The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration.Axons and dendrites,sometimes referred to as neurites,are extensions of a neuron's cellular body that are...The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration.Axons and dendrites,sometimes referred to as neurites,are extensions of a neuron's cellular body that are used to start networks.Here we explored the effects of diethyl(3,4-dihydroxyphenethylamino)(quinolin-4-yl)methylphosphonate(DDQ)on neurite developmental features in HT22 neuronal cells.In this work,we examined the protective effects of DDQ on neuronal processes and synaptic outgrowth in differentiated HT22cells expressing mutant Tau(mTau)cDNA.To investigate DDQ chara cteristics,cell viability,biochemical,molecular,western blotting,and immunocytochemistry were used.Neurite outgrowth is evaluated through the segmentation and measurement of neural processes.These neural processes can be seen and measured with a fluorescence microscope by manually tracing and measuring the length of the neurite growth.These neuronal processes can be observed and quantified with a fluorescent microscope by manually tracing and measuring the length of the neuronal HT22.DDQ-treated mTau-HT22 cells(HT22 cells transfected with cDNA mutant Tau)were seen to display increased levels of synaptophysin,MAP-2,andβ-tubulin.Additionally,we confirmed and noted reduced levels of both total and p-Tau,as well as elevated levels of microtubule-associated protein 2,β-tubulin,synaptophysin,vesicular acetylcholine transporter,and the mitochondrial biogenesis protein-pe roxisome prolife rator-activated receptor-gamma coactivator-1α.In mTa u-expressed HT22 neurons,we observed DDQ enhanced the neurite characteristics and improved neurite development through increased synaptic outgrowth.Our findings conclude that mTa u-HT22(Alzheimer's disease)cells treated with DDQ have functional neurite developmental chara cteristics.The key finding is that,in mTa u-HT22 cells,DDQ preserves neuronal structure and may even enhance nerve development function with mTa u inhibition.展开更多
Autism Spectrum Disorder(ASD)is marked by early-onset neurodevelopmental anomalies,yet the tem-poral dynamics of genetic contributions to these processes remain insufficiently understood.This study aimed to elu-cidate...Autism Spectrum Disorder(ASD)is marked by early-onset neurodevelopmental anomalies,yet the tem-poral dynamics of genetic contributions to these processes remain insufficiently understood.This study aimed to elu-cidate the role of the Shank3 gene,known to be associated with monogenic causes of autism,in early developmental processes to inform the timing and mechanisms for poten-tial interventions for ASD.Utilizing the Shank3B knockout(KO)mouse model,we examined Shank3 expression and its impact on neuronal maturation through Golgi staining for dendritic morphology and electrophysiological recordings to measure synaptic function in the anterior cingulate cortex(ACC)across different postnatal stages.Our longitudinal analysis revealed that,while Shank3B KO mice displayed normal neuronal morphology at one week postnatal,signifi-cant impairments in dendritic growth and synaptic activity emerged by two to three weeks.These findings highlight the critical developmental window during which Shank3 is essential for neuronal and synaptic maturation in the ACC.展开更多
Gila outnumber neurons and are the most abundant cell type in the nervous system. Whereas neurons are the major carriers, transducers, and processors of information, glial cells, once considered mainly to play a passi...Gila outnumber neurons and are the most abundant cell type in the nervous system. Whereas neurons are the major carriers, transducers, and processors of information, glial cells, once considered mainly to play a passive supporting role, are now recognized for their active contributions to almost every aspect of nervous system development. Recently, insights from the invertebrate organism Drosophila melanogaster have advanced our knowledge of glial cell biology. In particular, findings on neuron-glia interactions via intrinsic and extrinsic mechanisms have shed light on the importance of gtia during different stages of neuronal development. Here, we summarize recent advances in understanding the functions of Drosophila glia, which resemble their mammalian counterparts in morphology and function, neural stem-cell conversion, synapse formation, and developmental axon pruning. These discoveries reinforce the idea that glia are substantial players in the developing nervous system and further advance the understanding of mechanisms leading to neurodegeneration.展开更多
Type II DNA topoisomerases（Tops）are ATP-dependent enzymes that catalyze topological transformations of genomic DNA by the transport of one DNA double helix through another.In mammals,there are 2 isoforms of DNA Top ...Type II DNA topoisomerases（Tops）are ATP-dependent enzymes that catalyze topological transformations of genomic DNA by the transport of one DNA double helix through another.In mammals,there are 2 isoforms of DNA Top II, termed Top IIβ and Top IIβ.The IIβ isoform is abundantly expressed in cells that have undergone the final cell division and are committed to differentiation into neuronal cells.In recent years,there have been accumulating studies showing the significant role of Top IIβ in neuronal development through regulating expression of certain genes in cells committed to the neuronal fate after the final division.These genes are involved in the processes of neuronal differentiation,migration,axon guidance and so on.The present review mainly focused on the research progress on the role of Top IIβ in neuronal development over the recent decades.展开更多
Although numerous studies have examined the neurotoxicity of acrylamide in adult animals,the effects on neuronal development in the embryonic and lactational periods are largely unknown.Thus,we examined the toxicity o...Although numerous studies have examined the neurotoxicity of acrylamide in adult animals,the effects on neuronal development in the embryonic and lactational periods are largely unknown.Thus,we examined the toxicity of acrylamide on neuronal development in the hippocampus of fetal rats during pregnancy.Sprague-Dawley rats were mated with male rats at a 1：1 ratio.Rats were administered 0,5,10 or 20 mg/kg acrylamide intragastrically from embryonic days 6–21.The gait scores were examined in pregnant rats in each group to analyze maternal toxicity.Eight weaning rats from each group were also euthanized on postnatal day 21 for follow-up studies.Nissl staining was used to observe histological change in the hippocampus.Immunohistochemistry was conducted to observe the condition of neurites,including dendrites and axons.Western blot assay was used to measure the expression levels of the specific nerve axon membrane protein,growth associated protein 43,and the presynaptic vesicle membrane specific protein,synaptophysin.The gait scores of gravid rats significantly increased,suggesting that acrylamide induced maternal motor dysfunction.The number of neurons,as well as expression of growth associated protein 43 and synaptophysin,was reduced with increasing acrylamide dose in postnatal day 21 weaning rats.These data suggest that acrylamide exerts dose-dependent toxic effects on the growth and development of hippocampal neurons of weaning rats.展开更多
BACKGROUND As the third most abundant element,aluminum is widespread in the environment.Previous studies have shown that aluminum has a neurotoxic effect and its exposure can impair neuronal development and cognitive ...BACKGROUND As the third most abundant element,aluminum is widespread in the environment.Previous studies have shown that aluminum has a neurotoxic effect and its exposure can impair neuronal development and cognitive function.AIM To study the effects of aluminum on epigenetic modification in neural stem cells and neurons.METHODS Neural stem cells were isolated from the forebrain of adult mice.Neurons were isolated from the hippocampi tissues of embryonic day 16-18 mice.AlCl3 at 100 and 200μmol/L was applied to stem cells and neurons.RESULTS Aluminum altered the differentiation of adult neural stem cells and caused apoptosis of newborn neurons while having no significant effects on the proliferation of neural stem cells.Aluminum application also significantly inhibited the dendritic development of hippocampal neurons.Mechanistically,aluminum exposure significantly affected the levels of DNA 5-hydroxy methylcytosine,5-methylcytosine,and N6-methyladenine in stem cells and neurons.CONCLUSION Our findings indicate that aluminum may regulate neuronal development by modulating DNA modifications.展开更多
Background and early studies： Endogenous tri-potential neural stem cells （NSCs） exist in the adult mammalian central nervous system （CNS）. In the spinal cord, NSCs distribute throughout the entire cord, but exist...Background and early studies： Endogenous tri-potential neural stem cells （NSCs） exist in the adult mammalian central nervous system （CNS）. In the spinal cord, NSCs distribute throughout the entire cord, but exist predominately in white matter tracts. The phenotypic fate of these cells in white matter is glial, largely oligodendrocyte, but not neuronal.展开更多
Forkhead box protein P1（FOXP1）is a transcription factor belonging to the forkhead box（FOX）proteins,a family of transcriptional regulators sharing a highly conserved forkhead DNA-binding domain（Bacon and Rappold,2...Forkhead box protein P1（FOXP1）is a transcription factor belonging to the forkhead box（FOX）proteins,a family of transcriptional regulators sharing a highly conserved forkhead DNA-binding domain（Bacon and Rappold,2012）.Previous reports have proposed a role for FOXP1 in functionally regulating the central nervous system（CNS）,while mutations in FOXP1 have been implicated in cognitive abnormalities（Bacon and Rappold, 2012）.展开更多
The V-MYC avian myelocytomatosis viral-related onco- gene, a neuroblastoma-derived gene （MYCN, MIM： 164840） located on chromosome 2p24, was previously found to be associated with Feingold syndrome 1 （FGLDS1, MIM：...The V-MYC avian myelocytomatosis viral-related onco- gene, a neuroblastoma-derived gene （MYCN, MIM： 164840） located on chromosome 2p24, was previously found to be associated with Feingold syndrome 1 （FGLDS1, MIM： 164280） [1]. FGLDS1 is an autosomal dominant disorder characterized by variable combinations of microcephaly, limb malformations, esophageal and duodenal atresias, and learning disabilities. Cardiac and renal malformations, vertebral anomalies, and deafness have also been described in a minority of patients [2]. Despite the involvement of intellectual disability in FGLDS1, the molecular mechanisms of the MYCN gene in regulating brain development remain largely unclear.Some truncated mutations in the N terminus of the MYCN have been identified in FGLDS1 [1, 3].展开更多
How do individual neurons develop and how are they in- tegrated into neuronal circuitry？ To answer this question is essential to understand how the nervous system develops and how it is maintained during the adult li...How do individual neurons develop and how are they in- tegrated into neuronal circuitry？ To answer this question is essential to understand how the nervous system develops and how it is maintained during the adult life. A neural stem cell must go through several stages of maturation, including proliferation, migration, differentiation, and integration, to become fully embedded to an existing neuronal circuit. The knowledge on this topic so far has come mainly from cell culture studies. Studying the development of individual neurons within intact neuronal networks in vivo is inherently difficult. Most neurons are generated form neural stem cells during embryonic and early postnatal development.展开更多
BACKGROUND: Under the normal circumstance, there exist some synapses with inactive functions in central nervous system (CNS), but these functions are activated following nerve injury. At the early stage of brain injur...BACKGROUND: Under the normal circumstance, there exist some synapses with inactive functions in central nervous system (CNS), but these functions are activated following nerve injury. At the early stage of brain injury, the abnormal functions of brain are varied, and they have very strong plasticity and are corrected easily. OBJECTIVE: To observe the changes of neuronal morphology in hippocampal CA1 region and memory function in newborn rats with hypoxic-ischemic encephalopathy(HIE) from ischemia 6 hours to adult. DESIGN: Completely randomized grouping, controlled experiment. SETTING: Taian Health Center for Women and Children; Taishan Medical College. MATERIALS: Altogether 120 seven-day-old Wistar rats, of clean grade, were provided by the Experimental Animal Center, Shandong University of Traditional Chinese Medicine. Synaptophysin (SYN) polyclonal antibody was provided by Maixin Biological Company, Fuzhou. METHODS: This experiment was carried out in the Laboratory of Morphology, Taishan Medical College between October 2000 and December 2003. ① The newborn rats were randomly divided into 2 groups: model group and control group, 60 rats in each group. Five rats were chosen from each group at postoperative 6 hours, 24 hours, 72 hours, 7 days, 2 weeks and 3 weeks separately for immunohistochemical staining. Fifteen newborn rats were chosen from each group at postoperative 4 weeks and 2 months separately for testing memory ability (After test, 5 rats from each group were sacrificed and used for immunohistochemical staining)② The right common carotid artery of newborn rats of model group was ligated under the anesthetized status. After two hours of incubation, the rats were placed for 2 hours in a container filled with nitrogen oxygen atmosphere containing 0.08 volume fraction of oxygen, thus, HIE models were created; As for the newborn rats in the control group, only blood vessels were isolated, and they were not ligated and hypoxia-treated. ③ Thalamencephal tissue sections of newborn rats of two groups were performed DAB developing and haematoxylin slight staining. Cells with normal nucleous in 250 μm-long granular layer which started from hippocampal CA1 region were counted with image analysis system under high-fold optical microscope (×600), and the thickness of granular layer was measured. The absorbance (A) of positive reactant of SYN in immunohistochemically-stained CA1 region was measured. Learning and memory ability were measured with step through test 3 times successively. ④ t test and paired t test were used for comparing intergroup and intragroup difference of measurement data respectively, and Chi-square for comparing the difference of enumeration data. MAIN OUTCOME MEASURES: Comparison of cytological changes in hippocampal CA1 region and memory ability at different postoperative time points between two groups. RESULTS: Totally 120 newborn rats were involved in the result analysis. ① Cell morphological changes in hippocampal CA1 region: In the control group, with aging, perikaryon, nucleus and nucleolus in cortex of parietal lobe were significantly increased, Nissl body was compacted, the amount of neurons was declined, but the A of SYN positive reactant was relatively increased. In the model group, at postoperative each time point, neurons were seriously shrunk and dark-stained, nucleus was contracted, chromatin was condensed, nucleolus was unclear, even cells disappeared, especially the cells in 6 hours and 24 hours groups. The amount of neurons with normal morphology in hippocampal CA1 region and granular layer thickness in the model group at postoperative each time point were significantly less or smaller than those in the control group at postoperative 6 hours respectively (t =3.002-1.254, P < 0.01). The A value of SYN positive reactant at postoperative 2, 3 and 4 weeks was significantly higher than that at previous time point (t =2.011-2.716,P < 0.05-0.01). ② Test results of learning and memory ability: In the first test, there was no significant difference in the ratio of rats which kept memory ability between two groups (P > 0.05); In the third test, the ratio of rats which kept memory ability in the model group was significantly lower than that in the control group at postoperative 4 weeks and 2 months[53%(8/15),100%(15/15);60%(9/15),93%(14/15),χ 2=2.863,2.901,P < 0.01]. CONCLUSION: The destroyed hippocampal structure induces the decrease of learning and memory ability of developmental rats. Early interference can increase the quality of neurons and also promote functional development of the nervous system.展开更多
Basic helix-loop-helix （bHLH） transcription factors regulate the differentiation of various tissues in a vast diversity of species. The bHLH protein Atonal was first identified as a proneural gene involved in the fo...Basic helix-loop-helix （bHLH） transcription factors regulate the differentiation of various tissues in a vast diversity of species. The bHLH protein Atonal was first identified as a proneural gene involved in the formation of mechanosensory cells and photoreceptor cells in Drosophila （larman et al., 1993, 1994）. Atonal is expressed in sensory organ precursors and is required and sufficient for the development of chordotonal organs （Jar- man et al., 1993）. Moreover, Atonal expression is observed in the developing eye and is essential for the differentiation of R8 photoreceptors, which are the first photoreceptors that appear during development. Atonal is not involved in the formation of other photoreceptors （R1-R7） directly. However, R8 photore- ceptors recruit other photoreceptors from the surrounding cells （Jarman et al., 1994）.展开更多
Primary impairments of developmental coordination disorder (DCD) include impairments in motor skill, motor learning, and imitation. Such difficulties present challenges for individuals with DCD and may persist into ad...Primary impairments of developmental coordination disorder (DCD) include impairments in motor skill, motor learning, and imitation. Such difficulties present challenges for individuals with DCD and may persist into adulthood, negatively impacting daily life in school, work, and social domains. A better understanding of the neural correlates of motor and imitation impairments in DCD holds the potential for informing development of treatment approaches to address these impairments. Although the disorder is assumed to be of neurological origin, little is known of the brain-based etiology of DCD. In recent years the discovery of a fronto-parietal circuit—known as the mirror neuron system—has enabled researchers to better understand imitation, general motor functions, and aspects of social cognition. Given its involvement in imitation and other motor functions, we propose that dysfunction in the mirror neuron system may underlie the characteristic impairments of DCD. We review literature pertaining to the mirror neuron system and develop a theory of disordered mirror neuron functioning in DCD. Finally, we review the limited neuroimaging literature available on neural correlates of DCD and show that the findings from those investigations are congruent with a mirror neuron system theory of DCD. Future research in this population should be designed to investigate specifically mirror neuron regions in individuals with DCD during skilled motor tasks and imitation in particular.展开更多
This study examined the effects of clinically relevant concentrations of isoflurane on the amplitude of NMDA receptor current （INMDA） and the expression of cytochrome C in cultured developing rat hippocampal neurons...This study examined the effects of clinically relevant concentrations of isoflurane on the amplitude of NMDA receptor current （INMDA） and the expression of cytochrome C in cultured developing rat hippocampal neurons. The hippocampi were dissected from newborn Sprague-Dawley rats. Hippocampal neurons were primarily cultured for 5 days and then treated with different concentrations of isoflurane [（0.25, 0.5, 0.75, 1 minimum alveolar concentration （MAC））]. The peak of INMDA was re- corded by means of the whole cell patch clamp technique. The cytochrome C level was detected by Western blotting and quantitative real-time PCR. Our results showed that isoflurane （0.25, 0.5, 0.75 and 1 MAC） potentiated the amplitude of INMDA by （116±8.8）%, （122±11.7）%, （135±14.3）% and （132~14.6）%, respectively, and isoflurane increased the mRNA expression of cytochrome C in a concentration-dependent manner. The cytochrome C mRNA expression reached a maximum after 0.5 MAC isoflurane stimulation for 6 h （P〈0.05）. It was concluded that isoflurane enhances the expression of cytochrome C in cultured rat hippocampal neurons, which may be mediated by facilitation of NMDA receptor.展开更多
Abnormal synchronous neuronal activity has been widely detected by brain imaging of autistic patients,but its underlying neural mechanism remains unclear.Compared with wild-type mice,our in vivo two-photon imaging sho...Abnormal synchronous neuronal activity has been widely detected by brain imaging of autistic patients,but its underlying neural mechanism remains unclear.Compared with wild-type mice,our in vivo two-photon imaging showed that transgenic(Tgl)mice over-expressing human autism risk gene MeCP2 exhibited higher neuronal synchrony in the young but lower synchrony in the adult stage.Whole-cell recording of neuronal pairs in brain slices revealed that higher neuronal synchrony in young postnatal Tgl mice was atributed mainly to more prevalent giant slow inward currents(SICs).Both in vivo and slice imaging further demonstrated more dynamic activity and higher synchrony in astrocytes from young Tgl mice.Blocking astrocytic gap junctions markedly decreased the generation of SICs and overall cell synchrony in the Tgl brain.Furthermore,the expression level of Cx43 protein and the coupling efficiency of astrocyte gap junctions remained unchanged in Tgi mice.Thus,astrocytic gap junctions facilitate but do not act as a direct trigger for the abnormal neuronal synchrony in young Tgl mice,revealing the potential role of the astrocyte network in the pathogenesis of MeCP2 duplication syndrome.展开更多
The striatum, as the primary input nucleus in the basal ganglion,plays an important role in neural circuits crucial for the control of critical motivation, motor planning and procedural learning(Kreitzer and Malenka, ...The striatum, as the primary input nucleus in the basal ganglion,plays an important role in neural circuits crucial for the control of critical motivation, motor planning and procedural learning(Kreitzer and Malenka, 2008). Most cells in the striatum are GABAergic, including a large population (90%-95%) of medium spiny neurons (MSNs) and a small population of interneurons.展开更多
Sex-specific neurons play pivotal roles in regulating sexually dimorphic behaviors.In insects,the sex determination gene doublesex(dsx)establishes major sexual dimorphism of the nervous system,in which male-specific d...Sex-specific neurons play pivotal roles in regulating sexually dimorphic behaviors.In insects,the sex determination gene doublesex(dsx)establishes major sexual dimorphism of the nervous system,in which male-specific dsx^(M)promotes neuronal development,while female-specific dsx^(F)inhibits neuronal development by promoting neuronal apoptosis.In this study,we find that dsx regulates the number of dsx-expressing central neurons in Drosophila in cell-specific manners.Although dsx^(M)overall promotes an increase in the number of dsx neurons,it inhibits the emergence of specific pC1 neurons.dsx^(F)reduces the number of different pC1/pC2 subtypes,but promotes the formation of pC1d.We also find that dsx^(M)and dsx^(F)barely affect the number of some pC2 neurons.Changes in the number of pC1/pC2 neurons alter their roles in regulating different behaviors,including courtship,aggression,and locomotion.Our results illustrate the multifaceted functions of dsx in sexually dimorphic neuronal development and behaviors.展开更多
Neurons are polarized cells with a complex and unique morphology.Each specific type of neuron has distinct functional organelles and protein compositions.This compartmental complexity relies on adaptor protein(AP)comp...Neurons are polarized cells with a complex and unique morphology.Each specific type of neuron has distinct functional organelles and protein compositions.This compartmental complexity relies on adaptor protein(AP)complexes transporting intracellular components to target locations.Malfunctions in the AP complexes can result in a range of abnormalities in neurons that affect neuronal migration,axogenesis,dendritogenesis,neuronal protection,and neural differentiation.These abnormalities also have crucial consequences for the proper functioning of the nervous system.In this article,we review the neuronal functions of AP complexes and provide a comprehensive overview of their links to neurological diseases.展开更多
Kelch-like family member 17(KLHL17)is predominantly expressed in the brain and plays a crucial role in neuronal development and function,deletions and/or mutations in KLHL17 have been linked to neurodevelopmental diso...Kelch-like family member 17(KLHL17)is predominantly expressed in the brain and plays a crucial role in neuronal development and function,deletions and/or mutations in KLHL17 have been linked to neurodevelopmental disorders in humans,e.g.,intellectual disability,autism spectrum disorder,and infantile spasms,but the etiology and pathogenesis remain largely enigmatic.1,2 As a member of the family of the Kelch proteins,KLHL17 contains an N-terminal BTB/POZ domain followed by a BACK domain and four to six tandem Kelch motifs at the C-terminal region(Fig.S1A).1,3 Previously,we identified a novel de novo variant in KLHL17(c.701C>T;p.P234L)in a cohort of 225 Chinese children with developmental delay/intellectual disability based on whole-exome sequencing(1/225),the mutation located in the BACK domain,a very high conversed region(Fig.S1B),and the affected boy presented with developmental delay,intellectual disability,hypotonia,and abnormal brainstem auditory evoked potential signal.4 The finding may offer a new clue to investigate the molecular pathogenesis of KLHL17 gene in neurodevelopmental disorders.展开更多
基金supported by NIH grants AG079264(to PHR)and AG071560(to APR)。
文摘The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration.Axons and dendrites,sometimes referred to as neurites,are extensions of a neuron's cellular body that are used to start networks.Here we explored the effects of diethyl(3,4-dihydroxyphenethylamino)(quinolin-4-yl)methylphosphonate(DDQ)on neurite developmental features in HT22 neuronal cells.In this work,we examined the protective effects of DDQ on neuronal processes and synaptic outgrowth in differentiated HT22cells expressing mutant Tau(mTau)cDNA.To investigate DDQ chara cteristics,cell viability,biochemical,molecular,western blotting,and immunocytochemistry were used.Neurite outgrowth is evaluated through the segmentation and measurement of neural processes.These neural processes can be seen and measured with a fluorescence microscope by manually tracing and measuring the length of the neurite growth.These neuronal processes can be observed and quantified with a fluorescent microscope by manually tracing and measuring the length of the neuronal HT22.DDQ-treated mTau-HT22 cells(HT22 cells transfected with cDNA mutant Tau)were seen to display increased levels of synaptophysin,MAP-2,andβ-tubulin.Additionally,we confirmed and noted reduced levels of both total and p-Tau,as well as elevated levels of microtubule-associated protein 2,β-tubulin,synaptophysin,vesicular acetylcholine transporter,and the mitochondrial biogenesis protein-pe roxisome prolife rator-activated receptor-gamma coactivator-1α.In mTa u-expressed HT22 neurons,we observed DDQ enhanced the neurite characteristics and improved neurite development through increased synaptic outgrowth.Our findings conclude that mTa u-HT22(Alzheimer's disease)cells treated with DDQ have functional neurite developmental chara cteristics.The key finding is that,in mTa u-HT22 cells,DDQ preserves neuronal structure and may even enhance nerve development function with mTa u inhibition.
基金supported by the Natural Science Foundation of China(32394032,82201699,and 82221001)the Natural Science Foundation of Zhejiang Province(LTGD24H250001)+1 种基金the Kay R&D Program of Shaanxi Province(2023-YBSF-093),the Young Talent Fund of University Association for Science and Technology in Shaanxi(20220306)the Joint Founding Project of Innovation Research Institute,Xijing Hospital(LHJJ24JH02).
文摘Autism Spectrum Disorder(ASD)is marked by early-onset neurodevelopmental anomalies,yet the tem-poral dynamics of genetic contributions to these processes remain insufficiently understood.This study aimed to elu-cidate the role of the Shank3 gene,known to be associated with monogenic causes of autism,in early developmental processes to inform the timing and mechanisms for poten-tial interventions for ASD.Utilizing the Shank3B knockout(KO)mouse model,we examined Shank3 expression and its impact on neuronal maturation through Golgi staining for dendritic morphology and electrophysiological recordings to measure synaptic function in the anterior cingulate cortex(ACC)across different postnatal stages.Our longitudinal analysis revealed that,while Shank3B KO mice displayed normal neuronal morphology at one week postnatal,signifi-cant impairments in dendritic growth and synaptic activity emerged by two to three weeks.These findings highlight the critical developmental window during which Shank3 is essential for neuronal and synaptic maturation in the ACC.
基金supported by grants from the National Basic Research Program of China (973 Program 2010CB944900 and 2013CB945602)the National Natural Science Foundation of China (31270825 and 31171043)Fundamental Research Funds for the Central Universities We thank members of the Ho lab for discussion and comments
文摘Gila outnumber neurons and are the most abundant cell type in the nervous system. Whereas neurons are the major carriers, transducers, and processors of information, glial cells, once considered mainly to play a passive supporting role, are now recognized for their active contributions to almost every aspect of nervous system development. Recently, insights from the invertebrate organism Drosophila melanogaster have advanced our knowledge of glial cell biology. In particular, findings on neuron-glia interactions via intrinsic and extrinsic mechanisms have shed light on the importance of gtia during different stages of neuronal development. Here, we summarize recent advances in understanding the functions of Drosophila glia, which resemble their mammalian counterparts in morphology and function, neural stem-cell conversion, synapse formation, and developmental axon pruning. These discoveries reinforce the idea that glia are substantial players in the developing nervous system and further advance the understanding of mechanisms leading to neurodegeneration.
基金supported by the National Natural Science Foundation of China(No.39070925)Shanghai International Science and Technology Coopera-tion Program(No.075407066)National High Technology Research and Development Program of China(No.2006AA02A408)
文摘Type II DNA topoisomerases（Tops）are ATP-dependent enzymes that catalyze topological transformations of genomic DNA by the transport of one DNA double helix through another.In mammals,there are 2 isoforms of DNA Top II, termed Top IIβ and Top IIβ.The IIβ isoform is abundantly expressed in cells that have undergone the final cell division and are committed to differentiation into neuronal cells.In recent years,there have been accumulating studies showing the significant role of Top IIβ in neuronal development through regulating expression of certain genes in cells committed to the neuronal fate after the final division.These genes are involved in the processes of neuronal differentiation,migration,axon guidance and so on.The present review mainly focused on the research progress on the role of Top IIβ in neuronal development over the recent decades.
基金supported by the Guangdong Provincial Department of Science and Technology in China,No.2016A020225007
文摘Although numerous studies have examined the neurotoxicity of acrylamide in adult animals,the effects on neuronal development in the embryonic and lactational periods are largely unknown.Thus,we examined the toxicity of acrylamide on neuronal development in the hippocampus of fetal rats during pregnancy.Sprague-Dawley rats were mated with male rats at a 1：1 ratio.Rats were administered 0,5,10 or 20 mg/kg acrylamide intragastrically from embryonic days 6–21.The gait scores were examined in pregnant rats in each group to analyze maternal toxicity.Eight weaning rats from each group were also euthanized on postnatal day 21 for follow-up studies.Nissl staining was used to observe histological change in the hippocampus.Immunohistochemistry was conducted to observe the condition of neurites,including dendrites and axons.Western blot assay was used to measure the expression levels of the specific nerve axon membrane protein,growth associated protein 43,and the presynaptic vesicle membrane specific protein,synaptophysin.The gait scores of gravid rats significantly increased,suggesting that acrylamide induced maternal motor dysfunction.The number of neurons,as well as expression of growth associated protein 43 and synaptophysin,was reduced with increasing acrylamide dose in postnatal day 21 weaning rats.These data suggest that acrylamide exerts dose-dependent toxic effects on the growth and development of hippocampal neurons of weaning rats.
文摘BACKGROUND As the third most abundant element,aluminum is widespread in the environment.Previous studies have shown that aluminum has a neurotoxic effect and its exposure can impair neuronal development and cognitive function.AIM To study the effects of aluminum on epigenetic modification in neural stem cells and neurons.METHODS Neural stem cells were isolated from the forebrain of adult mice.Neurons were isolated from the hippocampi tissues of embryonic day 16-18 mice.AlCl3 at 100 and 200μmol/L was applied to stem cells and neurons.RESULTS Aluminum altered the differentiation of adult neural stem cells and caused apoptosis of newborn neurons while having no significant effects on the proliferation of neural stem cells.Aluminum application also significantly inhibited the dendritic development of hippocampal neurons.Mechanistically,aluminum exposure significantly affected the levels of DNA 5-hydroxy methylcytosine,5-methylcytosine,and N6-methyladenine in stem cells and neurons.CONCLUSION Our findings indicate that aluminum may regulate neuronal development by modulating DNA modifications.
文摘Background and early studies： Endogenous tri-potential neural stem cells （NSCs） exist in the adult mammalian central nervous system （CNS）. In the spinal cord, NSCs distribute throughout the entire cord, but exist predominately in white matter tracts. The phenotypic fate of these cells in white matter is glial, largely oligodendrocyte, but not neuronal.
文摘Forkhead box protein P1（FOXP1）is a transcription factor belonging to the forkhead box（FOX）proteins,a family of transcriptional regulators sharing a highly conserved forkhead DNA-binding domain（Bacon and Rappold,2012）.Previous reports have proposed a role for FOXP1 in functionally regulating the central nervous system（CNS）,while mutations in FOXP1 have been implicated in cognitive abnormalities（Bacon and Rappold, 2012）.
基金supported by grants from the National Natural Science Foundation of China(81701494)the Shanghai Municipal Commission of Health and Family Planning(2013ZYJB0015)the Science and Technology Commission of Shanghai Municipality(14411950402)
文摘The V-MYC avian myelocytomatosis viral-related onco- gene, a neuroblastoma-derived gene （MYCN, MIM： 164840） located on chromosome 2p24, was previously found to be associated with Feingold syndrome 1 （FGLDS1, MIM： 164280） [1]. FGLDS1 is an autosomal dominant disorder characterized by variable combinations of microcephaly, limb malformations, esophageal and duodenal atresias, and learning disabilities. Cardiac and renal malformations, vertebral anomalies, and deafness have also been described in a minority of patients [2]. Despite the involvement of intellectual disability in FGLDS1, the molecular mechanisms of the MYCN gene in regulating brain development remain largely unclear.Some truncated mutations in the N terminus of the MYCN have been identified in FGLDS1 [1, 3].
基金supported by DFG Schwerpunkt program 1392(project MA 4113/2-2)cluster of Excellence and DFG Research Center Nanoscale Microscopy and Molecular Physiology of the Brain(project B1-9)+1 种基金the German Ministry of Research and Education(BMBFproject 1364480)
文摘How do individual neurons develop and how are they in- tegrated into neuronal circuitry？ To answer this question is essential to understand how the nervous system develops and how it is maintained during the adult life. A neural stem cell must go through several stages of maturation, including proliferation, migration, differentiation, and integration, to become fully embedded to an existing neuronal circuit. The knowledge on this topic so far has come mainly from cell culture studies. Studying the development of individual neurons within intact neuronal networks in vivo is inherently difficult. Most neurons are generated form neural stem cells during embryonic and early postnatal development.
基金the Grant from Family Planning Commission of Shandong Province,No.97-15
文摘BACKGROUND: Under the normal circumstance, there exist some synapses with inactive functions in central nervous system (CNS), but these functions are activated following nerve injury. At the early stage of brain injury, the abnormal functions of brain are varied, and they have very strong plasticity and are corrected easily. OBJECTIVE: To observe the changes of neuronal morphology in hippocampal CA1 region and memory function in newborn rats with hypoxic-ischemic encephalopathy(HIE) from ischemia 6 hours to adult. DESIGN: Completely randomized grouping, controlled experiment. SETTING: Taian Health Center for Women and Children; Taishan Medical College. MATERIALS: Altogether 120 seven-day-old Wistar rats, of clean grade, were provided by the Experimental Animal Center, Shandong University of Traditional Chinese Medicine. Synaptophysin (SYN) polyclonal antibody was provided by Maixin Biological Company, Fuzhou. METHODS: This experiment was carried out in the Laboratory of Morphology, Taishan Medical College between October 2000 and December 2003. ① The newborn rats were randomly divided into 2 groups: model group and control group, 60 rats in each group. Five rats were chosen from each group at postoperative 6 hours, 24 hours, 72 hours, 7 days, 2 weeks and 3 weeks separately for immunohistochemical staining. Fifteen newborn rats were chosen from each group at postoperative 4 weeks and 2 months separately for testing memory ability (After test, 5 rats from each group were sacrificed and used for immunohistochemical staining)② The right common carotid artery of newborn rats of model group was ligated under the anesthetized status. After two hours of incubation, the rats were placed for 2 hours in a container filled with nitrogen oxygen atmosphere containing 0.08 volume fraction of oxygen, thus, HIE models were created; As for the newborn rats in the control group, only blood vessels were isolated, and they were not ligated and hypoxia-treated. ③ Thalamencephal tissue sections of newborn rats of two groups were performed DAB developing and haematoxylin slight staining. Cells with normal nucleous in 250 μm-long granular layer which started from hippocampal CA1 region were counted with image analysis system under high-fold optical microscope (×600), and the thickness of granular layer was measured. The absorbance (A) of positive reactant of SYN in immunohistochemically-stained CA1 region was measured. Learning and memory ability were measured with step through test 3 times successively. ④ t test and paired t test were used for comparing intergroup and intragroup difference of measurement data respectively, and Chi-square for comparing the difference of enumeration data. MAIN OUTCOME MEASURES: Comparison of cytological changes in hippocampal CA1 region and memory ability at different postoperative time points between two groups. RESULTS: Totally 120 newborn rats were involved in the result analysis. ① Cell morphological changes in hippocampal CA1 region: In the control group, with aging, perikaryon, nucleus and nucleolus in cortex of parietal lobe were significantly increased, Nissl body was compacted, the amount of neurons was declined, but the A of SYN positive reactant was relatively increased. In the model group, at postoperative each time point, neurons were seriously shrunk and dark-stained, nucleus was contracted, chromatin was condensed, nucleolus was unclear, even cells disappeared, especially the cells in 6 hours and 24 hours groups. The amount of neurons with normal morphology in hippocampal CA1 region and granular layer thickness in the model group at postoperative each time point were significantly less or smaller than those in the control group at postoperative 6 hours respectively (t =3.002-1.254, P < 0.01). The A value of SYN positive reactant at postoperative 2, 3 and 4 weeks was significantly higher than that at previous time point (t =2.011-2.716,P < 0.05-0.01). ② Test results of learning and memory ability: In the first test, there was no significant difference in the ratio of rats which kept memory ability between two groups (P > 0.05); In the third test, the ratio of rats which kept memory ability in the model group was significantly lower than that in the control group at postoperative 4 weeks and 2 months[53%(8/15),100%(15/15);60%(9/15),93%(14/15),χ 2=2.863,2.901,P < 0.01]. CONCLUSION: The destroyed hippocampal structure induces the decrease of learning and memory ability of developmental rats. Early interference can increase the quality of neurons and also promote functional development of the nervous system.
基金supported by grants from the Ministry of Education,Culture,Sports,Science and Technology in Japan and Naito Foundation to TCthe Japan Society for the Promotion of Science to MO and TC
文摘Basic helix-loop-helix （bHLH） transcription factors regulate the differentiation of various tissues in a vast diversity of species. The bHLH protein Atonal was first identified as a proneural gene involved in the formation of mechanosensory cells and photoreceptor cells in Drosophila （larman et al., 1993, 1994）. Atonal is expressed in sensory organ precursors and is required and sufficient for the development of chordotonal organs （Jar- man et al., 1993）. Moreover, Atonal expression is observed in the developing eye and is essential for the differentiation of R8 photoreceptors, which are the first photoreceptors that appear during development. Atonal is not involved in the formation of other photoreceptors （R1-R7） directly. However, R8 photore- ceptors recruit other photoreceptors from the surrounding cells （Jarman et al., 1994）.
文摘Primary impairments of developmental coordination disorder (DCD) include impairments in motor skill, motor learning, and imitation. Such difficulties present challenges for individuals with DCD and may persist into adulthood, negatively impacting daily life in school, work, and social domains. A better understanding of the neural correlates of motor and imitation impairments in DCD holds the potential for informing development of treatment approaches to address these impairments. Although the disorder is assumed to be of neurological origin, little is known of the brain-based etiology of DCD. In recent years the discovery of a fronto-parietal circuit—known as the mirror neuron system—has enabled researchers to better understand imitation, general motor functions, and aspects of social cognition. Given its involvement in imitation and other motor functions, we propose that dysfunction in the mirror neuron system may underlie the characteristic impairments of DCD. We review literature pertaining to the mirror neuron system and develop a theory of disordered mirror neuron functioning in DCD. Finally, we review the limited neuroimaging literature available on neural correlates of DCD and show that the findings from those investigations are congruent with a mirror neuron system theory of DCD. Future research in this population should be designed to investigate specifically mirror neuron regions in individuals with DCD during skilled motor tasks and imitation in particular.
基金supported by grants from the National Natural Science Foundation of China(No.30772086No.30901390)
文摘This study examined the effects of clinically relevant concentrations of isoflurane on the amplitude of NMDA receptor current （INMDA） and the expression of cytochrome C in cultured developing rat hippocampal neurons. The hippocampi were dissected from newborn Sprague-Dawley rats. Hippocampal neurons were primarily cultured for 5 days and then treated with different concentrations of isoflurane [（0.25, 0.5, 0.75, 1 minimum alveolar concentration （MAC））]. The peak of INMDA was re- corded by means of the whole cell patch clamp technique. The cytochrome C level was detected by Western blotting and quantitative real-time PCR. Our results showed that isoflurane （0.25, 0.5, 0.75 and 1 MAC） potentiated the amplitude of INMDA by （116±8.8）%, （122±11.7）%, （135±14.3）% and （132~14.6）%, respectively, and isoflurane increased the mRNA expression of cytochrome C in a concentration-dependent manner. The cytochrome C mRNA expression reached a maximum after 0.5 MAC isoflurane stimulation for 6 h （P〈0.05）. It was concluded that isoflurane enhances the expression of cytochrome C in cultured rat hippocampal neurons, which may be mediated by facilitation of NMDA receptor.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB32010100)a National Natural Science Foundation of China project(31671113)+1 种基金a Shanghai Municipal Science and Technology Major Project(2018SHZDZX05)and the State Key Laboratory of Neuroscience.
文摘Abnormal synchronous neuronal activity has been widely detected by brain imaging of autistic patients,but its underlying neural mechanism remains unclear.Compared with wild-type mice,our in vivo two-photon imaging showed that transgenic(Tgl)mice over-expressing human autism risk gene MeCP2 exhibited higher neuronal synchrony in the young but lower synchrony in the adult stage.Whole-cell recording of neuronal pairs in brain slices revealed that higher neuronal synchrony in young postnatal Tgl mice was atributed mainly to more prevalent giant slow inward currents(SICs).Both in vivo and slice imaging further demonstrated more dynamic activity and higher synchrony in astrocytes from young Tgl mice.Blocking astrocytic gap junctions markedly decreased the generation of SICs and overall cell synchrony in the Tgl brain.Furthermore,the expression level of Cx43 protein and the coupling efficiency of astrocyte gap junctions remained unchanged in Tgi mice.Thus,astrocytic gap junctions facilitate but do not act as a direct trigger for the abnormal neuronal synchrony in young Tgl mice,revealing the potential role of the astrocyte network in the pathogenesis of MeCP2 duplication syndrome.
基金supported by grants from the National Key Research and Development Program of China (2016YFA0100702 and 2016YFC0902502)the National Natural Science Foundation of China (31670789 and 31671316)the CAMS Innovation Fund for Medical Sciences (CIFMS, 2016I2M-2-001, 2016-I2M-1-001, 2016-I2M-1-004 and 2017-I2M-1004)
文摘The striatum, as the primary input nucleus in the basal ganglion,plays an important role in neural circuits crucial for the control of critical motivation, motor planning and procedural learning(Kreitzer and Malenka, 2008). Most cells in the striatum are GABAergic, including a large population (90%-95%) of medium spiny neurons (MSNs) and a small population of interneurons.
基金supported by the National Key R&D Program of China(2021YFA1101300)the National Natural Science Foundation of China(32371067 to Y.P.)+1 种基金the Natural Science Foundation from Jiangsu Province(BK20231418 to Q.P.)the Fundamental Research Funds for the Central Universities(2242023R40054 to Q.P.).
文摘Sex-specific neurons play pivotal roles in regulating sexually dimorphic behaviors.In insects,the sex determination gene doublesex(dsx)establishes major sexual dimorphism of the nervous system,in which male-specific dsx^(M)promotes neuronal development,while female-specific dsx^(F)inhibits neuronal development by promoting neuronal apoptosis.In this study,we find that dsx regulates the number of dsx-expressing central neurons in Drosophila in cell-specific manners.Although dsx^(M)overall promotes an increase in the number of dsx neurons,it inhibits the emergence of specific pC1 neurons.dsx^(F)reduces the number of different pC1/pC2 subtypes,but promotes the formation of pC1d.We also find that dsx^(M)and dsx^(F)barely affect the number of some pC2 neurons.Changes in the number of pC1/pC2 neurons alter their roles in regulating different behaviors,including courtship,aggression,and locomotion.Our results illustrate the multifaceted functions of dsx in sexually dimorphic neuronal development and behaviors.
基金supported by the Shanghai Municipal Commission of Science and Technology Research Project(19JC1411001)the National Key Research and Development Program from the Ministry of Science and Technology of the People’s Republic of China(2021YFC2700800)+2 种基金the National Natural Science Foundation of China(31972880,32170615,31371274,and U21A20347)the National Key Research and Development Plan for Stem Cell and Transformation Research(2017YFA0104202)the Collaborative Innovation Center Project Construction for Shanghai Women and Children’s Health.
文摘Neurons are polarized cells with a complex and unique morphology.Each specific type of neuron has distinct functional organelles and protein compositions.This compartmental complexity relies on adaptor protein(AP)complexes transporting intracellular components to target locations.Malfunctions in the AP complexes can result in a range of abnormalities in neurons that affect neuronal migration,axogenesis,dendritogenesis,neuronal protection,and neural differentiation.These abnormalities also have crucial consequences for the proper functioning of the nervous system.In this article,we review the neuronal functions of AP complexes and provide a comprehensive overview of their links to neurological diseases.
基金funded by the National Natural Science Foundation of China(No.82160620)the Natural Science Foundation of Guangxi Province,China(No.2023GXNSFAA026036)the Guangxi College Students Innovation and Entrepreneurship Training Program(China)(No.S202310601164).
文摘Kelch-like family member 17(KLHL17)is predominantly expressed in the brain and plays a crucial role in neuronal development and function,deletions and/or mutations in KLHL17 have been linked to neurodevelopmental disorders in humans,e.g.,intellectual disability,autism spectrum disorder,and infantile spasms,but the etiology and pathogenesis remain largely enigmatic.1,2 As a member of the family of the Kelch proteins,KLHL17 contains an N-terminal BTB/POZ domain followed by a BACK domain and four to six tandem Kelch motifs at the C-terminal region(Fig.S1A).1,3 Previously,we identified a novel de novo variant in KLHL17(c.701C>T;p.P234L)in a cohort of 225 Chinese children with developmental delay/intellectual disability based on whole-exome sequencing(1/225),the mutation located in the BACK domain,a very high conversed region(Fig.S1B),and the affected boy presented with developmental delay,intellectual disability,hypotonia,and abnormal brainstem auditory evoked potential signal.4 The finding may offer a new clue to investigate the molecular pathogenesis of KLHL17 gene in neurodevelopmental disorders.
