a5IA is a nootropic drug invented in 2004 by a team working for Merck, Sharp and Dohme, which acts as a subtype-selective inverse agonist at the benzodiazepine binding site on the GABAA receptor.
Gaboxadol hydrochloride (Lu 02-030 hydrochloride) is a selective agonist at GABAA receptors that contain α4-δ subunits, and has anxiolytic and sedative effects.