Phenytoin protected mouse cortical cell cultures against neurotoxicity induced by kainate but not by NMDA

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