Meeting Abstract

P1.171  Wednesday, Jan. 4  Using the Spinophilin Protein as a Method of Assessing Regional Neuronal Plasticity in the Brain of the Male Red-Sided Garter Snake PROKOP, J.A.*; MONZON, R.I.; KROHMER, R.W.; St. Xavier University, Chicago; St. Xavier University, Chicago; St. Xavier University, Chicago j.prokop@mymail.sxu.edu

In many seasonally breeding species, alteration of dendritic spine density and/or morphology appears to be an active process within neural regions regulating reproductive behaviors. Dendritic protrusions, known as dendritic spines, receive much of the incoming excitatory signals from associated contacts with surrounding neurons. In addition, these dendritic spines also appear to be somewhat transient and have the ability to mobilize, relocate and emerge from the dendritic shaft enabling a certain level of synaptic plasticity. In the male red-sided garter snake (Thamnophis sirtalis parietalis), dendritic spines on neurons within the anterior hypothalamus preoptic area (AHPOA) a region critical for the control of reproductive behaviors are dramatically denser during spring mating than in fall non-mating individuals. In addition, spine density appeared to be greater in animals treated with estrogen compared to testosterone. However, since the numbers of actual dendritic spines/synapses are immense, determining changes in spinophilin, a specific scaffold, cytoskeletal protein that is vital for the proliferation of novel spines and increased density, has been used as a method of quantifying regional changes. Therefore, using western immunoblots, this study was designed to examine regional variations in the concentration of spinophilin. Our data indicate that the concentration of spinophilin varies among the regions critical to the expression of reproductive behaviors depending on season, hormonal and reproductive status.