GLUTATHIONE-INDUCED SODIUM CURRENTS IN NEOCORTEX

THE present report demonstrates that glutathione (GSH), a tripeptide c omposed of glutamate, glycine and cysteine (gamma-L-glutamyl-L-cystein yl-glycine) and best known as a free radical scavenger, elicits a larg e, fast depolarizing potential when applied to cortical slices. This p otential is maximally larger than that produced by either NMDA or AMPA . Like AMPA, the GSH current appears to be carried by sodium ions, but cannot be blocked by the glutamate receptor antagonists AP5 or DNQX. In addition, removal of external calcium or blockade of potassium curr ents by TEA does not diminish the GSH-induced potential. Together, the se results suggest that GSH acts through its own receptor-mediated cha nnels, independently of the known EAA receptors, and that its receptor s may be a key, and previously unknown, component of cortical excitato ry neurotransmission.