Oxytocin, Chlorpyrifos & Their Modulatory Roles in Southern Flying Squirrel (Glaucomys volans) Social Behavior

Abstract

Social behaviors, such as cooperation, communication, and aggregation, enhance survival and reproductive success within groups. These behaviors are regulated by neuroendocrine functions like oxytocin signaling. Southern flying squirrels (Glaucomys volans) serve as an ideal model to study aggregation behaviors due to their co-nesting habits throughout the year and throughout their range. In behavioral trials, I dosed squirrels with oxytocin (OT), oxytocin antagonist (OTA), or saline, in both familiar and unfamiliar social contexts, and recorded their behaviors. I found no main effect of treatment on behavior, but OTA influenced aggregation, particularly when accounting for sex and familiarity. In my second project, I tested for endocrine disruptors (EDCs) in soil and squirrel tissue using gas chromatography-mass spectrometry (GC-MS). While chlorpyrifos was not detected, several EDCs, including steroid hormone analogues, plasticizers, and the banned pesticide endrin, were found. Two compounds, 2,4-DTBP and fluoxymesterone, were detected in both squirrel tissue and their environments, which suggest environmental contamination as the source. High concentrations of EDCs were often found in ditch samples, indicating runoff as a contamination route. This thesis explores the connection between OT signaling, EDCs, and social behavior, offering insights into OT’s role in social bonding and stress responses. The detection of EDCs highlights the potential environmental impact on neuroendocrine systems, which could contribute to social and behavioral dysfunctions.