Sodium valproate enhances responses to GABA receptor activation only at high concentrations

Sodium valproate (VPA) enhanced muscimol-induced depolarizations of rat cuneate afferent fibres, but only at millimolar concentrations. VPA (10 mM) also reduced the potency of picrotoxin as an antagonist of muscimol without affecting that of bicuculline. These findings are discussed in relation to the anticonvulsant properties and potency of VPA.