Electrophysiological pharmacology of the autoreceptor-mediated responses of dopaminergic cells to antiparkinsonian drugs

It is generally accepted that the dopamine receptor ligands currently used in the treatment of parkinsonian symptoms mainly stimulate dopamine (DA) receptors of the D2 family to produce beneficial effects. Although several animal models can provide useful indications on the activity of the antiparkinsonian drugs in the brain, the specific cellular sites and the mechanism of action of these therapeutic agents are not completely known. In this article, Nicola Mercuri, Antonello Bonci and Giorgio Bernardi suggest that the electrophysiological effects of antiparkinsonian drugs on nigral dopaminergic cells are related to their clinical efficacy. In addition, they report that the stimulation of the D2 'autoreceptors' located on the residual dopamine-containing cells is implicated in the therapeutic response elicited by dopamine receptor agonists in parkinsonism. Thus, an electrophysiological approach, which can give basic information regarding the actions of direct and indirect DA receptor agonists on the dopaminergic neurones, might be relevant for the evolution of the pharmacological strategies in Parkinson's disease.