ACTH1-24 effects on d-amphetamine self-administration and the dynamics of brain dopamine in rats.

ABSTRACT

The present experiments investigated the role of ACTH fragments in d-amphetamine self-administration in rats. Presession injections of 20 or 40 ug/80 ul ACTH1-24 (but not 10 ug/80 ul ACTH1-24 nor any dose of ACTH4-10) significantly reduced rates of d-amphetamine self-infusion for 2 days. Neurochemical experiments revealed that ACTH1-24, followed 24hr later by haloperidol, attenuated haloperidol-induced increases in HVA and DOPAC in both the caudate and nucleus accumbens. It was tentatively concluded that the corticosteroid mediated neuromodulatory action of ACTH1-24 on dopaminergic neurons might increase the rewarding quality of d-amphetamine, thus rendering control levels of self-infusion superfluous.