PHENOTYPIC CHARACTERIZATION OF 2ND GENERATION OFFSPRING OF ALCOHOL-SENSITIVE ANT AND ALCOHOL-INSENSITIVE AT RAT LINES

The alcohol-sensitive ANT and the alcohol-insensitive AT rat lines dev eloped by selective breeding for differential sensitivity to motor imp airment on the tilting plane by a moderate ethanol dose (2 g/kg, IP), were cross-bred to produce second generation (F-2) offspring to study phenotypic correlations between various behavioral and biochemical pro perties and the degree of initial alcohol sensitivity in the tilting p lane test. The F-2 population (n = 75) was subjected to alcohol sensit ivity tests using a tilting plane test and a sleep time test, and to t he elevated plus-maze test of sober activity and anxiety. Finally, the animals were sacrificed and the concentrations of dopamine and its ac idic metabolites were analyzed in their striatal tissues. Serum cortic osterone was determined to obtain information about the stress respons es of the animals after the tilting plane test. The behaviors studied had no significant correlations with each other, suggesting that the v arious genetic and environmental factors affecting these behavioral ph enotypes are different for each behavior. The biochemical measures yie lded some correlations with the tilting plane test results that were c ontrary to the differences between the parent rat lines (dopaminergic indices) or that were confounded by the correlations with the body wei ght of the animals (corticosterone). Body-weight independent correlati onal tendency between the alcohol-induced impairment in motel performa nce and serum corticosterone concentration, however, fitted the differ ences between the parent lines, suggesting that stress mechanisms cann ot be fully excluded as factors contributing to the differential alcoh ol sensitivity between the ANT and AT rat lines.