ABSTRACT
20 gerbils were subjected to ischemia for 20 minutes by bilateral occlusion of the common carotid arteries.The animals survived for 1 week or 1 month. By means of tile fast frozen section and stained with crystal violet, in many of the gerbils delayed neuronal deathin the CA1 pyramidal cells were found, while in 8 gerbils no clear ishemic changes were found under a light microscope. In order to clarify ischemic changes still further,the CA1 of Hipp was examined under the electron microscpe and many pathological changes were observed. The cytoplasm of the pyramidal cells was filled with stacks of rough endoplasmic reticulum(RER)and many granules were disconnected from RER. Cisternae of the Golgi apparatus showed reactive products. Lipofuscin granules increased; and the condensation of the mitochondria was remarkable.In addition, the changes of glia cells and cepillaries were observed.