Polygenic and Single-gene Determination of Responses to Ethanol in BXD/Ty Recombinant Inbred Mouse Strains

Male mice of parent inbred strains C57BL/6J and DBA/2J, and mice from several of the BXD/Ty Recombinant Inbred (RI) strains derived from the cross of the parent inbred strains were tested for responsiveness to ethanol. Separate groups of mice from these strains were characterized for sensitivity to ethanol's effects to increase activity in an open field and to induce ambulatory ataxia in the grid test. The strain distribution pattern of the RI strains indicated polygenic control of both responses to ethanol. Other mice from this battery were tested for acceptance of an ethanol solution, a measure related to preference drinking. This trait may be substantially influenced by a single gene. Mice were then rendered physically dependent on ethanol through inhalation of ethanol vapor for three days. Severity of handling-induced convulsions was used to index the severity of the ethanol withdrawal syndrome. The distribution of the RI strains indicated possible influence of a major gene on ethanol withdrawal severity.