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We studied the effect of various methods of transplantation of mesenchymal stem cells on neuronal survival in rat brain 1 and 6 weeks after severe traumatic brain injury. It was found that intracerebral and systemic transplantation of mesenchymal stem cells improves neuronal survival in the piriform cortex of the contralateral hemisphere without affecting neuronal survival in the marginal zone of the traumatic cavity and amygdaloid nuclei. Intracerebral transplantation of mesenchymal stem cells increases the content of the astroglial component of the scar in the borderline zone of the traumatic cavity.

The aims of the present work were to identify the neuronal form of nitric oxide synthase (nNOS type I) in brain structures in rats by immunocytochemistry, to compare the results with data from histochemical reactions for NADPH-diaphorase, and to develop the optimal conditions for fixation for detecting nNOS. The product of the histochemical reaction was found to be located strictly in the cytoplasm. Immunocytochemical detection of nNOS showed that along with the cytoplasmic reaction for nNOS, the nuclei of some neurons and gliocytes were immunopositive, though the cytoplasm of these cells gave negative reactions for nNOS. Selection of the optimal fixation conditions for specimens and the dilution of the primary antibody allowed reductions in the intensity of nuclear nNOS-type reactions without affecting the specific reaction of the cytoplasm for nNOS. These data provide evidence that the best detection of nNOS in paraffin sections is obtained using immersion fixation in Carnoy's fluid or post-fixation in this solution after perfusion with 4% paraformaldehyde.

The aim of the present work was to develop optimal protocols for immunocytochemical reactions for nuclear protein NeuN for light and laser confocal microscopy which avoid the thermal antigen demasking procedure, which degrades the state of the tissue and requires use of expensive adhesive-coated slices. Maximal antigen retention was obtained after fixation in zinc-formalin and Bouin's fluid (maximum one day). Two protocols are proposed allowing the thermal demasking procedure to be avoided during detection of neuron marker NeuN on paraffin sections examined by light and confocal microscopy.

The aim of the present study was to find optimal protocol of immunocytochemical reaction to NeuN nuclear protein for light and laser confocal microscopy, which would exclude the antigen heat unmasking procedure that results in deteriorating the state of the tissue and requires expensive adhesive-coated slides. Best preservation of the antigen was found to be provided by fixation in zinc-formalin and Bouin's fixative (for a period of less than 24 hrs). Two protocols allowing to avoid antigen heat unmasking procedure during demonstration of the NeuN neuronal label in paraffin sections by the light and confocal microscopy are presented.

Method of selective chemical injury of locus ceruleus (LC) has revealed the following serotonergic structures: axonal varicosities, terminals and synapses. Serotonergic structures in LC are numerous. Small neurons with peculiar structures are described which are the targets of serotonergic innervation in LC and are responsible for interrelation with the proper noradrenergic cells and for intermediate interactions.

Early stages in development of transplants of the embryonal anlages of the human neocortex into the brain of mature rats have been studied at light optic level. The main attention has been paid to processes of proliferation, migration and differentiation of cells. Increasing amount of cells in the transplants takes place only at the expense of neuroepithelium; its reorganization results in a peculiar rearrangement of cells with formation of so called rosellas with numerous mitotically dividing cells. Owing to this growth the differentiating cells migrate from the rosellas radially, unlike their layer-by-layer organization in the control. These deviations are probably dominant in the disturbance of cytoarchitectonic organization of cells in transplants of neocortex in mature mammalia.

Immunohistochemical studies addressed the distribution of α-tubulin microtubules in rat forebrain structures. Non-uniform staining was seen with the reaction for α-tubulin. High immunoreactivity was detected in the cingulate and piriform cortex, olfactory bulbs, and the optic chiasma. The weakest immunohistochemical reactions were seen in the corpus striatum, the superficial layers of the septum, the cingulum, and structures around the third ventricle. Immunoreactivity in neurons was clearly apparent at the periphery of the perikaryon and in the apical dendrite. It is suggested that the intensity of the immunohistochemical reaction for α-tubulin may reflect the functional state of neurons. [ABSTRACT FROM AUTHOR]

We performed morphological analysis of the structure of rat hippocampus after ablation of the left sensorimotor cortex. Four experimental groups were formed: two control groups (intravenous and intracerebral injections of the culture medium) and two experimental groups (intravenous and intracerebral transplantation of MSC). Ten weeks after surgery, disturbed cytoarchitectonics and great number of dead neurons were found in all zones of the hippocampus in animals of the control groups. In animals receiving cell therapy, no pathological changes in the structure of the hippocampus were found: hyperchromatic neurons were absent and the cells had regular shape and closely adjoined to each other. [ABSTRACT FROM AUTHOR]