56.3 Saturday, Jan. 5 Early Developmental Stress Alters HVC but not RA size in Male Zebra Finches CARRUTH, L.L.*; SHAHBAZI, M.; Georgia State University; Georgia State University firstname.lastname@example.org
Stress has long lasting effects on animal physiology, development, behavior, reproductive success and survival. The effects of stress are mediated by glucocorticoids, such as corticosterone (Cort), via membrane-bound or intracellular glucocorticoid receptors (GR). When an organism is exposed to repeated stressors early in life this can alter stress-responsive neurobiological systems persisting across all life history stages. Early developmental stress affects the size of the avian song control nuclei and song quality in many songbirds, suggesting a direct link between brain and behavior. Song nuclei including HVC (proper name) and RA (nucleus robustus arcopallii) are required for song learning and production, and the complexity of the male zebra finch (Taeniopygia guttata) courtship song is important in female mate choice. Early Cort treatment differentially reduced the HVC size, but not RA, in juvenile and adult male zebra finches. This suggests that the effect of developmental stress on the HVC size may be mediated through Cort via activation of GR within HVC. This may be a specific mechanism by which HVC size and song quality are altered in developmentally stressed birds. Taken together, this suggests a potential role for Cort in mediating adverse effects of developmental stress in adult male zebra finches and highlights the developmental plasticity of the zebra finch brain.