Sleep in Macaca arctoides and the effects of prazosin

Polygraphic (EEG, EOG, EMG) 12-hr recordings were made in 3 adult monkeys (Macaca arctoides) to document their normal sleep pattern and to examine the effects of prazosin, an alpha-1-adrenoceptor antagonist. In comparison to man, REM episodes appeared at shorter intervals (50 min) and they always ended in movement arousal or waking up. As in man the proportion of deep sleep decreased and the proportion of REM sleep increased towards morning. During eight hours after parenteral administration of prazosin, at doses without any noticeable behavioral side effects, the number of REM episodes and the amount of REM sleep was 30 to 80 percent greater than during the control nights. The changes were statistically nonsignificant. However, since the results were similar in all three monkeys, it can be suggested that prazosin had some effect on the cyclicity of sleep. Dose 1 mg/kg resulted in behavioral side effects and disturbed sleep.