The age of drinking onset and housing condition influences rat alcohol drinking behavior

We investigated whether age of drinking onset and/or the housing condition in experimental animals affected alcohol drinking behavior to extrapolate the experimental findings to alcohol drinking patterns of aged people. At the time of the experiments, all 1-, 4-, 10- and the 16-month-old rats were divided into two groups, isolated and aggregated groups, and then maintained in the same housing conditions for six months. The amounts of voluntary alcohol consumption (g/kg/day) of all rats were investigated by two-bottle methods at 7, 10, 16 and 22 months old. No significant difference in alcohol drinking behavior was shown in the 7- and 10-month-old rats. A decrease in voluntary alcohol consumption was shown in the 16-month-old rats of the aggregated groups. In the 22-month old rats, a significant suppression of voluntary alcohol consumption was found in the aggregated groups compared with the isolated group. The results demonstrate that an important determinant of EtOH intake is related to environmental factors. It was suggested that alcohol drinking behavior strongly depends on the housing conditions and the age of onset of alcohol drinking.