NEURONS THAT FUNCTION WITHIN AN INTEGRATOR TO PROMOTE A PERSISTENT BEHAVIORAL STATE IN DROSOPHILA
Innate behaviors involve both reflexive motor programs and internal states. In Drosophila, optogenetic activation of male-specific P1 interneurons triggers courtship song, as well as a persistent behavioral state that prolongs courtship and enhances aggressiveness. Here we identify pCd neurons as persistently activated by repeated P1 stimulation. pCd neurons are required for P1-evoked persistent courtship and aggression, as well as for normal social behavior. Activation of pCd neurons alone is inefficacious, but enhances and prolongs courtship or aggression promoted by female cues. Transient female exposure induced persistent increases in male aggressiveness, an effect suppressed by transiently silencing pCd neurons. Transient silencing of pCd also disrupted P1-induced persistent physiological activity, implying a requisite role in persistence. Finally, P1 activation of pCd neurons enhanced their responsiveness to cVA, an aggression-promoting pheromone. Thus, pCd neurons function within a circuit that integrates P1 input, to promote a persistent internal state that enhances multiple social behaviors.