Histopathological changes induced by disturbance of microcirculation in the rat brain.

Microcirculatory disturbance was induced in 8 rats after injecting microsphere latex (5 micron in diameter) from the right carotid artery. Ultrastructural observations revealed that initial changes occurred in the vascular feet of astroglial cells and the subsequent swelling of postsynapses. Succeedingly presynapses and nerve cells also became atrophic but this was considered to be caused by astrocytic degeneration. From these findings, it is speculated that the neuronal atrophy was secondary to the changes in the neuropil around the capillary caused by disturbance of the nutritional supply from the blood induced by microcirculatory disturbance. The above described findings seemed to have some similarity to those of nonspecific degeneration of the cortex observed in the brain, such as Alzheimer's disease.