Dopamine receptor manipulation does not alter patterns of partner preference in long-term marmoset pairs

The relationship between socially monogamous mates is dynamic and regulated by neurobiological influences. Research in rodent models has indicated a key role for the neurotransmitter dopamine (DA) and its receptors (DAR) in mediating the formation and maintenance of monogamous bonds. DAR activation was pharmacologically manipulated in marmosets housed in long-term pairs. Marmosets exposed to DAR manipulation were tested in a partner preference test under two social conditions: one in which their mate could visually observe their interactions with an opposite-sex individual, and one in which their pair mate could not visually observe these interactions. Marmosets displayed a spatial preference for the mate compared to an unfamiliar conspecific, however, they displayed a sexual preference for an unfamiliar conspecific over their mate. D1R manipulation had no impact on marmoset partner preference. However, activation of D2Rs reduced the time marmosets spent in contact with either stimulus animal, indicating a decrease in social interest, but did not reduce time spent in proximity to the stimulus animals nor number of sexual solicitations. Additionally, social context (visibility of the mate) did not influence marmoset behavior. These findings suggest that D2Rs may be involved in regulating generalized, but not partner-specific, social interest in marmoset monkeys.