Behavioral and electroencephalographic effects of a serotonin receptor agonist (5-methoxy-N,N-dimethyltryptamine) in a feline model of photosensitive epilepsy.

The effects of a serotonin (5-HT) receptor agonist, 5-methoxy-N,N-dimethyltryptamine (5-MeODMT), on epileptic photosensitivity were studied in the lateral geniculate-kindled cat. 5-MeODMT at 4 mg/kg significantly suppressed photically induced myoclonus, but not paroxysmal EEG activity, at 0.5-1 h after injection. This antiepileptic effect was seen in association with the appearance of behavioral signs similar to those seen in the 5-HT syndrome. The present data provide further evidence that 5-HT plays an important role in photosensitive epilepsy, and suggest that the inhibitory effect of 5-MeODMT on photosensitivity results from its agonist action at 5-HT1 receptors.