Abstract # 31:

Scheduled for Thursday, June 19, 2008 05:00 PM-07:00 PM: Session 4 (Ball Rooms A and B) Poster Presentation

Temperament and involvement in affiliative relationships predict later plasma concentrations of vasopressin, but not oxytocin, in juvenile rhesus macaques (Macaca mulatta)

T. Weinstein1,2, K. L. Bales1,2 and J. P. Capitanio1,2
1University of California, Davis, Department of Psychology, One Shields Ave, Davis 95616, USA, 2California National Primate Research Center
     The neuropeptides oxytocin (OT) and arginine-vasopressin (AVP) have been shown to affect social and emotional behavior in rodents, but their role in primate behavior is poorly understood. We investigated whether temperament in infancy and affiliation at age one related to plasma levels of OT and AVP in 48 rhesus monkeys at the California National Primate Center that were 2-3 years old. Blood was drawn during a brief capture-and-release in the animals’ half-acre natal corrals, and analyzed using an enzyme immunoassay. Animals had participated in a colony-wide biobehavioral assessment at 3-4 months of age, during which temperament ratings were collected, and their affiliative relationships were assessed at one year of age. We used multiple regression to test the effects of sex, infant temperament, and number of affiliative peer relationships on plasma neuropeptide levels, and found the regression equation for AVP, but not OT, to be statistically significant [R2=0.46, F(6,41)=5.69, p<0.001]. Subjects with a larger number of peer relationships had higher plasma AVP [b=0.549, p<0.001]. Additionally, the interaction between sex and the temperament factor Confidence (reflecting the degree of boldness, aggression, and curiosity) predicted plasma AVP [b=0.424, p<0.05]: females low in Confidence had higher AVP concentrations compared to either females high on this factor or to males. Our findings suggest that peripheral measures of neuroendocrine functioning in juvenile rhesus monkeys relate to earlier variation in temperament and affiliation.