L-655,708

L-655,708 is a ligand for a5 subunit-containing GABAA receptors that has nootropic activity.{56024} It selectively binds to a5 subunit-containing GABAA receptors over a1, a2, or a3 subunit-containing receptors (Kis = 1, 70, 48, and 31 nM, respectively, for recombinant human receptors). L-655,708 (10 nM) increases the amplitude of extracellular post-synaptic potentials (EPSPs) in mouse hippocampal slices. In vivo, L-655,708 (1.5 mg/animal) decreases the latency to find the platform and increases time spent in the target quadrant in the Morris water maze in mice.