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

We studied the density of the microvascular network in the pia mater, the tissue perfusion and saturation of the oxygen of sensorimotor cortex of hypertensive rats of different ages. Our investigations shown that the microvascular density in the pia mater was not only decreased, but also was increased. The perfusion of sensorimotor cortex was reduced and tissue saturation was enlarged. By the age of 12 months orienting-exploratory rats behavior became worse significantly in all major indicators of the test «open field¼.

[Efficacy of mesenchymal stem cells intracerebral transplantation for the correction of age-related cerebral microcirculation alterations in rats].

Using a television-based vital microscopy method and immunohystochemical analysis, we have assessed the effect of intracerebral transplantation of syngeneic mesenchymal stem cells (MSC) on the brain cortex structure and the microcirculation in the pia mater of old rats. Using "open field" system, we have studied the effect of MSC transplantation on position-finding and discovery behavior of older animals. We have found that density of microvascular network of the pia mater increased ca. 1.9-fold in MSC recipients, compared to age-matched intact animals. Density of the arteriolar area of microvascular network of the pia mater increased ca. 2-fold. Reactivity of the newly formed arterioles was nearly equal to that of native microvessels. Intracerebral transplantation procedure itself was traumatic for brain cortex of rats, but it had no effect on the microcirculation in the contralateral hemisphere. Intracerebral transplantation of MSC did not improve locomotor behavi- or and emotional stage of old rats, did not increase their position-finding and discovery activity.

[Influence of maternal factor on motor behavior and lipid turnover in rats exposed to severe psychoemotional stress].

Adverse condition of rat development during the prenatal period (rearing by mother survived brain injury) or during the early post-natal period (cross fostering), causes impairment of motor behavior and a lipid turnover in adult rats. Such rats under severe stress showed decrease of adaptation (as expressed or low indexes of motor impellent behavior and lipid metabolism) in comparison with rats that were grown up by own mother. The psychoemotional stress caused the most expressed deficient behavior in males that were grown up by mothers with brain injury (decrease in serum level of HC and HDL and depressively - similar behavior).

[The effect of intracerebral transplantation of mesenchymal stem cells on orientation and exploratory behavior of aged animals].

Male Wistar-Kyoto rats (12 and 22-24 months old) were intracerebrally transplantated with syngeneic mesenchymal stem cells (MSC). Three weeks or one year later, orientation and exploratory behavior of the same animals (not 2 years old) was assessed using an «open field¼ test. Older rats (22-24 months old) were inhibited in the basic behavioral acts in comparison to younger animals (2-3 months old). Transplantation of MSC did not cause improvement of an orientation and exploratory behavior of aged rats. Morphological and immunohistochemical analysis suggests intracerebral MSC transplantation led to the injury of the cortex of the ipsilateral hemisphere.

[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.

Mesenchymal stem cells restore orientation and exploratory behavior of rats after brain injury.

We studied the effects of intravenous and intracerebral transplantation of MSC on restoration of orientation and exploratory behavior of Wistar-Kyoto rats after removal of the left motor cortex. Removal of the motor cortex led to a significant reduction of the number of behavioral acts in the open field test. Two weeks after removal of the motor cortex and intravenous transplantation, the animals were as inhibited as the controls, but during the next 10 weeks, the behavioral status of these rats remained unchanged, while controls exhibited further behavioral degradation. After injection of MSC into the brain, the behavior of rats with trauma did not change in comparison with intact rats over 10 weeks.

Effect of mesenchymal stem cell transplantation on cognitive functions in rats with ischemic stroke.

The effect of intravenous transplantation of mesenchymal stem cells on the recovery of cognitive functions was studied in Wistar-Kyoto rats after brain stroke induced by occlusion of the middle cerebral artery in the left hemisphere. Analysis 2 and 5 weeks after stroke showed that transplantation of mesenchymal stem cells 3 days after middle cerebral artery occlusion reduced the area of cerebral injury, preserved cognitive functions, and decreased mortality in experimental animals.

[The influence of the rat maternal environment on the behavior of offspring].

In Wistar's rats, the postnatal influence of maternal behaviour on the motor and emotional state and the anxiety level of the posterity born from the intact rat-mothers-ambidexter but reared by the intact mothers-ambidexter with the motor deficit, were investigated. From the first day of life, the rat-mothers with the removed part of the sense-motor cortex (right or left) nursed and reared the litter. It was discovered that the reduction of motor activity and increase of negative emotional responses occurred in experimental litter at the age of 1 month as compared with the control group (intact litter reared by the ersatz healthy rat-mothers). In the test of elevated cruciform maze, a high level of anxiety was discovered. The experimental posterity showed an emotional tension as the dominant state. Left-side lesion of the sense-motor cortex of the ersatz mother resulted in a rougher disorder in the emotional state and movement than after right-side lesion.