Meeting Abstract
The monoamine neurotransmitter dopamine (DA) has roles in both reward and social behavior, and is a potential mediator through which social interactions are perceived as rewarding. Subfamilies of DA receptors (D1 and D2) differentially modulate specific behaviors underlying pair bonding in monogamous rodents, but have not been systematically examined in nonhuman primates. D1 and D2 receptor agonists and antagonists were administered to pair-living marmosets in either short term (n=7 pairs, average < .5 yrs.) or long-term (n=5 pairs, average > 2 yrs.) pairs. Subjects were tested using a partner preference paradigm in which access to both the pair mate and an unfamiliar opposite-sex conspecific was available. Affiliative and agonistic behaviors toward both stimulus animals were recorded. Under saline conditions, long-term pairs spent significantly more time with their pair-mate than the stranger, F(1,8)=5.60, p=.045, while short-term pair did not display a preference for either stimulus animal, F(1,12)=0.50, p=.492). Marmosets in short-term pairs treated with either a D1 (p=.008) or D2 (p=.027) receptor antagonist displayed reduced sexual solicitations to a stranger, while treatment with a D1 receptor agonist (p=.034) increased sexual solicitations to a stranger, compared to when treated with saline. DA treatment had no effect on sexual solicitations for members of long-term pairs. Marmosets in long-term pairs that were treated with a D2 agonist displayed reduced overall time spent in close proximity to either stimulus animal, F(4,28)=3.07, p=.032. However, this effect on proximity was not observed in short-term pairs, F(8,104)=1.79, p=.086. These findings suggest that the DA system plays a role in regulating social interactions between current or potential mating partners.
