Sexually dimorphic effects of alcohol self-administration on cognitive processes

Abstract

Chronic alcohol consumption is able to modify cognitive and emotional behaviour in humans. Many studies on gender diversity have identified swingeing differences between man and woman, not only in the propensity for alcohol abuse, but also in their behavioural effects. In this study we investigate in adult male and female rats: i) alcohol drinking behaviour and preference pattern using a 3-bottle choice paradigm with water, 10% ethanol solution and white wine (10%v/v), along a four-week period; ii) Alcohol free access (AFA) effects on locomotion and behavioural reactivity in the Open Field; iii) The influence of AFA on spatial learning and reference memory, employing the Morris Water Maze. Our results show that: 1) female rats display higher intake of alcoholic beverages compared to males in the first two weeks of the paradigm, while they reduce their alcoholic intake in the last two weeks, drinking the same amounts as males; female rats- as well as males - prefer ethanol 10% than white wine; 2) AFA increases locomotor activity and behavioural reactivity in response to novelty in male rats (p< 0.004); on the contrary, female rats display a decrease in behavioural reactivity and locomotion compared to controls (p< 0.0187); 3) AFA improves spatial information processing in the new-place learning task in male rats, while it has detrimental effects in place learning, reversal learning and reference memory in female rats. Our results show a sexually dimorphic pattern of alcohol drinking behaviour, highlighting a different sensitivity to the reinforcing properties of ethanol. Both male and female rats are able to self-regulate their alcoholic intake along the four-week paradigm. The sexually dimorphic different behavioural consequences of alcohol free-access indicate that female rats are more vulnerable to the detrimental effects of alcohol and this may be due to the gender-related differences in metabolic and neurochemical patterns