Fig. 3.
α-Bgtx inhibition at GABAARs expressed in HEK293 cells. A, GABA concentration response curves for α1β2γ2, α2β2γ2, α4β2γ2, and α5β2γ2 receptors expressed in HEK-293 cells. B, GABA current profiles for α4β2γ2 receptors in response to 3 μM GABA, and +20 μM α-Bgtx (with or without pre-application for 1 min). Inserts show expanded current profiles. C, Representative whole-cell GABA-activated currents in response to submaximal concentrations of GABA in the absence (left-panels) or presence of 1, 5 and 20 μM α-Bgtx (pre-applied for 1 min) for cells expressing α1β2γ2, α2β2γ2, α4β2γ2 and α5β2γ2 receptors. D, Inhibition of GABA-activated currents by α-Bgtx. GABA concentrations are 6 μM (α1β2γ2), and 3 μM (α2β2γ2, α4β2γ2, and α5β2γ2). Lines are drawn (n = 3). E, Inhibition at receptors by 1 and 5 μM α-Bgtx. With 5 μM α-Bgtx, the inhibition observed at α2β2γ2 was statistically significant compared to α1β2γ2 (**P < 0.01), and α4β2γ2 and α5β2γ2 (*P < 0.05) receptors, n = 3, One-way ANOVA. F, Representative whole-cell GABA-activated currents in response to maximal concentration of GABA (1 mM) in the presence of 5 μM α-Bgtx and after recovery from inhibition.