Genetic selection of mouse lines sensitive (cold) and resistant (hot) to acute ethanol hypothermia

Using the technique of within-family selective breeding, we have generated mouse lines that differ genetically in sensitivity to the acute hypothermia induced by injection of 3 g/kg ethanol (EtOH). After 5 generations of selection, the difference in maximal hypothermic response between COLD and HOT lines was 1.6 degrees C in the first replicate and 1.2 degrees C in the second replicate. Estimates of realized heritability were h2 = .17 in each replicate. No differences in EtOH metabolism have developed, so the differences between HOT and COLD mice are presumably in neurosensitivity. These lines of animals should be useful for studying the biological mechanisms underlying neurosensitivity to EtOH. In conjunction with other selectively bred lines, they should improve our understanding of the genetic relationships among EtOH neurosensitivity, tolerance and physical dependence.