Fig. 5.

NMDA receptor activation contributes to unitary EPSPs in human but not in mouse connections. a) Example average traces for a pyramidal-to-pyramidal connection in L2/L3 human MTG. Pre: presynaptic neuron; post: postsynaptic neuron. Control EPSP in black (aCSF), EPSP after application of NMDA receptor blocker AP5 (50 μM) in gray. The depolarization blocked by AP5 is labeled “blocked” and generated by subtracting the AP5 EPSP from the aCSF EPSP. b) Single sweep amplitude during aCSF (black) and AP5 (gray) conditions for the example connection from I1 (P < 0.05, Mann–Whitney test). c) In human, 4 out of 7 connections showed a significant reduction of EPSP amplitude upon AP5 application and in mouse, 1 out of 4 connections, respectively. d) Effect of AP5 on EPSP amplitude (left) and decay (right) in mouse. e) Effect of AP5 on EPSP amplitude (left, n = 7, P < 0.05, Wilcoxon, signed-rank test) and EPSP decay (right, n = 7, P < 0.05, Wilcoxon, signed-rank test) for human unitary connections. # Denotes example from Fig. 5a and b. Note that AP5 has inconsistent effect on mouse EPSP amplitude and decay (n = 4) but consistently reduces EPSP amplitude and decay kinetics for individual human unitary connections (n = 7).