Fig. 1: Multilevel conductance at low and high Glu concentrations.

a, Superposition of typical whole-cell currents recorded at –60 mV membrane potential from a HEK-293T cell expressing GluA2–γ2 in response to 1-s applications of Glu at different concentrations in the continuous presence of 100 µM CTZ. b, Dose–response curve for Glu measured for the amplitude of currents illustrated in a and normalized to their maximal value. The red line illustrates a logistic equation fit with the half maximal effective concentration value of 65 ± 5 µM (n = 7). Data are presented as the mean ± s.e.m. c, d, Representative single-channel currents recorded at –60 mV membrane potential from GluA2–γ2 reconstituted into lipid bilayers in the presence of 100 µM CTZ and 20 µM (c) or 10 mM (d) Glu. Horizontal dashed lines indicate different conductance levels. The conductance level of the closed channel is labelled (c). e, Relative occupancy of conductance levels at 20 µM and 10 mM of Glu averaged over n = 14 (n = 12 for O4 as O4 was not observed in some experiments) and n = 10 (n = 7 for O4) independent experiments illustrated in c and d, respectively, with the mean conductance of 8.2 pS for O1, 18.8 pS for O2, 27.0 pS for O3 and 37.0 pS for O4. Data are presented as the mean ± s.d.