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This work was performed on the offspring of 5 outbred female albino rats to give a comparative immunohistochemical evaluation of doublecortin (DCX) and NeuN expression in the neurons of the cerebellar cortex and nucleus interpositus in the early postnatal ontogenesis (postnatal days 2-15). DCX expression was detected in postmitotic neurons of the external granular layer and migrating neurons of the cerebellar cortex. At postnatal days 2 and 7 DCX expression in neocerebellum was higher than in paleocerebellum. NeuN expression was found to appear in migrating granule neurons, and reach the maximum in mature neurons of internal granular layer. DCX expression was not detected in Purkinje cells and in the nucleus interpositus of the cerebellum. In neurons of the nucleus interpositus the expression of NeuN progressively increased from postnatal days 2 to 15. Thus, a comparative immunohistochemical study of the dynamics of the expression of the pair of molecular markers studied proved to be an effective way of the assessment of the development of granular neurons of the cerebellum in early postnatal ontogenesis.

Objective. To analyze the changes in the size and shape of perikaryons and the degree of cytoplasm chromatophilia of the rat hippocampal and parietal cortex neurons at different periods after the modeling of total cerebral ischemia. Material and Methods. The experiments were performed on 42 male outbred white rats with an initial weight of 240 ± 20 g. Total cerebral ischemia in white outbred rats was modeled by decapitation. The material for further histological examination was taken at the 1st, 5th, 15th, 30th and 60th minutes, as well as 5 and 24 hours after decapitation. The study of histological preparations was carried out using an Axioscop 2 plus microscope, a digital video camera and the ImageWarp image analysis program. Among the total number, the cells were isolated by the intensity of cytoplasm staining (chromatophilia). After a preliminary check for the normal distribution of indicators, the data obtained were analyzed by non-parametric statistics. Results. With total cerebral ischemia, a decrease in the size of neurons and deformation of perikaryons were observed. Normochromic neurons completely disappeared at the 60th minute. The number of hyperchromic neurons increased, and then progressively decreased. Shrunken neurons made up the majority of cells in the studied cortical sections at the 30–60th minutes, and then, after 5 and 24 hours, cells with pericellular edema prevailed in the neuron population.Conclusion. The obtained data on histological changes in neurons of phylogenetically different parts of the cerebral cortex in the dynamics of total cerebral ischemia provide the basis for further detailed study of post-mortem changes of the brain as well as determining the time of death, thus creating a fundamental basis for studying the properties of neurons, including their transition from one functional state to another.

Background. Alcohol consumption during pregnancy induces the development of a number of specific disorders in offspring that are combined under the term Fetal Alcohol Syndrome (FAS), which is a part of Fetal Alcohol Spectrum Disorders (FASD). The aim of this study was to assess the effect of antenatal alcoholisation on synaptogenesis in the inner pyramidal layer of the frontal cerebral cortex of rats in postnatal ontogenesis. Material and methods: experiments were performed on 12 female white rats and their offspring, using immunohistochemistry and electron microscopy methods. Results: antenatal alcoholisation leads to decrease in the expression of the marker of synaptic vesicles, synaptophysin, disruption of the synapse ultrastructure, and a decrease in the number of synaptic vesicles. Conclusions: antenatal alcoholisation leads to disruption of synaptogenesis in the inner pyramidal layer of the frontal cerebral cortex of the rat.

Objectives. To study structural and histochemical changes in neurons in the frontal cortex of the brain in rats after ligation of the common bile duct. Materials and methods. The cortex of the frontal lobe was studied in 72 mongrel adult white male rats weighing 200 ± 25 g. Ligation of the common bile duct and development of cholestasis (experimental group) and sham surgery (control group) was followed by histological and histochemical studies of microstructural changes in pyramidal neurons in all layers of the frontal cortex on days 2, 5, 10, 20, 45, and 90. Results. Ligation of the common bile duct in rats producing cholestasis led to profound histological and histochemical changes in neurons in the frontal cortex of the brain: changes in size and shape, and appearance of hyperchromic shrunken neurons and ghost cells. Impairments to energy and plastic metabolism in neurons led to the death of the experimental animals. The consequences of cholestasis in the brains of rats were apparent on days 2-5 and reached a maximum on days 10-20. In the later post-operative period (45-90 days), groups of survivors showed gradual reductions in these changes, though the consequences of cholestasis consisted of foci of neuron loss in all layers of the frontal cortex. Conclusions. It is suggested that survival of rats after ligation of the common bile duct is due to formation of bypass bile ducts, with elimination of cholestasis and the high adaptive potential of neurons. [ABSTRACT FROM AUTHOR]

We report here quantitative structural and histochemical evaluation of the postnatal development of organelles in neurons in the inner pyramidal layer of the frontal cortex in rat pups aged 5, 20, and 45 days form birth (four animals of each age). Growth of the perikaryon was seen during postnatal ontogeny, along with the consistent development of organelles within neurons. With age there was a progressive increase in the number of mitochondria, which became more extended in shape. Mitochondria showed progressive increases in the number and lengths of cristae. These changes were accompanied by increases in the activities of mitochondrial marker enzymes SDH and NADHDH. On day 5 after birth, the neuron cytoplasm was dominated by free ribosomes and then by rough endoplasmic reticulum. Cistern size increased progressively. Golgi complexes were not yet formed on day 5 after birth, though they were present by day 20. Lysosome numbers and size increased significantly by day 20; the activity of the lysosomal marker enzyme acid phosphatase showed a similar pattern. [ABSTRACT FROM AUTHOR]

The aim of the present work was to undertake a comparative study of the effects of prenatal alcoholization of the histological characteristics of neurons in the frontal cortex of the brains of rats of different ages. Experiments were performed on 175 mongrel white rats - the offspring of 25 females given 15% ethanol as drinking solution throughout pregnancy. The cerebral cortex was studied on postnatal days 2-90 using histological, histochemical, and morphometric methods. An increase (on days 2 and 5) followed by a decrease (on days 10 and 90) was seen in cortical thickness, with a decrease in neuron body size (on days 20-90), a decrease in the number of neurons in cortical layer V, a decrease in the number of normochromic cells, and increases in the numbers of hyperchromic shrunken neurons and ghost cells throughout the study period. Antenatal alcoholization in rats induced various histological changes in the frontal cortex, which were long-lasting and progressive during postnatal ontogeny. [ABSTRACT FROM AUTHOR]

The aim of the study reported here was to assess structural and metabolic changes in rat parietal cortex neurons during complete external bile drainage. Quantitative histochemical and electron microscopic methods were used. The findings showed that drainage of bile from the body led to gradual increases in the numbers of hyperchromic pyknotic neurons and ghost cells, death and reductions in the numbers of neurons, and increases in the number of glial cells in all layers of the parietal cortex. There was a gradual decrease in neuron size, with loss of sphericity (elongation). The cytoplasm showed decreases in succinate dehydrogenase, NADH, NADPH, and glucose-6-phosphate dehydrogenases, and decreases in RNA content, though these changes were accompanied by activation of lactate dehydrogenase and acid phosphatase. Nuclei and organelles (mitochondria, endoplasmic reticulum, Golgi complexes) underwent destructive changes, which were accompanied by increase in the numbers and sizes of lysosomes and phagosomes. Some neurons showed activation of the nuclear apparatus and increases in the relative content of free ribosomes. Thus, loss of bile from the body induced progressive increases in structural and metabolic changes in parietal cortex neurons, leading to the death of some and compensatory changes in others. [ABSTRACT FROM AUTHOR]