Typical and atypical neuroleptics are potent antagonists at alpha 1-adrenoceptors of the dorsal lateral geniculate nucleus. An electrophysiological study.

The present electrophysiology studies examined the actions of neuroleptics at central alpha 1-adrenoceptors in the rat. In single-cell recording experiments, typical and atypical neuroleptics, when administered systemically or locally (iontophoresis and pressure ejection), were found to be potent antagonists of activating alpha 1-adrenoceptor responses in the dorsal lateral geniculate nucleus (dLGN). Doses of neuroleptics effective as antagonists at alpha 1-adrenoceptors had very weak effects at muscarinic receptors in the dLGN. Since doses of neuroleptics employed in the present study were within the clinical range, it appears likely that central alpha 1-adrenoceptors would be blocked during a neuroleptic therapy in humans.