Inhibition of calcium-permeable and calcium-impermeable AMPA receptors by perampanel in rat brain neurons

Perampanel is an antiepileptic drug that is used to treat partial -onset seizures and generalized tonicclonic seizures. It is a highly selective AMPA receptor allosteric antagonist. However, published data on perampanel activity vary in different studies. In the present work we studied the inhibition of native calcium -permeable and calcium-impermeable AMPA receptors in rat brain neurons by perampanel using whole-cell patch clamp technique. We found that inhibitory activity and kinetics of perampanel action do not differ between calcium-permeable AMPA receptors of rat giant striatum interneurons and calcium-impermeable receptors of hippocampal CA1 pyramidal neurons (the IC50 value about 60 nM). Also, perampanel caused the same inhibition of steady-state currents induced by kainate and glutamate. From the other side perampanel-induced inhibition was markedly reduced in the presence of cyclothiazide (IC50 value increased to 1.2 +/- 0.2 mu M). We demonstrated that perampanel competes with GYKI-52466 for binding site. (C) 2016 Elsevier Ireland Ltd. All rights reserved.