Achermann P, Borbély A A
Institute of Pharmacology, University of Zürich, Switzerland.
J Biol Rhythms. 1990 Summer;5(2):141-57. doi: 10.1177/074873049000500206.
The typical declining trend of electroencephalographic (EEG) slow-wave activity (SWA) within a sleep period is represented in the two-process model of sleep regulation by an exponentially decaying process (Process S). The model has been further elaborated to simulate not only the global changes of SWA, but also the dynamics within non-rapid-eye-movement (non-REM) sleep episodes. In this new model, the initial intraepisodic buildup of SWA is determined by the combined action of an exponentially increasing process and a saturation process, whereas its fall at the end of an episode is due to an exponentially decreasing process. The global declining trend of SWA over consecutive episodes results from the monotonic decay of the intraepisodic saturation level. In contrast to Process S in the two-process model, this decay is not represented by an exponential function, but is proportional to the momentary level of SWA. REM sleep episodes are triggered by an external function. The model allows one to simulate the ultradian pattern of SWA for baseline nights as well as changes induced by a prolonged waking period, a daytime nap, a partial slow-wave sleep deprivation, or an antidepressant drug.
脑电图（EEG）慢波活动（SWA）在睡眠期间的典型下降趋势，在睡眠调节的双过程模型中由指数衰减过程（过程S）表示。该模型已进一步完善，不仅可以模拟SWA的整体变化，还可以模拟非快速眼动（non-REM）睡眠阶段的动态变化。在这个新模型中，SWA在睡眠阶段内的初始积累由指数增长过程和饱和过程的联合作用决定，而其在睡眠阶段结束时的下降则是由于指数下降过程。连续睡眠阶段中SWA的整体下降趋势是由睡眠阶段内饱和水平的单调衰减导致的。与双过程模型中的过程S不同，这种衰减不是由指数函数表示，而是与SWA的瞬时水平成正比。快速眼动睡眠阶段由外部函数触发。该模型可以模拟基线夜晚的SWA超日模式，以及长时间清醒、白天小睡、部分慢波睡眠剥夺或抗抑郁药物引起的变化。
