Lesion of the dorsal raphe nucleus induces supersensitivity to serotonin in isolated cat middle cerebral artery

Abstract

Simultaneous lesions of dorsal adn median raphe nuclei were induced after 15 days postjunctional supersensitivity to serotonin in isolated segments of cat middle cerebral artery. Thesame result was obtained when only the dorsal raphe nucleus was destroyed. The lesion of the median raphe nucleus brought about an increased contractile response to serotonin only at the three first doses used. The contractile response to noradrenaline wa sunaffected by these treatments. These results suggests the existence of a serotonergic innervation of the cat middle cerebral artery whose main origin might be the dorsal raphe nucleus.