Paired associative stimulation is a relatively new non-invasive brain stimulation technique that combines transcranial magnetic stimulation and peripheral nerve stimulation. The effects of paired associative stimulati...Paired associative stimulation is a relatively new non-invasive brain stimulation technique that combines transcranial magnetic stimulation and peripheral nerve stimulation. The effects of paired associative stimulation on the excitability of the cerebral cortex can vary according to the time interval between the transcranial magnetic stimulation and peripheral nerve stimulation. We established a model of cerebral ischemia in rats via transient middle cerebral artery occlusion. We administered paired associative stimulation with a frequency of 0.05 Hz 90 times over 4 weeks. We then evaluated spatial learning and memory using the Morris water maze. Changes in the cerebral ultra-structure and synaptic plasticity were assessed via transmission electron microscopy and a 64-channel multi-electrode array. We measured mRNA and protein expression levels of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1 in the hippocampus using a real-time polymerase chain reaction and western blot assay. Paired associative stimulation treatment significantly improved learning and memory in rats subjected to cerebral ischemia. The ultra-structures of synapses in the CA1 area of the hippocampus in rats subjected to cerebral ischemia were restored by paired associative stimulation. Long-term potentiation at synapses in the CA3 and CA1 regions of the hippocampus was enhanced as well. The protein and mRNA expression of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1 increased after paired associative stimulation treatment. These data indicate that paired associative stimulation can protect cog-nition after cerebral ischemia. The observed effect may be mediated by increases in the mRNA and protein expression of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1, and by enhanced synaptic plasticity in the CA1 area of the hippocampus. The animal experiments were approved by the Animal Ethics Committee of Tongji Medical College, Huazhong University of Science & Technology, China(approval No. TJ-A20151102) on July 11, 2015.展开更多
The structural plasticity of synaptic terminals contributes to normal nervous system function but also to neural degeneration, in the form of terminal retraction, and regeneration, due to process growth. Synaptic morp...The structural plasticity of synaptic terminals contributes to normal nervous system function but also to neural degeneration, in the form of terminal retraction, and regeneration, due to process growth. Synaptic morphological change is mediated through the actin cytoskeleton, which is enriched in axonal and dendritic terminals. Whereas the three RhoGTPases, RhoA, Cdc42 and Rac, function as upstream signaling nodes sensitive to extracellular stimuli, LIMK-cofilin activity serves as a common downstream effector to up-regulate actin turnover, which is necessary for both polymerization and depolymerization. The dual effects of LIMK activity make LIMK a potential target of therapeutic intervention for iniury-induced synaptic plasticity, as LIMK inhibition can stabilize actin cytoskeleton and preserve existing structure. This therapeutic benefit of LIMK inhibition has been demonstrated in animal models of injury-induced axon retraction and neuritic sprouting by rod photoreceptors. A better understanding of the regulation of LIMK-cofilin activity and the interaction with the microtubular cytoskeleton may open new ways to promote synaptic regeneration that can benefit neuronal degenerative disease.展开更多
Schizophrenia(SCZ)is a severe mental illness that affects several brain domains with relation to cognition and behaviour.SCZ symptoms are typically classified into three categories,namely,positive,negative,and cogniti...Schizophrenia(SCZ)is a severe mental illness that affects several brain domains with relation to cognition and behaviour.SCZ symptoms are typically classified into three categories,namely,positive,negative,and cognitive.The etiology of SCZ is thought to be multifactorial and poorly understood.Accumulating evidence has indicated abnormal synaptic plasticity and cognitive impairments in SCZ.Synaptic plasticity is thought to be induced at appropriate synapses during memory formation and has a critical role in the cognitive symptoms of SCZ.Many factors,including synaptic structure changes,aberrant expression of plasticityrelated genes,and abnormal synaptic transmission,may influence synaptic plasticity and play vital roles in SCZ.In this article,we briefly summarize the morphology of the synapse,the neurobiology of synaptic plasticity,and the role of synaptic plasticity,and review potential mechanisms underlying abnormal synaptic plasticity in SCZ.These abnormalities involve dendritic spines,postsynaptic density,and long-term potentiation-like plasticity.We also focus on cognitive dysfunction,which reflects impaired connectivity in SCZ.Additionally,the potential targets for the treatment of SCZ are discussed in this article.Therefore,understanding abnormal synaptic plasticity and impaired cognition in SCZ has an essential role in drug therapy.展开更多
Our ability to learn and remember depends on the active formation,remodeling,and elimination of synapses.Thus,the development and growth of synapses as well as their weakening and elimination are essential for neurona...Our ability to learn and remember depends on the active formation,remodeling,and elimination of synapses.Thus,the development and growth of synapses as well as their weakening and elimination are essential for neuronal rewiring.The structural reorganization of synaptic complexes,changes in actin cytos keleton and organelle dynamics,as well as modulation of gene expression,determine synaptic plasticity.It has been proposed that dys regulation of these key synaptic homeostatic processes underlies the synaptic dysfunction observed in many neurodegenerative diseases.Much is known about downstream signaling of activated N-methyl-D-aspartate andα-amino-3-hydroxy-5-methyl-4-isoazolepro pionate receptors;howeve r,other signaling pathways can also contribute to synaptic plasticity and long-lasting changes in learning and memory.The non-receptor tyrosine kinase c-Abl(ABL1)is a key signal transducer of intra and extracellular signals,and it shuttles between the cyto plasm and the nucleus.This review focuses on c-Abl and its synaptic and neuronal functions.Here,we discuss the evidence showing that the activation of c-Abl can be detrimental to neurons,promoting the development of neurodegenerative diseases.Nevertheless,c-Abl activity seems to be in a pivotal balance between healthy synaptic plasticity,regulating dendritic spines remodeling and gene expression after cognitive training,and synaptic dysfunction and loss in neurodegenerative diseases.Thus,c-Abl genetic ablation not only improves learning and memory and modulates the brain genetic program of trained mice,but its absence provides dendritic spines resiliency against damage.Therefo re,the present review has been designed to elu cidate the common links between c-Abl regulation of structural changes that involve the actin cytos keleton and organelles dynamics,and the transc riptional program activated during synaptic plasticity.By summarizing the recent discove ries on c-Abl functions,we aim to provide an overview of how its inhibition co uld be a potentially fruitful treatment to improve degenerative outcomes and delay memory loss.展开更多
基金supported by the National Natural Science Foundation of China,No.81272156(to TCG)
文摘Paired associative stimulation is a relatively new non-invasive brain stimulation technique that combines transcranial magnetic stimulation and peripheral nerve stimulation. The effects of paired associative stimulation on the excitability of the cerebral cortex can vary according to the time interval between the transcranial magnetic stimulation and peripheral nerve stimulation. We established a model of cerebral ischemia in rats via transient middle cerebral artery occlusion. We administered paired associative stimulation with a frequency of 0.05 Hz 90 times over 4 weeks. We then evaluated spatial learning and memory using the Morris water maze. Changes in the cerebral ultra-structure and synaptic plasticity were assessed via transmission electron microscopy and a 64-channel multi-electrode array. We measured mRNA and protein expression levels of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1 in the hippocampus using a real-time polymerase chain reaction and western blot assay. Paired associative stimulation treatment significantly improved learning and memory in rats subjected to cerebral ischemia. The ultra-structures of synapses in the CA1 area of the hippocampus in rats subjected to cerebral ischemia were restored by paired associative stimulation. Long-term potentiation at synapses in the CA3 and CA1 regions of the hippocampus was enhanced as well. The protein and mRNA expression of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1 increased after paired associative stimulation treatment. These data indicate that paired associative stimulation can protect cog-nition after cerebral ischemia. The observed effect may be mediated by increases in the mRNA and protein expression of brain-derived neurotrophic factor and N-methyl-D-aspartate receptor 1, and by enhanced synaptic plasticity in the CA1 area of the hippocampus. The animal experiments were approved by the Animal Ethics Committee of Tongji Medical College, Huazhong University of Science & Technology, China(approval No. TJ-A20151102) on July 11, 2015.
基金supported by NIH grant EY021542 and the F.M.Kirby Foundation
文摘The structural plasticity of synaptic terminals contributes to normal nervous system function but also to neural degeneration, in the form of terminal retraction, and regeneration, due to process growth. Synaptic morphological change is mediated through the actin cytoskeleton, which is enriched in axonal and dendritic terminals. Whereas the three RhoGTPases, RhoA, Cdc42 and Rac, function as upstream signaling nodes sensitive to extracellular stimuli, LIMK-cofilin activity serves as a common downstream effector to up-regulate actin turnover, which is necessary for both polymerization and depolymerization. The dual effects of LIMK activity make LIMK a potential target of therapeutic intervention for iniury-induced synaptic plasticity, as LIMK inhibition can stabilize actin cytoskeleton and preserve existing structure. This therapeutic benefit of LIMK inhibition has been demonstrated in animal models of injury-induced axon retraction and neuritic sprouting by rod photoreceptors. A better understanding of the regulation of LIMK-cofilin activity and the interaction with the microtubular cytoskeleton may open new ways to promote synaptic regeneration that can benefit neuronal degenerative disease.
基金Supported by National Natural Science Foundation of China,No. 81971943, No. 81772196, No. 31470264, No. 81271820, No. 30870789 and No. 30300117Stanley Foundation from the Stanley Medical Research Institute (SMRI),United States,No. 06R-1366 (to Dr. Zhu F)Medical Science Advancement Program (Basic Medical Sciences) of Wuhan University,No. TFJC 2018002
文摘Schizophrenia(SCZ)is a severe mental illness that affects several brain domains with relation to cognition and behaviour.SCZ symptoms are typically classified into three categories,namely,positive,negative,and cognitive.The etiology of SCZ is thought to be multifactorial and poorly understood.Accumulating evidence has indicated abnormal synaptic plasticity and cognitive impairments in SCZ.Synaptic plasticity is thought to be induced at appropriate synapses during memory formation and has a critical role in the cognitive symptoms of SCZ.Many factors,including synaptic structure changes,aberrant expression of plasticityrelated genes,and abnormal synaptic transmission,may influence synaptic plasticity and play vital roles in SCZ.In this article,we briefly summarize the morphology of the synapse,the neurobiology of synaptic plasticity,and the role of synaptic plasticity,and review potential mechanisms underlying abnormal synaptic plasticity in SCZ.These abnormalities involve dendritic spines,postsynaptic density,and long-term potentiation-like plasticity.We also focus on cognitive dysfunction,which reflects impaired connectivity in SCZ.Additionally,the potential targets for the treatment of SCZ are discussed in this article.Therefore,understanding abnormal synaptic plasticity and impaired cognition in SCZ has an essential role in drug therapy.
基金supported by Comisión Nacional de Investigación Cientifica y Tecnologica-Chile Fondecyt 12011668(to ARA)Fondecyt 1190334(to SZ)+6 种基金Fondecyt 11200592(to MJY)Fondef ID21/10347(to ARA andSZ)Fondef D10E1077(to ARA and SZ)CARE-UCAFB 170005(to ARA)MSCA-RISE-2016-Lysomod-734825 European Union's Horizon 2020Research and Innovation Program under the Marie Sklodowska-Curie grant agreement N°953489(to SZ)Millennium Science Initiative Program-ICN09_016/ICN 2021_045(to ARA)。
文摘Our ability to learn and remember depends on the active formation,remodeling,and elimination of synapses.Thus,the development and growth of synapses as well as their weakening and elimination are essential for neuronal rewiring.The structural reorganization of synaptic complexes,changes in actin cytos keleton and organelle dynamics,as well as modulation of gene expression,determine synaptic plasticity.It has been proposed that dys regulation of these key synaptic homeostatic processes underlies the synaptic dysfunction observed in many neurodegenerative diseases.Much is known about downstream signaling of activated N-methyl-D-aspartate andα-amino-3-hydroxy-5-methyl-4-isoazolepro pionate receptors;howeve r,other signaling pathways can also contribute to synaptic plasticity and long-lasting changes in learning and memory.The non-receptor tyrosine kinase c-Abl(ABL1)is a key signal transducer of intra and extracellular signals,and it shuttles between the cyto plasm and the nucleus.This review focuses on c-Abl and its synaptic and neuronal functions.Here,we discuss the evidence showing that the activation of c-Abl can be detrimental to neurons,promoting the development of neurodegenerative diseases.Nevertheless,c-Abl activity seems to be in a pivotal balance between healthy synaptic plasticity,regulating dendritic spines remodeling and gene expression after cognitive training,and synaptic dysfunction and loss in neurodegenerative diseases.Thus,c-Abl genetic ablation not only improves learning and memory and modulates the brain genetic program of trained mice,but its absence provides dendritic spines resiliency against damage.Therefo re,the present review has been designed to elu cidate the common links between c-Abl regulation of structural changes that involve the actin cytos keleton and organelles dynamics,and the transc riptional program activated during synaptic plasticity.By summarizing the recent discove ries on c-Abl functions,we aim to provide an overview of how its inhibition co uld be a potentially fruitful treatment to improve degenerative outcomes and delay memory loss.
基金supported by the Natural Science Foundation of Henan Province(No.202300410267)the Key Research and Development Breakthrough-Science Program in Henan Province(No.212102311082)+1 种基金the PhD Research Fund of Henan University of Chinese Medicine(No.BSJJ-201510)the Young Backbone Teacher in Colleges and Universities Training Program of Henan Province(No.2021GGJS085),China。
文摘本研究旨在探讨不同疗程电针穴位干预对放射线照射所致脑损伤模型小鼠突触结构及突触功能相关蛋白表达的影响。60只1月龄C57BL/6J雄性小鼠随机分为对照组、放射性脑损伤模型组、电针1周组、电针2周组、电针3周组和电针对照组。模型组小鼠接受X-射线照射(8 Gy,10 min)建立放射性脑损伤模型,电针组在X-射线照射后分别接受1周、2周和3周电针穴位(百会、风府、双侧肾俞)干预,电针对照组在照射后进行非穴位电针干预。免疫组织化学染色检测海马CA1区突触超微结构,RT-qPCR和Western blot检测脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)、突触蛋白-1(synapsin-1)和突触后致密蛋白95(postsynaptic density 95,PSD95)的基因和蛋白表达。结果显示,与对照组比较,模型组和电针对照组小鼠神经元核间隙明显减小,神经元核质比显著增大,突触间隙和突触后致密物(postsynaptic density,PSD)厚度则明显降低,线粒体表面积密度、体密度和比表面均显著降低。与模型组比较,电针2周组小鼠的神经元核质比显著减小,PSD厚度显著增加,线粒体体密度显著增加;电针3周组小鼠核间隙显著增加,核质比显著减小,突触间隙和PSD厚度均显著增大,线粒体表面积密度和比表面均显著增加。此外,与对照组比较,模型组和电针对照组小鼠海马CA1区BDNF、synapsin-1、PSD95基因及蛋白表达均不同程度地下降。而与模型组比较,电针各组synapsin-1基因表达均显著上调,电针1和2周组BDNF基因表达显著上调,电针2周组PSD95基因表达显著上调,而电针各组3种蛋白表达均显著上调。以上结果表明,放射线照射损伤小鼠海马CA1区突触超微结构及突触功能相关蛋白表达,电针干预可显著改善放射线照射所导致的突触结构和功能损伤。
