Stages Of Postnatal Development Research Articles

Autophagy-Mediated Synaptic Refinement and Auditory Neural Pruning Contribute to Ribbon Synaptic Maturity in the Developing Cochlea.

In rodents, massive initial synapses are formed in the auditory peripheral nervous system at the early postnatal stage, and one of the major phenomena is that the number of afferent synapses in the cochlea is significantly reduced in the duration of development. This raises the hypothesis that the number of cochlear ribbon synapses are dramatically changed with hearing development and maturation. In this study, several tracers identifying activities of autophagy were applied to estimate the level of autophagy activity in the process of ribbon synapse development in mice; further, changes in the synaptic number and spiral ganglion nerve (SGN) fibers were quantitatively measured. We found robust expression of LC3B and lysosomal-associated membrane protein 1 as well as LysoTracker in or near inner hair cells and cochlear ribbon synapses in the early stage of postnatal development. Moreover, we found a significant loss in the intensity of SGN fibers at ribbon synaptic development and hearing onset. Thus, this study demonstrates that ribbon synaptic refinement and SGN fibers pruning are closely associated with the morphological and functional maturation of ribbon synapses and that synaptic refinement and SGN fiber pruning are regulated by the robust activities of autophagy in the earlier stages of auditory development.

Identification of differentially expressed genes at different post-natal development stages of longissimus dorsi muscle in Tianzhu white yak

The regulatory mechanisms controlling post-natal muscle development in the yak (Bos grunniens) are still largely unknown, yet the growth and development of muscle is a complex process that plays a crucial role in determining the yield and quality of an animal’s meat. In this study, we performed a transcriptome analysis based on the RNA sequencing (RNA-Seq) of yak longissimus dorsi muscle tissue obtained from calves (6 months of age; 6 M), young adults (30 months of age; 30 M) and adult (54 months of age; 54 M) to identify which genes are differentially expressed and to investigate their temporal expression profiles. In total, 1788 differentially expressed genes (DEGs) (|log2FC| ≥ 1, P-adjusted < 0.05) were detected by pairwise comparisons between the different age groups. The expression levels of 10 of the DEGs were confirmed using reverse transcription-quantitative PCR (RT-qPCR), and the results were consistent with the transcriptome profile. A time-series expression profile analysis clustered the DEGs into four groups that could be divided into two classes (P < 0.05): class 1 profiles, which had up-regulated patterns of gene expression and class 2 profiles, which featured down-regulated patterns. Based on that cluster analysis, GO enrichment analysis revealed 1073, 127, and 184 terms as significantly enriched in biological process (BP), cellular component (CC), and molecular function (MF) categories in the class 1 profiles, while 714, 66, and 206 terms were significantly enriched in BP, CC, and MF in the class 2 profiles. A KEGG pathway analysis revealed that DEGs from the class 1 profiles were enriched in 62 pathways, with the most enriched being the phosphoinositide 3-kinase (PI3K) - protein kinase B (Akt)-signaling pathway. The DEGs from the class 2 profiles were enriched in 16 pathways, of which forkhead box protein O (FoxO) - signaling was the most enriched. Taken together, these results provide insight into the mechanisms of skeletal muscle development, as well suggesting some potential genes of importance for yak meat production.

Approaches to the use of stem cells in regenerative medicine

PurposeThe goal of regenerative medicine is to replace or restore missing, dysfunctional, or damaged cells, tissues and organs of a person to reproduce their normal function. The main approaches are cell therapy, tissue engineering, and gene therapy. Postnatal neural crest-derived multipotent stem cells (NC-MSC) are a promising cell type for use in regenerative medicine. This is due to the specific features of their embryonic origin and the role of the neural crest in phylogeny and ontogeny of vertebrates. MethodsThe study used research in vitro culture (monolayer cell culture, 3D culture based on hydrogels, organotypic culture of hippocampal slices, spherogenesis, directed differentiation); flow cytometry; cytochemical, immune-cytochemical and histomorphometric analysis; molecular genetic (RNA (ribonucleic acid) isolation, PCR (polymerase chain reaction) with reverse transcription, real-time PCR, nucleic acid electrophoresis); microscopy (transmitted light, phase contrast, fluorescent, confocal laser scanning); microsurgical; statistical analysis. ResultsIn this systematic review, the results showed that recently the neural crest-derived cells have been isolated from a wide range of tissues and organs of mammals at the postnatal stage of development. These cells, at least in vitro, demonstrate the ability to self-repair and multilinear differentiation into neurons, Schwann cells, melanocytes, adipocytes, osteoblasts, chondrocytes, and other types of cells, that is, according to their functional characteristics, they are multipotent stem cells. ConclusionAccording to the obtained results, tissue sources of postnatal neural crest-derived multipotent stem cells differ considerably in the degree of invasiveness of biopsy sampling, as well as the possibility of obtaining a homogeneous population of NC-MSCs, which is important for further clinical use.

Histological Study of the Harderian Gland of Pati Duck (Anas platyrhynchos domesticus) of Assam during Postnatal Development

Background: The farmers are rearing duck in small scale in semi intensive system without investing more capital but it contributes a major part to uplift the socio-economic condition of the rural poor people of Assam. The Pati duck (Anas platyrhynchos domesticus) population constitutes a major indigenous non-descript economically important duck variety in the state of Assam. The Harderian gland acts as a part of the head associated lymphoid tissue (HALT) and provides local innate immunity to the upper respiratory system, to the eye and oral cavity. Since literature on histological study of Harderian gland of Pati duck is scant, hence the present study was designed to establish the basic histological details on Harderian gland at different stages of postnatal development of Pati duck of Assam. Methods: The present study was conducted on total forty five (45) numbers Pati duck of Assam at different stages of postnatal development. The experimental birds were brought to the Department of Anatomy and Histology, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-22 and was sacrificed according to the method of Gracy (1986). For histological study the tissue samples from the Harderian gland of all the age group were fixed in 10% neutral buffered formalin solution and processed to prepare paraffin blocks as per the procedure described by Luna (1968). The paraffin blocks were sectioned in Shandon Finesse microtome in 5 µm thickness and the sections were stained by different methods as described by Luna (1968). Result: The Harderian gland of Pati duck had a capsule, the thickness of the capsule of the Harderian gland was increased slightly along the advancement of the age. The capsular connective tissue penetrated the parenchyma of the Harderian gland in the form of septa. The collagen, reticular, elastic and nerve fibers were observed along with the capsule and as well as in the septa. The Harderian gland of the Pati duck was compound tubular gland. The columnar epithelial cells lined the tubules. There was no cortex and medulla in the gland and the tubular structure were uniformly distributed within the lobules. A central canal was present in the gland which converged to the duct of the gland. The lymphocytes, plasma cells were found in the intertubular connective tissue. The numbers or population of plasma cell and lymphocytes were accelerated by the advancement of age. The myoepithelial cells with spindle shaped nucleus were present near the basement membrane close to the secretary cells. The histology of the duct of the Harderian gland of Pati duck was like that of typical hollow tubular organs. There were few lymphatic nodules very distinctly present extended from the lamina propria to the muscle layer.

Behavioral Deficits in Adolescent Mice after Sub-Chronic Administration of NMDA during Early Stage of Postnatal Development.

Neurodevelopmental disorders are complex conditions that pose difficulty in the modulation of proper motor, sensory and cognitive function due to dysregulated neuronal development. Previous studies have reported that an imbalance in the excitation/inhibition (E/I) in the brain regulated by glutamatergic and/or GABAergic neurotransmission can cause neurodevelopmental and neuropsychiatric behavioral deficits such as autism spectrum disorder (ASD). NMDA acts as an agonist at the NMDA receptor and imitates the action of the glutamate on that receptor. NMDA however, unlike glutamate, only binds to and regulates the NMDA receptor subtypes and not the other glutamate receptors. This study seeks to determine whether NMDA administration in mice i.e., over-activation of the NMDA system would result in long-lasting behavioral deficits in the adolescent mice. Both gender mice were treated with NMDA or saline at early postnatal developmental period with significant synaptogenesis and synaptic maturation. On postnatal day 28, various behavioral experiments were conducted to assess and identify behavioral characteristics. NMDA-treated mice show social deficits, and repetitive behavior in both gender mice at adolescent periods. However, only the male mice but not female mice showed increased locomotor activity. This study implies that neonatal exposure to NMDA may illicit behavioral features similar to ASD. This study also confirms the validity of the E/I imbalance theory of ASD and that NMDA injection can be used as a pharmacologic model for ASD. Future studies may explore the mechanism behind the gender difference in locomotor activity as well as the human relevance and therapeutic significance of the present findings.

The mouse at the popcorn stage of development.

In mice, rats, and rabbits, vigorous jumping and hyperexcitability occur at the popcorn stage of postnatal development. In view of subcortical structures appearing before cortical ones, the trait is deemed to occur at the maturation time of ascending excitatory projections from the brainstem and to disappear at the maturation time of descending inhibitory projections from the forebrain. There is evidence that the popcorn stage may be due in part to the lack of a cholinergic influence on dopamine systems. Based mostly on results found in adult mice and rats, there may also be a role for cortico-subcortical systems that include the cerebellum and basal ganglia requiring the influence of biogenic amines, glutamate, and endocannabinoids.

Formation of the Looming-evoked Innate Defensive Response during Postnatal Development in Mice.

Environmental threats often trigger innate defensive responses in mammals. However, the gradual development of functional properties of these responses during the postnatal development stage remains unclear. Here, we report that looming stimulation in mice evoked flight behavior commencing at P14-16 and had fully developed by P20-24. The visual-evoked innate defensive response was not significantly altered by sensory deprivation at an early postnatal stage. Furthermore, the percentages of wide-field and horizontal cells in the superior colliculus were notably elevated at P20-24. Our findings define a developmental time window for the formation of the visual innate defense response during the early postnatal period and provide important insight into the underlying mechanism.

Postnatal exposure to lipopolysaccharide combined with high-fat diet consumption induces immune tolerance without prevention in spatial working memory impairment

High-fat diet (HFD) consumption has been related to metabolic alterations, such as obesity and cardiovascular problems, and has pronounced effects on brain plasticity and memory impairment. HFD exposure has a pro-inflammatory effect associated with microglial cell modifications in the hippocampus, a region involved in the working memory process. Immune tolerance can protect from inflammation in periphery induced by HFD consumption, when the immune response is desensitized in development period with lipopolysaccharide (LPS) exposure, maybe this previously state can change the course of the diseases associated to HFDs but is not known if can protect the hippocampus’s inflammatory response. In the present study, male mice were injected with LPS (100 μg.kg-1 body weight) on postnatal day 3 and fed with HFD for 16 weeks after weaning. Ours results indicated that postnatal exposure to LPS in the early postnatal developmental stage combined with HFD consumption prevented glycemia, insulin, HOMA-IR, microglial process, and increased pro-inflammatory cytokines mRNA expression, without changes in body weight gain and spatial working memory with respect vehicle + HFD group. These findings suggest that HFD consumption after postnatal LPS exposure induces hippocampal immune tolerance, without prevention in spatial working memory impairment on male mice.

BMP3 Affects Cortical and Trabecular Long Bone Development in Mice.

Bone morphogenetic proteins (BMPs) have a major role in tissue development. BMP3 is synthesized in osteocytes and mature osteoblasts and has an antagonistic effect on other BMPs in bone tissue. The main aim of this study was to fully characterize cortical bone and trabecular bone of long bones in both male and female Bmp3−/− mice. To investigate the effect of Bmp3 from birth to maturity, we compared Bmp3−/− mice with wild-type littermates at the following stages of postnatal development: 1 day (P0), 2 weeks (P14), 8 weeks and 16 weeks of age. Bmp3 deletion was confirmed using X-gal staining in P0 animals. Cartilage and bone tissue were examined in P14 animals using Alcian Blue/Alizarin Red staining. Detailed long bone analysis was performed in 8-week-old and 16-week-old animals using micro-CT. The Bmp3 reporter signal was localized in bone tissue, hair follicles, and lungs. Bone mineralization at 2 weeks of age was increased in long bones of Bmp3−/− mice. Bmp3 deletion was shown to affect the skeleton until adulthood, where increased cortical and trabecular bone parameters were found in young and adult mice of both sexes, while delayed mineralization of the epiphyseal growth plate was found in adult Bmp3−/− mice.

Dynamic Expression of the Homeobox Factor PBX1 during Mouse Testis Development

Members of the pre-B-cell leukemia transcription factor (PBX) family of homeoproteins are mainly known for their involvement in hematopoietic cell differentiation and in the development of leukemia. The four PBX proteins, PBX1, PBX2, PBX3 and PBX4, belong to the three amino acid loop extension (TALE) superfamily of homeoproteins which are important transcriptional cofactors in several developmental processes involving homeobox (HOX) factors. Mutations in the human PBX1 gene are responsible for cases of gonadal dysgenesis with absence of male sex differentiation while Pbx1 inactivation in the mouse causes a failure in Leydig cell differentiation and function. However, no data is available regarding the expression profile of this transcription factor in the testis. To fill this knowledge gap, we have characterized PBX1 expression during mouse testicular development. Real time PCRs and Western blots confirmed the presence Pbx1 mRNA and PBX1 protein in different Leydig and Sertoli cell lines. The cellular localization of the PBX1 protein was determined by immunohistochemistry and immunofluorescence on mouse testis sections at different embryonic and postnatal developmental stages. PBX1 was detected in interstitial cells and in peritubular myoid cells from embryonic life until puberty. Most interstitial cells expressing PBX1 do not express the Leydig cell marker CYP17A1, indicating that they are not differentiated and steroidogenically active Leydig cells. In adults, PBX1 was mainly detected in Sertoli cells. The presence of PBX1 in different somatic cell populations during testicular development further supports a direct role for this transcription factor in testis cell differentiation and in male reproductive function.

Lipidome Atlas of the Developing Heart Uncovers Dynamic Membrane Lipid Attributes Underlying Cardiac Structural and Metabolic Maturation.

Precise metabolic rewiring during heart organogenesis underlies normal cardiac development. Herein, we utilized high-coverage, quantitative lipidomic approaches to construct lipidomic atlases of whole hearts (861 lipids; 31 classes) and mitochondria (587 lipids; 27 classes) across prenatal and postnatal developmental stages in mice. We uncovered the progressive formation of docosahexaenoyl-phospholipids and enhanced remodeling of C18:2, C20:3, and C20:4 fatty acyl moieties into cardiolipins as cardiac development progresses. A preferential flow of ceramides toward sphingomyelin biosynthesis over complex glycosphingolipid formation was also noted. Using maSigPro and GPclust algorithms, we identified a repertoire of 448 developmentally dynamic lipids and mapped their expression patterns to a library of 550 biologically relevant developmentally dynamic genes. Our combinatorial transcriptomics and lipidomics approaches identified Hadha, Lclat1, and Lpcat3 as candidate molecular drivers governing the dynamic remodeling of cardiolipins and phospholipids, respectively, in heart development. Our analyses revealed that postnatal cardiolipin remodeling in the heart constitutes a biphasic process, which first accumulates polyunsaturated C78-cardiolipins prior to tetralinoleoyl cardiolipin forming the predominant species. Multiomics analyses supplemented with transmission electron microscopy imaging uncovered enhanced mitochondria-lipid droplet contacts mediated by perilipin-5. Our combinatorial analyses of multiomics data uncovered an association between mitochondrial-resident, docosahexaenoic acid-phospholipids and messenger RNA levels of proton-transporting adenosine triphosphate synthases on inner mitochondrial membranes, which adds credence to the membrane pacemaker theory of metabolism. The current findings offer lipid-centric biological insights potentially important to understanding the molecular basis of cardiac metabolic flexibility and disease pathology.

Age-dependent viscoelastic characterization of rat brain cortex

Recent efforts in biomaterial-assisted brain tissue engineering suggest that match of mechanical properties of biomaterials to those of native brain tissue may be crucial for brain regeneration. In particular, the mechanical properties of native brain tissue vary as a function of age. To date, detailed characterization of age-dependent viscoelastic properties of brain tissue throughout the postnatal development to adulthood is only available at sparse age points in animal studies. To fill this gap, we have characterized the linear viscoelastic properties of the cerebral cortex in rats at well-spaced ages from postnatal day 4 to 4 months old, the age range that is widely used in neural regeneration studies. Using an oscillatory rheometer, the viscoelastic properties of rat cortical slices were measured independently by storage moduli (G′) and loss moduli (G″). The data demonstrated increases in both the storage moduli and the loss moduli of cortex tissue over post-natal age in rats. At all ages, the damping factor (G″/G′ ratio) remained constant at low oscillatory strain frequencies (<10 rad/s) before it started to decline at medium frequency range (10-100 rad/s). Such changes were not age-dependent. The stress-relaxation response increased over post-natal age, consistent with the increasing tissue stiffness. Taken together, our study demonstrates that age is a crucial factor determining the mechanical properties of the cerebral cortex in rats during early postnatal development. This data may provide the guidelines for age-specific biomechanics study of brain tissue and help to define the mechanical properties of biomaterials for biomaterial-assisted brain tissue regeneration studies. Statement of significanceStudies about age-dependent viscoelastic properties of rat brain tissue throughout the postnatal development to adulthood is sparsely available. To fill up the gap of knowledge, in this study, we have characterized the age-dependent viscoelastic properties and the linear viscoelastic properties of the cerebral cortex throughout the postnatal development stage to adulthood in rats by measuring storage moduli (G′), loss moduli (G″), damping factor (G″/G′ ratio) and stress-relaxation response. We have found that age is a crucial factor determining the mechanical properties of the cerebral cortex in rats during early postnatal development. The findings of this study could provide guidelines for age-specific biomechanical study of brain tissue and help to define the mechanical properties of biomaterials for biomaterial-assisted brain tissue regeneration in experimental models in rats.

"Neural stem cells puzzle" missing piece: telomerase reverse transcriptase expression patterns during nervous system ontogenesis in rats.

For almost three decades, neural stem cells remain still up-to-date and enigmatic topic. The main problem for their studying is the non-existence of an exclusive neural stem cell marker and the heterogeneity of them across the nervous system. As one of the novel markers of neural stem/progenitor cells may serve telomerase reverse transcriptase (TERT), a catalytic subunit of the telomerase enzyme, responsible for retaining the cell immortality. Thus, the aim of our study was to reveal if TERT, as an enzyme for ensuring the immortality of proliferating cells, could be used as a potential marker of neural stem/progenitor cells during the ontogenesis of the rat central nervous system. In this study, we used various markers related to neural stem or progenitor cells character and examined their co-localization with TERT expression. Our experiments were performed on the tissue of the brain and spinal cord during several stages of postnatal development and the neural tube during the 14th embryonal day. Cytoplasmatic TERT expression was found in alar plate progenitors and ventral horn neuroblasts of E14 rats. In the postnatal stages of spinal cord ontogenesis, a cytoplasmatic expression in neurons and nuclear expression in astrocytes was defined. In the brain, nuclear TERT expression was found in neural progenitor cells of neurogenic areas. This study provides the first comparative study of TERT expression across the central nervous system ontogenesis. The nuclear presence of TERT may be used as a potential marker of neural stem/progenitor cells, however, further studies are required to confirm these assumptions.

Analysis of cellular and synaptic mechanisms behind spontaneous cortical activity in vitro: Insights from optimization of spiking neuronal network models

Spontaneous network bursts, the intervals of intense network-wide activity interleaved with longer periods of sparse activity, are a hallmark phenomenon observed in cortical networks at postnatal developmental stages. Generation, propagation and termination of network bursts depend on a combination of synaptic, cellular and network mechanisms; however, the interplay between these mechanisms is not fully understood. We study this interplay in silico, using a new data-driven framework for generating spiking neuronal networks fitted to the microelectrode array recordings. We recorded the network bursting activity from rat postnatal cortical networks under several pharmacological conditions. In each condition, the function of specific excitatory and inhibitory synaptic receptors was reduced in order to examine their impact on global network dynamics. The obtained data was used to develop two complementary model fitting protocols for automatic model generation. These protocols allowed us to disentangle systematically the modeled cellular and synaptic mechanisms that affect the observed network bursts. We confirmed that the change in excitatory and inhibitory synaptic transmission in silico, consistent with pharmacological conditions, can account for the changes in network bursts relative to the control data. Reproducing the exact recorded network bursts statistics required adapting both the synaptic transmission and the cellular excitability separately for each pharmacological condition. Our results bring new understanding of the complex interplay between cellular, synaptic and network mechanisms supporting the burst dynamics. While here we focused on analysis of in vitro data, our approach can be applied ex vivo and in vivo given that the appropriate experimental data is available.

INTELLECTUAL DISABILITIES IN PRESCHOOLERS: MENTAL HEALTH DETERMINANTS DURING THE PRENATAL, NATAL AND POSTNATAL DEVELOPMENT STAGES

Introduction. A person’s mental health is a successful performance of a mental function, the result of which is a productive activity, establishing relationships with other people and an ability to adapt to change and cope with adverse life circumstances. Particularly acute is the issue of the potential negative impact of impaired development on the mental health and social functioning of children with mental and physical disabilities.&#x0D; Purpose. The purpose of the paper was to identify correlations between the mental health indicators of mentally retarded preschoolers and the specifics of the prenatal, natal and postnatal stages of their development.&#x0D; Methodology. Analysis of special medical, psychological and pedagogical literature; comparison and systematization of research material to determine the mental health indicators of preschoolers of mild and moderate degrees of mental retardation; mathematical methods of statistics.&#x0D; Results and Discussion. These studies show that the events of the prenatal/natal period have a significant impact on the further life of the child. It is a clear fact that close interaction between the mother and the unborn child is confirmed (the child learns to perceive the world together with the mother). However, for the relatively harmonious mental health and social functioning of a child with mental retardation, the mother’s behavior after the birth of the child is of paramount importance. This study does not reveal the entire specifics of mental health indicators of MRP, because the article presents the results of a study covering senior preschool age. School-age children were left out of consideration.&#x0D; Conclusions. The obtained results confirm the conditionality of mental retardation by negative factors of prenatal, natal and postnatal stages of development. It is important to correctly diagnose the existing manifestations of mental health disorders exactly at the preschool age, in order to implement appropriate measures for correction and development

The laboratory rat: Age and body weight matter.

Animal experimentation helps us to understand human biology. Rodents and, in particular, rats are among the most common animals used in animal experiments. Reporting data on animal age, animal body weight, and animal postnatal developmental stages is not consistent, which can cause the failure to translate animal data to humans. This review summarizes age-related postnatal developmental stages in rats by addressing age-related changes in their body weights. The age and body weight of animals can affect drug metabolism, gene expression, metabolic parameters, and other dependent variables measured in animal studies. In addition, considering the age and the body weight of the animals is of particular importance in animal modeling of human diseases. Appropriate reporting of age, body weight, and the developmental stage of animals used in studies can improve animal to human translation.

Особливості перебігу гострих респіраторно-вірусних інфекцій у дітей раннього віку з тимомегалією

Вступ. Особливості перебігу гострої респіраторної вірусної інфекції (ГРВІ) у дітей із збільшеною загрудинною залозою пов’язані з наявністю у хворих більш чи менш значного імунодефіцитного стану та дисгормонозу з проявами наднирникової недостатності. Мета — вивчити особливості перебігу гострих респіраторних вірусних інфекцій та дослідити функцію наднирникових залоз у дітей раннього віку з тимомегалією. Матеріал та методи. У клінічні дослідження було залучено 41 дитину з тимомегалією, хвору на ускладнені форми ГРВІ, віком від 1 місяця до 3 років. Етіологічна розшифровка ГРВІ проводилася методом парних сироваток. Вміст кортизолу в плазмі крові визначався імуноферментним методом. Групу порівняння становили 36 дітей із тимомегалією без проявів ГРВІ впродовж не менше 3 місяців. Результати. Аналіз анамнестичних даних хворих із тимомегалією показав, що більшість із них зазнали впливу несприятливих умов на різних етапах антенатального, інтранатального та постнатального розвитку. Аналіз даних про розміри загрудинної залози вказав на те, що 3–4-й ступінь тимомегалії частіше спостерігався в дітей з ознаками стенозуючого ларинготрахеїту (75,0 %). У 23,5 % хворих на обструктивний бронхіт тимомегалія була 1-го ступеня, у решти — 3-го та 4-го. При необструктивному варіанті ураження бронхів відмічена протилежна тенденція: найменший ступінь збільшення загрудинної залози діагностовано в 62,5 %, а 3-й та 4-й — у 37,5 % хворих (р &lt; 0,05). Найменша забезпеченість кортизолом спостерігалася в гострому періоді стенозуючого ларинготрахеїту (409,4 ± 10,2 нмоль/мл проти 537,7 ± 11,5 нмоль/мл у групі порівняння; р &lt; 0,05). У гострому періоді ГРВІ, що ускладнилася бронхітом, рівень кортизолу не підвищувався і становив 432,3 ± 32,3 нмоль/мл). У групі хворих на пневмонію зареєстровано вірогідне, можливо, компенсаторне підвищення рівня кортизолу (787,3 ± 2,0 нмоль/мл, р &lt; 0,05). При обструктивному бронхіті в гострому періоді відзначена тільки тенденція до збільшення концентрації кортизолу в крові (562,9 ± 18,9 нмоль/мл). Неоднорідним було й відновлення функції кори наднирникових залоз під час одужання дітей раннього віку з тимомегалією. Найбільш значно до фізіологічних показників наблизилися діти, які одужували від гострого бронхіту. Забезпеченість кортизолом хворих на пневмонію на момент одужання практично не відрізнялася від вихідного рівня дітей із ти­момегалією. Найбільш швидко кількість кортизолу збільшувалася в динаміці стенозуючого ларинготрахеїту (до 528,5 ± 22,6 нмоль/мл). Висновок. Діти з тимомегалією становлять групу ризику за розвитком бронхолегеневих ускладнень гострих респіраторно-вірусних інфекцій.

Effects of Cannabinoid Exposure during Neurodevelopment on Future Effects of Drugs of Abuse: A Preclinical Perspective.

The endocannabinoid system plays a central role in the earliest stages of embryonic, postnatal and adolescent neurodevelopment. Aberrant activity of this system at key developmental phases has been shown to affect neural development. The aim of this review is to synthesise and analyse preclinical insights within rodent populations, focusing on the effects that perinatal (embryonic, gestational and early postnatal developmental stages) and adolescent (postnatal day 21–60) cannabinoid exposure impose across time on the subsequent activity of various drugs of abuse. Results in rodents show that exposure to cannabinoids during the perinatal and adolescent period can lead to multifaceted behavioural and molecular changes. In the perinatal period, significant effects of Δ9-THC exposure on subsequent opiate and amphetamine reward-related behaviours were observed primarily in male rodents. These effects were not extended to include cocaine or alcohol. In adolescence, various cannabinoid agonists were used experimentally. This array of cannabinoids demonstrated consistent effects on opioids across sex. In contrast, no significant effects were observed regarding the future activity of amphetamines and cocaine. However, these studies focused primarily on male rodents. In conclusion, numerous gaps and limitations are apparent in the current body of research. The sparsity of studies analysing the perinatal period must be addressed. Future research within both periods must also focus on delineating sex-specific effects, moving away from a male-centric focus. Studies should also aim to utilise more clinically relevant cannabinoid treatments.

Late gestation hyperthermia: epigenetic programming of daughter's mammary development and function

Exposure to stressors during early developmental windows, such as prenatally (i.e., in utero), can have life-long implications for an animal's health and productivity. The mammary gland starts developing in utero and, like other developing tissues and organs, may undergo fetal programming. Previous research has implicated factors, such as prenatal exposure to endocrine disruptors or alterations in maternal diet (e.g., maternal over or undernutrition), that can influence the developmental trajectory of the offspring mammary gland in postnatal life. However, the direct links between prenatal insults and future productive outcomes are less documented in livestock species. Research on in utero hyperthermia effects on early-life mammary development is scarce. This review will provide an overview of key developmental milestones taking place in the bovine mammary gland during the pre- and postnatal stages. We will showcase how intrauterine hyperthermia, experienced by the developing fetus during the last trimester of gestation, derails postnatal mammary gland development and impairs its synthetic capacity later in life. We will provide insights into the underlying histological, cellular, and molecular mechanisms taking place at key postnatal developmental life stages, including birth, weaning and the first lactation, that might explain permanent detriments in productivity long after the initial exposure to hyperthermia. Collectively, our studies indicate that prenatal hyperthermia jeopardizes the normal developmental trajectory of the mammary gland from fetal development to lactation. Further, in utero hyperthermia epigenetically programs the udder, and possibly other organs critical to lactation, yielding a less resilient and less productive cow for multiple lactations.

Histological and Histochemical Study of Radiofrequency Radiation effects on the Hippocampus during the Pre- and Postnatal Stages of Development

Background: The research was designed to model the exposure to radiofrequency radiation (RFR) by habitual users of RFR-enabled devices and to observe possible aberrations in tissues that are attributable to exposures. The RFR exposure regimen modelled cases of continuous, and intermittent exposures in human conditions, using Wistar rats. The primary objective of the study was to study intrauterine and postnatal exposure to RFR and study its effects on specific brain structural and functional attributes.&#x0D; Materials and Methods: Experimental Wistar rats were housed in facilities that enabled exposure to specific type of RFR source (the 4G RFR-emitting internet router) and for specific durations which included 21 days of pregnancy and 35 post-natal days, marking the point of puberty. Following exposure, animals were sacrificed to excise brain tissues for histological analysis using the haematoxylin and eosin technique, histochemical analysis using the Nissl technique, and immunohistochemical techniques including the IBA 1 and Caspase 3 techniques for inflammation and potential apoptosis. Representative histological and histochemical photomicrographs were analysed using principles of qualitative histology and histochemistry.&#x0D; Results and Conclusion: Findings from the current research showed that RFR-exposure did not produce teratogenic or neurodegenerative effects within the hippocampus. This was evident from the study of the hippocampus’ histoarchitectural organisation, morphologies of the cells as well as their spatial distribution. Functional integrity of cells in the different regions of the hippocampal formation, namely the CA 1-4 areas as well as the dentate gyrus also showed that Nissl substance expression, which is a marker of neuron functional integrity, was relatively normally expressed across the experimental animals. This experimental modelling of human habitual exposure to RFR showed no evidence of prenatal teratogenic effects or postnatally induced extensive neurodegeneration up until puberty. However, it would be very important to indicate that RFR-exposure enhanced apoptotic potentials via the Caspase-3 pathway. The implications of this effect on later life mental health and neurological attributes will require further investigation