Enhancement of auditory fear conditioning after housing in a complex environment is attenuated by prior treatment with amphetamine

Prior exposure to drugs Of abuse has been shown to occlude the structural plasticity associated with living in a complex environment. Amphetamine treatment may also Occlude some cognitive advantages normally associated with living in a complex environment. To test this hypothesis we examined the influence of prior exposure to amphetamine on fear conditioning in rats housed in either a standard or complex environment. Housing in a complex environment facilitated fear learning to all auditory conditioned Stimulus (G), but]lot to the training context, relative to animals housed singly or in a social group. Prior treatment with amphetamine eliminated this effect. These results indicate that living in a complex environment facilitates conditional freezing to all auditory CS, and that this effect is abolished by pretreatment with amphetamine.