Homeostatic Regulation of REM Sleep in Humans during Extended Sleep

Abstract

Benington and Heller (1994) recently proposed a sleep-dependent model for the homeostatic control of REM sleep in which the amount of REM sleep propensity discharged in each bout of REM sleep affects the timing of the subsequent REM episode. Consistent with their hypothesis, they reported that in rats the duration of a REM episode was positively correlated with the duration of the succeeding NREM episode and not with the duration of the preceding NREM episode. To assess this hypothesis in humans, we used 308 sleep records from 11 subjects who remained at bedrest in the dark and slept ad libitum during 14-hour periods each night for 4 weeks. The timing of the onset of the first REM episode of the long night was linked to the timing of sleep onset. NREM-REM cycle duration decreased progressively throughout the night as a result of a progressive decrease in duration of the NREM component. Durations of REM sleep episodes correlated significantly with durations of subsequent NREM episodes in three out of the eight rank cycles analyzed (p