Afizagabar (S44819) is a first-in-class, competitive, and selective antagonist at the GABA-binding site of the α5-GABAAR, with an IC50 of 585 nM for α5β2γ2 and a Ki of 66 nM for α5β3γ2. Afizagabar enhances hippocampal synaptic plasticity and exhibits pro-cognitive efficacy[1]. Afizagabar (S44819) is a competitive α5-GABAAR antagonist (Kb=221 nM). Afizagabar selectively inhibits extrasynaptic α5-GABAARs of mouse CA1 pyramidal neurons[1]. Afizagabar (1 and 3 mg kg; i.p.) significantly diminishes the marked increase in total errors induced by Scopolamine[1]. [1]. Etherington LA, et al. Selective inhibition of extra-synaptic α5-GABAA receptors by S44819, a new therapeutic agent. Neuropharmacology. 2017;125:353-364.