High doses of systemic DHEA-sulfate do not affect sleep structure and elicit moderate changes in non-REM sleep EEG in rats

Abstract

The hormone dehydroepiandrosterone (DHEA) and its metabolite DHEA-sulfate (DHEAS) occur in huge quantities in the plasma as well as in the brain of vertebrates. To investigate whether DHEAS modulates sleep-wake behavior, we assessed the sleep response to three doses (25, 50, and 100 mg/kg) of intraperitoneally administered DHEAS, mixed with oil, in 8 rats. DHEAS injections produced dose-dependent and long-lasting elevations in the plasma levels of both DHEAS and DHEA. DHEAS administration did not affect sleep time and architecture but exerted persistent effects on the electroencephalogram (EEG) within non–rapid eye movement sleep: 50 mg/kg DHEAS significantly augmented EEG power in the frequency range of sleep spindles, and 100 mg/kg DHEAS depressed EEG power in the slow-wave frequency bands. The findings indicate that DHEAS changes the sleep EEG in a dose-dependent way, possibly through a modulation of GABA- and glutamate-induced currents.