Susceptibility to amphetamine-induced place preference is predicted by locomotor response to novelty and amphetamine in the mouse.

ABSTRACT

RATIONALE It has been demonstrated that major differences between mice of the C57BL/6J and DBA/2J inbred strains for amphetamine-induced place conditioning (preference and avoidance, respectively) are evident in standard housing conditions but abolished by temporary restricted feeding. This gene-experience model may be usefully exploited to dissect behavioral phenotypes related to place conditioning induced by addictive drugs. OBJECTIVES: This study evaluated a number of behavioral phenotypes related to amphetamine-induced place preference for strain differences (C57BL/6J vs DBA/2J) susceptible to be abolished by temporary food restriction. METHODS: Mice of the two inbred strains were tested for (1) conditioned taste aversion and place preference induced by amphetamine within the same dose-range; (2) preference for a novel compartment 24 h after a single exposure to only one of two compartments; (3) amphetamine-induced behavioral sensitization and conditioned hyperactivity; and (4) locomotor activity during exploration of a novel environment. RESULTS: The two strains showed consistent taste aversion at doses of amphetamine that promoted opposite strain-dependent place conditioning. Both strains spent more time exploring the novel rather than the known compartment of the place conditioning apparatus. Instead, only mice of the C57 strain showed amphetamine-induced behavioral sensitization and conditioned hyperactivity. However, temporary food restriction did not affect strain differences for these phenotypes. Finally, C57 mice were more active than DBA in a novel environment and restricted feeding abolished this strain-dependent difference. CONCLUSIONS: These results relate individual differences for amphetamine-induced place conditioning with locomotor response to amphetamine and novelty.