Manipulation of alcohol preference in C57BL/6J mice by episodes of food poisoning

Differential effects of free versus imposed motor activity on alcohol consumption in C57BL/6J versus DBA/2J mice

Practicing sport regularly provides obvious physiological and psychological benefits, but intensive sport activity, for example, at the competition level, may be associated with an increased risk for addictive disorder, whether to improve results (doping), to tolerate consequences of important pressure and physical activities (drugs), or developing as a substitute when stopping, definitely or temporally, this activity that has been considered as potentially addictive (conversion). An animal model of voluntary versus imposed physical activity is described in which males of two mouse strains with high (C57BL/6J) versus (DBA/2J) low alcohol preference were tested for possible modifications of alcohol consumption during and after physical activity, when the activity was forced versus when it was recreative. Free access to a running wheel allowed a moderate physical activity that was associated with a decrease in voluntary alcohol intake in C57BL/6J mice. On the one hand, forced running at a higher speed than that occurring under free conditions led to increased alcohol intake, back to the initial level. On the other hand, alcohol intake remained at the same low level whether or not DBA/2J mice were subjected to free or forced running. The only effect of forced running in these alcohol-avoiding mice was a significant desynchronization of circadian motor activity rhythm, which was even more pronounced than that induced in alcohol-preferring C57BL/6J mice. These results highlight the positive aspects of moderate and entertaining sport activity and provide further support to the idea that it can decrease spontaneous alcohol intake. They also tend to demonstrate that, at least for vulnerable subjects, forced and intensive activities may not have the same benefits regarding alcohol consumption.

Early experience and the consumption of alcohol by adult C57BL/6J mice

Two types of early experience were examined for their effect on voluntary alcohol consumption by adult C57BL/6J mice: the experiences associated with belonging to a particular litter, and the experience of early postweaning choice between water and a 10% alcohol solution. Males from identified litters were individually caged from arrival at three weeks of age and given a choice between 10% alcohol and water when eight weeks old. Another group without notation of litter was given alcohol-water choice upon arrival at three weeks of age. Alcohol intake was examined by three measures: daily licks of 10% alcohol, alcohol selection (percent alcohol drinking), and volume of alcohol drunk daily. Belonging to a particular litter did affect body weight and growth, but had no effect on adult consumption of alcohol. Postweaning exposure to alcohol choice, however, produced a small but significant and prolonged increase in alcohol consumption by adults. Furthermore, a developmental trend was found in mice offered alcohol choice at an early age: alcohol preference developed as postweaning growth slowed.