Meeting Abstract

61.3  Thursday, Jan. 6  Downstream Regulation Of Melatonin Receptor in a Forebrain Vocal Control Nucleus TUCKER, S.A*; BENTLEY, G.E.; University of California, Berkeley; University of California, Berkeley shantuck88@gmail.com

In songbirds such as canaries and house sparrows (Passer domesticus ) adult neuroplasticity occurs in several forebrain areas that are involved in song learning and production. This neuroplasticity is modulated by gonadal steroids and the pineal hormone, melatonin. Area X, one such forebrain area that is involved in the learning and production of song, exhibits dramatic downregulation of melatonin receptors in response to environmental cues, suggesting a possible interaction between melatonin receptor regulation, vocal learning and neuroplasticity. The present study investigates this possibility through the examination of the downstream genomic regulation of the melatonin receptor. In particular, we are concerned with melatonin’s effect on the expression of genes for FoxP2 and ZENK because they are associated with song learning. Tissue punches were taken from one side of the bilaterally-distributed Area X in fresh-frozen house sparrow brains, leaving the other hemisphere intact for receptor autoradiography using ^125- iodomelatonin (IMEL). cDNA was generated from tissue punches taken from Area X and analyzed for FoxP2 and ZENK expression using quantitative real-time RT-PCR. Thus, in the same brain both melatonin receptor activity and gene expression in Area X were measured and compared. We predicted that low melatonin receptor expression would correlate with high FoxP2 and ZENK expression. Contrary to our prediction, we observed a positive correlation between melatonin receptor expression and ZENK expression. Combined with data on genes involved in neuroplasticity, our results will provide insight into the role of melatonin in the regulation of cellular mechanisms involved in vocal learning and neural plasticity in a vertebrate forebrain pathway.