The Effects of Proximal and Distal Social Stimulation on Ethanol Intake in Male and Female CD-1 Mice

Abstract

Background. Proximal and distal social stimulation increase ethanol drinking in humans. Purpose. Our study evaluated the effects of proximal and distal social stimulation on home-cage ethanol drinking in mice. Study design. Proximal cagemate drinking (PCD) procedures use a clear plastic barrier to separate the drinker mouse from the proximal cagemate mouse, to evaluate home-cage drinking of 10% ethanol and water. Eight groups of CD-1 mice were arranged in a 2 × 2 × 2 factorial design with two levels of sex of drinker (male vs. female), two levels of sex of cagemate (male vs. female), and two levels of distal group-housed mice in the colony room (present vs. absent). Results. Distal group-housed mice, located outside of the home cage, stimulated ethanol drinking in female drinkers and did so regardless of the sex of their proximal cagemate. This effect was observed in the male drinker but only when housed with a proximal male cagemate. Conclusion. This study provides the first report of distal social stimulation of ethanol drinking in mice. The distal social stimulation effect, like the effects of proximal social stimulation, was more pronounced in female drinkers.

Social modulation of drug use and drug addiction

“…Altogether, these results suggest the presence of a peer may either predispose drug use through imitation or distract from drug use depending at which stage of drug use the presence of a peer occurs and how receptive the user is to peers. Such complex interactions could explain the different directions that have been observed depending on the matching of drug experience, the sex and the social housing conditions (Tomie et al, 2014;Tomie et al, 2016). Characterizing the factors that influences these opposing processes are important to understand the effects of peer on drug use.…”