Antagonism of spontaneous and evoked bursts by 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX) in the CA3 region of the in vitro hippocampus

Superfusion of hippocampal slices with 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX) antagonized kainate-induced bursts and bursts of unknown origin in the CA3 region. CNQX also increased the latency of and eventually blocked evoked bursts which persist following kainate washout. In contrast, d-(−)-2-amino-7-phosphonoheptanoic acid did not alter burst latency or block bursts unless applied subsequent to CNQX. We conclude that the quisqualate type receptor has a prominent role in burst generation with a smaller contribution from N-methyl- d-aspartate receptors.