Lack of difference between HAD and LAD rats in the stimulus generalizationof ethanol to nicotine

High alcohol drinking (HAD) and low alcohol drinking (LAD) rats were traine d to discriminate 0.5 g/kg ethanol from saline. HAD and LAD rats learned th e discrimination at the same rate and to the same level of asymptotic perfo rmance. In substitution tests, increasing doses of ethanol produced increas ed responding on the ethanol lever with dose-effect curves that were very s imilar in HAD and LAD rats. There was no generalization from ethanol to nic otine, or d-amphetamine, in either HAD or LAD rats, These data may be contr asted with data obtained with alcohol preferring rats (P rats) and alcohol non-preferring rats (NP rats), where the ethanol discrimination was learned more rapidly, asymptotic performance was better in P than in NP rats, and ethanol discriminative stimulus generalized to nicotine and partially to d- amphetamine in P, but not in NP rats. These data suggest that the differenc es in ethanol consumption reported previously by P and HAD rats relative to NP and LAD rats is not necessarily related to strain differences in ethano l discrimination as the differences in ethanol discrimination previously ob served between P and NP rats do not occur in HAD and LAD rats, (C) 1999 Lip pincott Williams & Wilkins.