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Background. Currently, a large amount of reference information has been accumulated in the field of physiology of fur-bearing animals. The morphology and biochemistry of blood, immunological parameters were studied in detail. At the same time, there is significantly less data on the endocrine system and its effect on reproduction, and there is no information on the dynamics of cholesterol and testosterone in male foxes of different color types. There are few publications, especially those related to ontogenesis, that would analyze the formation of steroidogenesis. Considering that in the literature data on the endocrine system and its influence on the reproduction of fur-bearing animals are found in isolated cases, and there is no information on the dynamics of cholesterol and testosterone in male foxes, it is of great scientific and practical interest to clarify the ontogenetic dynamics of testosterone concentration in foxes of different color types and its relationship with cholesterol due to the latter’s direct participation in steroidogenesis. Therefore, the purpose of the study: to study the dynamics of testosterone and cholesterol concentrations in male foxes of different color types in postnatal ontogenesis. Materials and methods. The studies were carried out in the veterinary laboratory of the Federal State Budgetary Institution VNIIOZ named after. prof. B.M. Zhitkova (Kirov, Russia). The study used young domesticated foxes (Vulpes vulpes L., 1758), bred at Vyatka Animal Farm LLC (Kirov region, Russia). From clinically healthy male foxes of two color types: silver-black and red, 2 groups of 16 animals each were formed. Ontogenetic development was observed in animals aged from 45 days to 10 months. By the age of 9 months, animals become sexually mature and participate in the breeding process, which for foxes happens once a year - in January-February. Blood was taken from foxes at the age of 45 days, 4, 6, 9 and 10 months, which corresponded to the seasons of the year in July, September, November, February and March. The concentration of testosterone and cholesterol in the blood serum was determined. Testosterone was studied on an automatic microplate photometer Immunochem-2100 (High Technology Inc., USA) by enzyme-linked immunosorbent assay using a test system produced by Hema-Medica LLC (Russia). Cholesterol in blood serum was determined on a semi-automatic biochemical analyzer "Biochem SA" (USA) using kits from "Ecoservice" (Russia). The results were processed by statistical methods. The Mann-Whitney test was used to assess the significance of differences. The level of statistical significance of the obtained differences between the compared samples was accepted at p

This article presents a synthesis of the specialized literature regarding some aspects of the physiological state, growth, and development of calves in early postnatal ontogenesis. Calves have a distinct physiology, by comparison to adult cattle, adapted to their period of rapid development. Studying the physiology of calves during the early postnatal period is essential for ensuring their healthy growth and development, directly influencing long-term health and productivity. This critical period is marked by numerous physiological changes and adaptations, and understanding them is vital for implementing effective management and care strategies.

Epilepsy development can be caused by impaired postsynaptic action of GABA that is mediated by altered expression of GABA-A receptors and cation-chloride cotransporters, KCC2 (K+/Cl– cotransporter 2) and NKCC1 (Na+/K+/Cl– cotransporter 1). In the present study, we analyzed the expression of GABA-A receptors, KCC2, and NKCC1 in the hippocampus of Krushinsky–Molodkina (KM) rats, genetically prone to audiogenic seizures (AGS), during the first few months of the postnatal development (at P15, P60, and P120). Wistar rats of the corresponding ages were used as the control groups. In the hippocampus of KM pups, we observed downregulation of both KCC2 and NKCC1; however, the expression of GABA-A receptor α1-subunit (GABAAR(α1)) was increased. Moreover, KCC2 was not detected in an abnormally broad region of the granular layer, indicating the Cl– imbalance and impaired GABA-mediated inhibition in postsynaptic targets of GABA. These results suggested a delayed maturation of the hippocampal GABAergic system in KM rats in comparison with Wistar rats. In adult KM rats (P120) with fully developed susceptibility to AGS, normalization of both KCC2 and NKCC1 expression and KCC2 phosphorylation in the hippocampus was revealed. In contrast, GABAAR(α1) expression was decreased. We supposed that lower expression of GABA-A receptors in the hippocampus of adult KM rats might contribute either to the establishment of increased convulsive readiness or to hyperexcitation of the hippocampus during audiogenic kindling. [ABSTRACT FROM AUTHOR]

Background. Improving pediatric observation globally and in Kyrgyzstan is essential for early detection of developmental issues and monitoring normal physical parameters. The purpose of the study was to investigate the indicators of bone composition in children of Kyrgyz nationality of both sexes in the early childhood period. Materials and methods. To achieve the goal, 800 children from 4 to 7 years old were examined using anatomical-anthropometric and bioimpedance methods. Results. It was revealed that the absolute content of bone component in male respondents at the age of 4 years ranges from 3.24 to 5.17 (4.10 ± 0.01) kg, 5 years — from 3.27 to 5.81 (4.26 ± 0.01) kg, 6 years — from 3.34 to 5.87 (4.39 ± 0.01) kg and 7 years — from 3.23 up to 6.02 (4.59 ± 0.01) kg. The absolute index of the bone component in 4-year-old girls has an individual variability of 3.04–5.17 (3.97 ± 0.01) kg, 5-year-old — 3.27–5.61 (4.20 ± 0.01) kg, 6-year-old — 3.34–5.77 (4.34 ± 0.01) kg and 7-year-old — 3.43–6.02 (4.40 ± 0.01) kg. Conclusions. The highest bone content was found in individuals with muscular somatotype, while the lowest values were in asthenoid and thoracic somatotypes for both males and females. Boys had higher bone component index at ages of 4 and 7.

Epileptogenesis can be associated with altered genetic control of the GABAergic system. Here we analyzed Krushinsky–Molodkina (KM) rats genetically prone to audiogenic epilepsy. KM rats express fully formed audiogenic seizures (AGSs) not early, then they reach 3 months. At the age of 1–2 months, KM rats either do not express AGS or demonstrate an incomplete pattern of seizure. Such long‐term development of AGS susceptibility makes KM rats an especially convenient model to investigate the mechanisms and dynamics of the development of inherited epilepsy. The analysis of the GABAergic system of the hippocampus of KM rats was done during postnatal development at the 15th, 60th, and 120th postnatal days. Wistar rats of corresponding ages were used as a control. In the hippocampus of KM pups, we observed a decrease in the expression of glutamic acid decarboxylase 67 (GAD67) and parvalbumin (PV), which points to a decrease in the activity of GABAergic neurons. Analysis of the 2‐month‐old KM rats showed an increase in GAD67 and PV expression while synapsin I and vesicular GABA transporter (VGAT) were decreased. In adult KM rats, the expression of GAD67, PV, and synapsin I was upregulated. Altogether, the obtained data indicate significant alterations in GABAergic transmission in the hippocampus of audiogenic KM rats during the first postnatal months. [ABSTRACT FROM AUTHOR]

Objectives: The study aimed to account for baseline biometrical and histomorphometric testicu¬lar changes in Black Bengal goats during postnatal development. Materials and Methods: Black Bengal goats, divided into group I of VII; day 0; 1, 2 weeks; 1, 2, 4, and 6 months of age, respectively, were used in this study. Results: The biometrical and histomorphometric values of the testis varied significantly (p < 0.05) from postnatal 1–2 months. From day 0 to 2 months, seminiferous tubules, called sex cords, contained simply peripherally placed Sertoli cells and centrally placed gonocytes. Gonocytes, posi¬tioned in the center, moved centrifugally in the direction of the basement membrane of sex cords with the advancement of age, transformed into prespermatogonia, and were distributed among the Sertoli cells at the edge of sex cords that make up the basal cell layer in nearly all of the sem¬iniferous tubules by 2 months after birth. Initiation of spermatogenesis, i.e., stratification and lumination of seminiferous epithelium, took place in the 4th months. At 6 months, all types of spermatogenic cells had been identified. The onset of puberty, i.e., the establishment of sper¬matogenesis, was noticed to have been established at 6 months of postnatal age in Black Bengal goats, as shown by the spermatozoa that were adhered to the ad luminal border of the Sertoli cells and also in the tubular lumen. Conclusion: This research is the first to document the varying biometrical and histomorphometric measurements of the testis in Black Bengal goats from birth to puberty. [J Adv Vet Anim Res 2023; 10(2.000): 237-243]

Epilepsy is tightly associated with dysfunction of inhibitory GABA neurotransmission. In this study, Krushinsky–Molodkina (KM) rats genetically prone to audiogenic seizures (AGS) were used. KM rats are characterized by the development of audiogenic epilepsy during postnatal ontogenesis, with AGS onset at the age of 1.5–2 months and fully developed AGS expression by 3rd month. We analyzed GABAergic system of the inferior colliculi (IC) of KM rats at different stages of postnatal development. Wistar rats were used as a control. In the IC of young KM rats, Na+/K+/Cl– cotransporter 1 (NKCC1) expression was increased, while K+/Cl– cotransporter 2 (KCC2) was unchanged indicating impairment of postsynaptic GABA action at early stages of postnatal development. Moreover, we revealed also an increase in the expression of vesicular GABA transporter (VGAT) in the IC which additionally pointed on the higher activity of GABA release. In adult rats, in opposite, we revealed a decrease in the expression of KCC2 transporter indicating downregulation of GABA inhibition on the target cells. Thus, GABA dysregulation in the IC can mediate the seizure susceptibility in adult KM rats. [ABSTRACT FROM AUTHOR]

Objectives: The study aimed to account for baseline biometrical and histomorphometric testicular changes in Black Bengal goats during postnatal development. Materials and Methods: Black Bengal goats, divided into group I of VII; day 0; 1, 2 weeks; 1, 2, 4, and 6 months of age, respectively, were used in this study. Results: The biometrical and histomorphometric values of the testis varied significantly (p < 0.05) from postnatal 1–2 months. From day 0 to 2 months, seminiferous tubules, called sex cords, contained simply peripherally placed Sertoli cells and centrally placed gonocytes. Gonocytes, positioned in the center, moved centrifugally in the direction of the basement membrane of sex cords with the advancement of age, transformed into prespermatogonia, and were distributed among the Sertoli cells at the edge of sex cords that make up the basal cell layer in nearly all of the seminiferous tubules by 2 months after birth. Initiation of spermatogenesis, i.e., stratification and lumination of seminiferous epithelium, took place in the 4th months. At 6 months, all types of spermatogenic cells had been identified. The onset of puberty, i.e., the establishment of spermatogenesis, was noticed to have been established at 6 months of postnatal age in Black Bengal goats, as shown by the spermatozoa that were adhered to the ad luminal border of the Sertoli cells and also in the tubular lumen. Conclusion: This research is the first to document the varying biometrical and histomorphometric measurements of the testis in Black Bengal goats from birth to puberty. [ABSTRACT FROM AUTHOR]

Fishes of the Barbus (=Labeobarbus) intermedius complex (Actinopterigii, Cyprinidae), known in Russian-language literature as Large African Barbs, are widely distributed in Africa water bodies. A special feature of the morphological diversity of this group of fish is the sympatric coexistence of morpho-ecological forms in local populations. The most famous example of such coexistence takes place in Lake Tana located in the north of Ethiopia, where, according to different authors, up to 15 morpho-ecological forms (morphotypes) live. The diagnostic features of the barbs of Lake Tana morphotypes are clearly manifested upon reaching a standard length (SL) of approximately 15 cm. With a shorter length, representatives of most morphotypes are indistinguishable from each other. This suggests that, in ontogenesis, the main vectors of morphological variability of the Tana Lake barbs may be different before and after individuals reach a length of 15 cm. The aim of this study was to test this assumption. The results obtained confirm that, in this population, the standard length (SL), equal to approximately 15 cm, delimits two stages of postnatal ontogenesis in the studied group of fish. In individuals with SL < 15 cm, the main vector of variability is a consequence of changes in morphological proportions as the individual grows. In individuals with SL > 15 cm, the main vector of variability is most likely associated with the trophic resource partitioning. The original approach used in the study is considered promising in analyzing the peculiarities of variability at different stages of ontogenesis not only in the studied group but also in other systematic groups. [ABSTRACT FROM AUTHOR]

The proliferative properties of tanycyte subpopulations during postnatal development and aging were studied. Using immunohistochemical markers, we described the distribution of proliferative markers and markers of neural stem cells (NSC) in 4 tanycyte subpopulations (α1-, α2-, β1-, and β2-tanycytes). During the first postnatal week, all tanycyte subpopulations exhibit proliferative activity. During aging, β-tanycytes lose their proliferative activity and retain a limited set of NSC markers, whereas α-tanycytes maintain both the ability to proliferate and the properties of NSC throughout the entire postnatal development including aging. The data obtained significantly improve modern understanding of the proliferative potential of tanycytes and their subpopulation differences in early postnatal period and during aging. [ABSTRACT FROM AUTHOR]

The dynamics of changes in the live weight of saker falcon (Falco cherrug) chicks in the early postnatal period and the comparison of the growth energy of chicks of different morphometric groups during artificial feeding from hatching to transferring were investigated. The average period of minimum live weight gain in saker falcon chicks was 144–192 hours. The chicks with a smaller initial weight compensated it with higher growth energy on days 6–7 compared to the larger chicks.

The aim of our study was an anthropophysiological justification for the hemodynamic basis of the pressor (hyperresistive) installation in the circulatory state of the cardio-vascular system (CVS). Materials and methods. For the analysis, prefabricated materials were used according to agespecific blood pressure standards (BP), supplemented with their calculated data on the yearly increase in blood pressure values and were combined with the stages of postnatal adaptation of the CVS for the gravitational factor of the blood circulation. Based on the clinical observational study, an anthropophysiological diagnosis of the circulatory state of the CVS with a systemic assessment of the arterial impedance were carried out for the main circulatory blocks of the blood circulation (head, lungs, abdomen, pelvis, thigh, shin). Results. It was shown that with a permanent increase in blood pressure during postnatal ontogenesis, its highest increments were noted at the initial stages of the formation of the upright. This dynamic was based on a system pressor set in the regulation of the circulatory state of the CVS, which manifested itself, especially when standing, in the prevalence of hyperresistive syndromes of arterial vessels. The most pronounced throughout postnatal ontogenesis, hyperresistant syndromes in the standing position were manifested in the pelvis and lower limbs regions. Conclusions. Anthropophysiological approach, including syndromic analysis, were allowed early diagnosis of circulatory conditions that underlie circulatory failure.

Adrenergic innervation in the tissue of the cervical, mesenteric, and popliteal lymph nodes in rats of different age groups (from 2-45 days to 24 months) was studied using the specific fluorescence-microscopic imaging of catecholamines. Adrenergic innervation in the lymph nodes of rats is present from the first days of life, but it develops and complicates during postnatal ontogeny and is fully formed by thedays 20-30 of life. By the age of one month, adrenergic innervation represents a well-formed apparatus in all parts of the node, i.e. in the capsule, trabeculae, and cortical and medullary substance. These are brightly fluorescent nerve fibers that form plexuses with regularly located multiple varicosities. In senile animals, the density and number of plexuses in all parts of the lymph node are preserved, but the brightness of plexuses decreases, plexus fibers become discontinuous, varicosities become less frequent or disappear. These changes are seen in lymph nodes from different body regions. [ABSTRACT FROM AUTHOR]

The autonomic nervous system is involved in the regulation and formation of the heart rhythm. Most experimental studies about the influence of the autonomic nervous system on heart activity in ontogenesis were carried out on a whole organism or isolated tissue. An isolated heart by Langendorff can study arrhythmia, coronary vascular function, and can also help to understand the pathophysiology of modern human diseases, such as hypertension, diabetes, heart failure, or ischemia / reperfusion injury. The work is devoted to the study of isolated heart operation parameters according to Langendorff in postnatal ontogenesis with different levels of adrenergic innervation development. The analysis of the results showed that the stabilization of the isolated heart rate located in a perfused solution occurs during the 16th minute on average. The minimum heart rate values were recorded among newborn animals, the maximum heart rate was detected among 21 day old rats. CP stabilization in the studied age groups was recorded at different time intervals. 7 and 21 day old rats demonstrated the stabilization during the 16th minute, and 42 - 100-day old rat demonstrated such stabilization during the 14th minute. The minimum CP values were recorded among 7 and 21 day old rats; the maximum CP indices were found in adult rats. The stabilization of the contraction force among 42 and 100 day old animals was recorded during the 16th minutes. The minimum values of LVP were recorded in adult rats, the maximum values of LVP were found among 42 day old rats. [ABSTRACT FROM AUTHOR]

The formation of the alarm call's time–frequency characteristics at different stages of individual development was studied on the russet ground squirrel (S. major). The hypothesis about the vocalizations of young individuals of ground squirrels being emitted at lower frequencies than those of adults was tested. The results of the study indicate a differentiated formation of the sound signal in the different sexes of the russet ground squirrel in postnatal ontogenesis. The sound signal in females is formed in the first year of life during the season of activity, whereas it is formed in males in the year following the first hibernation. In terms of the studied call parameters, the voice of adult females is higher than that of young animals of both sexes, while the voice of adult males is lower. The possible causes and significance of the identified sex and age features of the alarm call of the russet ground squirrel are discussed. [ABSTRACT FROM AUTHOR]

Relevance. The immune response to gut antigens is initiated in the organized gut-associated lymphoid tissue, which regulates its specificity and modulates the gut microbiota. The study of the development of immune structures in early postnatal ontogenesis will make it possible to induce a sequence of their emergence in milk feeding. The aim of the study was to identify the features of the development of immune structures in the jejunum in newborn rabbits and during the period of milk feeding. Materials and methods. Morphological and morphometric methods were used to study the immune structures of the jejunum in 12 animals during the period of newborn and milk feeding (10 days after birth). Paraffin sections were stained using general histological methods. On a certain area of the field of view of the microscope, all types of lymphocytes, cellular elements of the mucous membrane were counted, and their ratio was determined. Research results. Afferent immune structures of the jejunal mucosa in newborn animals are represented by accumulations of lymphoid tissue without a definite shape, they are indistinctly limited from the surrounding connective tissue of the lamina propria, there are no structural and functional zones characteristic of lymph nodules. During the period of milk feeding, efferent immune structures are determined in the stroma of the villi and crypts, while the number of diffusely located lymphocytes and lymphoblasts increases sharply, lymphocytes are also found between epithelial cells. Conclusions. Morphological signs show that in postnatal ontogenesis there is an earlier development of the afferent link of immunogenesis in the jejunum of rabbits compared to the efferent one. [ABSTRACT FROM AUTHOR]

Diadenosine tetraphosphate (Ap4A) belongs to a group of endogenous purine compounds that have recently been considered as new neurotransmitters or cotransmitters in the autonomic nervous system. It has been shown that Ap4A affects electrophysiology of a pacemaker and working myocardium and modulates adrenergic control of the heart in adult mammals. Nevertheless, the physiological role of Ap4A in the regulation of bioelectric properties in the pulmonary vein (PV) myocardium has not yet been investigated. It is well known that myocardial tissue in the wall of the PV acts as source of the ectopic proarrhythmic activity that underlies supraventricular arrhythmias like atrial fibrillation. The aim of the present study was to elucidate the effects Ap4A on bioelectrical properties and proarrhythmic ectopy in PVs in adult rats and at early postnatal ontogenesis. Thus, the resting potentials and the electrically evoked and spontaneous action potentials were recorded with the use of the standard microelectrode technique in multicellular isolated PV specimens from male Wistar rats at postnatal days 1-, 7-, 14-, and 21- and also from 60-day-old animals, which were considered as mature. The application of Ap4A caused significant reduction of action potential duration in PV specimens from rats of all ages. Ap4A also caused significant resting membrane potential hyperpolar-ization in quiescent PVs specimens from 14-, 21-, and 60-day-old rats. In addition, Ap4A caused complete and significant suppression of ectopic automaticity caused by preliminary noradrenaline administration in PV from 21- and 60-day-old rats, but Ap4A was unable to alter spontaneous intrinsic activity in PV from neo-nate (1-day-old) rats. The Ap4A-caused attenuation of noradrenaline-induced ectopy in PV was accompanied by substantial resting membrane potential hyperpolarization in all cases. Our results allow suggesting that the release of Ap4A as a cotransmitter from autonomic nerve endings can reduce proarrhythmic ectopy caused by sympathetic stimulation of the PV myocardium in vivo. [ABSTRACT FROM AUTHOR]

Abstract It is known that audiogenic seizure (AGS) expression is based on the activation of the midbrain structures such as the inferior colliculus (IC). It was demonstrated that excessive sound exposure during the postnatal developments of the IC in rats led to AGS susceptibility in adulthood, which correlated with underdevelopment of the IC. In adult rodents, noise overstimulation induced apoptosis in the IC. The purpose of this study was to investigate postnatal development of the IC in rats genetically prone to AGS and to check if audiogenic kindling would activate apoptosis and/or proliferation in the IC. In our study, we used inbred audiogenic Krushinsky–Molodkina (KM) rats, which are characterized by age-dependent seizure expression. Analysis of postnatal development showed the increased number of proliferating cells in the IC central nucleus of KM rats on the 14th postnatal day (P14) in comparison with those of Wistar rats. Moreover, we also observed increased apoptosis level and decreased general cell population in the IC central nucleus. These data pointed towards a delayed development of the IC in KM rats. Analysis of the IC central nucleus of KM rat after audiogenic kindling for a week, with one AGS per day, demonstrated dramatically increased cell death, which was accompanied with a reduction of general cell population. Audiogenic kindling also decreased proliferation in the IC central nucleus. However, a week after the last AGS, the number of proliferating cells was increased, which supposes a certain compensatory mechanism to prevent cell loss. Graphical abstract Unlabelled Image Highlights • The IC of audiogenic KM rats develops later than the IC in control Wistar rats. • Cell proliferation was detected in the IC of adult Wistar and KM rats. • Audiogenic kindling stimulates neuronal apoptosis in the IC of KM rats. • The number of proliferating cells in the IC increased one week after audiogenic kindling. [ABSTRACT FROM AUTHOR]

The aim of the study was to identify the mechanisms of the toxic effect of intrauterine and early postnatal exposure to pesticides on the development of the immune system of offspring. Experiments were performed on white adult female rats, which are obtained respectively pesticidescyhalothrinor fipronil during the pregnancy and lactation periods. The offspring from experimental and control animals have been studied on days 3, 7, 14, 21 and 30 days after birth using morphology, electron microscopy, immunohistochemistry and biochemistry methods. In was shown, that the toxic effect of pesticide exposure through the maternal organism during pregnancy and lactation is manifested in the form of a violation of the growth and formation of the thymus, as well as thymusdependent zones of the peripheral organs of the immune system. In the mechanism of immunotoxic effect of pesticides a leading role plays the imbalance between proliferation and cells apoptosis of the thymus, caused both by direct toxic effects of drugs, and by the development of hypothyroidism and oxidative stress. [ABSTRACT FROM AUTHOR]

Objective: To investigate the state of femoral red bone marrow microvasculature of nonlinear white male rats in the course of an acute experiment. Materials and Methods: The ontogenesis of experimental animals were between 36 and 730 days: Intact ones, those subjected to the action of subtoxic doses of sulfur-bearing gas, and those receiving a protector-drug "Etoksidol". The data on microcirculation were obtained using laser Doppler flowmetry. The industrial sulfur-containing natural gas of the Astrakhan gas condensate field was used as a toxic agent. It was revealed that the reducing intensity of blood microcirculation in the red bone marrow of intact rats is statistically more significance in the presenile period of ontogenesis compared with the earlier periods. Results: The use of "Etoksidol" along with the influence of sulfur-containing pollutant on the experimental animals of different age groups led to improvement of microcirculation in the bone marrow at all the studied stages of ontogeny. However, such improvement was statistically highly significant (P < 0.01) in the mature age I, very close to significant in the mature age II, and was not statistically significant in the young and presenile age. Conclusions: As a result, the following findings were obtained: The toxic effect greatly reduces the intensity of the microcirculation in the bone marrow, which is most pronounced in younger animals; the experimental results suggest that the drug "Etoksidol," with an antihypoxic and antioxidant action, has a positive effect on red bone marrow microvasculature. [ABSTRACT FROM AUTHOR]

Using immunohistochemical methods, the morphological features of the sympathetic nerve structures in the pancreas of newborn, pubescent, and aging rats have been studied. The neural composition of intramural ganglia has been described. The intramural ganglia were shown to include chromaffin cells. In many ganglia of the pancreas, two types of pericellular nerve apparatuses have been detected simultaneously: tyrosine hydroxylase-containing catecholaminergic synaptic terminals and PGP 9.5-immunopositive cholinergic synapses. It was established that the density of catecholaminergic structures in the pancreas of rats decreases with age. [ABSTRACT FROM AUTHOR]

The histological structure and morphometric and some histochemical indices of thyroid gland of maral as a subspecies of red deer at the postnatal stage of ontogenesis were studied. It was established that the gland was structurally formed by the time of the birth. C-cells are detected at 6 months of age. With age, the ratio of follicles of different sizes changed: smaller forms predominate in newborns and those 6 months old, medium and large predominate in adults and in old deer. Histological, morphometric, and histochemical data indicate to activation of the thyroid gland in the period of intensive growth for up to 6 months and a gradual decrease in activity over the next years of life. During aging, along with an increase in stromal elements, large follicles with colloid are stretched and resorption processes in the follicles are reduced. [ABSTRACT FROM AUTHOR]

In order to identify the features of morphogenesis in postnatal ontogenesis examined histological structure of different departments and shells in the heart of rats 1-22 days after birth. There alternating periods of acceleration and deceleration of the growth rate increase in the thickness of the atrium and the ventricles. The thickness of the endocardial and epicardial increases less significantly. The growth rate of the ventricular myocardium thickness observed in rats 6 and 16 days of age. Structural changes occur due to the growth of the organism. A special feature of the structure and topography of the heart microvessels is their distribution in the course of the cardiomyocytes and the relationship with the fibrous structures of the connective tissue of cardiomyocytes. [ABSTRACT FROM AUTHOR]

Objective: Immunohistochemical evaluation of apoptosis and cells proliferation in the thyroid and thymus of offspring in a prenatal and early postnatal exposure to pesticides. Material and methods: Experiments were performed on white adult female rats, which were divided into 3 groups of 30 animals each. Two groups of animals for 30 days daily per os obtained respectively pesticides cyhalothrin (8 mg/kg), or fipronil (3.6 mg/kg). The third group receives only the same volume of sterile saline served as control. Apoptotic and proliferating cells of the thyroid gland and thymus were determined by immunohistochemistry method using monoclonal antibodies (Thermo Scientific, USA). Results: It was found that both fipronil and cyhalothrin under the influence through the mother causes a marked induction of apoptosis in the offspring thyroid and thymus. Simultaneously, these pesticides cause inhibition of proliferative activity of cells in these organs. Conclusions: Intrauterine and early postnatal exposure of pesticides to cause the induction of apoptosis, but the inhibition of proliferative activity of cells in the thyroid and thymus of offspring. In the mechanism of induction of apoptosis, besides the direct toxic effects of drugs are important hypothyroidism and oxidative stress observed in the offspring. These data contributes to the development of a new method of prevention and treatment of hidden toxic effects in pregnant women and their newborns. [ABSTRACT FROM AUTHOR]

The study focused on the changes of microcirculation indices and components of the vascular tone of endothelial, neural, and myogenic nature in symmetrical skin sites of temples, forehead, auricles, scapulae, and groin during postnatal ontogeny. Initially, microcirculation indices in the symmetrical regions decreased to postnatal day 10, thereafter they surpassed the initial level at the age of 30 days. The endothelial, neural, and myogenic indices of vascular tone changed differently in the symmetrical left and right sites. On the right side, all indices increased by the postnatal day 21 ('redundancy' phase), and by postnatal day 30 surpassed the initial level by two times. On the left side, the redundancy phase manifested in the endothelial component on postnatal day 10, but to postnatal day 30 all three indices dropped below the initial level. [ABSTRACT FROM AUTHOR]

The present study describes the data on the structural and functional changes of conjunctive tissue of the spleen in postnatal human ontogenesis. The study material includes 125 cadaver spleens obtained from individuals of both sexes who died from trauma and diseases that did not cause pathological changes in the spleen. The definition of ontogenetic phases and chronological confines of age ranges was identified according to V.V. Bunak (1965). The measurement of linear dimensions and organ mass, as well as histological, histochemical, and morphometric analyses, were performed. It was demonstrated that the increase in the content of lymphatic follicles was accompanied by a decrease in the conjunctive tissue component and red pulp in the area of the spleen section from the birth up to the age of four. The proportion of lymphoid tissue decreases, but the proportion of conjunctive tissue and red pulp increases by the age of eight to ten. The symptoms of aging detected at age 18 include an increase in the volume of the conjunctive-tissue component and destruction of external elastic membrane of trabecular artery of spleen. The destruction of elastic and reticulin fibers of the soft skeleton, the reduction of cellular elements (cells, fibroblasts, and fibrocytes), and the collagenization of conjunctive tissue stroma have been observed at mature and old ages. [ABSTRACT FROM AUTHOR]

Abstract: Expression of neuropeptide Y (NPY) in the sympathetic ganglia was investigated by immunohistochemistry and tract tracing. The distribution of NPY immunoreactivity (IR) was studied in the superior cervical ganglion (SCG), stellate ganglion (SG) and celiac ganglion (CG) from rats of different ages (newborn, 10-day-old, 20-day-old, 30-day-old, 2-month-old, 6-month-old, 24-month-old). We observed that the percentage of NPY-IR neuronal profiles increased during early postnatal development. In the SCG and SG, the percentage of NPY-IR profiles enlarged in the first month of life from 43±3.6% (SCG) and 46±3.8% (SG) until 64±4.1% (SCG) and 58±3.5% (SG). The percentage of NPY-IR profiles in the CG increased during the period between 20days (65±3.8%) and 30days (82±5.1%) of animals’ life and did not change in further development. In newborn and 10-day-old rats, a large portion of NPY-IR neurons was also calbindin D28K (CB)-IR in all sympathetic ganglia. The proportion of CB-IR substantially decreased during next 10days in the SCG, SG and CG. NPY-IR was approximately present in a half of the postganglionic neurons innervating muscle vessels of the neck and forearm, and the percentage of labeled NPY-IR profiles did not change during the development. Only single Ki67-IR neurons were also NPY-IR in the SCG, SG and CG in newborns and not in older animals. No NPY+/caspase 3+IR neurons were observed. Finally, the process of morphological changes in the size and percentages of NPY-IR profiles is complete in rats by the first month of life. [Copyright &y& Elsevier]

The study has shown that acute hypoxia in newborn rat pups can lead to disturbances in processes of formation of brain structures, behavior reactions, and learning in the subsequent ontogenesis. The single normobaric hypoxia at the 2nd day of life causes retardation of such integrative parameter or general development and growth as body mass at the period of feeding. In such animals, essential disturbances of the sensorimotor development were revealed in forms of delay of reflex reactions of turning on a plane, negative geotaxis, and avoidance of edge. Also detected was action of hypoxia on hanging on a rope by using front legs (a symptom of muscle weakness). Morphological study has shown all studied functional zones of neocortex (motor, sensomotor, auditory, visual) to response stereotypically to the early postnatal action of hypoxia. The death of nerve cells is predominant in the II-III associative layers, the sizes and number of pyramidal neurons are sharply decreased. Different hippocampus fields maturing after death in mammals show a characteristic response to hypoxia. In individual hippocampus fields there was detected a different degree of death of neurons, with predominance in the CA3 and CA4 fields. A possibility of modeling the perinatal encephalopathy with minimal brain dysfunctions in children is discussed. [ABSTRACT FROM AUTHOR]

The effects of daily trimming of the whiskers in rat pups from day 2 or day 9 to day 20 on eye opening time and the formation of early behavioral reactions, i.e., walking, rearing, grooming, and manipulatory activity, were studied in rat pups subjected to deprivation and siblings reared with them. Rat pups subjected to vibrissectomy from day 2 of life and their siblings showed acceleration of eye opening, maturation of grooming, and rearing without support; the formation of manipulatory activity was delayed, as were changes in the structures of correlational relationships between the times at which behavioral reactions formed and eye opening occurred. Vibrissectomy from day 9 of life eliminated most correlational relationships in deprived animals without impairing the dynamics of the development of early behavioral reactions. Siblings showed delayed formation of manipulatory activity, though changes in the structure of correlational relationships were less significant than in deprived animals. [ABSTRACT FROM AUTHOR]

We studied postnatal development of corticosteroid function of the adrenals in mice during the period of elevated activity of the hypothalamic-pituitary-adrenal axis and the influence of mutant gene A y on this process. Normally, a corticosterone peak in blood and increased basal and stimulated steroidogenesis in vitro are observed in 3-week old mice. In 3-week old A y/ a mice (hyperexpression of agouti protein) a corticosterone peak in blood is lowered and genotypic differences in steroidogenesis in vitro are absent, as compared to a/a mice (absence of agouti), while at the ages of 10 and 15 weeks, there were no genotypic differences in the blood level of corticosterone and steroidogenesis in vitro was elevated. Thus, a high level of corticosterone during the period of elevated activity of the hypothalamic-pituitary-adrenal axis in 3-week old mice is determined by enhanced steroidogenic function of the adrenals. Mutant gene A y in male mice affected the postnatal development of the adrenal function: the peak of corticosterone in blood was lowered during the period of elevated activity of the system. [ABSTRACT FROM AUTHOR]

Neurotransmitter features in sympathetic neurons are subject to change during development. To better understand the neuroplasticity of sympathetic neurons during early postnatal ontogenesis, this study was set up to immunocytochemically investigate the development of the catecholaminergic, cholinergic, and peptidergic phenotypes in the stellate ganglion of mice and rats. The present study was performed on Wistar rats and Swiss mice of different ages (newborn, 10-day-old, 20-day-old, 30-day-old, and 60-day-old). To this end, double labeling for tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), vasoactive intestinal (poly)peptide (VIP), neuropeptide Y (NPY), galanin (GAL), and somatostatin (SOM) was applied. The results obtained indicate that the majority of the neurons in the stellate ganglion of both species were TH-positive from birth onward and that a large part of these neurons also contained NPY. The percentage of neurons containing TH and NPY invariably increased with age up to 60 days postnatally. A smaller portion of the stellate ganglion neurons contained other types of neuropeptides and showed a distinct chronological pattern. The proportion of VIP- and ChAT-positive neurons was maximal in 10-day-old animals and then decreased up to 60 days of age, whereas the number of SOM-positive cells in rats significantly decreased from birth onward. In newborn rats, VIP-, ChAT- and SOM-positive neurons were largely TH-positive, while their proportions decreased in 10-day-old and older rats. Accordingly, the largest part of VIP-positive neurons also expressed SOM immunoreactivity at birth, after which the number of neurons containing both peptides diminished. The VIP- and SOM-positive cells did not contain NPY in any of the age groups studied. In rats up to 10 days of life, GAL-immunoreactive (-IR) neurons were scarce, after which their number increased to reach a maximal value in 30-day-old animals and then declined again. The SOM-reactive cells had the smallest size in all rats, while the largest neurons were those containing ChAT. In the mouse stellate ganglion, VIP- and ChAT-IR neurons were larger in comparison to NPY- and TH-IR cells. Our study further revealed some species differences: compared to mice the proportion of neurons containing TH and NPY was higher in rats at all ages under study. Furthermore, no GAL-immunostained neurons were found in mice and the number of SOM-positive cells in mice was limited compared to that observed in rats. In conclusion, the development of neurotransmitter composition is complete in rats and mice by their second month of life. At this age, the percentages of immunopositive cells have become similar to those reported in adult animals. [ABSTRACT FROM AUTHOR]

Changes in the distribution of NADPH-diaphorase (NADPH-d) and acetylcholinesterase (AChE) were studied in neurons of the stellate ganglion in newborn, 10-, 20-day-old, 1-, 2-, 4- and 6-month-old kittens. AChE-positive neurons were revealed in the stellate ganglion (SG) from birth onwards. The number of these neurons increased until 20 days of postnatal life and then declined in 1- and 2-month-old kittens. A small number of weakly stained, NADPH-d-positive cells were found in newborn kittens, while intensely stained neurons first appeared in 10-day-old animals and increased in number up to the second month of life. The size of AChE-positive neurons was larger in comparison with NADPH-d-positive cells in the stellate ganglion of all animals under study. We suggest that putative vasodilator neurons or cells innervating sweat glands exhibit different development patterns from the moment of birth. [Copyright &y& Elsevier]

Changes in in vitro testosterone production by Leydig cells induced by chorionic gonadotropin, dibutyryl-cAMP, and pregnenolone have been studied during postnatal development of four inbred mouse strains BALB/c, PT, CBA/Lac, and A/He, with contrast hormonal activity of testes in sexually mature males. The interlinear differences significantly change with age of the males by all studied indices indicating genotype-dependent formation of hormonal activity of Leydig cells during postnatal development. Coordinated interlinear variability between all indices of Leydig cells reactivity has been established for each studied period of postnatal development. Hence, we have established coordinated interlinear genetic variability of hormonal function of Leydig cells, which was confirmed by considerable changes in it during postnatal development at puberty. Definitive genotypic differences in hormonal activity of Leydig cells appeared by late pubertal and early postpubertal development (day 60) and coincided with termination of morphological differentiation of Leydig cells and appearance of the differentiated cell population. [ABSTRACT FROM AUTHOR]

• The hippocampus of audiogenic KM rats develops later than in normal Wistar rats. • Aberrant adult neurogenesis develops before audiogenic seizure expression. • Neuronal progenitors differentiate into the glutamate neurons in the hilus of adult audiogenic rats. The hippocampus plays an important role in epilepsy progression even if it is not involved in seizure generalization. We hypothesized that abnormal development of the hippocampus may underlie epileptogenesis. Here we analyzed postnatal development of the hippocampus of Krushinsky-Molodkina (KM) rats, which are the animal model of reflex audiogenic epilepsy. KM rats are genetically prone to audiogenic seizures that are expressed in age-dependent manner. The study was performed on seizure-naïve KM rats at several days of postnatal development (P15, P30, P60, P120). Wistar rats of the corresponding ages were used as a control. We showed that at early stages (P15, P30), the hippocampus of KM rats was characterized by significantly smaller cell population, but the number of proliferated cells was increased in comparison with control Wistar rats. Only at P60 proliferation and the total number of the hippocampal cells reached a level equal to Wistar rats. These data suggest delayed postnatal development of the hippocampus of KM rats. Analysis of apoptosis demonstrated significantly increased number of TUNEL-positive cells in the dentate gyrus (DG) of KM rats at P30 that was accompanied with expression of p53, Bcl-2 and cleaved caspases 3 and 9. Additionally, at all analyzed stages in the hilus of KM rats, the number of new-born glutamatergic cells was significantly increased that suggests formation of hilar ectopic granular cells. Our data suggest that in the case of hereditary epilepsy aberrant neurogenesis may be genetically determined. [ABSTRACT FROM AUTHOR]

Electrical activity of the sympathetic vertebral nerve (VN) was studied in kittens (0–180 days) using frequency domain analyzes. Rhythmical discharges in the studied nerve were observed from the moment of birth and correlated with cardiac (1.2–3 Hz) and respiratory frequency (0.15–0.7 Hz). Amplitude of discharges was minimal in newborn kittens and increased during ontogenesis. Relative spectral power was maximal at cardiac and respiratory frequencies in animals in all age groups. ‘10-Hz discharges’ (8–12 Hz band) in the VN oscillations appeared only in animals older than 20 days of life. In accordance to their sympathetic nerve discharge, kittens become mature at 2 month of their life. [Copyright &y& Elsevier]

Immunomorphological analysis revealed the presence of thymalin in human epidermis and in fetal reticuloepithelium. These structures are developed from the common embryonic primordium ectoderm. In embryos and adult humans thymalin is present only in young epidermal cells, which undergo age-related involution. By the age of 70 years, the layer of thymalin-containing cells looks thinned and discontinuous. The content of thymalin, a thymic factor, decreases with age. [ABSTRACT FROM AUTHOR]

Effects of morphine and of the protease inhibitor antipaine on RNA synthesis in nerve cells and hepatocytes of 1-, 6-, and 12-month WAG and F344 rats is studied. Slices of sensorimotor cortex, hypothalamic ventromedial nucleus, blue spot, superior cervical sympathetic ganglion, and liver were incubated with the drugs and3H-uridine in vitro. Control and experimental levels of transcription differed in examined structures and changed in the course of postnatal ontogenesis. [ABSTRACT FROM AUTHOR]

The effect of prenatal and early postnatal exposure to pesticides of new generation (cyhalothrin and fipronil) on the postnatal dynamics of the formation of pituitary-thyroid system of offspring has been studied. It was found that the impact of pesticides through the mother's body slows down the rate of formation of thyroid follicles offspring. Violation of the pituitarythyroid system is manifested in the form of hypothyroidism. All this leads to a thorough monitoring of thyroid function in pregnant women and newborns at increased risk of environmental pollution by pesticides. [ABSTRACT FROM AUTHOR]

Krushinsky-Molodkina (KM) rats genetically prone to audiogenic seizure are characterized by age-dependent expression of audiogenic seizures (AGS). It is known that the critical period of enhanced seizure susceptibility in rodents occurs at 2nd–3rd weeks of postnatal development. However, KM rats do not express AGS at this time-point, but start to demonstrate a stable AGS only after the age of 3 months. We hypothesized that this delay in AGS susceptibility in KM rats is genetically determined and may depend on some alterations in the development of the hippocampal glutamatergic system during the early postnatal period. We analyzed the expression and activity of seizure-related proteins, such as vesicular glutamate transporter 2 (VGLUT2), extracellular signal-regulated kinases 1 and 2 (ERK1/2), synapsin I, and NR2B subunit of the N -methyl- d -aspartate (NMDA) receptor (NR2B) in the hippocampus of KM rats during postnatal development. A significantly higher activity of ERK1/2 in KM rats was observed at 14th, 30th, and 60th days of postnatal development (P14, P30, P60) in comparison with control Wistar rats of the corresponding ages, while in adult (P120) KM rats it was at the same level with Wistar rats. Despite the increased activity of ERK1/2 at P14 and P30, the phosphorylation of synapsin I at Ser62/67 was significantly lower in the hippocampus of KM rats than in Wistar rats of the same ages; however, at P60 and P120, the phosphorylation of synapsin I was enhanced. Our data also revealed the increase of VGLUT2 and NR2B expression at P14, which dramatically decreased at the later stages. Our data indicate that a genetically determined increase in ERK1/2 kinase activity during postnatal ontogenesis in KM rats may be associated with the disturbances in synthesis and activity of the proteins, which are responsible for glutamatergic transmission in the KM rat hippocampus during the seizure susceptibility development. Unlabelled Image • Early stages of postnatal development of KM rats are characterized by high ERK1/2 activity in the hippocampus • High expression of VGLUT2 and NR2B at P14 is dramatically decreased during the adulthood • Phosphorylation of Synapsin I is decreased in the hippocampus of KM pups and increased in adults • Increased ERK1/2 activity is associated with impaired glutamate transmission during the seizure susceptibility development [ABSTRACT FROM AUTHOR]