Meeting Abstract

P3-53  Tuesday, Jan. 6 15:30  Seasonal Variation in orexigenic neuropeptides and aromatase within the social behavior network of a free-living songbird. FOKIDIS, BH; MA, CC; RADIN, BM*; PRIOR , NH; ADOMAT, HH; GUNS, ES; SOMA, KK; Rollins College, Winter Park; University of British Columbia, Vancouver; Rollins College, Winter Park; The Prostate Centre, Vancouver; The Prostate Centre, Vancouver; University of British Columbia, Vancouver; University of British Columbia, Vancouver bradin@rollins.edu

Animal reproduction in seasonal breeders is typically timed to periods of high food availability. During this time territorial behavior may be used to monopolize food resources, and this aggression is largely maintained by the neural conversion of testosterone to estrogen, by the enzyme aromatase. In birds, that are territorial year-round, non-breeding aggression may be related to accessing food resources. Neuropeptide Y (NPY) and orexin are neural proteins that stimulate food intake and maintain energy balance and immunoreactive cell and fiber populations have been observed within the avian social behavior network, yet their specific role has not been identified. We tested the hypothesis that NPY and orexin immunoreactivity differs between breeding and nonbreeding year-round territorial song sparrows (Melospiza melodia) in concordance with seasonal changes in energy balance. We also explored regional colocalization of these neuropeptides with the aromatase to gain support for a possible interaction between energy balance and aromatase activity.