Rector David M, Schei Jennifer L, Van Dongen Hans P A, Belenky Gregory, Krueger James M
Sleep and Performance Research Center and Program in Neuroscience, Washington State University, Spokane, WA 99210-1495, USA.
Eur J Neurosci. 2009 May;29(9):1771-8. doi: 10.1111/j.1460-9568.2009.06717.x. Epub 2009 Apr 27.
Substantial evidence suggests that brain regions that have been disproportionately used during waking will require a greater intensity and/or duration of subsequent sleep. For example, rats use their whiskers in the dark and their eyes during the light, and this is manifested as a greater magnitude of electroencephalogram (EEG) slow-wave activity in the somatosensory and visual cortex during sleep in the corresponding light and dark periods respectively. The parsimonious interpretation of such findings is that sleep is distributed across local brain regions and is use-dependent. The fundamental properties of sleep can also be experimentally defined locally at the level of small neural assemblies such as cortical columns. In this view, sleep is orchestrated, but not fundamentally driven, by central mechanisms. We explore two physiological markers of local, use-dependent sleep, namely, an electrical marker apparent as a change in the size and shape of an electrical evoked response, and a metabolic marker evident as an evoked change in blood volume and oxygenation delivered to activated tissue. Both markers, applied to cortical columns, provide a means to investigate physiological mechanisms for the distributed homeostatic regulation of sleep, and may yield new insights into the consequences of sleep loss and sleep pathologies on waking brain function.
大量证据表明，清醒时过度使用的脑区在随后的睡眠中需要更强的强度和/或更长的持续时间。例如，大鼠在黑暗中使用胡须，在光亮中使用眼睛，这分别表现为在相应的明暗周期睡眠期间，体感皮层和视觉皮层中脑电图（EEG）慢波活动的幅度更大。对此类发现的简单解释是，睡眠分布在局部脑区，且与使用情况有关。睡眠的基本特性也可以在诸如皮质柱等小神经集合水平上进行局部实验定义。从这个角度来看，睡眠是由中枢机制协调的，但并非从根本上由其驱动。我们探索局部的、与使用情况有关的睡眠的两种生理标记，即一种电标记，表现为电诱发反应的大小和形状的变化，以及一种代谢标记，表现为输送到激活组织的血容量和氧合的诱发变化。将这两种标记应用于皮质柱，为研究睡眠分布式稳态调节的生理机制提供了一种方法，并可能对睡眠剥夺和睡眠病理对清醒脑功能的影响产生新的见解。
