Effects of allylglycine on photosensitivity in the lateral geniculate-kindled cat.

The effects of DL-allylglycine, an inhibitor of GABA synthesis, on the responses to photic stimulation were studied in the cat kindled in the lateral geniculate body (GL). For 3 to 8 h after the injection of DL-allylglycine at a subconvulsant dose (30 or 40 mg/kg, i.v.), the kindled cat showed a stable level of photosensitivity without any toxic effects and responded with various degrees of myoclonus or a generalized tonic-clonic convulsion when photic stimulation was repeated at hourly intervals. The incidence of photically induced myoclonus reached its plateau during this period. Our results suggest that photosensitivity of the lateral geniculate-kindled cat is related to the modification of GABAergic mechanisms, and that when the GL-kindled cat is pretreated with DL-allylglycine it is a reliable model of photosensitive epilepsy.