Abstract

The neuropharmacology of 2,5-dimethoxy-4-methylamphetamine (DOM) was examined. A single 8 mg/kg dose of DOM elicits electroencephalogram hypersynchrony and elevates reticular formation multiple unit activity. A second dose, 24 hours later, is without effect. The behavioral effects of a single dose of DOM are antagonized by methysergide, brom-lysergic acid diethylamide (brom-LSD), chlorpromazine and tripelennamine, but not by reserpine, α-methyl-p-tyrosine, p-chlorophenylalanine, phenoxybenzarnine, propranolol, atropine and diphenhydramine. Cyproheptadine was weakly antagonistic. Methysergide and brom-LSD induced intermittent hypersynchrony in the electroencephalogram and prevented the continuous hypersynchrony induced by DOM. DOM caused an increase in medullary norepinephrine and a slight increase of serotonin in the diencephalon and cerebral hemispheres. A second dose of DOM again increased the medullary norepinephrine but reduced diencephalic serotomn. DOM induces hypersynchrony and behavioral changes similar to those induced by perception distorting psychotomimetic drugs such as LSD and mescaline. It does not induce the electroencephalogram desynchronization or stereotyped behavior previously described for amphetamine. DOM appears to act on postsynaptic serotonin receptors.