1-Aminocyclopropane-1-carboxylic Acid is a small molecule agonist at the glycine modulatory site of the NMDA receptor. Described to mimic the effects of glycine at the NMDA_R, 1-Aminocyclopropane-1-carboxylic Acid competitively inhibits binding of [³H]glycine and enhances the binding of [³H]MK-801 to NMDA_R-coupled cation channels similarly to glycine (though with less efficacy). 1-Aminocyclopropane-1-carboxylic Acid is shown to block convulsions and death produced by NMDA exposure, significantly reducing seizure induction and cell death of NMDA-treated hippocampal neurons.