[REACTIVE CHANGES IN THE ASTROCYTES OF FOREBRAIN NUCLEUS ACCUMBENS AFTER RESTRICTION OF BLOOD FLOW IN THE BASIN OF BOTH COMMON CAROTID ARTERIES IN RATS].

Reactive changes of astrocytes were studied in forebrain nucleus accumbens in rats (n = 12) after global cerebral ischemia induced by bilateral occlusion of both common carotid arteries, which is a frequently used model to assess the effectiveness of pharmacological agents that have anti-ischemic and neuroprotective properties. Under these conditions, the nucleus accumbens was in the area of partial ischemia. Morphometric study of nucleus accumbens was performed in three groups of rats (4 animals in each group) after ligation of both common carotid arteries, after a sham operation and in healthy animals. Astrocytes were demonstrated in serial sections using the reaction to glial fibrillary acidic protein counterstained with hematoxylin. 7 days after the surgery, in each animal the number of astrocytes was counted in the sections in 7 successiive squares of 0.01 mm2 each, the distance between their bodies and the capillary wall was measured within the circle of 20 μm radius, the cell body area and the length of their main processes were determined. It is found that astrocytes in the nucleus accumbens in the model of bilateral occlusion of the common carotid arteries for 7 days experienced a partial state of ischemia. Their reactive changes were manifested by the signs of the cytotoxic edema, damaging intermediate filament proteins in their bodies, processes and in the perivascular glial membranes. The concentration of the astrocyte cell bodies near blood capillaries is the adaptation mechanism and is a condition for the survival of cells under the restriction of blood flow in the brain.