Vol 142, No 5 (2012)

А comparative analysis of structural and functional organization of paleoamygdala was performed in 22 male WAG/Rij and Wistar rats using light microscopy (Nissl staining method and computer morphometric analysis), electron microscopy (using the criteria of the evaluation of the functional state of neurons) and the TUNEL method for apoptotic cell labeling. The results obtained suggest the involvement of the limbic brain structures in the pathogenesis of absence epilepsy. It was shown that the area occupied in the sections by amygdala was significantly greater in WAG/Rij rats (model of absence epilepsy). The assessment of ultrastructural characteristics of neurons in all the structures of paleoamygdala (dorsomedial, posterior medial and posterior cortical nuclei) has shown the signs of the reduction of their functional activity in WAG/Rij rats. In addition, WAG/Rij rats demonstrated the increased numbers of pyknomorphic neurons with the signs of apoptosis, as identified by the TUNEL method, which is indicative of the destructive processes.

The purpose of the present investigation was to examine the effect of single injection of alcohol on histaminergic neurons of rat brain. The study included 41 male albino rats, histological, histochemical, electron microscopic and morphometric methods were used. It was found that 1 hour after the intraperitoneal administration of ethanol in a dose of 4 g/kg the neurons become more spherical, the activity of NADH and glucose-6-phosphate dehydrogenases in their cytoplasm decreased, but the activity of lactate dehydrogenase, type B monoaminooxidase and acid phosphatase increased, at the same time significant ultrastructural disturbances were observed. Six hours following alcohol administration, the signs of histaminergic neuronal damage were reduced while the features of structural and metabolic adaptation became more expressed.

Using the histochemical method, the activity of 3β-hydroxysteroid dehydrogenase (HSDH) was studied in the brain of laboratory male albino rats of different age groups: 5-6 days (n=6), 45-50 days (n=12), and 6 months (n=15). The quantitative assessment of reaction intensity was performed with the cytospectrophotometer. The results obtained indicate that the ependimocytes lining the brain lateral ventricles and covering the villi of their vascular plexuses are characterized by the presence of HSDH activity typical to that of steroid-producing cells. In this regard ependimocytes may be attributed to the cells that can produce neurosteroids. It was established that HSDH activity in ependimocytes was minimal in the early postnatal period and considerably increased by the prepuberty period, remaining at this level in adult animals.

Retinal photoreceptors of six-month-old Pacific salmon fry (Oncorhynchus masou) (masu salmon) were found to respond to the ultraviolet radiation (UVR) in different combinations with constant magnetic field (MF) (80 G) in a special, previously undescribed manner. After exposure to UVR for 2 hours (1st experiment) the pigment index (PI) of retinomotor response increased from 0.30±0.10 to 1,31±0,20. The rods were located within the pigment layer, while cones, including double ones, were only partially screened with pigment. The whole retina demonstrated twilight (mesopic) response. After exposure to UVR for 2 hours and subsequent 2 hours-long exposure to MF (2nd experiment), PI rose to 2,08±0,10, while an average myoid height, and an average double cone diameter were increased. The whole retina demonstrated photopic response. In the 3rd experiment (2 hours of MF exposure, followed by 2 hours of a UVR exposure) value was minimal - 1.28±0.12. Average myoid height was decreased, while an average cone diameter was unchanged. The whole retina response was scotopic (as under conditions of darkness). On the basis of authors' own results and the data from the literature, the conclusion is drawn that MF distorts influence of UVR, resulting in the unusual responses of the retina. The results obtained confirm the previously proposed variant of light-dependent magnetoreception model in the vertebrates.

Left-ventricular surface of the interventricular septum (IVS) was studied in the heart of 85 human fetuses (at weeks 17-28 of development) formed without congenital defects and minor abnormalities. Two anatomical types of trabeculae (bridge-like and parietal) and their two topographical groups are described: trabeculae of the anterior corner of the left ventricle (LV) and the septal trabeculae. The prevalence of trabeculae in both groups was found to be equal (81-81.2%). No correlation between the numbers of septal trabeculae and the trabeculae of the anterior LV corner was found. While the parietal trabeculae were detected in both groups, the bridge-like type was found only in the anterior LV corner. The number of the bridge-like trabeculae of the anterior LV corner and the septal trabeculae increased from the base to the apex of the heart; this was accompanied by the decrease in the IVS myocardium compactness. Among the first topographical group, there were trabeculae in the shape of skewed cylinders or truncated cones, flattened perpendicularly to their long axis. As a rule, in cone-shaped trabeculae, their broad base was directed towards the IVS. In the second group, the ribbon-shaped trabeculae were prevalent. The data on trabecular width are presented. The formation of the cardiac LV and IVS trabecular pattern in prenatal period is discussed.

Pulmonary acinus architectonics and parameters were studied in six men aged 19-27 years that permanently lived in the city of Novosibirsk. The study was conducted on the serial histological sections by using morphometry and volumetric graphic reconstruction of the acini. In a typical acinus, three generations of the respiratory bronchioles, four generations of the alveolar ducts, and one generation of the alveolar sacs (AS) were found. All the intraacinar components branched in the form of dichotomy, most commonly, irregular. It was shown that the acini were regularly asymmetrical, 32% of branches of the alveolar ducts of the second order had no continuation and ended with AS. In the same way, two thirds of the third order alveolar ducts also continued into AS, i. e. about 40% of branches are rudimentary. Intra-acinar path from the first alveoli in the respiratory bronchioles to the terminal alveoli is equal to 7.2±1.0 mm. The peculiar feature of the acinus of the Siberian residents is an increased transitional zone and a distal shift of respiratory zone by one generation of branches in the direction from the conducting airways, which reduces its cooling during breathing cold air in winter.

The placenta of 20 women with normal pregnancy was studied during II and III trimesters to obtain the complex characteristic of the structures participating in the formation of syncytio-capillary membranes. Immunocytochemical endothelial cell marker CD34 and morphometry were used for the assessment of some villous parameters: villous area, villous stromal area, villous epithelial area and vascular endothelium area. The main attention was given to the remodeling of the villous epithelium and capillary network. The significant reduction of the epithelial area and that of the villous stroma was detected simultaneously with intensive their vascularization. Morpho-functionally, most of the terminal villi were specialized, containing sinusoid-type capillaries which were in close contact with attenuated, anuclea regions of syncytiotrophoblast. The proportion of terminal villous endothelium in respect to the stroma was significantly increased. Thus, in II and III trimesters of physiological pregnancy the structural changes take place in the placenta, in particular, the capillaries are transformed into thin-walled sinusoids, that approach and closely interact with syncytiotrophoblast resulting in the formation of the syncytio-capillary membranes necessary for an adequate diffusion and meeting the growing needs of the fetus.

The results of the application of a pixel method for the automated measurement of the intensity of histochemical reaction in the neurons are presented. The method is based on measuring principle, which includes the automatic counting the sum of brightnesses of all the pixels forming the image with the help of standard computer programs. The potential of this method is demonstrated on the example of NADPH-diaphorase activity study in the nitroxidergic neurons of sensory and motor nuclei of the medulla of healthy rats.