Fig. 2.

Whole-cell recording of spontaneous NMDA receptor channels in mature wild-type granule cells. A, Representative records of spontaneous NMDA receptor-mediated currents in a mature wild-type mouse granule cell. Two channel opening events with distinct unitary conductance and gating kinetics are clearly resolvable. B, Dwell-time distribution of open times with the fit of a double exponential (solid line) superimposed.C, Amplitude–frequency histogram with the fit of a double Gaussian distribution superimposed. Both conductances have extrapolated reversal potentials near 0 mV (D) and have corresponding conductances of 42 and 31 pS. All data were recorded in the same granule cell voltage-clamped at −60 mV in the absence of extracellular Mg²⁺.