Comparative characteristics of the cyto- and angioarchitectonics of the inferior olives and the dentate nuclei of the cerebellum during human prenatal ontogenesis]

The development of the inferior olives and the denticulate nuclei of the cerebellum and their capillary network were studied in human fetuses 4--10 months old. General regularities in the formation of the inferior olives and the denticulate nuclei of the cerebellum were stated. During prenatal ontogenesis, nuclear cytoarchitectonics becomes more complex that is especially evident after 7th month of the intrauterine development: the density of the neural cells arrangement decreases, while the density of the glia arrangement and that of the glial index increases. At the same time, essential alterations occur in the capillary network: int acquires three-dimensional structure, becomes longer with more complicated interrelations between the neural cells and the capillaries.     

The role of serotonin in the immune system development and functioning during ontogenesis

In this study, we investigated the influence of serotonin on the development and functioning of T- and B-cell-mediated immunity during ontogenesis using the pharmacological model of serotonin depletion in rat fetuses. It has been demonstrated that prenatal serotonin deficiency resulted in a decrease in thymus and spleen weights, changes in their cellular composition, and long-lasting disturbances in cell-mediated and humoral immunity in postnatal ontogenesis. The data obtained suggest that serotonin may be considered a morphogenic factor in development of the immune system.     

Morphological, cytochemical and radioautographic analysis of the development of a population of mitral cells of the rat olfactory bulb in prenatal ontogeny]

The dynamics of DNA synthesis, its ratio to the proliferative activity and changes in the amount of genetic material in mitral cells of the white rat olfactory bulb during prenatal ontogenesis, as well as in newborn rats are considered. The lengthening of G2-phase, decrease of mitotic activity and increase of DNA content in the nuclei of forming mitral cells were shown to occur in the period from 18 till 20 days of embryogenesis.     

Morphologic changes in the pineal gland of rats exposed to continuous darkness

We examined the pineal structure of rats exposed to constant darkness (DD) at light microscopic level. Two groups of rats were exposed to 12:12 light/dark cycle (LD) or DD from their prenatal ontogenesis and then for 3 months after birth. The gland structure of DD rats was observed to have an active appearance. Some of the observed pinealocytes with light nuclei from DD rats were determined to contain double nucleoli. Nuclear area and perimeter of both dark and light types were greater in rats kept in DD than in LD. Rats exposed to DD had more cells with light nuclei and lesser cells with dark ones than rats kept in LD. No significant differences in nuclear characteristics of intermediate type were found between rats kept in LD and those kept in DD. The activity of mammalian pineal can be altered by light conditions to which the animal is exposed.     

Main principles of the organization of the microcirculatory bed of the human greater omentum in early ontogenesis

The formation process of the terminal blood bed of the greater omentum has been studied in 42 human fetuses 14--28-week-old. The main peculiarities of the greater omentum blood bed by the 14th week of development are: paired arrangement of the afferent and deferent blood vessels and loop-shaped type of capillary growth, that joining the arteriole and venule, lend the blood stream a maximally centralized character. In 15--16 weeks of the fetal development in the omentum another type of the vascular growth occurs, characterized with appearance of single angioblastic processes that branch off the apex of the capillary loops. As a result new capillaries form; they connect apices of the capillary loops, that in their turn make bases for developing a true capillary network. Together with this, presence in ontogenesis of an autochthonous way of capillary appearance is proved, their connection with the closed blood stream is followed. Distinguishing of the loop-shaped stage in the capillary growth determines certain difference between vasculogenesis in ontogenesis and the vascular growth at reparative regeneration, since the base for the latter is only the capillary growth by means of single angioblastic processes.     

Development of the habenulointerpeduncular tract of rats

Development of the habenulointerpeduncular tract has been carried out on fixed brains obtained from 21 day rat embryos and from neonatal animals on the 0 and 9 days of postnatal development by DiI tracing method (1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate) along neuronal membranes. The marker was inserted into the nuclei of the habenula, the interpeduncular nucleus, and into the area of raphe nuclei. Neurons and fibers that contained DiI were identified on vibratome sections by fluorescent and confocal microscopy. We have found that reciprocal connections between the lateral habenular nucleus and raphe nuclei are formed in the prenatal period by stage E21. Raphe nuclei innervating neurons were located in dorso- and ventrocaudal parts of the lateral habenular nucleus. Projections of the medial habenular nucleus onto interpeduncular nucleus were found only in the postnatal period from P2. Neurons that provide a source of these projections form characteristic groups inside the medial habenular nucleus. Therefore, the present study for the first time describes heterogenic formation of different projection systems that are included in the habenulointerpeduncular tract of rats at perinatal ontogenesis.     

Quantitative changes in the total proteins of the cells of the hypothalamic supraoptic nucleus after extreme exposures: acute immobilization and deprivation of the paradoxical sleep phase

It has been shown that 1-hour acute immobilization of rats resulted in a decrease of total protein content (per 1 cell) in neurones (by 17% in cytoplasm and 22% in nucleus) of the supraoptic nucleus of the hypothalamus and in their glial satellite cells (by 10%), mainly at the expense of the nuclei of the latter. These changes remained at the same level in the neuronal cytoplasm and satellite cells within 6 hours after cessation of acute immobilization, being abolished in the neuronal nuclei. Deprivation of REM sleep for 24 hours affected these parameters to the same extent as acute immobilization. However, 6-hour rest was sufficient for normalisation in satellite cells and for decrease in protein deficiency in the neuronal nuclei; yet protein deficiency still sustained in the neuronal cytoplasm. REM sleep deprivation was also accompanied by a decrease in tritium incorporation into satellite cell proteins (by 18%); after 3-hour rest, incorporation of the label into satellite cells was restored to the initial level being increased by 20% in neuronal nuclei; another 3-hour rest resulted in normalisation of labeling in the neuronal nuclei and in 27% increase of labeling in the satellite cells.     

Postnatal development of the cerebellar Purkinje cell shape in guinea pig ontogenesis

In sagittal cerebellum sections, morphometrical study of cerebellum of mature-born animals - guinea pigs - was performed using Nissl's procedure. A change of shape and volume of Purkinje cells and their nuclei in the course of the guinea pig postnatal ontogenesis was studied. It has been shown that both the growth process itself and the rate of formation of the definite form of Purkinje cells and of their nuclei in the course of ontogenesis proceeds non-uniformly. The most intensive growth of vertical and horizontal diameters of Purkinje cells and of their nuclei is observed during the 1st and 4th weeks of postnatal life. Especially rapid is an increase of horizontal diameters of Purkinje cells and of their nuclei, which impairs the ovoid-bear-like shape to the cerebellar Purkinje cells of adult guinea pigs.     

Morphologic mechanisms of blood flow regulation in the hemomicrocirculatory system of the human heart during ontogenesis

Hearts of 220 human corpses, who had not any cardiovascular system disease during their life, have been distributed into age groups, beginning from fetuses up to old age. By means of injection, silver nitrate impregnation and scanning electron microscopy methods, applied to corrosive preparations, morphological mechanisms of the blood stream regulation in the hemomicrocirculatory bed of the human heart have been revealed in ontogenesis. The first group of the regulation mechanisms includes proper mechanisms inherent in the links of the microbed: spatial orientation of microvessels, precapillary sphincters, anastomoses between these vessels, sequence in arrangement of the endothelial cell nuclei, length, diameter and number of links in the microcirculatory bed. The second group embraces those mechanisms, that depend on structure of the myocardial wall, influencing the microcirculatory bed.     

Postnatal development of the shape of cerebellar Purkinje cells in guinea pig ontogenesis

In sagittal cerebellum sections, morphometrical study of cerebellum of mature-born animals—guinea pigs—was performed using Nissl’s procedure. A change of shape and volume of Purkinje cells and their nuclei in the course of the guinea pig postnatal ontogenesis was studied. It has been shown that both the growth process itself and the rate of formation of the definite form of Purkinje cells and of their nuclei in the course of ontogenesis proceeds non-uniformly. The most intensive growth of vertical and horizontal diameters of Purkinje cells and of their nuclei is observed during the 1st and 4th weeks of postnatal life. Especially rapid is an increase of horizontal diameters of Purkinje cells and of their nuclei, which impairs the ovoid-bear-like shape to the cerebellar Purkinje cells of adult guinea pigs.     

Tissue-Specific Differences in the Spatial Interposition of X-Chromosome and 3R Chromosome Regions in the Malaria Mosquito Anopheles messeae Fall.

Spatial organization of a chromosome in a nucleus is very important in biology but many aspects of it are still generally unresolved. We focused on tissue-specific features of chromosome architecture in closely related malaria mosquitoes, which have essential inter-specific differences in polytene chromosome attachments in nurse cells. We showed that the region responsible for X-chromosome attachment interacts with nuclear lamina stronger in nurse cells, then in salivary glands cells in Anopheles messeae Fall. The inter-tissue differences were demonstrated more convincingly in an experiment of two distinct chromosomes interposition in the nucleus space of cells from four tissues. Microdissected DNA-probes from nurse cells X-chromosome (2BC) and 3R chromosomes (32D) attachment regions were hybridized with intact nuclei of nurse cells, salivary gland cells, follicle epithelium cells and imaginal disсs cells in 3D-FISH experiments. We showed that only salivary gland cells and follicle epithelium cells have no statistical differences in the interposition of 2BC and 32D. Generally, the X-chromosome and 3R chromosome are located closer to each other in cells of the somatic system in comparison with nurse cells on average. The imaginal disсs cell nuclei have an intermediate arrangement of chromosome interposition, similar to other somatic cells and nurse cells. In spite of species-specific chromosome attachments there are no differences in interposition of nurse cells chromosomes in An. messeae and An. atroparvus Thiel. Nurse cells have an unusual chromosome arrangement without a chromocenter, which could be due to the special mission of generative system cells in ontogenesis and evolution.     

The autonomic division of oculomotor nerve nuclei in mammals and during human development]

Development of the vegetative component of the oculomotor nerve nuclei was studied in the main mammalia orders and in human ontogenesis. In phylogenesis parasympathetic nuclei of Jakubovitch--Edinger--Westphal and those of Perlia are formed later than somatic nuclei of the oculomotor nerve. The animals studied have, together with well developed somatic components of the oculomotor nerve nuclei, gomologues of parasympathetic nuclei, which are rather well developed in carnivores and monkeys. In human prenatal ontogenesis, somatic nuclei are formed first and then parasympathetic ones. Both parts of the oculomotor nerve nuclei are fully developed in adult man.     

Formation of Coordinational Function of the Central Nervous System: Phylo- and Ontogenetic Aspects

A comparative-ontogenetic analysis has been performed of literature and authors' own data obtained in studies on regularities of formation of interrelations of somatic-autonomic reactions in the process of phylo- and ontogenetic development in the row of vertebrates. This analysis has allowed showing universality in formation of the motor-cardiac reflex both in phylo- and in ontogenesis on the basis of maturation of these reactions and the coordinational function of the nervous system in the process of phylogenesis (fish, amphibians) and prenatal ontogenesis of mammals (human fetuses). This indicates the common character of embryonal and neuronal mechanisms of the autorhythmical nature both in phylo- and in ontogenesis of vertebrates.     

Histomorphogenesis and immunohistochemical study of the bovine pineal gland (Bos taurus) during prenatal development (160 days of gestation to birth)

The ontogenesis of the pineal gland of 20 bovine embryos (Bos taurus) has been analysed from 160 days of gestation to birth by means of optical microscopy and immunohistochemical techniques. For this study, the specimens were grouped into two stage in accordance with the most relevant histological characteristics: Stage 1 (160 to 200 days of prenatal development) and Stage 2 (220 days of prenatal development to birth). At 160 days of gestation some rounded structures with a central lumen, which we refer to as glandular rosettes, begin differentiation from the epithelium of the pineal recess, experiencing an extraordinary increase in number and size at 200 days of intrauterine life. In the interior of the pineal parenchyma we observed some morphologically rounded cells with oval euchromatic nuclei and a well-differentiated nucleolus that we refer to as the pinealoblasts. We also observed other cells characterised by the presence of low cytoplasm and rounded and highly stained nuclei that we refer to as the interstitial cells. The glandular stroma is formed from the capsular, trabecular, and perivascular connective tissue as well as from the reticular network that comes from the cellular processes of the interstitial cells. The blood vessels, at 240 of gestation, show well-formed walls where the endothelial cells stand out. At 160 days of gestation we witnessed some cells with small, dense, oval nuclei, positive to the glial fibrillary acidic protein (GFAP). At this age NPY positive fibres were detected, distributed around the blood vessels and among the pinealoblasts. We conclude by clarifying that the changes detected in the morphology as well as in the number and size of glandular rosettes appear to be related to the functional activity of the pineal gland during embryonic development.     

Sensitivity of the rabbit embryonal Leydig cells to the action of different pituitary hormones

Leydig cells reaction of rabbits testis to choriogonin action has been investigated during the prenatal period of ontogenesis. It has been found, that these cells sensitivity to the hormones studied has been detected at the early stages of embryogenesis. The specialization of Leydig cells response to choriogonin, thyrotrophin and prolactin in the process of prenatal period has been shown.     

Postnatal physiological development of rats after acute prenatal hypoxia

The aim of study was to investigate the physiological development of the brain and behaviour in rats subjected to prenatal hypoxia on the 13.5th day of embryogenesis. We have found that such rats manifested a delayed physiological development and a change in nervous tissue of the sensorimotor cortex, as well a disturbed formation of motor responses during the first month of postnatal ontogenesis. During maturation these modifications were in part compensated, however we observed a decrease of the rats' ability to learn new forepaw movements. The destruction of the brain tissue and the modification of neurons composition in the sensorimotor cortex correlated with changes of behaviour at different stages of ontogenesis. Thus, changes of the conditions under which an organism develops during embryogenesis, predetermine a disturbance in ontogenesis and the learning ability.     

Effect of thyroid hormones and diacylglycerols on sphingomyelin metabolism in liver cell nuclei in rats of various ages]

Sphingomyelin metabolism in liver cell nuclei of rats of various age has been studied. It was found that the level of sphingomyelin hydrolysis in cell nuclei is the highest in young animals, showing a decrease in 24-month-old animals. The age-specific fluctuations in the activity of phospholipase C may be one of possible reasons for sphingomyelinase activity changes in liver nuclei during ontogenesis. It has been shown that thyroid hormones and diacylglycerols control the sphingomyelinase activity in rat liver cells.     

Morphofunctional characteristics of microcirculation in the skin of girls 5-17 years of age

In 261 girls year-to-year morphofunctional transformations of spatial composition of the skin microcirculatory bed have been studied at rest and after a dynamic local load. By means of biomicroscopy main regularities in development of the skin capillary network have been revealed in the nail torus in the postnatal ontogenesis. Formation of the microvessels reactivity during various age periods and maturation of mechanisms of the compensatory-adaptive reactions are connected with formation of the definitive composition of the microcirculatory bed, that in girls corresponds to 11-12 years. Qualitative transformations in the skin capillary network bring certain quantitative changes in the structural microcirculatory parameters--increasing diameter of microvessels and increasing density of functioning capillaries.     

Age-associated reduction of nuclear shape dynamics in excitatory neurons of the visual cortex

Neurons decline in their functionality over time, and age-related neuronal alterations are associated with phenotypes of neurodegenerative diseases. In nonneural tissues, an infolded nuclear shape has been proposed as a hallmark of aged cells and neurons with infolded nuclei have also been reported to be associated with neuronal activity. Here, we performed time-lapse imaging in the visual cortex of Nex-Cre;SUN1-GFP mice. Nuclear infolding was observed within 10 min of stimulation in young nuclei, while the aged nuclei were already infolded pre-stimulation and showed reduced dynamics of the morphology. In young nuclei, the depletion of the stimuli restored the nucleus to a spherical shape and reduced the dynamic behavior, suggesting that nuclear infolding is a reversible process. We also found the aged nucleus to be stiffer than the young one, further relating to the age-associated loss of nuclear shape dynamics. We reveal temporal changes in the nuclear shape upon external stimulation and observe that these morphological dynamics decrease with age.     

Development of glomerular capillaries of the definitive kidney in the prenatal ontogenesis of man

The morphology of development of the glomerular capillaries in the human definitive kidney has been studied during prenatal ontogenesis. They are laid down in two ways: in the renal corpuscule rudiment from the migrated angioblasts and by ingrowth of the capillaries from the precapillary branchings of afferent arterioles into the nondifferentiated aggregate of nephrogenic cells. Both types of glomerulogenesis are observed after the afferent arterioles reach the corpuscule rudiments.