Цель исследования-сравнительное изучение структурно-функционального состояния нейро-глио-сосудистых микроструктурных комплексов соматосенсорной коры (ССК), СА1 гиппокампа и миндалевидного тела (МТ) головного мозга белых крыс в норме и после острой ишемии, вызванной 20-минутной окклюзией общих сонных артерий. Материалы и методы. В эксперименте с помощью электронной и флуоресцентной микроскопии (окраска DAPI) были изучены нейроны, астроциты, эндотелиоциты, перициты, базальная мембрана микрососудов головного мозга в норме (n=5) и реперфузионном периоде (1-, 3-, 7-, 14-, 21-и 30-е сут.; n=30). Морфометрический анализ провели с помощью программы ImageJ 1.46. Результаты. В восстановительном периоде после ишемии отметили реактивные (отек-набухание, тинкториальные свойства клеток) и компенсаторно-восстановительные (гиперплазия, гипертрофия, пролиферация, усиление трансцитоза) изменения нейро-глио-сосудистых комплексов. После ишемии количество нейронов уменьшалось (на 8,7%-55,3%), а содержание глиальных клеток возрастало в 2-3 раза. Увеличение нейроглиального индекса (НГИ) сопровождалось: 1) появлением микрососудов с многочисленными разветвленными отростками перицитов, 2) усложнением пространственной организации базальных мембран, 3) структурными признаками активации процессов трансцитоза (большое количество кавеол, гладких и клатриновых везикул, крупных везикул) в перицитах и эндотелиальных клетках. Заключение. Полученные данные свидетельствуют об компенсаторно-восстановительных изменениях компонентов нейро-глио-сосудистых комплексов ССК, СА1 гиппокампа и МТ головного мозга белых крыс после 20-минутной окклюзии общих сонных артерий. Наиболее полно реализация механизмов защиты и восстановления поврежденных нейронов происходит в ССК и МТ, обладающих высоким НГИ.

Aim. To study the distribution and spatial organization of dentate gyrus (DG) astrocytes and CA4 area of hippocampus of Wistar rats following 20-minute occlusion of common carotid arteries (OCCA) compared to sham-operated control animals.Material and methods. Histological (Nissl staining with hematoxylin and eosin), immunohistochemical (GFAP, MAP-2) and morphometric methods were used. Astrocytes and neurons in control (sham-operated animals, n = 5) group, after 6 hours (n=5), 1 days (n=5), 3 days (n=5), 7 days (n=5), 14 days (n=5) and 30 days (n=5) after 20-minute OCCA were studied on thin (4 µm) serial frontal sections of the hippocampus. Fractal analysis (ImageJ 1.52; fraclac 2.5 plugin) was used to obtain additional quantitative information on the spatial organization of astrocyte networks. Statistical hypotheses were tested using nonparametric criteria.Results. 30 days after the 20-minute OCCA, only 5.3% of CA4 neurons were irreversibly destroyed and the total numerical density of DG granular cells remained at the control level. Hypertrophy and increased complexity of the spatial organization of astrocyte processes were observed 6 hours and 1 day after OCCA and persisted for 30 days. Astrogliosis was accompanied by an increased relative area of GFAP-positive material and fractal dimension and reduced lacunarity of the astrocyte network. The latter was especially evident in 1, 14 and 30 days after the OCCA.Conclusion. After the 20-minute OCCA, the density of GFAP-positive material increased, the fibroarchitecture reorganized and gained more complexity due to the branching of astrocyte processes. At the same time, the total numerical density of neurons changed only slightly. All this indicated the probable role of astrocytes in post-ischemic activation of natural neuroprotection mechanisms.

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Purpose. The study is focused on glioarchitectonics of the neocortex, archicortex and amygdala of Wistar white rats in normal state and after a 20-minute occlusion of the common carotid arteries.Materials and methods. Light (stained with hematoxylin and eosin) microscopy, immunohistochemistry (GFAP), and morphometry were used to study the distribution, shape, and area of GFAP-immunopositive brain cells in the normal range (n = 5) and at days 1, 3, 7, 14, 30 (n = 25) after acute ischemia.Results. Focal changes were found in the density of the glial network: decrease and increase in the local content of GFAP-positive material. Reactive, dystrophic and necrobiotic changes in neurons after acute ischemia were accompanied by reorganization of neuroglia and increase in the neuroglia index in certain zones by 1.2–1.5 times. The surface area of the particles in GFAP-positive astrocytes in sections of the neocortex in the control was 8.4–18.1, but after 3 days after ischemia this rate in some parts of the neocortex rose to 45.0–59.3%. In the hippocampus this rate was 8.1% and 16.2%, and in the amygdala it was 12.6% and 21.2%. Hypertrophy of mature astrocytes was manifested by the increase in the diameter, degree of branching and length of their processes.Conclusion. The obtained data are considered as a phenomenon of ischemic preconditioning and activation of protective processes in neuro-glio-vascular microcomplexes.

The aimof research was to study morphofunctional signs of the sensorimotor "dark neurons" formation in the cerebrum of sexually mature white rats under normal conditions and in 40 minutesafter the common carotid arteries (CCA) occlusion.Material and methods.Acute ischemia was simulated in white Wistar rats by a 40-min CCA occlusion. The brain was fixed by immersion and perfusion methods. A comparative morphometric assessment of cyto-and gliocytoarchitectonics of the neocortex was carried out under normal conditions (n = 6), 1 (n = 6), 3 (n= 6), and in 7 days (n = 6) after the common carotid arteries (CCA) occlusion. The Nissl staining, hematoxylin and eosin staining, immunohistochemical typing NSE, MAP-2, HSP-70, p38, CASP3, GFAP and AIF1 were applied. The numerical density of normochromic and hyperchromic (dark) pyramidal neurons, oligodendrocytes, microgliocytes, and the relative area of edema –swelling zones were determined. Statistical hypotheses were tested by nonparametric methods using Statistica 8.0 software.Results.The method of the brain fixation significantly influenced the content of the artifact dark neurons,which are similar in morphology and tinctorial properties to degeneratively altered dark neurons. The appearance of reversibly and irreversibly degeneratively altered dark neurons in the sensorimotor cortex after the CCA occlusion was accompanied by an increase in the relative area of edema  –swelling zones (control  –5.4%, 1st day  –17.6%). The maximum content of degeneratively altered dark neurons (53%) was found in layer V in 7 days after ischemia. According to the findings of immunohistochemical typing NSE, MAP-2, HSP-70, p38, CASP3, the specific proteins of the most degeneratively altered dark neurons were retained, ensuring their restoration and the neural network functioning. The total number density of sensorimotor neurons decreased by 26.4% (p =0.001) in layer III, and by 18.5% in layer V (Mann –Whitney U Test; p = 0.01) in 7 days after the intervention. The revealed changes were of a diffuse focal character. In the zones of degeneratively altered dark neurons accumulation, the content of astrocytes, microgliocytes and oligodendrocytes increased. The neuro-astroglial index (control  –1.62) increased to 2.72 in 3 days after the CCA occlusion. The peak in the number density of microgliocyte s was noted in 1 day, and the oligodendrocytes in 7 days after acute incomplete ischemia (Mann –Whitney U Test; p0.001).Conclusion.After a 40-minute common carotid arteries occlusion, dark neurons were detected in layers III and V of the sensorimotor cortex with underlying hydropic dystrophy; their cytomorphological pro perties indicated the dynamics of their in vivo degenerative changes. Restoration of degeneratively altered dark neurons was accompanied  by  an  increase  in  the  number  of  satellite  oligodendrocytes,  astrocytes  and  microgliocytes. The  revealed changes were considered as one of the variants of reversible changes in neurons in response to moderate ischemic damage.