The vitamin E analog, trolox, protected cultured cortical neurons against damage induced by exposure to either iron ions or ultraviolet (UV) light, consistent with an ability to inhibit free radical-mediated cytotoxicity. Trolox also reduced neuronal death induced by 24 h exposure to alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA), but not that induced by N-methyl-D-aspartate (NMDA). When combined with the NMDA receptor antagonist dextrorphan, trolox also reduced the neuronal injury induced by glucose deprivation.