Figure 2.

The recovery of EPSCs from irreversible MK-801 block suggests adding of new receptors through lateral diffusion. A, The competitive NMDA blocker AP-5 did not prevent recovery of evoked EPSCs, suggesting that the recovery was not attributable to MK-801 unbinding. After MK-801 was washed out, the averaged EPSC amplitude was measured before and after 10 min AP-5 (100 μm) block. After removal of AP-5, the extent of recovery was even higher than that before AP-5 application. B, Irreversible block of NMDAR-mediated EPSCs by whole-cell coapplication of NMDA and MK-801 after EPSC recovery from MK-801 block suggested that unbinding of receptors with lower affinity for MK-801 was not responsible for the recovery. D, AP-5 was added in the first recovery period to match the protocol used in A, as was previously conducted by Tovar and Westbrook (2002). C, Statistical graph shows partial recovery of EPSCs after synaptic stimulation (Synaptic), postblock application of AP-5 (Ap5 post; measured as the difference of recovery level before and after AP-5 application in A), and coapplication of NMDA and MK-801 after recovery from AP-5 block (Recovery/block).