Individual differences in the effect of novel environmental stimuli prior to amphetamine self-administration in rats...

These experiments determined whether individual differences in response to novelty subsequently predict the ability of novel stimuli, presented prior to the session, to decrease amphetamine self-administration. Using an inescapable locomotor test, the authors found that high-responder rats (Rattus norvegicus) showed a greater novelty-induced decrease in the acquisition of self-administration compared with low-responder rats. This effect was dose dependent and generalized to sucrose-reinforced responding. Using a free-choice place preference test, the authors found that high-novelty-seeking rats also showed a greater novelty-induced decrease in the acquisition of self-administration compared with low-novelty- seeking rats. Regardless of individual differences, novelty had little effect on amphetamine self-administration during the maintenance phase. These results suggest that exposure to novel environmental stimuli may reduce acquisition of drug-taking behavior, especially among high-novelty-seeking individuals.