Fig. 3From: Pathophysiology of and therapeutic options for a GABRA1 variant linked to epileptic encephalopathyThe R214C subunit mutation decreases GABA-evoked currents, without affecting chloride selectivity. a Representative GABA-evoked current traces from WT (Black) or R214C (Red) GABAAR expressing HEK293 cells, in response to fast applications of GABA at indicated concentrations. The cells were held at -60 mV and perfused with GABA at increasing concentrations. GABA application (1 s) is indicated as a black line at the top of the traces. b Quantification of the averaged peak current amplitudes from WT (n = 14) or R214C (n = 14) GABAAR expressing cells at increasing GABA concentrations (10 μM-1 mM). Statistical differences were determined using student’s t-test (**p < 0.01, ***p < 0.001). c Dose-response curves comparing GABA-evoked currents from R214C GABAAR expressing cells to WT GABAAR expressing cells. The peak current amplitude from R214C was normalized to the maximum response (1 mM GABA) from WT. Statistical differences was determined using student’s t-test (**p < 0.01, ***p < 0.001). d Dose-response curves for GABA-evoked currents from WT (n = 14) or R214C (n = 14) GABAAR expressing cells. The peak current amplitude at each GABA concentration for WT or R214C, was normalized to the maximum response (1 mM GABA) from each receptor, respectively. Data from (c) and (d) were fitted to the Hill eq. (e) Quantification of current-voltage (I/V) plots for GABA-evoked currents from of WT (n = 11) or R214C (n = 11) GABAARs. Cells were clamped from -80 mV to + 60 mV with a step of 20 mV. Data is represented as +SEMBack to article page