GABAA receptor inverse agonist selective for the α5-subtype (EC50 = 3 nM). Exhibits affinity at benzodiazepine binding site of recombinant human GABAA receptors (Ki values are 0.77 nM, 0.83 nM, 0.85 nM and 1.4 nM for α3-, α1-, α2-, and α5-containing respectively). Increases long-term potentiation (LTP) in mouse hippocampal slices. Exhibits no anxiogenic or proconvulsant activity.