Nonapeptide receptor expression in relation to mating system and social behavior in Richardson's ground squirrels

Abstract

Arginine vasopressin and oxytocin influence many aspects of behavior, including sociality. However, there are only a few studies of non-reproductive social relationships. Richardson’s ground squirrel (Urocitellus richardsonii) is an excellent choice for a study of this nature because the sexes differ in their social behavior; females are sociable with related females and males are agonistic, so sexual receptor differences are expected in the brains of males and females of this species. Using autoradiography, I identified the neuroanatomical distribution of arginine vasopressin receptors (V1aR) and oxytocin receptors (OTR) in the brains of male and female and found sex differences in the mitral layer of the olfactory bulb and the bed nucleus of the stria terminalis (V1aR) and in the medial amygdala and the molecular layer of the dentate gyrus (OTR). Based on previous studies, these sex differences seem to be related to social memory, aggression, exploratory behavior, and spatial performance.