Temporal aspects of the dependency of a dimorphic rate of extinction on testosterone.

Previous work has shown that rate of extinction of a conditioned taste aversion is affected by concurrent levels of testosterone in adult rats. In the present study, castrated male and female adult rates were given either oil or testosterone during acquisition of the conditioned taste aversion and then either oil or testosterone during extinction. The males and females that received testosterone during the extinction of the aversion showed the slower, masculine rate of extinction regardless of the type of injections they received during acquisition. Conversely, the animals that received oil during extinction showed the faster, feminine rate of extinction regardless of the type of injection during acquisition. In light of these findings, a number of alternative behavioral changes that could account for the effect of testosterone on the rate of extinction were evaluated.