AMPA-KA or NMDA receptor antagonists blocked paroxysmal responses. a, b, Slices showing paroxysmal activity under aCSF (CON) were perfused with 30 μm of CNQX to block the AMPA-KA receptors. The abolition of late paroxysmal events (middle trace and black bars) and the significant reduction of early potentials (white bars) are shown by measuring the integral of the maximal response. This effect was partially reversible. c, d, NMDA receptors were blocked by APV (30 μm). Although early PSPs were not affected, late paroxysmal activity was significantly reduced. This effect was fully reversible. ^*p < 0.05 (in comparison to control values).