CNQX (6-cyano-7-nitroquinoxaline-2,3-dione) is an AMPA and kainate receptor antagonist with IC50 values are 0.3 μM and 1.5 μM for AMPA and kainate receptors, respectively. CNQX is also an antagonist at the glycine modulatory site on the NMDA receptor complex (IC50 = 25 μM). CNQX shows neuroprotective effects in models of ischemia and inhibits seizure-like activity in hippocampal neurons.