Separation of taste-aversion-prone and taste-aversion-resistant rats through selective breeding: implications for individual differences in conditionability and aversion-therapy alcoholism treatment.
Both rats and alcoholic humans display considerable variability in acquisition of illness-induced consummatory aversions. Differential conditionability may be a significant modulator of outcome in alcoholics who elect taste aversion (TA) approaches to abstinence facilitation. This is a report of the ongoing development of rat strains suitable for studies of biological bases of individual differences in TA conditionability. Sprague-Dawley-derived rats have been selectively bred over seven generations as strong or weak learners of a cyclophosphamide-induced saccharin aversion. Efficiency of aversion acquisition is a selectable propensity, as indicated by progressively divergent strain separation that attained significance in the second selected generation. Subjects have also been studied with respect to shock-motivated environmental avoidance (SMEA), but efficiency of SMEA performance has not been a selection factor. Results have produced an unexpected trend across generations indicative of a within-strain reversal of TA and SMEA learning efficiency. Continuation of this reversal in subsequent generations could have important implications for studies of genetic contributions to different learning capacities and for the selection of biologically appropriate noxious stimuli for aversive therapy treatments of various target problems.