Androgen receptor modulation of vocal circuitry in Alston's singing mouse

Animal advertisement displays are dramatic, often sexually dimorphic behaviors that function in both courtship and competition, and require the coordinated modulation of diverse motivational and motor circuits. In Alston's singing mice, Scotinomys teguina, a novel and elaborate advertisement vocalization is sexually dimorphic and steroid sensitive. Males sing more often than females, and on average male songs have more notes. Song is influenced by circulating androgens, but how such hormonal differences influence the diverse brain regions involved in vocal display is not understood. To characterize androgen-sensitive sites in the vocal pathway, we used two isoforms of pseudorabies virus (PRV) to double-label circuits ending in laryngeal and jaw muscles involved in vocalization, and co-labeled these neurons for androgen receptor (AR). Next, we manipulated circulating androgens and observed the effects on AR distribution and male song. We find androgens drive coordinated changes in AR abundance across motor and motivational circuits, and group differences in song are associated with AR abundance. The results reveal how circulating androgens can coordinate the diverse circuits necessary for elaborate advertisement displays.