Meeting Abstract
Zebra finches (T. guttata) demonstrate selective affiliation between juvenile offspring and parents which, like affiliation between pair partners, is characterized by proximity, vocal communication and contact behaviors. In addition, they exhibit vocal learning, in which juvenile males learn courtship song through socially-guided feedback from adult tutors. This research investigates development of affiliative behavior and tests the hypothesis that the nonapeptide arginine vasotocin (AVT, avian homologue of vasopressin) and the V1a receptor subtype (V1aR) play organizational roles prior to fledging in species-typical vocal learning, courtship and affiliative behavior. Zebra finch hatchlings of both sexes received daily intracranial injections (posthatch days 2-8) of either AVT, Manning Compound (MC, a V1aR antagonist) or a saline control. We assessed affiliation through a series of behavioral assays throughout development. Profound differences were observed between the treatment groups on the first day following fledging and group differences continued throughout life. Once the subjects reached adulthood, we measured courtship and pair maintenance behaviors. We then tested whether administration of AVT or MC altered adult distribution of neurons expressing V1aR mRNA in the extended medial amygdala and whether the neurons expressing V1aR were active during pair maintenance behaviors by staining for the colocalization of ZENK, an immediate early gene. These results suggest that AVT and the V1aR are involved in the organization of social development, perhaps modifying early attentiveness to social stimuli or motivation, leading to downstream differences in socially-relevant behaviors.
