Excitotoxic injury mediated by glutamate or related compounds contributes to central neuronal death in several human pathological conditions, such as after food ingestion, hypoxia-ischemia, trauma, or prolonged seizures.'4 Whether excitotoxicity also contributes to neuronal loss in certain neurodegenerative disorders, such as Alzheimer's disease, Huntington's disease, or motor neuron disease, is unknown, but is the subject of current inquiry. In any case, the mission of gaining insight into the basis of Alzheimer's disease is served by elucidating the mechanisms underlying excitotoxic neuronal death, because excitotoxic death may converge, that is, share common aspects with other forms of neuronal death. Thus, even if excitotoxicity has no direct involvement in Alzheimer's disease, its elucidation may lead to useful insights into the nature of other pathological neuronal deaths and aid the development of possible therapeutic approaches.