Fig. 1.
External pH modulates the GABA concentration–response relationships. For α1β1 (A) and α1β2 (B) GABAA receptors, peak amplitude responses were measured at pH 7.4 (○) and pH 5.4 (▪) and were normalized to the responses induced by 10 μm GABA at pH 7.4 (= 1). In this and comparable figures, the curves were generated according to Equations 1and/or 2, presented in Materials and Methods. All points in this and comparable figures represent the mean ± SEM fromn = 3–5 cells. The insetsillustrate sample GABA-activated currents induced by 10 μm GABA applied for the duration of the solid line at the indicated external pH. Calibration: 200 pA, 2 sec.