Cyanide induces Ca2+-dependent and -independent release of glutamate from mouse brain slices

Abstract The effect of cyanide-induced histotoxic hypoxia on endogenous glutamate release from mouse cortical, cerebellar and hippocampal slices was studied. Incubation of slices with cyanide over a 30 min period resulted in extracellular accumulation of glutamate which was decreased in the absence of Ca 2+ in the incubation media. When glutamate release was continuously monitored by fluorometry, cyanide initiated a rapid release of glutamate. This initital release was found to be independent of extracellular calcium. Depolarizing concentrations of potassium chloride produced a predominantly Ca 2+ -dependent release. It is concluded that cyanide exposure induced a rapid release of endogenous glutamate mediated by both Ca 2+ -dependent and Ca 2+ -independent mechanisms.