Study of mitochondrion and nucleus damage and caspase-3 expression in hippocampal CA_3 neurons of kainic acid induced epileptic rats

Objective To observe the mitochondrion and nucleus ultrastructural damage and caspase-3 expression in hippocampal CA_3 neurons during kainic acid(KA) induced status epilepticus(SE) in rats.Methods SE was induced for 2 h with KA in adult male Wistar rats.3,12 and 24 h later the rats were killed and the hippocampal CA_3 subareas were taken out to make brain sections.The neuronal damage on the whole with light microscope and the ultrastructure of mitochondrion and nucleus with electron microscope.Caspase-3 expression of the same area was examined with immunohistochemical staining.Results 24 h after SE,by the light microscope examination,the KA group showed that the neurons put scattered disorder and nucleus shrink firmly.3 h after SE,electron microscope examination showed swelling cristae and ruptured membrane of mitochondria.The change of nucleus were significant margination of chromatin 24 h after SE.Compared to normal control group,the caspase-3 expression increased 12 h after SE,the average number of positive cell and the gray scale were obviously higher(all(P)0.05);24 h after SE,the results were more noticeable(all(P)0.01).Conclusion The ultrastructural damage of mitochondrion occurs in the early period after SE in rats,which may be critical in neuronal damage.