Abstract # 115:

Scheduled for Sunday, September 14, 2014 02:00 PM-02:15 PM: Session 18 (Henry Oliver) Oral Presentation


OXYTOCIN FACILITATES FIDELITY IN WELL-ESTABLISHED MARMOSET PAIRS BY REDUCING SOCIOSEXUAL BEHAVIOR TOWARD OPPOSITE-SEX STRANGERS

J. Cavanaugh, A. C. Mustoe, J. H. Taylor and J. A. French
University of Nebraska - Omaha, Omaha, NE, USA
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     Behavioral strategies that facilitate the maintenance of social bonds are critical for the preservation of high-quality social relationships. Central oxytocin (OT) activity modulates the behavioral features of socially monogamous relationships in a number of mammalian species (including marmosets; Callithrix), and plays a vital role in the behavioral maintenance of long-term social relationships. Two distinct variants of OT have been identified in some New World primates (Lee et al., 2011). The marmoset variant of the oxytocin ligand (Pro8-OT) is structurally distinct from the consensus mammalian variant (Leu8-OT), due to a proline substitution at the 8th amino-acid position. The goal of the present study was to evaluate the impact of pharmacological manipulations of the OT system on patterns of sociosexual behavior and partner/stranger preferences in well-established marmoset pairs. Male and female marmosets were pair-housed throughout the study, and were treated individually 30 minutes prior to testing, during four counterbalanced treatment periods (Pro8-OT; Leu8-OT; OT antagonist, vehicle). Marmosets treated with Pro8-OT spent proportionately less time in proximity with an opposite-sex stranger [F(3,30)=3.13,P=0.04]. Furthermore, treatment with Pro8-OT significantly delayed the expression of sexual-solicitation behavior toward an opposite-sex stranger, but had no effect on sociosexual behavior directed toward their partner [F(3,30)=4.19,P=0.014]. These results suggest that the OT system is highly involved in reducing fidelity-threatening behaviors in well-established marmoset pairs, and that the effects were only produced by species-specific OT ligands.