Kaufmann C, Wehrle R, Wetter T C, Holsboer F, Auer D P, Pollmächer T, Czisch M
Max Planck Institute of Psychiatry, Munich, Germany.
Brain. 2006 Mar;129(Pt 3):655-67. doi: 10.1093/brain/awh686. Epub 2005 Dec 9.
Regional differences in sleep EEG dynamics indicate that sleep-related brain activity involves local brain processes with sleep stage specific activity patterns of neuronal populations. Macroscopically, it is not fully understood which cerebral brain regions are involved in the successive discontinuation of wakefulness. We simultaneously used EEG and functional MRI on 9 subjects (6 female: mean = 24.1 years, 3 male: mean = 26.0 years) and analyzed local blood oxygenation level dependent signal changes linked to the transition from wakefulness to different non-rapid eye movement (NREM) sleep stages (according to Rechtschaffen and Kales) of the first sleep cycles after 36 h of total sleep deprivation. Several brain regions throughout the cortex, the limbic lobe, the thalamus, the caudate nucleus, as well as midbrain structures, such as the mammillary body/hypothalamus, showed reduced activity during NREM sleep across all sleep stages. Additionally, we found deactivation patterns specific to NREM sleep stages compared with wakefulness suggesting that a synchronized sleeping state can be established only if these regions interact in a well-balanced way. Sleep stage 2, which is usually linked to the loss of self-conscious awareness, is associated with signal decreases comprising thalamic and hypothalamic regions, the cingulate cortex, the right insula and adjacent regions of the temporal lobe, the inferior parietal lobule and the inferior/middle frontal gyri. The hypothalamic region known to be of particular importance in the regulation of the sleep-wake cycle shows specific temporally correlated network activity with the cortex while the system is in the sleeping state, but not during wakefulness. We describe a specific pattern of decreased brain activity during sleep and suggest that this pattern must be synchronized for establishing and maintaining sleep.
睡眠脑电图动态的区域差异表明，与睡眠相关的大脑活动涉及局部脑过程，神经元群体具有特定睡眠阶段的活动模式。从宏观上看，目前尚不完全清楚哪些大脑区域参与了清醒状态的连续中断。我们对9名受试者（6名女性，平均年龄24.1岁；3名男性，平均年龄26.0岁）同时进行了脑电图和功能磁共振成像检查，并分析了在完全睡眠剥夺36小时后第一个睡眠周期中，与从清醒状态过渡到不同非快速眼动（NREM）睡眠阶段（根据 Rechtschaffen 和 Kales 的标准）相关的局部血氧水平依赖信号变化。整个皮层、边缘叶、丘脑、尾状核以及中脑结构（如乳头体/下丘脑）的几个脑区在所有睡眠阶段的NREM睡眠期间均表现出活动减少。此外，我们发现与清醒状态相比，NREM睡眠阶段特有的失活模式，这表明只有当这些区域以平衡的方式相互作用时，才能建立同步的睡眠状态。通常与自我意识丧失相关的睡眠第2阶段，与包括丘脑和下丘脑区域、扣带回皮层、右侧岛叶及颞叶相邻区域、顶下小叶以及额下回/额中回的信号减弱有关。已知在睡眠-觉醒周期调节中特别重要的下丘脑区域，在系统处于睡眠状态而非清醒状态时，与皮层表现出特定的时间相关网络活动。我们描述了睡眠期间大脑活动减少的一种特定模式，并表明这种模式必须同步才能建立和维持睡眠。
