Alcohol Binge Drinking and Anxiety‐Like Behavior in Socialized Versus Isolated C57BL/6J Mice

Abstract

BackgroundBinge alcohol drinking has been characterized as a key feature of alcoholism. The drinking‐in‐the‐dark (DID) preclinical model, a procedure that promotes high levels of ethanol (EtOH) intake in short periods of time, has been extensively used to investigate neuropharmacological and genetic determinants of binge‐like EtOH consumption. Using DID methodology, alcohol‐preferring strains of mice such as C57BL/6J (B6) mice consume enough EtOH to achieve blood concentrations (≥1.0 mg/ml) associated with behavioral intoxication (i.e., motor incoordination). DID procedures typically involve the use of socially isolated animals (single‐housed prior to and during the experiment). Previous research indicates that stress associated with social isolation can induce anxiety‐like behavior and promote increases in EtOH intake. The present study investigates the role of housing conditions in anxiety‐like behavior and binge‐like EtOH intake using a DID procedure.MethodsMale and female B6 mice were isolated or pair‐housed for a period of 6 weeks prior to evaluation of anxiety‐like (elevated plus maze, light and dark box, open field) and drinking (water, 10% sucrose, 10 to 30% EtOH) behavior. In order to measure intake, a variation of the standard DID procedure using a removable, transparent, and perforated plastic barrier strip (designed to temporarily divide the cage in 2) was introduced. This allowed for individual intake records (2‐hour test) of isolated and socially housed animals.ResultsIncreased anxiety‐like behavior and reduced sucrose consumption were found in isolated mice. The effects of housing conditions on EtOH intake were sex‐ and concentration‐dependent. In male mice, isolation increased 20 and 30% EtOH intake. In females, however, an increased intake of EtOH (30%) was found in socialized animals. No effects of housing or sex were found at EtOH 10%.ConclusionsTogether with previous literature, the present study suggests that social isolation can promote anxiety‐associated behavior and produce sex‐dependent changes in binge‐like EtOH consumption.

Adolescent intermittent ethanol exposure induces sex‐dependent divergent changes in ethanol drinking and motor activity in adulthood in C57BL/6J mice

“…Housing conditions during adolescence, but not adulthood, altered social and anxiety‐like behavior and not ethanol consumption (Rivera‐Irizarry et al., 2020). However, others have observed that mice single housed during adolescence did indeed increase ethanol consumption, which can be influenced by ethanol concentration, sex, and environmental enrichment conditions (Evans et al., 2020; Lopez & Laber, 2015). In the present work, adolescent mice were group housed until 2 days before the onset of the ethanol drinking paradigm.…”

Sleep Modulates Alcohol Toxicity in Drosophila

“…In Drosophila , social isolation has been found to decrease synapse number in PDF neurons and reduce alcohol sensitivity [ 67 , 68 ]. Studies using rodent models have shown that social isolation increases alcohol preferences [ 141 , 142 , 143 , 144 ]. Therefore, we used a group-housed sleep deprivation method that significantly increased homeostatic sleep pressures in both male and females, as seen by increased sleep in the 36 h following the period of sleep deprivation.…”

Ethanol intake in male mice exposed to social defeat: Environmental enrichment potentiates resilience

“…In addition, social isolation is known to induce profound behavioral and neurobiological alterations ( Mumtaz et al, 2018 ). Besides inducing anxiety and depressive-like behaviors in rodents ( Amiri et al, 2015 ), several studies pointed that isolation induces an increase in ethanol consumption in mice and rats ( Advani et al, 2007 ; Evans et al, 2020 ; Juárez and Vázquez-Cortés, 2003 ; Lopez et al, 2011 ; Sanna et al, 2011 ).…”