Daan S, Beersma D G, Borbély A A
Am J Physiol. 1984 Feb;246(2 Pt 2):R161-83. doi: 10.1152/ajpregu.1984.246.2.R161.
A model for the timing of human sleep is presented. It is based on a sleep-regulating variable (S)--possibly, but not necessarily, associated with a neurochemical substance--which increases during wakefulness and decreases during sleep. Sleep onset is triggered when S approaches an upper threshold (H); awakening occurs when S reaches a lower threshold (L). The thresholds show a circadian rhythm controlled by a single circadian pacemaker. Time constants of the S process were derived from rates of change of electroencephalographic (EEG) power density during regular sleep and during recovery from sleep deprivation. The waveform of the circadian threshold fluctuations was derived from spontaneous wake-up times after partial sleep deprivation. The model allows computer simulations of the main phenomena of human sleep timing, such as 1) internal desynchronization in the absence of time cues, 2) sleep fragmentation during continuous bed rest, and 3) circadian phase dependence of sleep duration during isolation from time cues, recovery from sleep deprivation, and shift work. The model shows that the experimental data are consistent with the concept of a single circadian pacemaker in humans. It has implications for the understanding of sleep as a restorative process and its timing with respect to day and night.
本文提出了一个人类睡眠定时模型。该模型基于一个睡眠调节变量（S）——可能但不一定与一种神经化学物质相关——它在清醒时增加，在睡眠时减少。当S接近上限阈值（H）时触发睡眠开始；当S达到下限阈值（L）时醒来。这些阈值呈现出由单个昼夜节律起搏器控制的昼夜节律。S过程的时间常数源自正常睡眠期间和睡眠剥夺恢复期间脑电图（EEG）功率密度的变化率。昼夜节律阈值波动的波形源自部分睡眠剥夺后的自发醒来时间。该模型允许对人类睡眠定时的主要现象进行计算机模拟，例如1）在没有时间线索时的内部去同步，2）连续卧床休息期间的睡眠碎片化，以及3）在与时间线索隔离、从睡眠剥夺中恢复和轮班工作期间睡眠时间的昼夜节律相位依赖性。该模型表明，实验数据与人类存在单个昼夜节律起搏器的概念一致。它对于理解睡眠作为一种恢复过程及其与白天和黑夜的定时关系具有启示意义。
