Anticonvulsant action of diazepam: increase of cortical postsynaptic inhibition.

The action of intravenously administered diazepam (Valium) on postsynaptic inhibition was studied in cat motor cortex. The efficacy of postsynaptic inhibition of pyramidal tract cells was measured as the ability to suppress action potential generation. Diazepam increased the suppression of action potentials by inhibition. This effect may explain the anticonvulsant action of diazepam.