Intracellular free calcium increases in cultured cortical neurons deprived of oxygen and glucose.

Dissociated neocortical cultures from fetal mice exposed transiently to a medium lacking both glucose and oxygen developed neuronal degeneration without glial degeneration. We have found that this injury depends on extracellular calcium and is associated with uptake of calcium from the culture medium. We measured free cytoplasmic calcium in individual neurons using the fluorescent calcium indicator fluo-3 and provide evidence that oxygen and glucose deprivation injury increases the intracellular calcium signal. Both intracellular calcium elevation and subsequent neuronal loss could be blocked by the N-methyl-D-aspartate receptor antagonist dextrorphan.