Abstract
Sleep is a biological process regulated by the circadian clock and a homeostatic\r mechanism. Several structures, such as the dorsal fan-shaped body (dFSB) in Drosophila\r melanogaster, have been implicated in the regulation of sleep homeostasis. The dFSB and\r dopamine together play a role in the transition between sleep and wake in flies, but it is unclear\r whether these two also function in the transition from wake to sleep. Here, we provide evidence\r that the transition from wake to sleep may involve Gq, a heterotrimeric G-protein that increases\r cytosolic calcium levels. We show that the dFSB neurons respond to the removal of\r dopaminergic inhibition by exhibiting a disinhibitory rebound (DR). Our work also shows that\r the disinhibitory rebound is dependent on the duration of dopamine exposure. Moreover, the\r disruption of Gq expression in dFSB alters the normal disinhibitory rebound. Without normal Gq\r expression, total sleep duration is significantly reduced, similar to dFSB inhibition-induced sleep\r reduction. We conclude that Gq-signaling pathways contribute to the activation of dFSB to\r promote sleep.