CP 465022 hydrochloride is a potent and selective antagonist of AMPA receptor with IC50 value of 25 nM . The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA receptor) is an ionotropic transmembrane receptor for glutamate and mediates fast synaptic transmission in the central nervous system. AMPA receptors are oligomeric assemblies of four protein subunits, GluR1-4. CP 465022 hydrochloride is a noncompetitive and selective AMPA receptor antagonist. In rat cortical neurons, CP-465022 inhibited currents induced by kainate (100 μM) with IC50 value of 25 nM and completely inhibited at concentration up to 3.2 μM. In hNT human teratocarcinoma cells, CP-465022 inhibited kainate-induced currents with IC50 value of 15 nM, which was mediated by AMPA receptors. In cultured cortical neurons stimulated by kainate, CP-465022 dose-dependently inhibited kainate-induced responses by 54% and 88% at 10 nM and 100 nM, respectively . In HEK cells expressing the Nav1.6 channel, CP465022 dose-dependently inhibited Nav1.6-mediated persistent current. In rats after stimulation of Schaeffer collateral/commissural pathway, CP-465022 reversibly inhibited the evoked population spike amplitude in the CA1 region. In pentylenetetrazole-induced seizure rats, CP-465022 dose-dependently reduced the incidence of tonic seizures, clonic seizures and lethality. CP-465022 inhibited vertical and horizontal locomotor activity with ED50 values of 6.6 and 11.9 mg/kg, respectively .