Fig 3. Functional properties of clobazam, N-desmethylclobazam and clonazepam at four human GABA_ARs expressed in Xenopus oocytes.

(A) Representative traces for various concentrations of clobazam (top), N-desmethylclobazam (middle) and clonazepam (bottom) co-applied with GABA EC₂₀ to oocytes expressing the α₅β₂γ_2S GABA_AR. The black bars represent applications of GABA EC₂₀ and of 3 mM GABA that elicits maximal current through the receptor. The grey bars represent applications of various concentrations of clobazam, N-desmethylclobazam or clonazepam (a 30 s pre-incubation with the compound followed by co-application of the compound and GABA EC₂₀). (B) Concentration-response relationships for clobazam (top), N-desmethylclobazam (middle) and clonazepam (bottom) at α₁β₂γ_2S, α₂β₂γ_2S, α₃β₂γ_2S and α₅β₂γ_2S GABA_ARs in the presence of GABA EC₂₀ (means ± S.E.M.; N = 2–6).