Cells were cotransfected with equivalent amounts of cDNA encoding for the a1, g2S, and one of the b3-v2, b3-v2(P11S), b3-v2(S15F), or b3-v2(G32R) subunits. Saturating concentrations of GABA (1 mM) were applied to positively transfected cells for 4 s.