Why do animals across the animal kingdom sleep? This question is still one of the great mysteries of biology. Several hypotheses propose that sleep plays important roles in memory consolidation, in maintaining synaptic balance, and in clearing metabolic waste from the brain. Nevertheless, a definitive and universal function of sleep has yet to be established. Interestingly, a new significant body of evidence converges on the notion that repairing DNA damage accumulated during wakefulness is a crucial function of sleep. These intriguing findings raise multiple key questions: Is this cellular function evolutionarily conserved from flies to mammals? How DNA damage in the neurons, a cellular consequence of its activity, translate into an increase in sleep pressure? Are canonical arousal/sleep centers involved? Are all neurons responsible for sleep induction by DNA damage, or are some neuronal populations more important than others? Drosophila melanogaster is the perfect model organism to answer these questions and elucidate the evolutionarily conserved cellular substrates and mechanisms that link DNA repair processes to sleep behavior. We will present preliminary results of a thermogenetic screen that will help us answer these important biological questions. To achieve our goals we exploit different methods, including sleep behavior analysis, thermogenetic neuronal activation and immunofluorescence to detect DNA damage in the brains of Drosophila.