Dijk D J, Brunner D P, Borbély A A
Institute of Pharmacology, University of Zurich, Switzerland.
Electroencephalogr Clin Neurophysiol. 1991 Mar;78(3):203-14. doi: 10.1016/0013-4694(91)90034-2.
Sleep was recorded under baseline conditions (waking prior to sleep 16 h; lights off 23.00 h) and during recovery sleep in the morning (waking prior to sleep 24 h; lights off 07.00 h). Slow-wave activity (SWA; EEG power density in the range of 0.75-4.5 Hz) declined progressively over consecutive nonREM-REM cycles in both conditions despite the different circadian phase at which sleep occurred. SWA in nonREM sleep in the first 5 h of sleep was significantly higher in recovery than in baseline. Also SWA within the first 20 min of nonREM-episodes 2 and 3 was significantly higher in recovery sleep, and a tendency in the same direction was seen for nonREM-episode 1. These data show that homeostatic processes are expressed in the EEG also when sleep is initiated at a circadian phase where REM sleep propensity is high. However, comparison of the power spectrum in the first cycle of day-time recovery sleep with published data on recovery sleep at various circadian phases suggests that circadian factors influence the EEG spectra.
睡眠记录是在基线条件下（睡眠前清醒16小时；23:00熄灯）以及早晨恢复睡眠期间（睡眠前清醒24小时；07:00熄灯）进行的。尽管睡眠发生在不同的昼夜节律阶段，但在这两种情况下，慢波活动（SWA；脑电图功率密度在0.75 - 4.5赫兹范围内）在连续的非快速眼动-快速眼动周期中逐渐下降。恢复睡眠时，睡眠最初5小时的非快速眼动睡眠中的SWA显著高于基线水平。同样，在恢复睡眠中，非快速眼动期2和3的前20分钟内的SWA也显著更高，非快速眼动期1也呈现相同方向的趋势。这些数据表明，即使在快速眼动睡眠倾向较高的昼夜节律阶段开始睡眠时，稳态过程也会在脑电图中表现出来。然而，将白天恢复睡眠的第一个周期的功率谱与已发表的关于不同昼夜节律阶段恢复睡眠的数据进行比较表明，昼夜节律因素会影响脑电图频谱。
