Sleep regulates visual selective attention in Drosophila

Although sleep-deprivation is known to impair attention in humans and other mammals, the underlying reasons are not well understood, and whether similar effects are present in non-mammalian species is not known. We therefore sought to investigate whether sleep is important for optimising attention in an invertebrate species, the genetic model Drosophila melanogaster. We developed a high-throughput paradigm to measure visual attention in freely-walking Drosophila, using competing foreground/background visual stimuli. We found that whereas sleep-deprived flies could respond normally to either stimulus alone, they were more distracted by background cues in a visual competition task. Other stressful manipulations such as starvation, heat exposure, and mechanical stress had no effects on visual attention in this paradigm. In contrast to sleep-deprivation, providing additional sleep using the GABA-A agonist 4,5,6,7-tetrahydroisoxazolo-[5,4-c]pyridine-3-ol (THIP) did not affect attention in wild-type flies, but significantly improved attention in the learning mutant dunce. Our results reveal a key function of sleep in optimising attention processes in Drosophila, and establish a behavioural paradigm that can be used to explore the molecular mechanisms involved.\n\nSummary statementSleep deprivation specifically impairs visual selective attention in fruit flies, without affecting behavioural responses to simple visual stimuli.