Observations of microvessels in the brain with Alzheimer's disease by the scanning electron microscopy

Microvessels in the brain with Alzheimer's disease and those of a control group were observed by means of the scanning electron microscopy. There were no morphological differences between the relatively large arteries in Alzheimer's disease and those of the control. Remarkable differences existed in terminal arterioles and capillaries. In Alzheimer's brain, the terminal arterioles frequently had focal constriction and smooth muscle cells with an irregular shape and arrangement, and the capillaries also showed an irregular abluminal surface and irregular constriction and dilatation along their paths. In the control brain, there were no changes such as those observed in Alzheimer's disease. The findings suggest that diffuse neuronal loss in Alzheimer's cerebral cortex might be induced by circulatory disturbance through the changed microvessels.