Social investigation in a memory task relates to natural variation in septal expression of oxytocin receptor and vasopressin receptor 1a in prairie voles (Microtus ochrogaster).
Arginine vasopressin (AVP) and oxytocin (OT) influence social behavior and cognitive processes and may explain some of the variance associated with individual differences in behavior. Although great focus has been placed on the roles of these peptides in learning and memory, less attention has been given to the receptors to which they bind. The authors exposed male prairie voles (Microtus ochrogaster) to novel females in a multitrial social recognition test to investigate whether individual differences in vasopressin receptor (V1aR) or oxytocin receptor (OTR) related to social recognition. The authors also explored differences in OTR and V1aR throughout the brain to determine whether patterns of receptor coexpression emerged in functionally related structures. Male investigation of females was highly variable, and those that investigated females the most did not habituate to repeated female presentation. Moreover, high investigators expressed significantly more V1aR and less OTR in the lateral septum. Coexpression patterns of these receptors emphasize the role of OT and AVP in neural circuits involved in social behavior, reward, learning, and memory. Understanding individual differences in the laboratory may provide insight into evolved natural behavior.