Potassium channel activators abolish excitotoxicity in cultured hippocampal pyramidal neurons

Abstract

When hippocampal pyramidal neurons are grown in culture they develop excitatory synaptic contacts. If these cultures are perfused with Mg2(+)-free, glycine supplemented medium the neurons exhibit fluctuations in [Ca2+]i and associated cell death ('excitotoxicity'). These phenomena involve the activation of NMDA receptors. When cultures are treated with the K(+)-channel activators cromakalim and diazoxide both the [Ca2+]i fluctuations and the neuronal death are abolished. These effects are reversed by the sulfonylurea glyburide. It thus appears that K(+)-channel activators may be a novel therapeutic intervention in epilepsy and associated disorders.