the common age-related histologic changes include loss of capillary endothelial cells , elongation of the remaining endothelial cells , and decreased capillary diameter in rat cortex , but not in the monkey or human cortex , and a decrease in the number of mitochondria in endothelial cells of the brain capillaries in the monkey but not in the rat .
C0026237
mitochondria
C0007634
cells