Chronic D-amphetamine in nucleus accumbens: lack of tolerance or reverse tolerance of locomotor activity

An experiment was designed to test the ability of chronic intra-accumbens amphetamine injections to produce the augmentation of locomotor activity noted with repeated intraperitoneal injections. Results revealed increased response variability with chronic injections; but no augmentation or tolerance occurred, in spite of preservation of a dose dependent locomotor response to amphetamine in the nucleus accumbens.