Figure 4.

Subunit dependence and sensitivity to Ro15-1788 and to a point mutation of the potentiation by AM251. Currents were measured in Xenopus oocytes expressing recombinant α₁β₂, α₁β₂γ₂, α₂β₂γ₂, α₃β₂γ₂, α₅β₂γ₂, α₆β₂γ₂, α₁β₁γ₂, α₁β₃γ₂ and α₄β₂δ GABA_A receptors. Two applications of 0.5 µM GABA were followed by a combined application of the same concentration of GABA with 3 µM AM251. Mean ± SEM of experiments carried out with at least four oocytes are shown. Potentiation by 0.5 µM AM251 was tested as above and subsequently we tried to counteract potentiation by 1 µM Ro15-1788. Potentiation by 3 µM AM251 was also tested in point mutated α₁β₂N265Sγ₂ receptors.