N-Methyl-DL-Aspartic Acid (NMDLA) represents a racemic mixture of D and L enantiomers (NMDA; NMLA). Each enantiomer has different biological activities and different natural tissue/species abundances. Therefore, each enantiomer should be considered separately. NMDA is a widely studied neurotoxin which is an agonist of the NMDA receptor and induces brain legions. NMDA is not normally found in tissues, while NMLA can be found naturally in some bivalves.