Social housing and alcohol drinking in male-female pairs of prairie voles (Microtus ochrogaster).

RATIONALE

Social environment influences alcohol consumption in humans; however, animal models have only begun to address biological underpinnings of these effects.

OBJECTIVES

We investigated whether social influences on alcohol drinking in the prairie vole are specific to the sex of the social partner.

METHODS

In Experiment 1, control, sham, and gonadectomized voles were placed either in mesh-divided housing with a same-sex sibling or isolation with access to ethanol. In Experiment 2, animals were given an elevated plus maze test (EPM) and then females were paired with a castrated male followed by isolation or mesh-divided housing with access to ethanol. In Experiment 3, subjects categorized as low or high drinkers based on initial ethanol intake were placed in mesh-divided housing with an opposite-sex partner of the same or opposite drinking group and ethanol access. Subjects were then moved back to isolation for a final ethanol access period.

RESULTS

Same-sex pairs showed social facilitation of drinking similar to previous reports. Gonadectomy did not affect alcohol drinking. Opposite-sex paired animals in Experiment 2 did not differ in alcohol drinking based on social housing. EPM measures suggested a relationship between anxiety-like behaviors and drinking that depended on social environment. Experiment 3 identified moderate changes in alcohol preference based on social housing, but these effects were influenced by the animal's own drinking behavior and were independent of their partner's drinking.

CONCLUSIONS

Social influences on alcohol self-administration in prairie voles differ based on the sex of a social partner, consistent with human drinking behavior.