[Age-related changes of microcirculation in pia mater of rats' sensorimotor cortex].

We studied the density of whole microvascular network and separately the density of arterioles in the pia mater of sensorimotor cortex of rats of different ages. Also pial arteriolar reactivity on exposure to norepinephrine or acetylcholine chloride was evaluated. The microvascular density and the arteriolar reactivity in the pia mater were not significantly changed before the age of 12 months. In the age of 22-24 months the density of whole microvascular network decreased 1,7 times at the mean and the density of arterioles decreased 1,2 times. There were no significant changes of pia arterioles constriction during the animals life but dilatation was noticeably worse in senility. Orientation and exploratory behavior got worse to the age of 22-24 months: the number of behavioral acts in the "open field" test decreased 1,5-2,3 times in comparison with young animals.