AIM and METHODS: To observe the effects of glucose-free and Mg 2+ -free in the extracellular fluid on the changes of [Ca 2+ ] i in the cerebro-cortical neurons damaged by 1 mmol/L glutamate using laser confocal scanning microscope. RESULTS: Both frequency and amplitude of neuronal calcium oscillation induced by glutamate were lowered in glucose-free and Mg 2+ -free buffers. The basic [Ca 2+ ] i concentration was lowered in the former case , but it was elevated in the latter case. CONCLUSION: Mg 2+ -free aggravates [Ca 2+ ] i overload induced by 1 mmol/L glutamate ,under certain conditions the glucose-free might resist damage role of glutamate and Mg 2+ -free.

AIM: The purpose of the present study was to detect intracellular Ca 2+ changes in living brain slices during focal cerebral ischemia/reperfusion (I/R) and reveal the role of intracellular Ca 2+ in the cerebral I/R injury. METHODS: The model of focal cerebral I/R was established in rats by reversible inserting a nylon thread, and dynamic change of intracellular Ca 2+ in brain slices was determined using laser confocal imaging system. RESULTS: ① Ca 2+ gradually enhanced with increase in ischemic time in cortex and striatum. ②At 1 h ischemia/ 10 min reperfusion, Ca 2+ increased significantly in striatum, but Ca 2+ decreased at 3 h reperfusion compared with 10 min reperfusion. ③ Ca 2+ markedly enhanced at 6 h ischemia compared with 1 h ischemia, and after 3 h reperfusion Ca 2+ decreased, but was still higher than that in sham-operation group. ④The striatum is more sensitive than cortex to ischemia/reperfusion. CONCLUSION: Ca 2+ overload in the area of cortex and striatum may play an important role in cerebral ischemia/reperfusion injury in rats.