BRAIN GENE-REGULATION BY TERRITORIAL SINGING BEHAVIOR IN FREELY RANGING SONGBIRDS

To investigate the ecological relevance of brain gene regulation assoc iated with singing behavior in songbirds, we challenged freely ranging song sparrows with conspecific song playbacks within their breeding t erritories. Males responded by approaching the speaker, searching for an intruder and actively singing. In situ hybridization of brain secti ons revealed expression of the transcriptional regulator ZENK in chall enged birds than in unstimulated controls in several auditory structur es and song control nuclei. We conclude that singing behavior in the c ontext of territorial defense is associated with gene regulation in br ain centers that control song perception and production, and that beha viorally regulated gene expression can be used to investigate brain ar eas involved in the natural behaviors of freely ranging animals.