N-methyl-D-aspartic acid (NMDA) is a derivative of the amino acid aspartic acid that acts as a specific agonist on the NMDA receptor, and therefore mimics the action of the neurotransmitter glutamate on the receptor.
Unlike glutamate, it binds only to the NMDA receptor, and not to other receptors that use glutamate.
Examples of NMDA receptor inhibitors are APV, ketamine, dextromethorphan and PCP (phencyclidine). Ketamine, dextromethorphan and PCP are used recreationally as dissociative drugs. Usually these substances are designated as NMDA receptor antagonists.
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