Effect of ethanol on sleep-awake state in sleep-disturbed rats.

The present study was undertaken to investigate the effect of ethanol on the sleep-wake cycle in normal rats and sleep-disturbed rats. In normal rats, no significant difference was observed by ethanol in sleep latency, total awake time and total non-rapid eye movement (NREM) sleep time, except for total REM sleep time. On the other hand, in sleep-disturbed rats, ethanol at doses of 1 and 2 g/kg caused significant decreases in sleep latency and total wake time, and an increase in total NREM sleep time. In addition, ethanol showed a significant increase in delta activity in the sleep-disturbed model rat, different from triazolam. These results suggested that ethanol had not only a hypnotic but also a sleep-maintaining effect in sleep-disturbed rats at reasonable blood ethanol concentrations.