Vol 140, No 6 (2011)

Relative quantitative distribution of all the associative and descending efferent fibers and the ultrastructural organization of the terminals of the parietal cortex areas 5 and 7 in the caudate (NC) and red nucleus (NR) in the cat were analyzed after a local, pointed destruction of the cortex of these areas. The maximal numbers of the associative fibers were found to project to the fundus areas of the motor cortex and to the area of Clare-Bishop; moderate projections were detected to the areas 31, 19 and single degenerating fibers were registered in the areas 1, 2, 3a, 3b, 30, and 23. The descending efferents were maximally projecting to NC, NR, reticular nuclei of the thalamus, midbrain, and pons, in all of which, according to the immunocytochemical studies, GABA-ergic terminals are prevalent. On the basis on the electron microscopical studies, it was suggested that the influence of the parietal cortex is mediated by the axo-spinal synapses of the medium shortaxonal spiny cells of the dorsolateral part of NC caput and by the axo-dendritic synapses of Golgi II cells of the parvocellular part of NR. On the basis of the maximal involvement of the fundus areas of the motor cortex, as well as of the inhibitory subcortical (NC) and stem nuclei (NR, reticular nuclei of the thalamus, midbrain, and nuclei pontis), it is suggested that these structures serve as the morphological substrates for the realization of the inhibitory, integrative function of the parietal cortex.

Development of axonal connections between cat primary visual area 17 and visual mo tion processing center was studied to investigate cortico-cortical connection plasticity in ontogenesis as affected by an experimental modification of visu al environment (flickering light stimulation). By using a retrograde axonal labeling by horseradish peroxidase, a distribution of initial neurons in area 17 that s end afferent projections to PMLS (posterior medial part of lateral suprasylvian sulcus) was analyzed. Sixteen 5-week-old and 12-14-week-old kittens, than were reared in normal visual e nvironment or were subjected to a flickering light of 15 Hz frequency, were examined. It was shown that session stimulation by flickering light led to an impairment of normal development of regular organization of the connections between these visual ar eas including the decrease of labeled surface area and labeled initial neuron density in area 17. The data obtained elucidate the structural bases of cortical mechanisms that underlie moti on processing disturbances in kittens stimulated by a flickering light.

Using the model of the rat spinal cord dosed contusion injury at T8 level, cross sectional area of the pathological cavities was measured and the number of myelinated nerve fibers was calculated in the outer zones of white matter after immediate single injection in the damaged area of human umbilical cord blood mononuclear cells (UCB-MC) transfected with plasmid with vegf and fgf2 genes. UCB-MC transfected with pEGFP-N2 plasmid with egfp gene of enhanced green fluorescent protein were injected into the rats of control group under similar conditions. By Day 30 after the injection of UCB-MC transfected with vegf and fgf2 genes, total cross-sectional area of the cavities in outer zones of white matter at a distance of 3 mm caudally from the epicenter of the injury was reduced more than twice as compared with that found in control group. Number of myelinated nerve fibers in the same zones of white matter at the same distance from the epicentre in rostral and caudal directions, was increased by 20% on the average as compared with control, and at a distance of 5 mm in rostral direction - by 40 to 70%. Thus, the delivery to the injury region of the therapeutic genes vegf and fgf2 reduced cavitation, restrained the processes of secondary degeneration and supported the number of myelinated fibers in the injured spinal cord.

The aim of this study was to obtain the morphological basis for ocular desympathetization as a method for cataract modeling in vivo. The study was conducted on 20 outbred rabbits, in which the bilateral removal of superior cervical ganglia of sympathetic trunk resulted in the change of tone of the sympathetic division of the nervous system. 5-7 months after this operation, biomicroscopy of the anterior portion of both eyes was performed that has demonstrated in 16 out of 20 rabbits the initial manifestations of lenticular opacity. 12-14 months after the operation, their area was significantly increased, and the formation of wedge-shaped opacity with its basis facing the lens periphery, was documented. This was associated with the dissociation of lens fibers, as well as the extracellular liquid accumulation. Histological and phenotypic changes of the lens were similar to those in age-related cortical cataract, detected in man. In both age-related cataract, and that one received by a proposed modeling method, the immunopositive reaction was found demonstrating neuron-specific enolase, vimentin and S-100 protein in lenticular cortex. The proposed method of cataract modeling in vivo may be used for the study of cataract pathogenesis and for the development of measures of its prophylaxis and therapy.

Morphological changes in myocardium resulting from experimental stress loads were investigated. Experiment model: group 1 - unloaded swimming (30 rats), group 2 - loaded swimming (30 rats), group 3 - control animals (30 rats - no swimming, maintenance in vivarium). The experimental groups were further divided into 4 subgroups: 1A (adapted animals, n=20), 1NA (unadapted animals, n=10), 2A (adapted animals, n=13), 2NA (unadapted animals, n=17). Histological study of myocardium in subgroups 2A, 1NA and 2NA demonstrated dystrophic changes that were either moderate (subgroups 2A and 1NA) or expressed (subgroup 2NA). Foci of interstitial edema and perivascular hemorrhages were detected. In subgroups 1NA and 2NA, cardiomyocyte cross striation disappeared, cell cytoplasm became vacuolated, foci of cardiomyocyte destruction and necrosis were present. The degree of myocardial changes was found to depend upon stress intensity and individual tolerance of rats. Computer morphometry was unable to detect any significant differences in the thickness of cardiomyocyte fibers between the subgroups.

Under physiological conditions, the germinal center (GC) area of aggregated lymphoid nodules of the small intestine in adult male Wistar rats was greater than that of the similar structures in the mesenteric lymph nodes. Moreover, these differences were more pronounced in a group of stress-resistant rats as compared to stress-prone animals. The exposure to acute emotional stress (immobilization in plexiglas boxes for 1 hour with the irritation of the back area with the electric current) reduced GC size. Restoration of the morphometric parameters studied in the group of stress-resistant rats was completed at an earlier date (by Day 3 after exposure to stress), while in susceptible animals it took place by Day 7. By Day 14 after an acute emotional stress, GC size in a group of stress-resistant rats were similar to those in control group, while in susceptible animals they were lower than the baseline values, indicating that the depletion of the functional capacities of lymphoid tissue in this group of animals.

Cellular composition of the lymphoid tissue in the superior and inferior segments of ureteral mucous membrane was studied using quantitative method in newborns, infants and children of the first years of life on autopsy material (n=12). It was found that during the first years of life lymphoid tissue was poorly developed in the lamina propria of the ureteral mucous membrane and it was represented by diffuse lymphoid tissue. Processes of lymphocytopoiesis were not expressed, while high degree of cell destruction was observed that was increased with age. The content of plasma cells was increased by the early period of infancy, indicating the activation of local humoral immunity. Regional peculiarities included higher content of plasma cells, granulocytes and lower concentration of destroyed cells in the superior ureteral segment as compared with the inferior one. These peculiarities were preserved during all childhood ages.

Ezrin (cytovillin or p81 protein) is an actin-binding protein, a member of ERM (ezrin, radixin and moesin) family, which species contribute to stabilization of the plasma membrane-formed structures. The aim of the present study was to demonstrate the ezrin-containing cells in the rat brain and to describe their topography and morphological features. The most pronounced immunohistochemical reaction to ezrin was found in the epithelium of the choroid plexus, cells of the subcommissural organ and ventricular ependyma. Moreover, ezrin staining was also detected in the unidentifiable cells in the subventricular zone, rostral migration pathway and astrocytes in various brain areas. Preferential ezrin localization in the brain cells contributing to formation of barrier structures suggests its involvement in transport processes in the CNS.