Mesolimbic deficits exacerbate amphetamine treatment. Clinical implications for drug abusers.

Amphetamine, a common drug used by abusers, is able to produce a schizophreniform psychosis in man. The experiment reported here examined amphetamine in relation to its role in the nucleus accumbens septi (NAS) and the globus pallidus. The effects produced by apomorphine, a direct dopamine (DA) agonist, were compared with those of amphetamine, a known indirect DA agonist. The data revealed that amphetamine in NAS-lesioned animals produced very active stereotypy which intensified with time. This effect was blocked by pallidal lesioning. Apomorphine in pallidectomised rats produced persistent stereotypy, but of diminished intensity. The results are discussed in terms of the mediating roles of the NAS and globus pallidus on behavioural sequelae.