Alcohol and Alcoholism Advance Access originally published online on November 18, 2005
Alcohol and Alcoholism 2006 41(1):44-53; doi:10.1093/alcalc/agh242
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DIFFERENT EFFECTS OF STRESS ON ALCOHOL DRINKING BEHAVIOUR IN MALE AND FEMALE MICE SELECTIVELY BRED FOR HIGH ALCOHOL PREFERENCE
Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907, USA
* Author to whom correspondence should be addressed at: Purdue University, Psychological Sciences, 703 Third Street, West Lafayette, IN 47907-2081, USA. Tel.: +1 765 494 6863; Fax: +1 765 496 1264; E-mail: jchester{at}psych.purdue.edu
(Received 18 August 2005; first review notified 27 September 2005; in final revised form 20 October 2005; accepted 21 October 2005)
Aims: The purpose of the present study was to examine the effects of stress on alcohol drinking behaviour in male and female mice with a genetic predisposition toward high alcohol preference (HAP2 line). Methods: Alcohol-naïve male (n = 22) and female (n = 23) HAP2 mice were assigned to a restraint stress or no stress control group. Stress was initially applied for 2 h per day on 10 consecutive days. All mice were then given daily 2 h limited-access to a 10% v/v alcohol solution or water, with food freely available, for 21 days. Over the next 20 days, 2 h restraint stress was applied every other day immediately prior to 2 h access to alcohol and water. On intervening days, all mice received 2 h access to alcohol and water in the absence of stress. Following this phase of the study, the effects of restraint stress on acoustic startle reactivity was assessed in all mice. Finally, all mice were given continuous access to alcohol and water for 8 days. Results: Ten days of prior stress exposure did not significantly alter the acquisition of limited-access alcohol drinking. Subsequent exposures to intermittent restraint stress produced subtle but consistent effects on alcohol intake that differed in males vs females: stress increased alcohol intake in males and decreased alcohol intake in females. Restraint stress did not alter acoustic startle reactivity. Under continuous-access conditions after stress termination, the stress-induced increase in alcohol intake in males became more robust; however, in females, alcohol intake returned to the control group level. Conclusions: These findings suggest that the effects of stress on alcohol drinking in mice with a genetic predisposition toward high alcohol preference depend on sex.