Potent, selective inverse agonist for the benzodiazepine site of GABA A receptors containing the α 5 subunit (K i = 0.45 nM). Displays 50-100-fold selectivity over GABA A receptors containing α 1, α 2, α 3 or α 6 subunits in combination with β 3 and γ 2. Enhances LTP in? a mouse hippocampal slice model and increases spatial learning, without displaying proconvulsant activity.