Brain & Mind Institute, Western Interdisciplinary Research Building, Western University, London, N6A 5B7, Canada.
Department of Neuroscience, Western University, 1151 Richmond St. N., London, N6A 3K7, Canada.
Sci Rep. 2021 Jun 7;11(1):11943. doi: 10.1038/s41598-021-91211-5.
Sleep resting state network (RSN) functional connectivity (FC) is poorly understood, particularly for rapid eye movement (REM), and in non-sleep deprived subjects. REM and non-REM (NREM) sleep involve competing drives; towards hypersynchronous cortical oscillations in NREM; and towards wake-like desynchronized oscillations in REM. This study employed simultaneous electroencephalography-functional magnetic resonance imaging (EEG-fMRI) to explore whether sleep RSN FC reflects these opposing drives. As hypothesized, this was confirmed for the majority of functional connections modulated by sleep. Further, changes were directional: e.g., positive wake correlations trended towards negative correlations in NREM and back towards positive correlations in REM. Moreover, the majority did not merely reduce magnitude, but actually either reversed and strengthened in the opposite direction, or increased in magnitude during NREM. This finding supports the notion that NREM is best expressed as having altered, rather than reduced FC. Further, as many of these functional connections comprised "higher-order" RSNs (which have been previously linked to cognition and consciousness), such as the default mode network, this finding is suggestive of possibly concomitant alterations to cognition and consciousness.
睡眠静息态网络 (RSN) 的功能连接 (FC) 理解不足，特别是在快速眼动 (REM) 睡眠和非睡眠剥夺的受试者中。REM 和非快速眼动 (NREM) 睡眠涉及竞争驱动；NREM 中朝向皮质同步振荡；而在 REM 中朝向类似于清醒的去同步振荡。本研究采用同时进行的脑电图-功能磁共振成像 (EEG-fMRI) 来探讨睡眠 RSN FC 是否反映了这些相反的驱动。正如假设的那样，这在大多数由睡眠调节的功能连接中得到了证实。此外，变化是有方向性的：例如，与清醒相关的正相关在 NREM 中呈负相关，在 REM 中又呈正相关。此外，大多数情况下，连接不仅降低了强度，实际上还会发生反转并在相反方向上增强，或者在 NREM 中增强。这一发现支持了这样一种观点，即 NREM 最好被表示为具有改变的而不是降低的 FC。此外，由于这些功能连接中的许多都包含“更高阶”的 RSN（先前与认知和意识相关），例如默认模式网络，因此这一发现表明认知和意识可能同时发生改变。
