Fig. 7.

Concentration–response curves for I_GABA enhancement by a kushenol I (EC₅₀ = 5.0 ± 2.3 μM, n_H = 1.3 ± 0.3, n = 5); b (–)-kurarinone (EC₅₀ = 8.1±1.4 μM, n_H = 1.9±0.1, n = 4); c sophoraflavanone G (EC₅₀ = 15.0±3.6 μM, n_H = 1.5±0.2, n = 3); and d kuraridine (EC₅₀ = 4.0±2.4 μM, n_H = 0.9±0.1) in Xenopus oocytes expressing GABA_A receptors composed of α₁,β₂, and γ_2S subunits. A maximum potentiation of I_GABA by kushenol I (a, 267.6 ± 56.6%, n = 5), (–)-kurarinone (b, 578.5 ± 68.8%, n = 4), sophoraflavanone G (c, 604.9 ± 108.2%, n = 3), kuraridine (d, 891.5 ± 163.0%, n = 3) was observed. e Representative currents through α₁β₂γ_2S GABA_A receptors in the presence of GABA (EC_3–10, single bar, control) and currents recorded during co-application of GABA (EC_3–10) and 0.001, 0.01, 0.1, 1, 10, and 100 μM of kuraridine (double bar)