CHANGES OF INTRACELLULAR FREE CALCIUM IN CULTURED HIPPOCAMPAL-NEURONSDEPRIVED OF OXYGEN AND GLUCOSE

Dynamic of intracellular free calcium ([Ca2+]i) d in cultured mouse em bryonal hippocampal neurons deprived of oxygen and glucose has been mo nitored using the fluorescent calcium indicator fura-2 A/AM. Our exper iments have shown that oxygen and glucose deprivation of nerve cells c ause a rapid increase in [Ca2+]i which can by effectively prevented by noncompetitive (Mg2+) or competitive (D, L-2-amino-5-phosphonovalerat e) N-methyl-D-aspartate (NMDA) receptor/channel antagonists. These res ults strongly indicate that endogenous glutamate excessively released and accumulated in synaptic clefts under hypoxic/ischemic conditions m ay play a key role in the [Ca2+]i elevation underlying a delayed neuro nal death.