Ventral tegmental area involvement in pair bonding in male prairie voles.

Dopamine is known to play a critical role in social attachment in monogamous voles. However, little is known about the neurochemical regulation of central dopamine release during pair bond formation. Here we examine the effects on partner preference formation in male prairie voles of neurochemical manipulations in the ventral tegmental area (VTA), a major source of dopamine to brain regions implicated in pair bonding. Administration of NBQX, an AMPA receptor antagonist, or bicuculline, a GABA receptor antagonist, into the VTA induced partner preferences within 6 h in the absence of mating. We also found that, after unilateral administration of NBQX into the VTA, neuronal activation, as indicated by the expression of the immediate early gene c-fos, was decreased in the nucleus accumbens, prefrontal cortex, and medial amygdala, but was unchanged in the lateral septum and in a control region, the arcuate nucleus. These results confirm a role for the VTA in partner preference formation in monogamous voles and extend the list of neurochemicals important in pair bonding to include glutamate and GABA.