ABSTRACT
Gerbils were sacrificed at 12 hours,1,2,4 and 7 days after a 20 minute occlusion of both carotid arteries.The morphological changes of the dorsal hippocampus were observed at varying times of recirculation.Under a light microscope,the histopathologis changes of the hippocampus were observed in several subfields.The neurons in CA_1 sector were particularly sensitive to ischemia.The changes in the CAl subfield were very slow,and almost all of the pyramidal cells in the CAl sector were destroyed and disappeared after a 4 day recirculation. The CAl subfield was selected for electron microscopy,and an increase in the cisterns of the endoplasmic reticulum was observed after the 1-2 day recirculation.The results suggest that the hippocampal damage in CAl sector after transient cerbral ischemia is different from the neuronal damage of the other parts of the brain.Delayed neuronal death and selective vulnerability were the main characteristics.