Figure 3.

Modulation of male behavior by sexual arousal state. Female cues activate P1 neurons, which acutely promote courtship and aggression. P1 activation also elicits a state of sexual arousal that lasts for several minutes and enhances sexual behaviors. This state is mediated by persistent activity in pCd neurons. On longer timescales, a recurrent circuit comprising pCd and NPF-expressing cells maintains a sexual arousal state. Activity in this circuit builds up over days if males do not copulate, and this activity promotes mating by enhancing P1 activity via DANs. Copulation suppresses activity in the recurrent circuit, as does juvenile hormone circulating in young males, thus suppressing mating behavior. Gray arrows depict sensory input; solid black arrows depict neural circuit connectivity; red arrows depict inhibitory modulation. Dashed black arrows represent more complex or unknown forms of modulation: DANs enhance P1 responses by desensitizing P1 to inhibition, and the targets of pCd are unknown.