Effects of dopamine receptor antagonism with haloperidol on nurturing behavior in the biparental prairie vole

Dopamine (DA) receptor activity in lactating rats is critical for retrieval and licking of pups, whereas its inactivity facilitates quiescent nursing. The role of DA in the maternal behavior of other species and its role in paternal behavior are unknown. This experiment examined the effects of the DA antagonist haloperidol (HAL) on parental behavior in the biparental prairie vole (Microtus ochrogaster). Three days after birth of pups, parental behavior of male and female voles was observed for 30 min beginning 1 h after intraperitoneal injection of 0.1, 0.5, or 2.5 mg/kg of HAL. Controls received the propylene glycol vehicle. Control males were slower to contact pups, licked them more, and quiescently huddled/nursed less than control females. Even at the lowest dose of HAL that had no effect on general activity, pup licking was decreased in both sexes and the latency to contact pups increased in males. The latency to contact pups was most increased in females by the highest HAL dose. Retrieval of pups was not often displayed by any group. HAL dose-dependently decreased the latency and increased the duration of huddling/nursing in both sexes, but did not affect litter weight gains. These data indicate some subtle species differences in the dopaminergic regulation of parenting, as well as sex differences in the sensitivity of some vole parental behaviors to HAL.