Temporal kinetics of calcium in neocortical neuronal nuclei after global cerebral ischemia and reperfusion. An ultrastructural study.

: New facts about control of nuclear milieu were recently described. Because calcium is known as an important cellular regulator we designed this study to describe temporal calcium kinetics in neuronal nuclei in canine neocortex after ischemia-reperfusion injury. Seven-minute global cerebral ischemia was followed by reperfusion phase lasting from 0 to 24 hours. Ultrastructural histopathology of brain tissue was assessed both qualitatively and semi quantitatively using scoring system. For electron microscopic calcium detection pyroantimonate histochemistry was used. Significant increases in calcium-pyroantimonate deposits were noted in reperfusion time 0, 8 and 24 hours. Reperfusion time 30 minutes showed lower load of calcium deposits than control, this, however, did not reach statistical significance. In conclusion we have found biphasic pattern of nuclear sequestration of calcium in neocortical neurons, which is in agreement with phasic changes of calcium content in other neuronal compartments.