Neurosciences Graduate Program, University of California San Diego, La Jolla, California, United States of America.
Medical Scientist Training Program, University of California San Diego, La Jolla, California, United States of America.
PLoS Biol. 2024 Nov 19;22(11):e3002855. doi: 10.1371/journal.pbio.3002855. eCollection 2024 Nov.
In the neocortex, ~90 Hz ripples couple to ~12 Hz sleep spindles on the ~1 Hz Down-to-Up state transition during non-rapid eye movement sleep. This conjunction of sleep waves is critical for the consolidation of memories into long-term storage. The widespread co-occurrences of ripples ("co-ripples") may integrate information across the neocortex and hippocampus to facilitate consolidation. While the thalamus synchronizes spindles and Up states in the cortex for memory, it is not known whether it may also organize co-ripples. Using human intracranial recordings during NREM sleep, we investigated whether cortico-cortical co-ripples and hippocampo-cortical co-ripples are either: (1) driven by directly projected thalamic ripples; or (2) coordinated by propagating thalamic spindles or Up states. We found ripples in the anterior and posterior thalamus, with similar characteristics as hippocampal and cortical ripples, including having a center frequency of ~90 Hz and coupling to local spindles on the Down-to-Up state transition. However, thalamic ripples rarely co-occur or phase-lock with cortical or hippocampal ripples. By contrast, spindles and Up states that propagate from the thalamus strongly coordinate co-ripples in the cortex and hippocampus. Thus, thalamo-cortical spindles and Up states, rather than thalamic ripples, may provide input facilitating spatially distributed co-rippling that integrates information for memory consolidation during sleep in humans.
在非快速眼动睡眠期间，新皮层中的90 Hz 涟漪与12 Hz 的睡眠纺锤波在1 Hz 的下至上状态转变上耦合。这种睡眠波的结合对于将记忆巩固到长期存储中至关重要。涟漪的广泛共同发生（“共涟漪”）可能会整合新皮层和海马体中的信息，以促进巩固。虽然丘脑为皮层中的纺锤波和上状态同步，以促进记忆，但尚不清楚它是否也可以组织共涟漪。使用人类在非快速眼动睡眠期间的颅内记录，我们研究了皮层-皮层共涟漪和海马-皮层共涟漪是否：（1）由直接投射的丘脑涟漪驱动；或（2）由传播的丘脑纺锤波或上状态协调。我们发现了前丘脑和后丘脑中的涟漪，其特征与海马和皮层中的涟漪相似，包括具有90 Hz 的中心频率，并与下至上状态转变上的局部纺锤波耦合。然而，丘脑涟漪很少与皮层或海马的涟漪共同发生或相位锁定。相比之下，从丘脑传播的纺锤波和上状态强烈协调皮层和海马中的共涟漪。因此，丘脑-皮层的纺锤波和上状态，而不是丘脑的涟漪，可能为促进睡眠期间人类信息整合的空间分布式共涟漪提供输入，以促进记忆巩固。
