[Study of the effect of Unifuzol on cognitive impairment and damage to the hippocampus and cerebral cortex during course administration to rats with bilateral stenosis of the common carotid arteries, causing chronic circulatory failure]. / Vliyanie preparata Unifuzol na sostoyanie kognitivnykh funktsii v usloviyakh eksperimental'nogo khronicheskogo narusheniya mozgovogo krovoobrashcheniya.

OBJECTIVE: To study the effect of Unifuzol (L-arginine sodium succinate) on cognitive impairment, cerebral blood flow, and damage to the tissues of the hippocampus and cerebral cortex during a 10-day course of administration to rats with chronic cerebral ischemia (CCI) caused by bilateral stenosis of the common carotid arteries (CCA). MATERIAL AND METHODS: The study was conducted on male rats with CCI caused by bilateral stenosis of the CCA by 60%. 40 days after surgery, rats received Unifusol (21, 42 and 84 ml/kg), nicergoline (10 mg/kg), citicoline (500 mg/kg) or placebo (0.9% NaCl) for 10 days. Next, cognitive impairments were assessed in the Morris Water Maze and the New Object Recognition (NOR) test, as well as the level of motor and exploratory activity in the Open Field test. The level of cerebral blood flow was determined immediately after the CCA stenosis and at the end of the experiment. Animals were euthanized in a CO2 incubator, after which the brain was removed and subjected to morphometric analysis. RESULTS: In animals that were modeled with CCA stenosis, pronounced behavioral and cognitive impairments occurred as a result of a decrease in blood flow in the vessels of the brain and subsequent changes in the tissues of the hippocampus and the cerebral cortex. Intravenous course administration of Unifuzol at doses of 42 and 84 ml/kg to animals with CCI was comparable in efficiency to nicergoline and citicoline, which was expressed in greater preservation of the cognitive abilities of animals in the Morris Water Maze and NOR tests. In the Open Field test, animals injected with Unifusol at doses of 42 and 84 ml/kg performed more acts of motor and exploratory activity than animals from the placebo group, and had a higher level of cerebral blood flow (compared to animals that were injected with citicoline). Based on the results of a morphological study, it was found that the most significant neuroprotective effect was provided by nicergoline and Unifuzol (at doses of 42 and 84 ml/kg). CONCLUSION: Unifuzol at a course of administration at doses of 42 and 84 ml/kg, comparable to the reference drugs nicergoline and citicoline, reduces the severity of psychoneurological deficit in animals with CCI, comparable to them improves the microcirculation of brain tissues, preventing damage to brain tissues.

Expression of Beclin-1 and LAMP-2 in Rat Hippocampus under Conditions of Simulated Gravity Overload in the Caudocranial Vector.

Structural changes in the rat hippocampus in response to chronic cerebrovascular disorders induced by gravity exposure in the caudocranial vector were studied. Qualitative and quantitative morphological analysis detected significant cytoarchitectonic changes in the pyramidal layer: spongiosis, manifest pericellular and perivascular edema, and a drastic increase in the counts of pyramidal neurons with signs of impairment in all hippocampal zones. The density of perikarya in the pyramidal layer decreased. Immunohistochemical study detected high expression of Beclin-1 in CA1 field. High expression of LAMP-2 was detected in CA4 field. Field CA2 was characterized by the maximum counts of damaged cells and high expression of Beclin-1 and LAMP-2.

Effect of Combined Stress on Morphological Changes and Expression of NO Synthases in Rat Ventral Hippocampus.

Adult rats were subjected to 7-day combined stress with stochastic changes of stressors of different modalities (noise, vibration, pulsating bright light) along with mobility restriction and elevated temperature in the chamber during stress exposures (daily 30-min sessions). Circulatory disorders, inhibition of endothelial NO-synthase expression in endothelial cells of the microcirculatory bed, perivascular edema, pronounced degenerative changes, and enhanced expression of inducible NO synthase in CA3 pyramidal neurons in the ventral hippocampus of stressed 12-month-old rats were observed. These findings can attest to the involvement NOdependent mechanisms and different contribution of NO synthase isoforms into the formation of hippocampal neuronal damage.

Patterns of TRPM7 expression in hypothalamic and hippocampal neurons in modeling of nutritional magnesium deficiency.

Patterns of expression of TRPM7, the major cellular magnesium transporters in neurons of the hypothalamic region and hippocampus, were studied immunohistochemically. Multidirectional nature and different levels of the expression of the above antigen were revealed during modeled magnesium deficiency with regard to structural and functional features of neuron organization in the hypothalamic paraventricular and supraoptic nuclei as well as hippocampal field CA1 and CA3. Changes in the structural characteristics of neurons in the studied areas (absolute and relative indicators) and TRPM7 expression patterns were quantitatively analyzed considering the data on the role of the studied antigen in magnesium homeostasis, cell damage, and compensation.

[The morphofunctional state of the blood-brain barrier at the level of the medulla oblongata in experimental West Nile encephalitis].

Pronounced clinical and morphological changes were found in the neurons and microcirculatory bed (MCB) vessels at the level of the medulla oblongata in experimental West Nile encephalitis (WNE). At the same time, the magnitude of changes in MCB vessels and nerve cells in the cores of the medulla oblongata correlated with the state of the surrounding astrocytic glia. It is suggested that the intensive astroglial reaction revealed during this experimental WNE reproduction promotes the prevention of neuronal lesion.

[Astrocytic morphological responses in different murine brain regions in the simulation of West Nile fever].

The brains from the mice infected intraperitoneally (with development of these or those symptoms of viral encephalitis) or intramuscularly with the Astrakhan West Nile fever virus strain (AcT 986) was pathomorphologically studied. Clinicomorphological changes in the neurons and vessels of the microcirculatory bed were found in the dorsal regions of medulla oblongata. Immunohistochemicall analysis showed that mature and/or activated astrocytes increased in number, largely in the animals without clinical manifestations of encephalitis. The findings provide evidence that cerebral astrocytes play a protective and adaptive role that seems to depend on the biological properties of the pathogen.