Research Service, VA Greater Los Angeles Healthcare System, 16111 Plummer Street, North Hills, Los Angeles, CA 91343, USA.
Curr Opin Pulm Med. 2010 Nov;16(6):530-5. doi: 10.1097/MCP.0b013e32833eec92.
Regions of the neocortex most strongly activated during waking exhibit increased sleep intensity during subsequent sleep. The novel concept that aspects of sleep homeostasis are determined locally in the cortex contrasts with the established views that global changes in neocortical activity during sleep are achieved through inhibition of ascending arousal systems that originate in the brainstem and hypothalamus.
Experiments in animals and humans document asymmetries in neocortical electroencephalogram (EEG) slow-wave activity (SWA), a marker of homeostatic sleep need, as a result of functional activity during waking. In addition to local, use-dependent augmentation of EEG SWA and evoked potentials, expression of plasticity-related genes and of sleep-regulatory cytokines and neuromodulators have been shown to be elevated in a use-dependent manner in neocortex. The functional consequences of local sleep are hypothesized to involve regulation of synaptic plasticity, synaptic homeostasis and energy balance.
The evidence for use-dependent modulation of neocortical activity during sleep is compelling and provides novel insights into sleep function. However, local changes in neocortex are generally expressed on a background of global sleep. It remains to be determined if events initiated in the cortex have global sleep-promoting effects and how neocortical and hypothalamic mechanisms of sleep control interact.
目的综述：在清醒状态下被强烈激活的新皮层区域在随后的睡眠中表现出睡眠强度增加。睡眠内稳态的各个方面是在皮层局部决定的这一新颖概念，与睡眠期间新皮层活动的全局变化是通过抑制起源于脑干和下丘脑的觉醒系统的既定观点形成对比。
最新发现：动物和人类实验记录了由于清醒时的功能活动，新皮层脑电图（EEG）慢波活动（SWA）的不对称性，SWA 是内稳态睡眠需求的标志物。除了 EEG SWA 和诱发电位的局部、使用依赖性增强外，还表明可塑性相关基因以及睡眠调节细胞因子和神经调质的表达以使用依赖性方式在新皮层中升高。局部睡眠的功能后果假设涉及调节突触可塑性、突触内稳态和能量平衡。
总结：睡眠期间新皮层活动的使用依赖性调节的证据令人信服，并为睡眠功能提供了新的见解。然而，新皮层的局部变化通常是在全局睡眠的背景下表达的。目前尚不清楚皮层中启动的事件是否具有全局促进睡眠的作用，以及新皮层和下丘脑的睡眠控制机制如何相互作用。
