APStracts 2:0198R, 1995.

Homeostatic sleep regulation in habitual short sleepers and long sleepers. Aeschbach, Daniel, Christian Cajochen, Hanspeter Landolt, and Alexander A. Borb[acute]ely. Institute of Pharmacology, University of Zurich, Zurich

APStracts 2:0198R, 1995.

Homeostatic sleep regulation in habitual short sleepers (sleep episode &LT6 h,N=9) and long sleepers (&GT9 h, N=7) was investigated by studying their sleep structure and sleep EEG during baseline conditions and after prolonging their habitual waking time by 24 h. In each sleep episode, total sleep time was more than 3 h longer in the long sleepers than in the short sleepers. Sleep deprivation decreased sleep latency and rapid eye movement (REM) density in REM sleep more in long sleepers than in short sleepers. The enhancement of EEG slow-wave activity (SWA; spectral power density in the 0.75 -4.5 Hz range) in nonREM sleep after sleep loss was larger in long sleepers (+47%) than in short sleepers (+19%). This difference in the SWA response was predicted by the two-process model of sleep regulation on the basis of the different sleep durations. The results indicate that short sleepers live under a higher 'nonREM sleep pressure' than long sleepers. However, the two groups do not differ with respect to the homeostatic sleep regulatory mechanisms.

Received 8 August 1994; accepted in final form 6 July 1995.
APS Manuscript Number R437-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 18 July 1995.