Rapid-eye-movement sleep deprivation inhibits clonidine-induced sedation in rats

The effects of 24 and 48 h of rapid-eye-movement sleep deprivation (REMD) on clonidine-induced sedation and [3H]clonidine binding to cortical membranes were studied in rats. REMD did not affect the exploratory behaviour (ambulation, rearing + peeping) of normal rats. The sedative effect of clonidine (0.2 mg/kg s.c.) on the rearing + peeping behaviour of rats was inhibited by REMD. [3H]Clonidine binding in the cerebral frontal cortex remained unaffected. The results are discussed in terms of changes in the noradrenergic system.