TPA 023

TPA 023 is a GABAA α2/α3 subtype-selective agonist, with K_i of 0.19-0.41 nM. IC50 & Target: Ki: 0.19-0.41 nM (GABAA)^[1] In Vivo: TPA023 displays good receptor occupancy, when administered orally to rats. The dose of TPA023 resulting in 50% occupancy of rat brain GABAA receptors is 0.42 mg/kg, with the corresponding plasma concentration being 25 ng/mL. TPA023 is also efficacious in the mouse pentylenetetrazole-induced seizure model, providing full seizure protection at a dose of 10 mg/kg i.p. (84% occupancy), with the ED₅₀ of 0.19-0.41 nM, for protection against tonic convulsions (1.4 mg/kg i.p.) corresponding to around 50% occupancy. TPA023 (3 mg/kg p.o. in 0.5% methyl cellulose) shows anxiolytic-like effect on rats^[1]. TPA023 (0.7, 2.0, and 5 mg/kg, p.o.) blocks ketamine's cognitive-impairing ability but does not influence the behavioral symptoms of rhesus monkeys^[2].