Meeting Abstract
The Red-sided Garter snake Thamnophis sirtalis parietalis is an ideal animal for examining neuroendocrine factors associated with reproduction. Mating behavior in the Red-sided Garter snake, like many other hibernating animals, normally occurs during the spring season and this behavior has been shown to be correlated with the sex-steroid hormones estrogen and testosterone. It is believed that seasonal levels of sex hormones influence growth of neuronal dendritic spines, allowing for a greater number of synapses in the regions of the brain believed to be associated with the control of mating behaviors. Both sexes undergo aromatase dependent conversion of testosterone to the more potent hormone, estrogen. However, female Red-sided Garter Snakes have shown a greater neuronal response to estrogen, implicating a differential effect of hormones on dendritic spine formation in the associated brain regions. Spinophilin, an actin-binding scaffolding protein associated with dendritic spines in post-synaptic neurons, is used as a biochemical marker of dendritic spine formation. In this study, we perform western analysis to measure the concentration of spinophilin in four different brain regions (the olfactory bulb, pre-optic area, nucleus sphericus, and the hindbrain) from animals treated with testosterone or estrogen. Histological analysis of brains from hormone treated animals is also conducted to correlate morphological differences in dendritic spine formation with spinophilin levels.
