Representative data for single channel recordings from outside-out patches. A, B, C. Unitary currents recorded at −80 mV are shown on compressed and expanded scale for (A) GluN1/GluN2AC1/GluN2AC2, (B) GluN1/GluN2CC1/GluN2CC2, and (C) GluN1/GluN2AC1/GluN2CC2. Openings of diheteromeric GluN1/GluN2AC1/GluNAC2 and triheteromeric GluN1/GluN2AC1/GluN2CC2 NMDARs channels are clustered into bursts, separated by inactive periods. By contrast, openings of diheteromeric GluN1/GluN2CC1/GluN2CC2 NMDARs show no burst structure. D. Representative open duration histogram from a one channel outside-out patch for GluN1/GluN2AC1/GluN2AC2 (31,655 events), GluN1/GluN2CC1/GluN2CC2 (3,004 events), and GluN1/GluN2AC1/GluN2CC2 (2,737 events) NMDARs fitted by three exponential components. Representative shut duration histograms from GluN1/GluN2AC1/GluN2AC2, GluN1/GluN2CC1/GluN2CC2, and GluN1/GluN2AC1/GluN2CC2 NMDARs from single patch recordings fitted with six exponential components.