Homeostatic control of slow-wave and spindle frequency activity during human sleep: effect of differential sleep pressure and brain topography.
The impact of a 40 h sleep deprivation versus a 40 h multiple nap paradigm on topographic and temporal aspects of electroencephalographic (EEG) activity during the subsequent recovery sleep was investigated in 10 young volunteers in a controlled 'constant posture' protocol. The accumulation of sleep pressure with extended wakefulness could be significantly attenuated by intermittent naps. The differential sleep pressure conditions induced frequency- and topographic-specific changes in the EEG slow wave range (0.5-5 Hz) and in the low (LSFA, 12.25-13.25 Hz) and high spindle frequency activity range (HSFA, 13.75-16.5 Hz) during non-REM sleep. The observed increase of EEG slow-wave activity (SWA) after high sleep pressure was significantly more pronounced in the fronto-central (Fz, Cz) than in the parieto-occipital (Pz, Oz) derivations. Low sleep pressure after the nap paradigm decreased SWA with an occipital predominance. Spindle frequency activity showed a dissimilar homeostatic regulation: HSFA was significantly decreased after high sleep pressure and increased after low sleep pressure, exclusively in the centro-parietal brain region (Cz, Pz). LSFA was significantly enhanced after both manipulations. The data indicate that EEG activity, in particular frontal SWA and centro-parietal HSFA, are under a clear sleep-wake-dependent homeostatic control and imply a reciprocal relationship in the homeostatic regulation of SWA and HSFA, which however shows different spatio-temporal aspects.
Knoblauch
V
V
Center for Chronobiology, Psychiatric University Clinic, CH-4025 Basel, Switzerland.
Kräuchi
K
K
Renz
C
C
Wirz-Justice
A
A
Cajochen
C
C
D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D018592:Cross-Over Studies; D004569:Electroencephalography / Q000706:statistics & numerical data; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008297:Male; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology*