Meeting Abstract

36.3  Monday, Jan. 5  How Song Competition Changes the Brain and Behavior of a Male Songbird SOCKMAN, K.W.**; SALVANTE, K.G.; Univ. of North Carolina, Chapel Hill; Univ. of North Carolina, Chapel Hill kws@unc.edu

If male advertisement signals attract females because the signals reflect some aspect of the male’s quality, then incidental receivers, such as eavesdropping males, also should glean information about the quality of these competitors and should adjust their behavior and its neural substrates accordingly. In European starlings (Sturnus vulgaris), females base mate choice, in part, on the length of a male’s song, which positively correlates with his reproductive success, immunocompetence, and age. We periodically exposed male starlings to either long songs or short songs over 7 days and followed this by 1 day of no song. We previously reported that males exposed to long songs sing more than males exposed to short songs do. This raises questions about how the brain integrates information about the song environment and modulates song effort accordingly. Serotonin has well-known modulatory effects on auditory processing. In songbirds, a discrete network of forebrain vocal-control nuclei regulate song production, learning, and plasticity. We now report that, compared to males exposed to short songs, those exposed to long songs had greater serotonin secretion in the auditory telencephalon, which itself was positively correlated with song effort, and had a 30% larger vocal-control nucleus RA (robust nucleus of the arcopallium), even when we statistically controlled for total song-count. These findings raise the hypothesis that competition-induced serotonergic secretion in the auditory telencephalon modulates input to the vocal-control nuclei, which, in turn, modulate behavioral responses to song competition.