PRAZOSIN SELECTIVELY ANTAGONIZES NEURONAL RESPONSES MEDIATED BY ALPHA-1-ADRENOCEPTORS IN BRAIN

The ability of systemically and locally administered prazosin, an antihypertensive, to block .alpha.1-adrenoceptors was examined in 2 brain areas in the rat. Using single unit recording of neurons in the lateral geniculate and dorsal raphe nuclei, evidence was obtained for the selective blockade of .alpha.1-adrenoceptors by both i.v. and iontophoretic prazosin. Since effective systemic doses of prazosin were within the clinical range, brain .alpha.1-adrenoceptors may be blocked during prazosin therapy in humans.