ACTIONS OF AMPHETAMINE ON NEUROTRANSMITTERS - BRIEF REVIEW

Abstract

The central stimulant actions of d-amphetamine are not altered in animals [rats and cats] in which brain stores of catecholamines were depleted with reserpine, but they are blocked by .alpha.-methyltyrosine, which inhibits catecholamine synthesis. The central actions of amphetamine result primarily from the ability of the drug to facilitate the release of newly synthesized dopamine from nerve terminals in the forebrain. In animals in which dopaminergic nerve terminals in various brain regions were selectively destroyed by intracranial microinjection of 6-hydroxydopamine, the locomotor stimulant actions of relatively low doses of amphetamine are dependent upon mesolimbic dopaminergic neurons, whereas the stereotyped behaviors induced by relatively larger doses of amphetamine are dependent upon nigrostriatal dopaminergic neurons. The central actions of amphetamine appear to be the primary result of interactions with dopamine neurons, but secondarily the drug also alters the dynamics of other putative neurotransmitters (e.g., acetylcholine, 5-hydroxytryptamine) in the brain.