Early explorations of spider and scorpion venoms provided clues for the discovery of new classes of compounds, including delucemine, that act as neuroprotectants in animal models of stroke. This compound targets open NMDA receptor-operated calcium channels and blocks the channel. By blocking these channels, which open in response to the neurotransmitter glutamate, delucemine prevents excessive calcium influx during ischemia. This stabilizes cell chemistry and minimizes cell death. Delucemine attenuated short-term cognitive deficits and histopathological changes associated with traumatic brain injury. Delucemine improved measures of brain tissue edema and ion homeostasis.