VOLUNTARY CONSUMPTION OF ETHANOL IN 15 INBRED MOUSE STRAINS

To determine genetic differences in ethanol consumption, 15 commonly u sed inbred strains of mice were given ad libitum two-bottle choice bet ween ethanol, 0.2% saccharin, or ethanol plus saccharin in one bottle versus tap water in the other bottle. Three different concentrations o f ethanol were used: 3%, 6% and 10% (v/v). Of the 15 strains, the C57B L/6J, C57BR/cdJ and C57L/J strains showed the most consistent higher i ntake of ethanol either with or without 0.2% saccharin. In marked cont rast, the DBA/1J and DBA/2J strains consistently showed the lowest int ake. Consumption of 3% ethanol without saccharin was highly geneticall y correlated with saccharin consumption (r=0.77), suggesting that low concentrations of ethanol may have a sweet taste that affects voluntar y consumption. Most strains showed very different patterns of response to ethanol with or without saccharin. Three patterns of strain respon ses were identified. Some strains avoided higher concentrations of eth anol whether in water or saccharin; some appeared to be sensitive to t he ability of saccharin to mask the odor of ethanol; and some may have reduced consumption only when ethanol concentrations were high enough to produce aversive postingestational effects. Whereas earlier studie s generally attempted to explain strain differences in consumption by invoking a single mechanism, our results demonstrate that more than on e mechanism is necessary to explain the preferential ethanol intake of all strains studied.