Self-Inhibition by Dopaminergic Neurons An alternative to the “neuronal feedback loop” hypothesis for the mode of action of certain psychotropic drugs

The mechanisms of action of amphetamine and the antipsychotic drugs have been the subject of intense empirical and theoretical interest for a number of years. Amphetamine appears to act, in large measure, by promoting the release of catecholamines from central and peripheral ncrvc cndings and blocking their reuptake across the presynaptic membrane (1, 2). Antipsychotic drugs such as the phenothiazines and butyrophenones are currently believed to act in part by blocking catecholaminergic transmission; especially synaptic transmission in dopaminergic pathways in the central nervous system (3-5). These findings support the view that alterations in catecholaminergic transmission in the central nervous system may be significant in drug-induced or idiopathic psychotic disorders (6, 7).