Detection of calcium and aluminum in pyramidal neurons in the gerbil hippocampal CA1 region following repeated brief cerebral ischemia: X-ray microanalysis

Abstract

To elucidate the interrelationship between delayed neuronal death and calcium accumulation, an X-ray microanalysis technique was used to detect the elemental composition of deposits in mitochondria and nuclei after three 3-min bilateral common carotid arterial occlusion at 1-h intervals. Morphological changes in the CA1 pyramidal neurons were also observed. After 3 days of ischemia-recirculation, damaged mitochondria, electron-dense deposits in mitochondria, and rupture of nuclear membranes were evident. Calcium and aluminum were detected in those electron deposits in the mitochondria and nuclei. These findings support the hypothesis on delayed calcium-related cell death. Accumulation of aluminum in mitochondria and nuclei may be an additional factor involved in delayed neuronal death.