Article

Alcohol Intake in Prairie Voles is Influenced by the Drinking Level of a Peer

Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon, USA.
Alcoholism Clinical and Experimental Research (Impact Factor: 3.31). 05/2011; 35(10):1884-90. DOI: 10.1111/j.1530-0277.2011.01533.x
Source: PubMed

ABSTRACT Peer interactions can have important effects on alcohol-drinking levels, in some cases increasing use, and in other cases preventing it. In a previous study, we have established the prairie vole as a model animal for the effects of social relationships on alcohol intake and have observed a correlation of alcohol intake between individual voles housed together as pairs. Here, we investigated this correlated drinking behavior, hypothesizing that 1 animal alters its alcohol intake to match the drinking of its partner.
Adult prairie voles were tested for baseline drinking levels with continuous access to 10% alcohol and water for 4 days. In Experiment 1, high alcohol drinkers (>9 g/kg/d) were paired with low alcohol drinkers (<5 g/kg/d) of the same sex on either side of a mesh divider for 4 days with continuous access to the same 2-bottle choice test. In Experiment 2, high drinkers were paired with high drinkers and low drinkers paired with low drinkers. In both experiments, animals were again separated following pairing, and drinking was retested in isolation. In Experiment 3, alcohol-naïve animals were tested for saccharin consumption (0.05%) first in isolation and then in high saccharin drinkers paired with low saccharin drinkers, and then in another isolation period.
In Experiment 1, high drinkers paired with low drinkers significantly decreased their alcohol intake and preference from baseline drinking in isolation, and drinking levels remained significantly lower during isolation following pairing. Interestingly, there was variability between pairs in whether the high drinker decreased or the low drinker increased intake. In Experiment 2, high drinkers paired with high drinkers did not significantly change their intake level or preference, nor did low drinkers paired with low drinkers, and no changes occurred during the subsequent isolation. In Experiment 3, there was no change in saccharin intake or preference when high drinkers were paired with high drinkers or low paired with low, or in the subsequent isolation.
Alcohol drinking of prairie voles can be altered under social conditions, such that 1 animal changes its alcohol intake to more closely match the intake of the other animal, helping to explain previous findings of correlated alcohol drinking. The effect does not extend to saccharin, a naturally rewarding sweet substance. This behavior can be used to model the peer pressure that can often affect alcohol intake in humans.

Full-text

Available from: Andrey E Ryabinin, May 11, 2015
0 Followers
 · 
175 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dominance hierarchies are an important aspect of group-living as they determine individual access to resources. The existence of dominance ranks in access to space has not been described in socially monogamous, communally nesting prairie voles (Microtus ochrogaster). Here, we tested whether dominance could be assessed using the tube test. We also tested whether dominance related to alcohol intake, similar to what has been demonstrated in nonmonogamous species. Same-sex pairs of unfamiliar peers were tested in a series of three trials of the tube test, then paired and allowed individual access to alcohol and water for 4 days, and then tested again in the tube test. For all pairs, the same subjects won the majority of trials before and after alcohol drinking. The number of wins negatively correlated with alcohol intake on the first day of drinking and positively correlated with levels of Fos in the paraventricular nucleus of the hypothalamus following the tube test in a separate group of voles. Dominance was not related to Fos levels in other brain regions examined. Together, these results indicate that prairie voles quickly establish stable dominance ranks through a process possibly involving the hypothalamus and suggest that dominance is linked to alcohol drinking.
    Social Neuroscience 06/2014; 9(5):1-11. DOI:10.1080/17470919.2014.931885 · 2.87 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The recent study by Anacker, Loftis, and Ryabinin used a novel animal model, the prairie vole, to investigate social effects on drinking. Their finding that same‐sex peers modulate their drinking to match each other has intriguing implications for the fields of alcohol research as well as research on social relationships.
    Alcoholism Clinical and Experimental Research 06/2011; 35(8). DOI:10.1111/j.1530-0277.2011.01582.x · 3.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The present experiment evaluated the effects of the Number of Cagemates (0 vs 1 vs 2) on home cage ethanol drinking during Proximal Cagemate Drinking (PCD) procedures in Male and Female CD-1 mice. Continuous-access home cage 2-bottle (ethanol vs. water) free-choice procedures were employed. PCD procedures eliminate the distracting effects of direct physical contact between Drinkers and their Cagemates on ethanol drinking by imposing a translucent plastic barrier strip between them. If direct physical contact distracts from drinking, then one Cagemate would drink more ethanol and more water than two Cagemates housed together on the same side of the barrier. This would be the case even if two Cagemates stimulated more ethanol drinking in the Drinker housed on the other side of the barrier, due to the social stimulation effects of additional Cagemates. Results revealed that the ethanol intake of Female Drinkers was directly related to the number of Cagemates on the other side of the barrier strip, but this social stimulation effect was not observed in Male Drinkers. For Male Cagemates and Female Cagemates, the single Cagemate provided elevated ethanol intake and elevated water intake relative to the ethanol intake and water intake of each Cagemate in the two Cagemates condition. The data revealed that direct physical contact between Cagemates reduced their ethanol intake, even while stimulating ethanol intake of the Drinker on the other side of the barrier, indicating that the effects of social stimulation on ethanol drinking are not entirely due to effects of modeling or peer pressure. The PCD procedures allow the evaluation of effects of a broad range of social factors on home cage ethanol drinking in mice.
    Progress in Neuro-Psychopharmacology and Biological Psychiatry 03/2015; 57. DOI:10.1016/j.pnpbp.2014.10.001 · 4.03 Impact Factor