Inhibition of [3H]α -amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid [AMPA] binding by the anticonvulsant valproate in clinically relevant concentrations : an autoradiographic investigation in human hippocampus

Abstract The interaction of the anticonvulsant valproate with AMPA glutamate receptors in human post mortem hippocampus was investigated. At concentrations of ≥100 μ M valproate decreased binding of 40 nM [ 3 H]AMPA to 45±56% of control level (CA 1). Clinically effective brain concentrations for valproate are estimated at 100–200 μ M. Our results thus provide evidence that the anticonvulsant effects of valproate may partially be caused by interaction with AMPA receptors.