Identification of subpopulations of prairie voles differentially susceptible to peer influence to decrease high alcohol intake

Abstract

Peer influences are critical in the decrease of alcohol (ethanol) abuse and maintenance of abstinence. We previously developed an animal model of inhibitory peer influences on ethanol drinking using prairie voles and here sought to understand whether this influential behavior was due to specific changes in drinking patterns and to variation in a microsatellite sequence in the regulatory region of the vasopressin receptor 1a gene (avpr1a). Adult prairie voles’ drinking patterns were monitored in a lickometer apparatus that recorded each lick a subject exhibited during continuous access to water and 10% ethanol during periods of isolation, pair housing of high and low drinkers, and subsequent isolation. Analysis of fluid consumption confirmed previous results that high drinkers typically decrease ethanol intake when paired with low drinkers, but that a subset of voles do not decrease. Analysis of bout structure revealed differences in the number of ethanol drinking bouts in the subpopulations of high drinkers when paired with low drinkers. Lickometer drinking patterns analyzed by visual and by cross-correlation analyses demonstrated that pair housing did not increase the rate of subjects drinking in bouts occurring at the same time. The length of the avpr1a microsatellite did not predict susceptibility to peer influence or any other drinking behaviors. In summary, subpopulations of high drinkers were identified, by fluid intake and number of drinking bouts, which did or did not lower their ethanol intake when paired with a low drinking peer, and these subpopulations should be explored for testing the efficacy of treatments to decrease ethanol use in groups that are likely to be responsive to different types of therapy.

Drinking alcohol has sex-dependent effects on pair bond formation in prairie voles

“…Combined with the above data, this finding indicates that Ucn1 cells were activated in response to alcohol, particularly in male voles. To test the hypothesis that alcohol decreases anxiety-like behaviors in prairie voles as has been demonstrated for other animals, we tested the effect of an injection of a low dose of alcohol (1.06 g/kg), comparable to what is consumed in a drinking bout (16,18), on anxiety-like behavior in the elevated plus maze (EPM). As expected, the alcohol-treated voles spent more time in the open arms [t(13) = 2.02, P = 0.032] and less time in the closed arms [t(13) = 1.87, P = 0.042]; accordingly, they had a greater proportion of time in the open arms [t(13) = 1.97, P = 0.035] than did saline-treated subjects.…”

“…In both species, social reward and drug reward show striking parallels at the behavioral and neurobiological levels (5-9). Prairie voles are now being used to explore the interactions between social relationships and drug abuse (10)(11)(12)(13)(14)(15)(16)(17)(18)(19).We previously demonstrated that prairie voles voluntarily selfadminister substantial amounts of alcohol (ethanol) and can influence the drinking patterns of a social partner (16)(17)(18)(19), similar to social drinking in humans (20). Because alcohol is known to influence social bonds in humans (21-24), we asked here whether alcohol consumption can affect the formation of adult social attachments in prairie voles.…”

“…We previously demonstrated that prairie voles voluntarily selfadminister substantial amounts of alcohol (ethanol) and can influence the drinking patterns of a social partner (16)(17)(18)(19), similar to social drinking in humans (20). Because alcohol is known to influence social bonds in humans (21-24), we asked here whether alcohol consumption can affect the formation of adult social attachments in prairie voles.…”

“…In both species, social reward and drug reward show striking parallels at the behavioral and neurobiological levels (5-9). Prairie voles are now being used to explore the interactions between social relationships and drug abuse (10)(11)(12)(13)(14)(15)(16)(17)(18)(19).…”

New frontiers in the neuropsychopharmacology of mental illness

“…In order to better understand the processes by which peer influences take effect in prairie voles, Anacker and Ryabinin (2013) measure alcohol intake during periods of isolation, pair housing of high and low drinkers, and subsequent isolation. By using a new method ("lickometer" apparatus) and cross-correlation analyses, they managed to differentiate subpopulations of high drinkers that were and were not responsive to social influence to decrease ethanol intake.…”