Abstract # 181:

Scheduled for Monday, September 21, 2009 10:15 AM-10:25 AM: Session 16 (Mission Bay Ballroom AB) Oral Presentation


A. S. Smith1,2, A. Ågmo3, A. K. Birnie2 and J. A. French1,2,4
1Department of Psychology, UNOmaha, Omaha, NE 68182-0274, USA, 2Callitrichid Research Center, UNOmaha, Omaha, NE 68182, 3Department of Psychology, University of Tromsø, Norway, 4Department of Biology, UNOmaha, Omaha, NE 68182-0040

Pair-bonding is marked by mutual attraction and selective sociosexual behavior. Central oxytocin (OT) affects social preference and behavior in rodents but has not been studied in heterosexual primate relationships. The present study evaluated the effect of OT on social behavior during pair-bond formation and maintenance of marmosets (Callithrix penicillata). Central OT activity was stimulated by intranasal OT, and inhibited by an orally-administered nonpeptide OT-receptor antagonist (OTA). Social behavior throughout the pair-bond varied as a function of treatment condition. Individuals actively sought social contact with a partner at different rates depending on treatment condition, measured by initiating close proximity [F(2,18)=7.03, p<0.01] and starting huddling with partner [F(2,18)=16.96, p<0.001]. Compared to the control condition, individuals came into close proximity [t(9)=2.11, p=0.06] and started huddling [t(9)=3.71, p<0.005] with a social partner more often when receiving intranasal OT but reduced both close proximity [t(9)=-2.60, p<0.05] and huddling [t(9)=-2.92, p<0.05] when receiving an oral OTA. The amount of food that an individual shared with a social partner depended on treatment condition [F(2,18)=5.14, p<0.05]. Both males and females shared food equally in the OT and control conditions [t(9)=-0.04, p=0.97] but was all but eliminated in the OTA condition [t(9)=-2.99, p<0.05]. Individuals receiving intranasal OT increased social contact and affiliative behavior, but these behaviors were reduced when individuals received oral OTA. Our findings imply that oxytocin is involved in pair interactions and close relationships in marmoset monkeys.