The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and contin...The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development studies.Thus,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo retina.In this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in vivo.Initially,we used SOX2 and PAX6 immunostaining to identify retinal progenitor cells.We then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,respectively.Ki-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between groups.Additionally,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,respectively.The timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant retinas.Our study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina development.The findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.展开更多
The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is well-documented.Nevertheless,the role of non-excitatory amino acids in brain damage following a stroke ...The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is well-documented.Nevertheless,the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely understudied.The release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the penumbra.Our findings indicated that the reversible loss of field excitato ry postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids(L-alanine,glycine,L-glutamine,and L-serine)at their plasma concentrations.These amino acids induce swelling in the somas of neurons and astrocytes during hypoxia,along with permanent dendritic damage mediated by N-methyl-D-aspartate receptors.Blocking N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during hypoxia.It is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels,leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor activation.Thus,previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain injury.Understanding these pathways co uld highlight new therapeutic targets to mitigate brain injury.展开更多
Astrocytes are intimately involved in the formation and development of retinal vessels. Astrocyte dysfunction is a major cause of blood-retinal barrier injury and other retinal vascular diseases. In this study, the de...Astrocytes are intimately involved in the formation and development of retinal vessels. Astrocyte dysfunction is a major cause of blood-retinal barrier injury and other retinal vascular diseases. In this study, the development of the retinal vascular system and the formation of the blood-ret-inal barrier in mice were investigated using immunolfuorescence staining, gelatin-ink perfusion, and transmission electron microscopy. The results showed that the retinal vascular system of mice develops from the optic disc after birth, and radiates out gradually to cover the entire retina, taking the papilla optica as the center. First, the superifcial vasculature is formed on the inner retinal layer;then, the vasculature extends into the inner and outer edges of the retinal inner nuclear layer, forming the deep vasculature that is parallel to the superifcial vasculature. The blood-retinal barrier is mainly composed of endothelium, basal lamina and the end-feet of astrocytes, which become mature during mouse development. Initially, the naive endothelial cells were immature with few organelles and many microvilli. The basal lamina was uniform in thickness, and the glial end-feet surrounded the outer basal lamina incompletely. In the end, the blood-retinal barrier matures with smooth endothelia connected through tight junctions, rela-tively thin and even basal lamina, and relatively thin glial cell end-feet. These ifndings indicate that the development of the vasculature in the retina follows the rules of“center to periphery”and“superifcial layer to deep layers”. Its development and maturation are spatially and tempo-rally consistent with the functional performance of retinal neurons and photosensitivity. The blood-retinal barrier gradually becomes mature via the process of interactions between astro-cytes and blood vessel cells.展开更多
In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebr...In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebral ischemia followed by 1, 6, 12, 24 and 48 h reperfusion respectively in rats treated with or without hypoxic preconditioning before cerebral ischemia. In addition, the apoptosis of neural cells and the behavioral scores for neurological functions recovery were evaluated by TUNEL staining and "crawling method", respectively. Compared with control group (cerebral ischemia-reperfusion without hypoxic preconditioning), the expression of Bcl-2 was significantly increased, but that of Bax decreased in the hypoxic preconditioning group (cerebral ischemiareperfusion with hypoxie preconditioning), both P〈0.05. The pre-treatment with hypoxic preconditioning could reduce the apoptosis of neural cells and promote the neurological function recovery as compared to control group. It was suggested that hypoxic preconditioning may have protective effects on the cerebral ischemia-reperfusion injury by inhibiting the apoptosis of neural cells, increase the expression of Bcl-2 and decrease the expression of Bax.展开更多
Objective Ligustrazine, also named as tetramethylpyrazine, is a compound purified from Ligusticum chuanxiong hort and has ever been testified to be a calcium antagonist. The present investigation was to determine the ...Objective Ligustrazine, also named as tetramethylpyrazine, is a compound purified from Ligusticum chuanxiong hort and has ever been testified to be a calcium antagonist. The present investigation was to determine the antinociceptive effect of ligustrazine and, if any, the peripheral ionic mechanism involved. Methods Paw withdrawal Latency (PWL) to noxious heating was measured in vivo and whole-cell patch recording was performed on small dorsal root ganglion (DRG) neurons. Results Intraplantar injection of ligustrazine (0.5 mg in 25 μl) significantly prolonged the withdrawal latency of ipsilateral hindpaw to noxious heating in the rat. Ligustrazine not only reversibly inhibited high-voltage gated calcium current of dorsal root ganglion (DRG) neuron in dose-dependent manner with IC50 of 1.89 mmol/L, but also decreased tetrodotoxin (TTX) -resistant sodium current in relatively selective and dose-dependent manner with IC50 of 2.49 mmol/L. Conclusion The results suggested that ligustrazine could elevate the threshold of thermal nociception through inhibiting the high-voltage gated calcium current and TTX-resistant sodium current of DRG neuron .in the rat.展开更多
Age-related hearing loss (AHL), or presbycusis, is the most common neurodegenerative disorder and top communication deficit of the aged population. Genetic predisposition is one of the major factors in the development...Age-related hearing loss (AHL), or presbycusis, is the most common neurodegenerative disorder and top communication deficit of the aged population. Genetic predisposition is one of the major factors in the development of AHL. Generally, AHL is associated with an age-dependent loss of sensory hair cells, spiral ganglion neurons and stria vascularis cells in the inner ear. Although the mechanisms leading to genetic hearing loss are not completely understood, caspase-family proteases function as important signals in the inner ear pathology. It is now accepted that mouse models are the best tools to study the mechanism of genetic hearing loss or AHL. Here, we provide a brief review of recent studies on hearing improvement in mouse models of AHL by anti-apoptotic treatment.展开更多
The clinical"gold standard"technique for attempting to restore function to nerves with a gap is to bridge the gap with sensory autografts.However,autografts induce good to excellent recovery only across shor...The clinical"gold standard"technique for attempting to restore function to nerves with a gap is to bridge the gap with sensory autografts.However,autografts induce good to excellent recovery only across short nerve gaps,in young patients,and when repairs are performed a short time post nerve trauma.Even under the best of conditions,<50%of patients recover good recovery.Although many alternative techniques have been tested,none is as effective as autografts.Therefore,alternative techniques are required that increase the percentage of patients who recover function and the extent of their recovery.This paper examines the actions of lithium,and how it appears to trigger all the cellular and molecular events required to promote axon regeneration,and how both in animal models and clinically,lithium administration enhances both the extent of axon regeneration and neurological recovery.The paper proposes more extensive clinical testing of lithium for its ability and reliability to increase the extent of axon regeneration and functional recovery.展开更多
In this study, biotinylated dextran amine (BDA) was microinjected into the left cortical motor area of the canine brain. Fluorescence microscopy results showed that a large amount of BDA-labeled pyramidal cells were...In this study, biotinylated dextran amine (BDA) was microinjected into the left cortical motor area of the canine brain. Fluorescence microscopy results showed that a large amount of BDA-labeled pyramidal cells were visible in the left cortical motor area after injection. In the left medulla oblongata, the BDA-labeled corticospinal tract was evenly distributed, with green fluorescence that had a clear boundary with the surrounding tissue. The BDA-positive corticospinal tract entered into the right lateral funiculus of the spinal cord and descended into the posterior part of the right lateral funiculus, close to the posterior horn, from cervical to sacral segments. There was a small amount of green fluorescence in the sacral segment. The distribution of BDA labeling in the canine central nervous system was consistent with the course of the corticospinal tract. Fluorescence labeling for BDA gradually diminished with time after injection. Our findings indicate that the BDA anterograde tracing technique can be used to visualize the localization and trajectory of the corticospinal tract in the canine central nervous system.展开更多
Undernutrition produces morphological brain alterations and cognitive deficiencies in children of underdeveloped countries. The central nervous system (CNS) alterations mainly interfere with the anatomical organizatio...Undernutrition produces morphological brain alterations and cognitive deficiencies in children of underdeveloped countries. The central nervous system (CNS) alterations mainly interfere with the anatomical organization of areas undergoing a phase of intense postnatal cell proliferation, disrupting plastic processes like learning, memory, and phonation. In the rat pup, prenatal malnutrition interferes with the elaboration of ultrasonic vocalizations (USVs) by poorly understood mechanisms. The neuronal caudal portion of the nucleus ambiguus (Ambc) innervates the laryngeal intrinsic muscles to produce phonation, a basic USV communication system. During postnatal development, enhanced plasticity phenomena play a fundamental role in improving brain function. Thus, the massage stimulation (MS) may accelerate growth and induce neurogenesis in different areas of the brain. The current study analyzed the effects of a daily 10-min MS on the dendritic tree and perikarya measurements of Ambc multipolar motoneurons (Golgi-Cox) of perinatally underfed (U), control (C), control massage-stimulated (CMS), and underfed massage-stimulated (UMS) groups at postnatal days (PDs) 8, 12, and 15. The data indicated that the dendritic scores were reduced (p < 0.05) in both number and density at PD8 and PD15 in the U subjects and that MS increased the values of these parameters (p < 0.05). In addition, MS induced body weight gain in both U and CMS groups, and it enhanced the dendritic density in CMS subjects. These results show that MS during the pre-weaning period restores the plastic properties of the Ambc over the hypoplastic multipolar motoneuron after the alterations caused by perinatal undernutrition.展开更多
Cajal-Retzius cells are reelin-secreting neurons in the marginal zone of the neocortex and hippocampus. The aim of this study was to investigate Cajal-Retzius cells in Alzheimer's disease pathology. Results revealed ...Cajal-Retzius cells are reelin-secreting neurons in the marginal zone of the neocortex and hippocampus. The aim of this study was to investigate Cajal-Retzius cells in Alzheimer's disease pathology. Results revealed that the number of Cajal-Retzius cells markedly reduced with age in both wild type and in mice over-expressing the Swedish double mutant form of amyloid precursor protein 695 (transgenic (Tg) 2576 mice). Numerous reelin-positive neurons were positive for activated caspase 3 in Tg2576 mice, suggesting that Cajal-Retzius neuronal loss occurred via apoptosis in this Alzheimer's disease model. Compared with wild type, the number of Cajal-Retzius cells was significantly lower in Tg2576 mice. Western blot analysis confirmed that reelin levels were markedly lower in Tg2576 mice than in wild-type mice. The decline in Cajal-Retzius cells in Tg2576 mice was found to occur concomitantly with the onset of Alzheimer's disease amyloid pathology and related behavioral deficits. Overall, these data indicated that Cajal-Retzius cell loss occurred with the onset and development of Alzheimer's disease.展开更多
BACKGROUND: Transplantation of in vitro, cultured, neural stem cells or bone marrow stem cells into the cochlear wall or oval window has been used to observe survival, proliferation, and differentiation of cochlear s...BACKGROUND: Transplantation of in vitro, cultured, neural stem cells or bone marrow stem cells into the cochlear wall or oval window has been used to observe survival, proliferation, and differentiation of cochlear stem cells, as well as migration of differentiated hair cells in scala tympani over a short period of time. OBJECTIVE: To investigate the relationship between survival, proliferation, differentiation, and migration of transplanted cochlear stem cells and hearing recovery from sensorineural hearing loss. DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Laboratory of Neurobiology, Southeast University in 2009. MATERIALS: Stem cells were isolated from neonatal rats, followed by primary and passaged cultures. METHODS: A total of 30 adult, male rats with normal hearing were treated with gentamicin sulfate to establish models of sensorineural hearing loss. The model rats were randomly assigned to cochlear stem cell transplantation and control groups, which were respectively injected with a 10μL cochlear stem cell suspension (1 × 10^5μL) and phosphate-buffered saline into the scala tympani. MAIN OUTCOME MEASURES: Rat hearing recovery was detected by brainstem auditory-evoked potential at 1, 9, and 15 months following transplantation. The location of stem cells was detected using nestin immunofluorescence, proliferative capacity was detected using bromodeoxyuridine immunofluorescence, and hair cell differentiation was detected using Myosin VIIA immunofluorescence. RESULTS: Cochlear stem cells migrated from the needle track to the spiral organ along the scala tympani following transplantation, and the hair cell-like cells migrated to the basal membrane and organ of Corti. The threshold of brainstem auditory-evoked potential increased with increasing time (P 〈 0.05). CONCLUSION: Transplanted cochlear stem cells from the internal ear migrated to the basal membrane and reached the injury site. The cells differentiated into cells with internal ear functions to improve hearing in rat models of sensorineural hearing loss.展开更多
BACKGROUND: It is not possible to reconstruct the inner structure of the spinal cord, such as gray matter and spinal tracts, from the Visual Human Project database or CT and MRI databases, due to low image resolution...BACKGROUND: It is not possible to reconstruct the inner structure of the spinal cord, such as gray matter and spinal tracts, from the Visual Human Project database or CT and MRI databases, due to low image resolution and contrast in macrosection images. OBJECTIVE: To explore a semi-automatic computerized three-dimensional (3D) reconstruction of human spinal cord based on histological serial sections, in order to solve issues such as low contrast. DESIGN, TIME AND SETTING: An experimental study combining serial section techniques and 3D reconstruction, performed in the laboratory of Human Anatomy and Histoembryology at the Medical School of Nantong University during January to April 2008. SETTING: Department of Anatomy, Institute of Neurobiology, Jiangsu Province Key Laboratory of Neural Regeneration, Laboratory of Image Engineering. MATERIALS: A human lumbar spinal cord segment from fresh autopsy material of an adult male. METHODS: After 4% paraformaldehyde fixation for three days, serial sections of the lumbar spinal cord were cut on a Leica cryostat and mounted on slides in sequence, with eight sections aligned separately on each slide. All sections were stained with Luxol Fast Blue to reveal myelin sheaths. After gradient dehydration and clearing, the stained slides were coverslipped. Sections were observed and images recorded under a light microscope using a digital camera. Six images were acquired at x25 magnification and automatically stitched into a complete section image. After all serial images were obtained, 96 complete serial images of the human lumbar cord segment were automatically processed with "Curves", "Autocontrast", "Gray scale 8 bit", "Invert", "Image resize to 50%" steps using Photoshop 7.0 software. All images were added in order into 3D-DOCTOR 4.0 software as a stack, where serial images were automatically realigned with neighboring images and semi-automatically segmented for white matter and gray matter. Finally, simple surface and volume reconstruction were completed on a personal computer. The reconstructed human lumbar spinal cord segment was interactively observed, cut, and measured. MAIN OUTCOME MEASURES: The reconstructed human lumbar spinal cord segment. RESULTS: Compared with serial images obtained from other image modalities, such as CT, MRI, and macrosections from The Visual Human Project database, the Luxol Fast Blue stained histological serial section images exhibited higher resolution and contrast between gray and white matter. Image processing and 3D reconstruction steps were semi-automatically performed with related software. The 3D reconstructed human lumbar cord segment were observed, cut, and measured on a PC. CONCLUSION: A semi-automatically computerized method, based on histological serial sections, is an effective way to 3D-reconstruct the human spinal cord.展开更多
Background: On the analogy of the non-pathogenic microbiota found in oral cavity, skin and gastrointestinal tract, existence of blood microbiota was confirmed by DNA sequencing, but never deeply characterized. Hypothe...Background: On the analogy of the non-pathogenic microbiota found in oral cavity, skin and gastrointestinal tract, existence of blood microbiota was confirmed by DNA sequencing, but never deeply characterized. Hypothesis for the existence of dormant blood microbiota in healthy humans have been arisen and single species have been isolated. The aim of our study was to resuscitate and investigate the biodiversity of bacterial and fungal dormant blood microbiota in healthy individuals by blood culturing and NGS DNA sequencing. Results: Twenty eight blood samples of healthy individuals, seven for each blood type, were studied. Several culture media were tested. Blood microbiota resuscitation was performed in BHI broth supplemented with vitamin K 1 mg/ml, 2% sucrose, 0.25% sodium citrate and 0.2% yeastolate at 43?C for 72 h. All tested blood samples were culture positive, as confirmed by Gram staining and TEM. TEM images demonstrated well defined cell structures. Analysis for bacterial and eukaryotic species was performed by 16S rRNA and ITS2 targeted sequencing. The obtained sequences were clustered (≥97% identity) in Operational Taxonomic Units (OTUs). Among cultured and uncultured samples we identified OTUs similarity with 47 bacterial orders belonging to 15 phyla and 39 fungi orders blonging to 2 phyla. For the first time we demonstrated isolation and sequencing identification of fungal blood microbiota in healthy individuals. Blood-group differences were identified among the bacterial microbiome compositions. Conclusion: The dormant blood microbiome is innate of the healthy individuals. Interventional strategies to bind the host blood microbiome with the states of health and disease remain an unmet research goal.展开更多
BACKGROUND: Severe injury to dopaminergic neuronal cell bodies and their axon terminals in the substantia nigra pars compacta (SNC) has been observed in both Parkinson's disease (PD) patients or in 1-methy-4-phe...BACKGROUND: Severe injury to dopaminergic neuronal cell bodies and their axon terminals in the substantia nigra pars compacta (SNC) has been observed in both Parkinson's disease (PD) patients or in 1-methy-4-phenyl-1,2,3,6-tetrahydropyrindine(MPTP)-induced PD animal models, but only slight injury occurs in the adjacent ventral tegmentat area (VTA). The mechanisms underlying this selective injury remain poorly understood. OBJECTIVE: To comparatively observe astrocyte reactivity in the SNC, caudate putamen (CPu), VTA, and frontal association cortex (FrA). DESIGN, TIME AND SETTING: A cellular and molecular biology, randomized, controlled experiment was performed at the Institute of Neurobiology, Department of Human Anatomy, Medical School of Nantong University, between December 2006 and September 2008. MATERIALS: A total of 80 healthy adult male C57BL/6 mice were included in this study. MPTP was purchased from Sigma, USA. METHODS: Mice were randomly divided into a model group (n = 64) and a sham-operated group (n = 16). PD was induced in the mice from the model group by intraperitoneal injection of 20 mg/kg MPTP, once every three hours, for a total of 4 times. MAIN OUTCOME MEASURES: Tyrosine hydroxylase (TH)-immunoreactive neurons and glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes were examined by dual immunofluorescence labeling. GFAP-immunoreactive astrocytes in the CPu and FrA were determined by immunofluorescent staining. GFAP mRNA expression in the SNC, CPu, VTA, and FrA was detected using real-time polymerase chain reaction. TH protein levels in the TH-immunoreactive axon terminals of the CPu and FrA were detected by Western blotting. RESULTS: Numbers of TH-immunoreactive neurons in the SNC, and TH protein level in the CPu, markedly decreased (by approximately 68%) 1 day after MPTP injection, and gradually increased at 3 days. Simultaneously, astrocyte reactivity was strengthened, in particular at 7 days. However, after MPTP injection, decreases in the numbers of TH-immunoreactive neurons in the VTA, and TH protein levels in the FrA, were less apparent (approximately 15%). Also, no obvious astrocyte reactivity was observed. CONCLUSION: In a mouse model of PD, astrocyte reactivity was apparent in the SNC and CPu, but not the VTA or FrA. In addition, astrocyte reactivity was greater in regions where injury to dopaminergic neurons was more severe.展开更多
Metabotropic glutamate receptor 5 (mGluR5) is expressed by neurons in zones of active neurogenesis and is involved in the development of neural stem cells in vivo and in vitro. We examined the expression of mGluR5 i...Metabotropic glutamate receptor 5 (mGluR5) is expressed by neurons in zones of active neurogenesis and is involved in the development of neural stem cells in vivo and in vitro. We examined the expression of mGluR5 in the cortex and hippocampus of rats during various prenatal and postnatal periods using immunohistochemistry. During prenatal development, mGluR5 was pdmadly localized to neuronal somas in the forebrain. During early postnatal periods, the receptor was mainly present on somas in the cortex, mGluR5 immunostaining was visible in apical dendrites and in the neuropil of neurons and persisted throughout postnatal development. During this period, pyramidal neurons were strongly labeled for the receptor. In the hippocampal CA1 region, mGluR5 immunoreactivity was more intense in the stratum oriens, stratum radiatum, and lacunosum moleculare at P0, P5 and P10 relative to P60. mGluR5 expression increased significantly in the molecular layer and decreased significantly in the granule cell layer of the dentate gyrus at P5, P10 and P60 in comparison with P0. Furthermore, some mGluR5-positive cells were also bromodeoxyuridine- or NeuroD-positive in the dentate gyrus at P14. These results demonstrate that mGluR5 has a differential expression pattern in the cortex and hippocampus during early growth, suggesting a role for this receptor in the control of domain specific brain developmental events.展开更多
Fimbria-fornix transection induces both exogenous and endogenous neural stem cells to differentiate into neurons in the hippocampus.This indicates that the denervated hippocampus provides an environment for neuronal d...Fimbria-fornix transection induces both exogenous and endogenous neural stem cells to differentiate into neurons in the hippocampus.This indicates that the denervated hippocampus provides an environment for neuronal differentiation of neural stem cells.However,the pathways and mechanisms in this process are still unclear.Seven days after fimbria fornix transection,our reverse transcription polymerase chain reaction,western blot assay,and enzyme linked immunosorbent assay results show a significant increase in ciliary neurotrophic factor m RNA and protein expression in the denervated hippocampus.Moreover,neural stem cells derived from hippocampi of fetal(embryonic day 17) Sprague-Dawley rats were treated with ciliary neurotrophic factor for 7 days,with an increased number of microtubule associated protein-2-positive cells and decreased number of glial fibrillary acidic protein-positive cells detected.Our results show that ciliary neurotrophic factor expression is up-regulated in the denervated hippocampus,which may promote neuronal differentiation of neural stem cells in the denervated hippocampus.展开更多
In our previous study,we showed that with increasing time in culture,the growth characteristics of enteric neural crest-derived cells(ENCCs)change,and that the proliferation,migration and neural differentiation potent...In our previous study,we showed that with increasing time in culture,the growth characteristics of enteric neural crest-derived cells(ENCCs)change,and that the proliferation,migration and neural differentiation potential of these cells in vitro notably diminish.However,there are no studies on the developmental differences in these characteristics between fetal and early-postnatal stages in vitro or in vivo.In this study,we isolated fetal(embryonic day 14.5)and postnatal(postnatal day 2)ENCCs from the intestines of rats.Fetal ENCCs had greater maximum cross-sectional area of the neurospheres,stronger migration ability,and reduced apoptosis,compared with postnatal ENCCs.However,fetal and postnatal ENCCs had a similar differentiation ability.Fetal and postnatal ENCCs both survived after transplant into a rat model of Hirschsprung’s disease.In these rats with Hirschsprung’s disease,the number of ganglionic cells in the myenteric plexus was higher and the distal intestinal pressure change was greater in animals treated with fetal ENCCs compared with those treated with postnatal ENCCs.These findings suggest that,compared with postnatal ENCCs,fetal ENCCs exhibit higher survival and proliferation and migration abilities,and are therefore a more appropriate seed cell for the treatment of Hirschsprung’s disease.This study was approved by the Animal Ethics Committee of the Second Affiliated Hospital of Xi’an Jiaotong University(approval No.2016086)on March 3,2016.展开更多
One of biggest recent achievements of neurobiology is the study on neurotrophic factors. The neurotrophins are exciting examples of these factors. They belong to a family of proteins consisting of nerve growth fac-tor...One of biggest recent achievements of neurobiology is the study on neurotrophic factors. The neurotrophins are exciting examples of these factors. They belong to a family of proteins consisting of nerve growth fac-tor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), NT-4/5, NT-6, and NT-7. Today, NGF and BDNF are well recognized to mediate a diz-zying number of trophobiological effects, ranging from neurotrophic through immunotrophic and epitheliotro-phic to metabotrophic effects. These are implicated in the pathogenesis of various diseases. In the same vein, recent studies in adipobiology reveal that this tissue is the body’s largest endocrine and paracrine organ producing multiple signaling proteins collectively termed adipokines, with NGF and BDNF being also produced from adipose tissue. Altogether, neurobio-logy and adipobiology contribute to the improvement of our knowledge on diseases beyond obesity such as cardiometabolic (atherosclerosis, type 2 diabetes, and metabolic syndrome) and neuropsychiatric (e.g. , Alzheimer’s disease and depression) diseases. The present review updates evidence for (1) neurotrophic and metabotrophic potentials of NGF and BDNF linking the pathogenesis of these diseases, and (2) NGF- and BDNF-mediated effects in ampakines, NMDA receptor antagonists, antidepressants, selective deacetylase inhibitors, statins, peroxisome proliferator-activated receptor gamma agonists, and purinergic P2X3 recep-tor up-regulation. This may help to construct a novel paradigm in the feld of translational pharmacology of neuro-metabotrophins, particularly NGF and BDNF.展开更多
The dorsolateral prefrontal cortex (dlPFC) of the rat plays a role in the encoding of neuronal signals involved in conflict-induced behavioral adjustment, working memory, planning and executive abilities, attentional ...The dorsolateral prefrontal cortex (dlPFC) of the rat plays a role in the encoding of neuronal signals involved in conflict-induced behavioral adjustment, working memory, planning and executive abilities, attentional control and other cognitive responses. In altricial species, early perinatal undernutrition interferes with the morphofunctional organization of a number of central nervous system (CNS) structures including the prefrontal cortex. The effects of neonatal undernutrition on dendritic arbor density, perikaryon measurements, and the number of spines (detected by rapid-Golgi) of basilar dendritic segments in layer III pyramidal neurons of the dlPFC were examined in male Wistar rats on postnatal (PDs) 12, 20, and 30. In the underfed (U) subjects the distal portions of the dendritic arbors had a consistent hipoplasia, mainly on PD 30, with reduced cross sectional area, perimeter, and spine densities on the basilar dendrites on all days studied. Thus, the alterations of the dlPFC pyramidal neurons may interfere with the plastic synaptic activity and cognitive performance of rats subjected to the stress of early underfeeding. Characterizing these anatomical alterations may help to understand the disrupted cognitive processes associated with neonatal undernutrition.展开更多
Early mother-litter bonds alterations elicited by pre- and neonatal undernutrition are a source of long-lasting brain and functional disorders such as exploratory and emotional deficits and maternal unresponsiveness t...Early mother-litter bonds alterations elicited by pre- and neonatal undernutrition are a source of long-lasting brain and functional disorders such as exploratory and emotional deficits and maternal unresponsiveness to the newborn. Here, we examined the prolonged effects of gestational and neonatal food restriction on the retrieval of pups and nest building activity by primiparous adult Wistar rats on postnatal days (PDs) 4, 8, and 12. In early undernourished dams, the latency to retrieve the first or the fifth pups in the litter was extended;and nest building activity was significantly reduced. Additionally, early underfed dams retrieved the pups in a rough manner, eliciting distress cries and grasping the pups by unusual body areas. The current findings suggest that pre- and neonatal food restriction may affect the anatomical and functional forebrain structures, modulating the cognitive and motor components underlying maternal responsiveness.展开更多
基金supported by the National Natural Science Foundation of China,Nos.81901156(to ZZ),82271200(to ZZ),82171308(to XC)the Fundamental Research Funds for the Central Universities,No.xzy012022035(to ZZ)+1 种基金the Natural Science Foundation of Shaanxi Province,Nos.2021JM-261(to QK),2023-YBSF-303(to ZZ)Traditional Chinese Medicine Project of Shaanxi Province,No.2019-ZZ-JC047(to QK)。
文摘The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development studies.Thus,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo retina.In this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in vivo.Initially,we used SOX2 and PAX6 immunostaining to identify retinal progenitor cells.We then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,respectively.Ki-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between groups.Additionally,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,respectively.The timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant retinas.Our study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina development.The findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.
基金supported by MICIU(grant number PID2021-128133NB-100/AEI/FEDER10.13039/501100011033 to JMHG)by the National Institutes of Health(grant number R01 NS083858 to SAK)+1 种基金the Intramural Grants Program IGPP00057(to SAK)VIC enjoys a FPU contract from the Comunidad de Madrid(PIPF-2022/SAL-GL-25948)。
文摘The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is well-documented.Nevertheless,the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely understudied.The release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the penumbra.Our findings indicated that the reversible loss of field excitato ry postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids(L-alanine,glycine,L-glutamine,and L-serine)at their plasma concentrations.These amino acids induce swelling in the somas of neurons and astrocytes during hypoxia,along with permanent dendritic damage mediated by N-methyl-D-aspartate receptors.Blocking N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during hypoxia.It is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels,leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor activation.Thus,previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain injury.Understanding these pathways co uld highlight new therapeutic targets to mitigate brain injury.
基金supported by the National Natural Science Foundation of China,No.30771140,31070952 and U1204311
文摘Astrocytes are intimately involved in the formation and development of retinal vessels. Astrocyte dysfunction is a major cause of blood-retinal barrier injury and other retinal vascular diseases. In this study, the development of the retinal vascular system and the formation of the blood-ret-inal barrier in mice were investigated using immunolfuorescence staining, gelatin-ink perfusion, and transmission electron microscopy. The results showed that the retinal vascular system of mice develops from the optic disc after birth, and radiates out gradually to cover the entire retina, taking the papilla optica as the center. First, the superifcial vasculature is formed on the inner retinal layer;then, the vasculature extends into the inner and outer edges of the retinal inner nuclear layer, forming the deep vasculature that is parallel to the superifcial vasculature. The blood-retinal barrier is mainly composed of endothelium, basal lamina and the end-feet of astrocytes, which become mature during mouse development. Initially, the naive endothelial cells were immature with few organelles and many microvilli. The basal lamina was uniform in thickness, and the glial end-feet surrounded the outer basal lamina incompletely. In the end, the blood-retinal barrier matures with smooth endothelia connected through tight junctions, rela-tively thin and even basal lamina, and relatively thin glial cell end-feet. These ifndings indicate that the development of the vasculature in the retina follows the rules of“center to periphery”and“superifcial layer to deep layers”. Its development and maturation are spatially and tempo-rally consistent with the functional performance of retinal neurons and photosensitivity. The blood-retinal barrier gradually becomes mature via the process of interactions between astro-cytes and blood vessel cells.
文摘In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebral ischemia followed by 1, 6, 12, 24 and 48 h reperfusion respectively in rats treated with or without hypoxic preconditioning before cerebral ischemia. In addition, the apoptosis of neural cells and the behavioral scores for neurological functions recovery were evaluated by TUNEL staining and "crawling method", respectively. Compared with control group (cerebral ischemia-reperfusion without hypoxic preconditioning), the expression of Bcl-2 was significantly increased, but that of Bax decreased in the hypoxic preconditioning group (cerebral ischemiareperfusion with hypoxie preconditioning), both P〈0.05. The pre-treatment with hypoxic preconditioning could reduce the apoptosis of neural cells and promote the neurological function recovery as compared to control group. It was suggested that hypoxic preconditioning may have protective effects on the cerebral ischemia-reperfusion injury by inhibiting the apoptosis of neural cells, increase the expression of Bcl-2 and decrease the expression of Bax.
文摘Objective Ligustrazine, also named as tetramethylpyrazine, is a compound purified from Ligusticum chuanxiong hort and has ever been testified to be a calcium antagonist. The present investigation was to determine the antinociceptive effect of ligustrazine and, if any, the peripheral ionic mechanism involved. Methods Paw withdrawal Latency (PWL) to noxious heating was measured in vivo and whole-cell patch recording was performed on small dorsal root ganglion (DRG) neurons. Results Intraplantar injection of ligustrazine (0.5 mg in 25 μl) significantly prolonged the withdrawal latency of ipsilateral hindpaw to noxious heating in the rat. Ligustrazine not only reversibly inhibited high-voltage gated calcium current of dorsal root ganglion (DRG) neuron in dose-dependent manner with IC50 of 1.89 mmol/L, but also decreased tetrodotoxin (TTX) -resistant sodium current in relatively selective and dose-dependent manner with IC50 of 2.49 mmol/L. Conclusion The results suggested that ligustrazine could elevate the threshold of thermal nociception through inhibiting the high-voltage gated calcium current and TTX-resistant sodium current of DRG neuron .in the rat.
基金supported by National Natural Science Foundation of China (No. 81271092, 81570927)Scientific and Technological Developing Grant in Shandong Province (2014GSF118083)+1 种基金Scientific and Technological Developing Grant for Medicine and Health in Shandong Province (2015WS0507)Research Initiation Grant of Binzhou Medical University (BY2012KYQD01, BY2013KYQD15)
文摘Age-related hearing loss (AHL), or presbycusis, is the most common neurodegenerative disorder and top communication deficit of the aged population. Genetic predisposition is one of the major factors in the development of AHL. Generally, AHL is associated with an age-dependent loss of sensory hair cells, spiral ganglion neurons and stria vascularis cells in the inner ear. Although the mechanisms leading to genetic hearing loss are not completely understood, caspase-family proteases function as important signals in the inner ear pathology. It is now accepted that mouse models are the best tools to study the mechanism of genetic hearing loss or AHL. Here, we provide a brief review of recent studies on hearing improvement in mouse models of AHL by anti-apoptotic treatment.
文摘The clinical"gold standard"technique for attempting to restore function to nerves with a gap is to bridge the gap with sensory autografts.However,autografts induce good to excellent recovery only across short nerve gaps,in young patients,and when repairs are performed a short time post nerve trauma.Even under the best of conditions,<50%of patients recover good recovery.Although many alternative techniques have been tested,none is as effective as autografts.Therefore,alternative techniques are required that increase the percentage of patients who recover function and the extent of their recovery.This paper examines the actions of lithium,and how it appears to trigger all the cellular and molecular events required to promote axon regeneration,and how both in animal models and clinically,lithium administration enhances both the extent of axon regeneration and neurological recovery.The paper proposes more extensive clinical testing of lithium for its ability and reliability to increase the extent of axon regeneration and functional recovery.
基金Fsupported by the Priority Academic Development Program of Jiangsu Higher Education Institutions
文摘In this study, biotinylated dextran amine (BDA) was microinjected into the left cortical motor area of the canine brain. Fluorescence microscopy results showed that a large amount of BDA-labeled pyramidal cells were visible in the left cortical motor area after injection. In the left medulla oblongata, the BDA-labeled corticospinal tract was evenly distributed, with green fluorescence that had a clear boundary with the surrounding tissue. The BDA-positive corticospinal tract entered into the right lateral funiculus of the spinal cord and descended into the posterior part of the right lateral funiculus, close to the posterior horn, from cervical to sacral segments. There was a small amount of green fluorescence in the sacral segment. The distribution of BDA labeling in the canine central nervous system was consistent with the course of the corticospinal tract. Fluorescence labeling for BDA gradually diminished with time after injection. Our findings indicate that the BDA anterograde tracing technique can be used to visualize the localization and trajectory of the corticospinal tract in the canine central nervous system.
文摘Undernutrition produces morphological brain alterations and cognitive deficiencies in children of underdeveloped countries. The central nervous system (CNS) alterations mainly interfere with the anatomical organization of areas undergoing a phase of intense postnatal cell proliferation, disrupting plastic processes like learning, memory, and phonation. In the rat pup, prenatal malnutrition interferes with the elaboration of ultrasonic vocalizations (USVs) by poorly understood mechanisms. The neuronal caudal portion of the nucleus ambiguus (Ambc) innervates the laryngeal intrinsic muscles to produce phonation, a basic USV communication system. During postnatal development, enhanced plasticity phenomena play a fundamental role in improving brain function. Thus, the massage stimulation (MS) may accelerate growth and induce neurogenesis in different areas of the brain. The current study analyzed the effects of a daily 10-min MS on the dendritic tree and perikarya measurements of Ambc multipolar motoneurons (Golgi-Cox) of perinatally underfed (U), control (C), control massage-stimulated (CMS), and underfed massage-stimulated (UMS) groups at postnatal days (PDs) 8, 12, and 15. The data indicated that the dendritic scores were reduced (p < 0.05) in both number and density at PD8 and PD15 in the U subjects and that MS increased the values of these parameters (p < 0.05). In addition, MS induced body weight gain in both U and CMS groups, and it enhanced the dendritic density in CMS subjects. These results show that MS during the pre-weaning period restores the plastic properties of the Ambc over the hypoplastic multipolar motoneuron after the alterations caused by perinatal undernutrition.
基金supported by the National Natural Science Foundation of China,No.31070952,81071029the Joint Funds of the NSFC with Henan Provence Government for Fostering Talents,No.U1204809the Henan Province Science Research Project,No.132102310111
文摘Cajal-Retzius cells are reelin-secreting neurons in the marginal zone of the neocortex and hippocampus. The aim of this study was to investigate Cajal-Retzius cells in Alzheimer's disease pathology. Results revealed that the number of Cajal-Retzius cells markedly reduced with age in both wild type and in mice over-expressing the Swedish double mutant form of amyloid precursor protein 695 (transgenic (Tg) 2576 mice). Numerous reelin-positive neurons were positive for activated caspase 3 in Tg2576 mice, suggesting that Cajal-Retzius neuronal loss occurred via apoptosis in this Alzheimer's disease model. Compared with wild type, the number of Cajal-Retzius cells was significantly lower in Tg2576 mice. Western blot analysis confirmed that reelin levels were markedly lower in Tg2576 mice than in wild-type mice. The decline in Cajal-Retzius cells in Tg2576 mice was found to occur concomitantly with the onset of Alzheimer's disease amyloid pathology and related behavioral deficits. Overall, these data indicated that Cajal-Retzius cell loss occurred with the onset and development of Alzheimer's disease.
基金the Natural Science Foundation of Ji-angsu Higher Education Institutes, No. 08KJB360005Basic Re-search and Key Develop-ment Program of Nanjing University of Traditional Chinese Medicine, No. 08XJC03
文摘BACKGROUND: Transplantation of in vitro, cultured, neural stem cells or bone marrow stem cells into the cochlear wall or oval window has been used to observe survival, proliferation, and differentiation of cochlear stem cells, as well as migration of differentiated hair cells in scala tympani over a short period of time. OBJECTIVE: To investigate the relationship between survival, proliferation, differentiation, and migration of transplanted cochlear stem cells and hearing recovery from sensorineural hearing loss. DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Laboratory of Neurobiology, Southeast University in 2009. MATERIALS: Stem cells were isolated from neonatal rats, followed by primary and passaged cultures. METHODS: A total of 30 adult, male rats with normal hearing were treated with gentamicin sulfate to establish models of sensorineural hearing loss. The model rats were randomly assigned to cochlear stem cell transplantation and control groups, which were respectively injected with a 10μL cochlear stem cell suspension (1 × 10^5μL) and phosphate-buffered saline into the scala tympani. MAIN OUTCOME MEASURES: Rat hearing recovery was detected by brainstem auditory-evoked potential at 1, 9, and 15 months following transplantation. The location of stem cells was detected using nestin immunofluorescence, proliferative capacity was detected using bromodeoxyuridine immunofluorescence, and hair cell differentiation was detected using Myosin VIIA immunofluorescence. RESULTS: Cochlear stem cells migrated from the needle track to the spiral organ along the scala tympani following transplantation, and the hair cell-like cells migrated to the basal membrane and organ of Corti. The threshold of brainstem auditory-evoked potential increased with increasing time (P 〈 0.05). CONCLUSION: Transplanted cochlear stem cells from the internal ear migrated to the basal membrane and reached the injury site. The cells differentiated into cells with internal ear functions to improve hearing in rat models of sensorineural hearing loss.
基金Natural Science Research Plan forJiangsu Colleges, No.05KJB180105 Postgraduate Innovation Cultivating Projectin Jiangsu Province, No.CX07s_035z
文摘BACKGROUND: It is not possible to reconstruct the inner structure of the spinal cord, such as gray matter and spinal tracts, from the Visual Human Project database or CT and MRI databases, due to low image resolution and contrast in macrosection images. OBJECTIVE: To explore a semi-automatic computerized three-dimensional (3D) reconstruction of human spinal cord based on histological serial sections, in order to solve issues such as low contrast. DESIGN, TIME AND SETTING: An experimental study combining serial section techniques and 3D reconstruction, performed in the laboratory of Human Anatomy and Histoembryology at the Medical School of Nantong University during January to April 2008. SETTING: Department of Anatomy, Institute of Neurobiology, Jiangsu Province Key Laboratory of Neural Regeneration, Laboratory of Image Engineering. MATERIALS: A human lumbar spinal cord segment from fresh autopsy material of an adult male. METHODS: After 4% paraformaldehyde fixation for three days, serial sections of the lumbar spinal cord were cut on a Leica cryostat and mounted on slides in sequence, with eight sections aligned separately on each slide. All sections were stained with Luxol Fast Blue to reveal myelin sheaths. After gradient dehydration and clearing, the stained slides were coverslipped. Sections were observed and images recorded under a light microscope using a digital camera. Six images were acquired at x25 magnification and automatically stitched into a complete section image. After all serial images were obtained, 96 complete serial images of the human lumbar cord segment were automatically processed with "Curves", "Autocontrast", "Gray scale 8 bit", "Invert", "Image resize to 50%" steps using Photoshop 7.0 software. All images were added in order into 3D-DOCTOR 4.0 software as a stack, where serial images were automatically realigned with neighboring images and semi-automatically segmented for white matter and gray matter. Finally, simple surface and volume reconstruction were completed on a personal computer. The reconstructed human lumbar spinal cord segment was interactively observed, cut, and measured. MAIN OUTCOME MEASURES: The reconstructed human lumbar spinal cord segment. RESULTS: Compared with serial images obtained from other image modalities, such as CT, MRI, and macrosections from The Visual Human Project database, the Luxol Fast Blue stained histological serial section images exhibited higher resolution and contrast between gray and white matter. Image processing and 3D reconstruction steps were semi-automatically performed with related software. The 3D reconstructed human lumbar cord segment were observed, cut, and measured on a PC. CONCLUSION: A semi-automatically computerized method, based on histological serial sections, is an effective way to 3D-reconstruct the human spinal cord.
文摘Background: On the analogy of the non-pathogenic microbiota found in oral cavity, skin and gastrointestinal tract, existence of blood microbiota was confirmed by DNA sequencing, but never deeply characterized. Hypothesis for the existence of dormant blood microbiota in healthy humans have been arisen and single species have been isolated. The aim of our study was to resuscitate and investigate the biodiversity of bacterial and fungal dormant blood microbiota in healthy individuals by blood culturing and NGS DNA sequencing. Results: Twenty eight blood samples of healthy individuals, seven for each blood type, were studied. Several culture media were tested. Blood microbiota resuscitation was performed in BHI broth supplemented with vitamin K 1 mg/ml, 2% sucrose, 0.25% sodium citrate and 0.2% yeastolate at 43?C for 72 h. All tested blood samples were culture positive, as confirmed by Gram staining and TEM. TEM images demonstrated well defined cell structures. Analysis for bacterial and eukaryotic species was performed by 16S rRNA and ITS2 targeted sequencing. The obtained sequences were clustered (≥97% identity) in Operational Taxonomic Units (OTUs). Among cultured and uncultured samples we identified OTUs similarity with 47 bacterial orders belonging to 15 phyla and 39 fungi orders blonging to 2 phyla. For the first time we demonstrated isolation and sequencing identification of fungal blood microbiota in healthy individuals. Blood-group differences were identified among the bacterial microbiome compositions. Conclusion: The dormant blood microbiome is innate of the healthy individuals. Interventional strategies to bind the host blood microbiome with the states of health and disease remain an unmet research goal.
基金Supported by:Natural Science Research Plan for Jiangsu Colleges,No. 06KJD310148
文摘BACKGROUND: Severe injury to dopaminergic neuronal cell bodies and their axon terminals in the substantia nigra pars compacta (SNC) has been observed in both Parkinson's disease (PD) patients or in 1-methy-4-phenyl-1,2,3,6-tetrahydropyrindine(MPTP)-induced PD animal models, but only slight injury occurs in the adjacent ventral tegmentat area (VTA). The mechanisms underlying this selective injury remain poorly understood. OBJECTIVE: To comparatively observe astrocyte reactivity in the SNC, caudate putamen (CPu), VTA, and frontal association cortex (FrA). DESIGN, TIME AND SETTING: A cellular and molecular biology, randomized, controlled experiment was performed at the Institute of Neurobiology, Department of Human Anatomy, Medical School of Nantong University, between December 2006 and September 2008. MATERIALS: A total of 80 healthy adult male C57BL/6 mice were included in this study. MPTP was purchased from Sigma, USA. METHODS: Mice were randomly divided into a model group (n = 64) and a sham-operated group (n = 16). PD was induced in the mice from the model group by intraperitoneal injection of 20 mg/kg MPTP, once every three hours, for a total of 4 times. MAIN OUTCOME MEASURES: Tyrosine hydroxylase (TH)-immunoreactive neurons and glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes were examined by dual immunofluorescence labeling. GFAP-immunoreactive astrocytes in the CPu and FrA were determined by immunofluorescent staining. GFAP mRNA expression in the SNC, CPu, VTA, and FrA was detected using real-time polymerase chain reaction. TH protein levels in the TH-immunoreactive axon terminals of the CPu and FrA were detected by Western blotting. RESULTS: Numbers of TH-immunoreactive neurons in the SNC, and TH protein level in the CPu, markedly decreased (by approximately 68%) 1 day after MPTP injection, and gradually increased at 3 days. Simultaneously, astrocyte reactivity was strengthened, in particular at 7 days. However, after MPTP injection, decreases in the numbers of TH-immunoreactive neurons in the VTA, and TH protein levels in the FrA, were less apparent (approximately 15%). Also, no obvious astrocyte reactivity was observed. CONCLUSION: In a mouse model of PD, astrocyte reactivity was apparent in the SNC and CPu, but not the VTA or FrA. In addition, astrocyte reactivity was greater in regions where injury to dopaminergic neurons was more severe.
基金the National Natural Science Foundation of China,No.30500575,30770673,81070998Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education MinistryTechnology Plan of Shaanxi Province,No.2009K01-80
文摘Metabotropic glutamate receptor 5 (mGluR5) is expressed by neurons in zones of active neurogenesis and is involved in the development of neural stem cells in vivo and in vitro. We examined the expression of mGluR5 in the cortex and hippocampus of rats during various prenatal and postnatal periods using immunohistochemistry. During prenatal development, mGluR5 was pdmadly localized to neuronal somas in the forebrain. During early postnatal periods, the receptor was mainly present on somas in the cortex, mGluR5 immunostaining was visible in apical dendrites and in the neuropil of neurons and persisted throughout postnatal development. During this period, pyramidal neurons were strongly labeled for the receptor. In the hippocampal CA1 region, mGluR5 immunoreactivity was more intense in the stratum oriens, stratum radiatum, and lacunosum moleculare at P0, P5 and P10 relative to P60. mGluR5 expression increased significantly in the molecular layer and decreased significantly in the granule cell layer of the dentate gyrus at P5, P10 and P60 in comparison with P0. Furthermore, some mGluR5-positive cells were also bromodeoxyuridine- or NeuroD-positive in the dentate gyrus at P14. These results demonstrate that mGluR5 has a differential expression pattern in the cortex and hippocampus during early growth, suggesting a role for this receptor in the control of domain specific brain developmental events.
基金supported by grants of Jiangsu Natural College Foundation of China,No.13KJB310010,14KJB310015the Natural Foundation of Nantong University of China,No.14ZY022
文摘Fimbria-fornix transection induces both exogenous and endogenous neural stem cells to differentiate into neurons in the hippocampus.This indicates that the denervated hippocampus provides an environment for neuronal differentiation of neural stem cells.However,the pathways and mechanisms in this process are still unclear.Seven days after fimbria fornix transection,our reverse transcription polymerase chain reaction,western blot assay,and enzyme linked immunosorbent assay results show a significant increase in ciliary neurotrophic factor m RNA and protein expression in the denervated hippocampus.Moreover,neural stem cells derived from hippocampi of fetal(embryonic day 17) Sprague-Dawley rats were treated with ciliary neurotrophic factor for 7 days,with an increased number of microtubule associated protein-2-positive cells and decreased number of glial fibrillary acidic protein-positive cells detected.Our results show that ciliary neurotrophic factor expression is up-regulated in the denervated hippocampus,which may promote neuronal differentiation of neural stem cells in the denervated hippocampus.
基金supported by the National Natural Science Foundation of China,Nos.82071692(to HY),81741096(to HY),81770513(to YG),81270435(to WKP)Shaanxi Youth Science and Technology Project of China,No.2019KJXX-044(to HY)+1 种基金the National Natural Science Foundation of Shaanxi Province of China,No.2020JM-407(to HY)Fund Project of the Second Affiliated Hospital,Xi’an Jiaotong University No.RC(XM)201703(to HY).
文摘In our previous study,we showed that with increasing time in culture,the growth characteristics of enteric neural crest-derived cells(ENCCs)change,and that the proliferation,migration and neural differentiation potential of these cells in vitro notably diminish.However,there are no studies on the developmental differences in these characteristics between fetal and early-postnatal stages in vitro or in vivo.In this study,we isolated fetal(embryonic day 14.5)and postnatal(postnatal day 2)ENCCs from the intestines of rats.Fetal ENCCs had greater maximum cross-sectional area of the neurospheres,stronger migration ability,and reduced apoptosis,compared with postnatal ENCCs.However,fetal and postnatal ENCCs had a similar differentiation ability.Fetal and postnatal ENCCs both survived after transplant into a rat model of Hirschsprung’s disease.In these rats with Hirschsprung’s disease,the number of ganglionic cells in the myenteric plexus was higher and the distal intestinal pressure change was greater in animals treated with fetal ENCCs compared with those treated with postnatal ENCCs.These findings suggest that,compared with postnatal ENCCs,fetal ENCCs exhibit higher survival and proliferation and migration abilities,and are therefore a more appropriate seed cell for the treatment of Hirschsprung’s disease.This study was approved by the Animal Ethics Committee of the Second Affiliated Hospital of Xi’an Jiaotong University(approval No.2016086)on March 3,2016.
文摘One of biggest recent achievements of neurobiology is the study on neurotrophic factors. The neurotrophins are exciting examples of these factors. They belong to a family of proteins consisting of nerve growth fac-tor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), NT-4/5, NT-6, and NT-7. Today, NGF and BDNF are well recognized to mediate a diz-zying number of trophobiological effects, ranging from neurotrophic through immunotrophic and epitheliotro-phic to metabotrophic effects. These are implicated in the pathogenesis of various diseases. In the same vein, recent studies in adipobiology reveal that this tissue is the body’s largest endocrine and paracrine organ producing multiple signaling proteins collectively termed adipokines, with NGF and BDNF being also produced from adipose tissue. Altogether, neurobio-logy and adipobiology contribute to the improvement of our knowledge on diseases beyond obesity such as cardiometabolic (atherosclerosis, type 2 diabetes, and metabolic syndrome) and neuropsychiatric (e.g. , Alzheimer’s disease and depression) diseases. The present review updates evidence for (1) neurotrophic and metabotrophic potentials of NGF and BDNF linking the pathogenesis of these diseases, and (2) NGF- and BDNF-mediated effects in ampakines, NMDA receptor antagonists, antidepressants, selective deacetylase inhibitors, statins, peroxisome proliferator-activated receptor gamma agonists, and purinergic P2X3 recep-tor up-regulation. This may help to construct a novel paradigm in the feld of translational pharmacology of neuro-metabotrophins, particularly NGF and BDNF.
文摘The dorsolateral prefrontal cortex (dlPFC) of the rat plays a role in the encoding of neuronal signals involved in conflict-induced behavioral adjustment, working memory, planning and executive abilities, attentional control and other cognitive responses. In altricial species, early perinatal undernutrition interferes with the morphofunctional organization of a number of central nervous system (CNS) structures including the prefrontal cortex. The effects of neonatal undernutrition on dendritic arbor density, perikaryon measurements, and the number of spines (detected by rapid-Golgi) of basilar dendritic segments in layer III pyramidal neurons of the dlPFC were examined in male Wistar rats on postnatal (PDs) 12, 20, and 30. In the underfed (U) subjects the distal portions of the dendritic arbors had a consistent hipoplasia, mainly on PD 30, with reduced cross sectional area, perimeter, and spine densities on the basilar dendrites on all days studied. Thus, the alterations of the dlPFC pyramidal neurons may interfere with the plastic synaptic activity and cognitive performance of rats subjected to the stress of early underfeeding. Characterizing these anatomical alterations may help to understand the disrupted cognitive processes associated with neonatal undernutrition.
文摘Early mother-litter bonds alterations elicited by pre- and neonatal undernutrition are a source of long-lasting brain and functional disorders such as exploratory and emotional deficits and maternal unresponsiveness to the newborn. Here, we examined the prolonged effects of gestational and neonatal food restriction on the retrieval of pups and nest building activity by primiparous adult Wistar rats on postnatal days (PDs) 4, 8, and 12. In early undernourished dams, the latency to retrieve the first or the fifth pups in the litter was extended;and nest building activity was significantly reduced. Additionally, early underfed dams retrieved the pups in a rough manner, eliciting distress cries and grasping the pups by unusual body areas. The current findings suggest that pre- and neonatal food restriction may affect the anatomical and functional forebrain structures, modulating the cognitive and motor components underlying maternal responsiveness.