Potent positive allosteric modulator of GABA A receptors. Enhances GABA-evoked chloride currents in Xenopus oocytes expressing GABA A receptors (EC 50 values are 94, 122 and 213 nM for α 2 β 1 γ 2 L , α 3 β 1 γ 2 L and α 1 β 1 γ 2 L receptors respectively). Exerts anticonvulsive effects in a broad range of animal seizure models.