Figure 3. Effect of hUII on different GABA_AR subunit combinations.

(A) Typical Iso-evoked currents at the holding potential of −60 mV, in the whole-cell configuration, on CHO stably expressing human UT (CHO-UT) and transiently transfected with cDNAs encoding α₂β₃γ₂, α₂β₁γ₂, α₂β₃γ₁, α₂β₁γ₁, β₃γ₂, β₁γ₂, α₂β₃ or α₂β₁ subunits of the GABA_AR. Iso (10⁻⁴ M) was repeatedly applied for 2 s at 2 min intervals and increasing concentrations of hUII (10⁻¹³ to 10⁻⁷ M) were bath perfused in the vicinity of cells. (B) Corresponding concentration-response curves for hUII on α₂β₁γ₂ and α₂β₃γ₂, α₂β₁γ₁ and α₂β₃γ₁, β₁γ₂ and β₃γ₂, α₂β₁ and α₂β₃ receptor subunits. Data are normalized to the control Iso response immediately prior to lower hUII concentration application. Data are mean ± SEM of 3 to 23 cells.