A paradoxical impact of alcohol on sleep-memory coupling

Abstract Sleep serves a fundamental role in memory consolidation, and yet it must adapt to the organism’s physiological state. Acute ethanol consumption has a profound impact on animal physiology, but whether intoxication affects the role of sleep in memory consolidation remains unexplored. We demonstrate that acute ethanol exerts a paradoxical dual impact on sleep-memory coupling in Drosophila. Typically, satiated flies require sleep for memory consolidation, but starved flies that must forage for food switch to sleep-independent memory. Ethanol selectively impairs memory consolidation in satiated flies, whereas memories in starved flies remain intact despite intoxication. The observed impairment in satiated flies is due to a switch to sleep-independent memory, which then can’t be supported because of ethanol-induced sedation. Mechanistically, the ethanol-induced switch to sleep-independent memory is driven by neuropeptide F-mediated modulation of dopamine signaling. These findings reveal that ethanol intoxication inverts the canonical function of sleep, wherein it becomes detrimental to memory consolidation. Competing Interest Statement The authors have declared no competing interest.