Effect of 10 days reserpine or apomorphine administration on sleep cycles in rats.

The duration of sleep-wakefulness periods and sleep cycles was investigated by means of EEG and EMG in rats with implanted brain electrodes and myographic electrodes in neck muscles during 5 hr trials after repeated administration of 2 depressant drugs, reserpine and apomorphine. Ten days administration of reserpine at a dose of 0.05 mg/day, SC, decreased the duration of both slow-wave and paradoxical sleep, whereas apomorphine had no effect on sleep duration or occurance of sleep phases in either the low dose (0.2 mg/kg/day, SC) or in the high dose of 0.6 mg/kg/day, SC. This finding might be correlated with previously found differences in catecholamine levels in the brain in the same model experiments.