uncoupled spindles; suggesting a role for uncoupled spindles in sleep maintenance. These findings advance our understanding the functional significance of SW-SP coupling for enhancing memory in a regionally-specific manner, that is functionally dissociable from uncoupled spindles.
睡眠对于新获得的记忆的最佳巩固至关重要。本研究通过再激活来检查睡眠期间记忆巩固的神经生理过程。在这里，我们研究了慢波-纺锤波（SW-SP）耦合对运动序列学习后区域特定大脑再激活的影响。我们利用睡眠期间的同步 EEG-fMRI，发现记忆再激活与耦合的 SW-SP 复合体时间锁定，并且特别是在对运动序列学习至关重要的区域。值得注意的是，这些再激活仅限于主动参与学习任务的半球。这种区域特异性突出了一种精确和有针对性的神经机制，强调了 SW-SP 耦合的关键作用。此外，我们观察到双重分离，即主要感觉区域与未耦合的纺锤波时间锁定；表明未耦合的纺锤波在睡眠维持中的作用。这些发现提高了我们对 SW-SP 耦合以区域特异性方式增强记忆的功能意义的理解，这与未耦合的纺锤波在功能上是可分离的。
