Changes in Rat Cerebral Blood Flow Velocities at Different Stages of Aging.

Changes in the velocity of cerebral blood flow may significantly contribute to the formation of age-related cerebrovascular diseases. The age-related dynamics in cerebral blood flow velocity indicators were studied here in rats at different stages of aging. Using Doppler ultrasound, the blood flow in the cortex and subcortical structures of the cerebral hemispheres was comparatively analyzed by linear velocity values and blood flow indices in young (4-month-old) and aging (18- and 23-month-old) Sprague–Dawley rats. It was found that aging is accompanied by changes in the parameters of cerebral blood flow in the cortex and subcortical structures of the rat brain, which develop gradually and differ at different stages of aging. By the age of 18 months, perfusion in the frontal and parietal hemispheric regions increases due to an increase in peak velocities and mean velocity per cardiac cycle, as well as a decrease in the level of cerebrovascular resistance. These processes precede the development of hypoperfusion-induced blood flow disorders observed at later stages of aging. Hypoperfusion-related changes in 23-month-old rats are most pronounced in the frontal region of the cerebral hemispheres, being characterized by a decrease in peak velocities and an increase in blood flow indices. [ABSTRACT FROM AUTHOR]