Circadian rhythms of water and alcohol intake: effect of REM-sleep deprivation and lesion of the suprachiasmatic nucleus.

The recently discovered increase in alcohol drinking produced by a 7 day period of rapid eye movement (REM)-sleep deprivation with a modified flowerpot technique and the subsequent decrease during REM-rebound were now examined through continual monitoring of drinking with a computer attached to drinkometers. REM-sleep deprivation abolished the circadian rhythms of both alcohol and water intake. The circadian rhythm of water drinking returned during the first post-deprivation day but alcohol drinking was almost eliminated during the first 18 hr and there was no circadian rhythm to the alcohol drinking on the following 3 days. In an additional study, the circadian rhythms of both water and alcohol intake were abolished by electrolytic lesioning of the suprachiasmatic nuclei. The lesion did not, however, alter the mean level of alcohol drinking. Thus the abolition of circadian rhythms is not sufficient for increasing alcohol consumption and the increase produced during REM-sleep deprivation appears to be mediated by other mechanisms.