Acute blockade of dopamine receptors with haloperidol: a retinal model to study impairments of dopaminergic transmission.

A pulse of dopamine produces a transient dose-correlated increase in the transepithelial potential (TEP) of the chicken eye, mimicking the light-induced response, the light peak (LP). Acute blockade of retinal dopaminergic transmission with haloperidol, a mixed antagonist, produced a dose-correlated TEP voltage decrease which was rapidly reversed by intravitreal injection of dopamine. The LP recorded thereafter was strongly reduced. These data confirm the hypothesis that dopamine released by light from amacrine cells triggers light-induced changes in the TEP of the intact chicken eye, and that these potentials could well provide an electrophysiological tool to evaluate retinal dopaminergic deficiency.