DIFFERENTIAL EFFECTS OF ETHANOL AND PENTOBARBITAL ON SLEEP TIME IN C57BL AND BALB MICE

¹ Center of Alcohol Studies, Rutgers University, New Brunswick, New Jersey

The lesser central nervous system sensitivity of C57BL as compared to BALB mice measured by the length of sleep induced by 4.0 g/kg of ethanol has been confirmed. Since C57BL mice prefer and BALB mice avoid drinking an alcohol solution in a choice situation, one aspect of the relation between the lesser central nervous system responsivity and the alcohol drinking was studied by a determination of the alcohol-specificity of the central nervous system effect. Sleep induced by pentobarbital (50 mg/kg) was of equal duration in these strains. Inasmuch as C57BL mice metabolized pentobarbital more rapidly (half-life of 49 vs. 78 minutes) and awakened at a lower level of brain and blood pentobarbital, it was concluded that C57BL mice had a greater sensitivity to pentobarbital than to ethanol, the reverse being true for the BALB mice. The hypnotic effect of ethanol is thus not generalizable and the results support the notion that different brain sites are involved and suggest that alcohol preference of various strains of mice may indeed be related to the central responsivity to alcohol.