Age-related changes of microcirculation in pial blood vessels of the sensorimotor cortex of the rat brain

Abstract

We studied the density of the entire microvascular network and arterioles in the pia mater of the sensorimotor cortex in rats of different ages. The responses of pial arterioles to noradrenaline and acetylcholine chloride were also studied. Our results showed that the density of the microvascular network and reactivity of arterioles in the pia mater did not significantly change before the age of 12 months. At the age of 22–24 months, the density of the entire microvascular network was decreased by 1.7 times; the density of arterioles was decreased by 1.2 times. The contractility of pial arterioles did not significantly change during the rat lifespan; however, their ability to dilate became poorer with age. Exploratory behavior was impaired by the age of 22–24 months: the number of events in the open-field test was decreased by 1.5–2.3 times in comparison with young animals.