Low alcohol preference among the "high alcohol preference" C57 strain of mice; preference increased by saline injections

Rationale and objective: This study investigated individual alcohol preference among the "high alcohol preferring" strain of C57BL10 (line ScSn) mice. Methods: Alcohol preference was assessed in free choice two-bottle preference tests, using 8% ethanol and tap water, under various conditions. Results: Between 15 and 40% of the mice, bred in house, showed a low preference for alcohol with ethanol/water ratios of 0.4 or less. There was a biphasic distribution of preference, and no relationship between alcohol preference and gender. Mice of the C57BL/6 strain from an outside breeder also contained animals with low preference for alcohol. Selective breeding from "in house" stock did not demonstrate evidence of a simple genetic link. Ethanol preference showed no correlation with locomotor activity or the effects of alcohol on such activity. Daily intraperitoneal injections of saline increased the preference of low preference mice, an effect prevented by the CCK, antagonist, CAM1028. The preference of "low preference" mice was significantly increased when the effects of saline injections were compared with those of handling alone. Diazepam, at 1 mg/kg, did not affect the low preference, compared with Tween vehicle. This demonstration of C57 strain mice with low preference for alcohol may provide a valuable model for the effects of stress on alcohol consumption.