PHENYTOIN PROTECTED MOUSE CORTICAL CELL-CULTURES AGAINST NEUROTOXICITY INDUCED BY KAINATE BUT NOT BY NMDA

Phenytoin (PHT) protected cultured mouse cortex neurons against kainat e-induced excitotoxicity, but failed to protect against the N-methyl-D -aspartate (NMDA)-induced excitotoxicity. The voltage-clamp experiment s showed that PHT significantly blocked kainate-induced currents but d id not block NMDA-induced currents in the cultured neurons. These resu lts indicate that PHT protects the cultures by blocking non-NMDA recep tors and suggest that PHT has clinical efficacy against neuronal cell death through the excessive stimulation of non-NMDA receptors.