EFFECTS OF LISURIDE AND LSD ON CEREBRAL MONO-AMINE SYSTEMS AND HALLUCINOSIS

THE levels and turnover of 5-hydroxytryptamine (5-HT), noradrenaline (NA) and dopamine (DA) suggest that monoaminergic neurones (particularly serotoninergic ones) and their postsynaptic receptors are the main targets of LSD action in man and animals1-4. Because this evidence still seems inconclusive4, we have compared here the effects of LSD with those of lisuride on the biochemistry of brain amines in the rat. Lisuride is an ergot derivative recently introduced for the treatment of migraine, and in oral doses of up to 600 μg, is without hallucinogenic properties in man5. This lack of psychotomimetic effect is unlikely to be due to poor bioavailability after oral administration, because, at least in the rat, oral lisuride was even more effective than after intraperitoneal injection in altering monoamine turnover6. In addition, we have studied the effects of LSD and lisuride after intracerebral injection into the raphe nuclei. The present findings do not support the hypothesis that the hallucinogenic effect of LSD is reflected by variations in the level and turnover of the brain amines. In particular, a stimulation of 5-HT autoreceptors is also evident after the non-hallucinogenic lisuride. © 1978 Nature Publishing Group.