Modulation of flight and feeding behaviours requires presynaptic IP3Rs in dopaminergic neurons

Abstract

Innate behaviours, although robust and hard wired, rely on modulation of neuronal circuits, for eliciting an appropriate response according to internal states and external cues. <i>Drosophila</i> flight is one such innate behaviour that is modulated by intracellular calcium release through inositol 1,4,5-trisphosphate receptors (IP₃Rs). Cellular mechanism(s) by which IP₃Rs modulate neuronal function for specific behaviours remain speculative, in vertebrates and invertebrates. To address this, we generated an inducible dominant negative form of the IP₃R (IP₃R^DN). Flies with neuronal expression of IP₃R^DN exhibit flight deficits. Expression of IP₃R^DN helped identify key flight-modulating dopaminergic neurons with axonal projections in the mushroom body. Flies with attenuated IP₃Rs in these presynaptic dopaminergic neurons exhibit shortened flight bouts and a disinterest in seeking food, accompanied by reduced excitability and dopamine release upon cholinergic stimulation. Our findings suggest that the same neural circuit modulates the drive for food search and for undertaking longer flight bouts.