Glucocorticoid receptor involvement in pair bonding in female prairie voles: The effects of acute blockade and interactions with central dopamine reward systems

Induction of partner preferences in monogamous prairie voles (Microtus ochrogaster) was used to examine the possibility that blockade of glucocorticoid receptors may be rewarding in females of this species. We first examined the ability of either a mineralocorticoid receptor antagonist (spironolactone) or a glucocorticoid receptor antagonist (RU-486) to induce partner preferences in females. Peripheral administration of either of the antagonists was capable of inducing partner preferences, although the effective dose for RU-486 was an order of magnitude lower than that for spironolactone. We then examined a potential interaction of glucocorticoid receptor with central dopamine in pair bonding by treating females with i.c.v. dopamine receptor antagonists (haloperidol, SCH23390, or eticlopride) prior to peripheral administration of RU-486. All of the dopamine antagonists were capable of reversing the effects of glucocorticoid receptor blockade on pair bonding. These results establish the ability for acute blockade of glucocorticoid to induce pair bonds in female voles. Further, this effect appears to be mediated via an interaction with central dopamine systems. Together these findings support the possibility that, unlike other model systems, reductions in glucocorticoid receptor activity may enhance reward in female prairie voles.