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.
Neurons and glial cells were studied by means of computerassisted morphometry in the segments of the ventral and dorsal regions of the compact part of the substantia nigra (CPSN) of the brain. The material obtained at autopsy from 6 males and 3 females aged from 52 to 87 years. It was found that in segments of the ventral CPSN region the neuronal cell bodies and nuclei were larger than those in the segments of the dorsal region. The numerical density of neurons and gliocytes in the ventrolateral segment was higher than in the segments of the dorsal region. In the ventromedial segment the glial index was lower than in the segments of the dorsal region. The morphometric differences found between CPSN segments must be taken into account in the assessment of the morphological changes in substantia nigra of the brain, due to both age involution or pathological process.
The characteristics of the structure of the temporomandibular joint (TMJ) in individuals with different direction of growth of the facial part of the skull were studied. Cone beam computed tomography data were analyzed in 16 young (mean age 29±7 years) orthodontic patients (32 joints) before treatment, which had class II dentition ratio. The patients were divided into 2 groups (4 men and 4 women in each): with strongly expressed vertical and horizontal types of facial growth. In patients with a vertical type of facial growth, the reduction of the size of joint spaces was noted in anterior, posterior, upper, oral and buccal parts of TMJ. In patients with a vertical type of facial growth anterior articular angle was smaller than in those with a horizontal growth type. The data obtained indicate the relationship of the structure of TMJ and the direction of growth of the facial part of the skull.
Iba-1 protein which is a recognized marker of the microglial cells, was previously detected by the authors in the nucleus of microgliocytes. The present study was aimed to define more exactly these data using the methods of immunohistochemistry and confocal laser microscopy. The study was performed on the fragments of the human brain (n=18, age 25–78 years). The areas examined included cortex, striatum, substantia nigra, and nucleus rubrum. The Iba-1 protein was shown to accumulate in one or several parts of microgliocyte nucleus not identical to the nucleolus or the heterochromatin granules. The reasons for this fact are unclear. It may be speculated that Iba-1 protein besides its major function (involvement in phagocytosis) can perform the role of a transcriptional factor.
The aim of the study was an analysis of the peculiarities of morphological changes of the placenta in rats with experimental chronic hepatic lesion. Liver injury was modeled in 3-month-old sexually mature female rats by 2-fold intragastric administration of paracetamol at a dose of 2.5 g/kg body weight (drug group, n=15) and a single intraperitoneal injection of D-galactosamine at a dose of 250 mg/kg of body weight (toxic group, n=15). Intact rats served as a control. The placenta examined at Day 21 of pregnancy using histological and morphometric methods. Рroliferative activity of placental cells was evaluated with the immunocytochemical method using antibodies against Ki-67 antigen. The membrane permeability in different trophoblast compartments was examined. It was found that experimental chronic liver pathology caused morphological changes in the placenta, which were manifested by a decrease in the area of its labyrinthine portion, maternal sinusoids in the basal area, fetal capillaries and maternal lacunae of the labyrinth. In addition, in the experiments with an intraperitoneal injection of trypan blue it was shown that changes in the liver caused increased permeability of the placental barrier, and reduced the proliferative activity of trophoblast cells.
Using the methods of immunocytochemistry and confocal laser microscopy, structural organization and spatial distribution of microgliocytes in the molecular layer of the cerebellar cortex were studied in 5 adult male rabbits. Reaction to microglial cell marker Iba-1 was highly specific, while until recently their selective detection was impossible in rabbits. In the molecular layer of the cerebellar cortex, two patterns of microgliocyte organization were observed. Most common were the cells with tortuous intricately ramified processes, the main branches of which often had radial direction. Perivascular sparsely-branched spindleshaped microgliocytes were also found. The peculiarities of the structural organization of these cells are related to the protective functions they perform at the level of the blood-brain barrier.
A new variant of the method of natural periodization of biological processes is proposed. In contrast to the original variant, in which each parameter is coordinated with respect to its average value during all the period of observation, in the proposed modification the parameters are coordinated with respect to their control values, that seems to be more logical in the experimental studies. Both variants were applied for the evaluation of twomonth-long dynamics of 19 morphological parameters of the part of an adrenal medulla surviving after laser damage. Three natural periods of were identified of the remodelling of the organ structure and their functional interpretation is given. It is shown that the original variant more clearly highlights the important nodal points, while the proposed modification more accurately reflects the general nature of the changes. Thus, both the variants are complementary and their combined use improves the efficiency of the method for experimental studies.
The paper presents a method of analysis of cell populations that combines the use of normalized spatial coordinates of the neurons with the morphometric criteria of their evaluation. These algorithms were applied to check the heterogeneity of apopulation of neurons Y-conducting channel in cat at the level of the lateral geniculate body (LGB). As a specific marker of Y-neurons, SMI-32 antibodies were used. Evaluated The dynamics of the distribution of the number of cells and the orientation of their soma within each layer and mediolaterally along the length of LGB dorsal nucleus (LGBDN). Among the SMI-32-positive neurons, the existence of at least two populations was detected differing in number, orientation and distribution of the soma in different layers of LGBDN. The heterogeneity of Y-neuron population in LGBDN detected in this study is consistent with the earlier electrophysiological data. We believe that the described algorithm for neuronal analysis may be successfully applied to study not only LGB, but also other extensive structures of the brain, including those having laminar organization.
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