STIMULATION OF A(1) ADENOSINE RECEPTORS MIMICS THE ELECTROENCEPHALOGRAPHIC EFFECTS OF SLEEP-DEPRIVATION

N-6-Cyclopentyladenosine (CPA), an A(1) adenosine receptor agonist, in creased EEG slow-wave activity in nonREM sleep when administered eithe r systemically (0.1-3 mg/kg) or intracerebroventricularly (3.5-10 mu g ) in the rat. The power spectrum of EEG changes (as calculated by Four ier analysis) matched that produced by total sleep deprivation in the rat. The effects of CPA on the nonREM-sleep EEG were dose-dependent. T hese findings suggest that adenosine is an endogenous mediator of slee p-deprivation induced increases in EEG slow-wave activity, and therefo re that increased adenosine release is a concomitant of accumulation o f sleep need and may be involved in homeostatic feedback control of sl eep expression.