Meeting Abstract

45.11  Tuesday, Jan. 5  Quality of the song environment affects monoaminergic activity in the forebrain of male Lincoln’s sparrows SEWALL, K.B.*; CARO, S.P.; SOCKMAN, K.W.; Univ. of North Carolina, Chapel Hill; Univ. of North Carolina, Chapel Hill; Univ. of North Carolina, Chapel Hill ksewall@email.unc.edu

Male songbirds often establish territories and attract mates by singing, and some song features reflect the singer’s quality or condition because they are costly to learn or produce. The condition of competitors and hence the quality of the song environment can change with ecological conditions, and in a recent study we showed that male Lincoln’s sparrows (Melospiza lincolnii) modulate their own singing effort in response to the quality of the song environment. Socially-induced shifts of singing effort could be mediated by neuromodulatory effects of monamines including norepinephrine, dopamine and serotonin in brain regions that control signal perception and regulate song output. To evaluate this possibility, we exposed male Lincoln’s sparrows to chronic playback of songs that were either “high” or “low” quality, depending on the songs’ length and complexity and the performance of trills within them. We then used high pressure liquid chromatography to quantify levels of monoamines and their metabolites in two forebrain auditory processing regions, the caudomedial nidopallium and caudomedial mesopallium, and in the song control regions HVC, Area X and robust nucleus of the arcopallium (RA). We found that males exposed to the high quality song environment, who sang more, had lower levels of dopamine metabolite in HVC and lower levels of serotonin and its metabolite in RA, even when we statistically controlled for differences in singing effort. Thus, exposure to high quality song and subsequent shifts in singing effort may be mediated in part by dopamingergic and serotonergic activity in nuclei of the song motor control pathway.