Figure 4.
Block of NMDA receptor-mediated responses by MK-801 is faster in neocortex than in hippocampus. (A) Representative examples of NMDA receptor-mediated field potentials in the neocortex (Left) and in the hippocampus (Right) pathways before and after activity-dependent block with MK-801. Slices were bathed in CNQX and 1 mM [Mg2+]o, and recording electrodes contained bicuculline. (B) Percentage change of NMDA receptor-mediated responses to the second stimulus in a pair with respect to the first as a function of interstimulus interval, in the neocortex (n = 3; mean ± SEM). (C) Normalized NMDA receptor-mediated responses (amplitude) in the neocortex (•) and in the hippocampus (○) pathways as single stimuli were delivered at 0.1 Hz in the presence of MK-801 (n = 10 per group; mean ± SEM).