Abstract
Drosophila melanogaster relies on complex brain circuits and neuromodulation for experience-dependent sexual behavior, yet the role of neuropeptide signaling in behavioral refinement remains unclear. We investigate SIFamide (SIFa) and its receptor (SIFaR) in regulating male Drosophila sexual behavior. SIFaR is essential for these behaviors, particularly interval timing. Knockdown in fru-positive neurons impairs courtship index (CI) and mating duration (MD) but not copulation latency (CL). Critically, SIFaR in GABAergic mAL neurons (fru[+], dsx[-]) specifically controls MD and CI, not CL. Additionally, SIFa signaling in mAL neurons of experienced males increases presynaptic terminals, indicating context-dependent synaptic plasticity. These results reveal a complex SIFa/SIFaR interaction with specific neurons in modulating male behavior. The distinct roles of SIFaR in fru-positive versus other neurons, alongside its plasticity function, provide new insights into neural mechanisms of context-dependent behavioral adaptation.
