Meeting Abstract
P3.94 Jan. 6 CAROTENOIDS, VOCAL PERFORMANCE, AND THE BRAIN: AN EARLY-LIFE NUTRITIONAL AND ANTIOXIDATIVE MECHANISM UNDERLYING NEURAL CONTROL OF ANIMAL COMMUNICATION GEORGES, Joseph*; DEVICHE, Pierre; MCGRAW, Kevin; NOLAN, Paul; Arizona State University, Tempe; Arizona State University, Tempe; Arizona State University,Tempe; Dept. Biology, The Citadel, Charleston, NC joseph.georges@asu.edu
We tested whether carotenoids influence development of song control regions (SCR) in brain of the Zebra Finch, Taeniopygia guttata. During ontogeny, high metabolic rates induce free radical formation, potentially damaging developing tissues including the brain. In songbirds, free radicals may influence developing SCR such as the HVC and RA, which control song acquisition/expression. To investigate the hypothesis that carotenoids affect SCR development, we studied the effects of experimentally elevated dietary carotenoids on HVC and RA development in male finches. Hatchlings, randomly divided into low (n=6) or high (n=7) carotenoid feeding groups from hatch until 100 days old, received a standard seed diet. The high carotenoid group also received supplementary dietary carotenoids daily at approximately twice their regular intake level. We collected plasma samples when males were 14, 60, and 100 days old, and measured plasma carotenoid concentrations by high performance liquid chromatography (HPLC). Finches were sacrificed when 100-107 days old and brain sections were immunocytochemically stained for the neuronal marker, NeuN. Carotenoid administration increased plasma concentrations of these pigments. It did not influence HVC or RA volumes, but contrary to our hypothesis, decreased the estimated number of HVC neurons by 22%. This decrease was region-specific as estimated RA neuron numbers did not differ between groups. The results provide evidence for brain region-specific carotenoid-mediated alterations in neural morphology and will be discussed with regards to mechanisms that may mediate these alterations. Support: ASU Research Initiative Award (KM, PD, PN).
