Meeting Abstract
Male red-sided garter snakes (Thamnophis sirtalis parietalis) have been shown to exhibit seasonal changes in the morphology of the forebrain. This neuronal plasticity appears to be due to changes in dendritic spine formation. The current study is designed to examine seasonal and hormonal influences on neuronal plasticity and how it might relate to the regulation and control of sexual behavior. Since the number of actual dendritic spines/synapses is immense, quantifying changes can pose a serious challenge. Spinophilin, a specific scaffold, cytoskeletal protein is essential for the proliferation of dendritic spines. Subsequently, measurement of spinophilin offers a method for quantifying regional changes in neuronal plasticity. In a previous study, we found that dendritic spines were significantly increased during the breeding season and in response to testosterone and estrogen implants, with estrogen causing a greater effect than testosterone. Therefore, we hypothesize that, in the male red-sided garter snake, estrogens will have a greater effect on the production of spinophilin in regions critical for the control of reproductive behavior. Using western immunoblots, we examined regional variations in the concentration of dendritic spinophilin in the brains of male red-sided garter snakes; 1.) collected in an out of the breeding season and 2.) following implantation with either estrogen or testosterone.
