Figure 2.

AM251 affects GABA_A receptor currents. (A) Low concentrations of AM251 strongly potentiate currents mediated by recombinant α₁β₂γ₂ GABA_A receptors. Currents were measured in Xenopus oocytes expressing recombinant receptors. Two applications of 0.5 µM GABA were followed by a combined application of the same concentration of GABA with 0.3 µM AM251. (B) Concentration-response curves of the potentiation by AM251 and by rimonabant. Either no AM251 or increasing concentrations of AM251 or rimonabant were co-applied with 0.5 µM GABA. Individual curves were first normalized to the observed maximal current amplitude and subsequently averaged. Mean ± SEM of experiments carried out with four oocytes from two batches of oocytes are shown.