Alterations in the stages of continuous amphetamine intoxication produced by lesions of locus coeruleus and substantia nigra.

1. Slow-release silicone pellets containing d-amphetamine base were implanted subcutaneously in rats 20 days following radio-frequency lesions of the locus coeruleus (LC), substantia nigra (SN), or control operations. 2. LC-lesioned rats exhibited enhanced motor stereotypies soon after implantation, while SN-lesioned animals showed increased locomotion but decreased stereotypy and anorexia. 3. The later behavioral stages of continuous amphetamine intoxication were attenuated in both lesioned groups as controls then entered the most intense stereotypy, showed the greatest withdrawal to the burrows, and maximally exhibited the increase in socially disruptive behaviors which appear following four days of constant amphetamine intoxication. 4. The integrity of both dopaminergic and noradrenergic systems was necessary for the full expression of the late stages of this animal model of amphetamine psychosis.