1
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Gonzalez D, Cuenca X, Allende ML. Knockdown of tgfb1a partially improves ALS phenotype in a transient zebrafish model. Front Cell Neurosci 2024; 18:1384085. [PMID: 38644973 PMCID: PMC11032012 DOI: 10.3389/fncel.2024.1384085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 03/15/2024] [Indexed: 04/23/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) corresponds to a neurodegenerative disorder marked by the progressive degeneration of both upper and lower motor neurons located in the brain, brainstem, and spinal cord. ALS can be broadly categorized into two main types: sporadic ALS (sALS), which constitutes approximately 90% of all cases, and familial ALS (fALS), which represents the remaining 10% of cases. Transforming growth factor type-β (TGF-β) is a cytokine involved in various cellular processes and pathological contexts, including inflammation and fibrosis. Elevated levels of TGF-β have been observed in the plasma and cerebrospinal fluid (CSF) of both ALS patients and mouse models. In this perspective, we explore the impact of the TGF-β signaling pathway using a transient zebrafish model for ALS. Our findings reveal that the knockdown of tgfb1a lead to a partial prevention of motor axon abnormalities and locomotor deficits in a transient ALS zebrafish model at 48 h post-fertilization (hpf). In this context, we delve into the proposed distinct roles of TGF-β in the progression of ALS. Indeed, some evidence suggests a dual role for TGF-β in ALS progression. Initially, it seems to exert a neuroprotective effect in the early stages, but paradoxically, it may contribute to disease progression in later stages. Consequently, we suggest that the TGF-β signaling pathway emerges as an attractive therapeutic target for treating ALS. Nevertheless, further research is crucial to comprehensively understand the nuanced role of TGF-β in the pathological context.
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Affiliation(s)
- David Gonzalez
- Departamento de Ciencias Químicas y Biológicas, Facultad de Ciencias de la Salud, Universidad Bernardo O’Higgins, Santiago, Chile
- Escuela de Terapia Ocupacional, Facultad de Ciencias de la Salud, Universidad Bernardo O’Higgins, Santiago, Chile
- Millennium Institute Center for Genome Regulation, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Xiomara Cuenca
- Escuela de Terapia Ocupacional, Facultad de Ciencias de la Salud, Universidad Bernardo O’Higgins, Santiago, Chile
| | - Miguel L. Allende
- Millennium Institute Center for Genome Regulation, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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2
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Deng Z, Fan T, Xiao C, Tian H, Zheng Y, Li C, He J. TGF-β signaling in health, disease, and therapeutics. Signal Transduct Target Ther 2024; 9:61. [PMID: 38514615 PMCID: PMC10958066 DOI: 10.1038/s41392-024-01764-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 08/31/2023] [Accepted: 01/31/2024] [Indexed: 03/23/2024] Open
Abstract
Transforming growth factor (TGF)-β is a multifunctional cytokine expressed by almost every tissue and cell type. The signal transduction of TGF-β can stimulate diverse cellular responses and is particularly critical to embryonic development, wound healing, tissue homeostasis, and immune homeostasis in health. The dysfunction of TGF-β can play key roles in many diseases, and numerous targeted therapies have been developed to rectify its pathogenic activity. In the past decades, a large number of studies on TGF-β signaling have been carried out, covering a broad spectrum of topics in health, disease, and therapeutics. Thus, a comprehensive overview of TGF-β signaling is required for a general picture of the studies in this field. In this review, we retrace the research history of TGF-β and introduce the molecular mechanisms regarding its biosynthesis, activation, and signal transduction. We also provide deep insights into the functions of TGF-β signaling in physiological conditions as well as in pathological processes. TGF-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are highlighted. Through the summary of previous knowledge and recent updates, this review aims to provide a systematic understanding of TGF-β signaling and to attract more attention and interest to this research area.
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Affiliation(s)
- Ziqin Deng
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Tao Fan
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Chu Xiao
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - He Tian
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Yujia Zheng
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China
| | - Chunxiang Li
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China.
| | - Jie He
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China.
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3
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Fontenas L. Glial plasticity at nervous system transition zones. Biol Open 2023; 12:bio060037. [PMID: 37787575 PMCID: PMC10562931 DOI: 10.1242/bio.060037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023] Open
Abstract
The central and peripheral nervous systems (CNS and PNS, respectively) are two separate yet connected domains characterized by molecularly distinct cellular components that communicate via specialized structures called transition zones to allow information to travel from the CNS to the periphery, and vice versa. Until recently, nervous system transition zones were thought to be selectively permeable only to axons, and the establishment of the territories occupied by glial cells at these complex regions remained poorly described and not well understood. Recent work now demonstrates that transition zones are occupied by dynamic glial cells and are precisely regulated over the course of nervous system development. This review highlights recent work on glial cell migration in and out of the spinal cord, at motor exit point (MEP) and dorsal root entry zone (DREZ) transition zones, in the physiological and diseased nervous systems. These cells include myelinating glia (oligodendrocyte lineage cells, Schwann cells and motor exit point glia), exit glia, perineurial cells that form the perineurium along spinal nerves, as well as professional and non-professional phagocytes (microglia and neural crest cells).
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Affiliation(s)
- Laura Fontenas
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL 33458, USA
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4
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Zhang M, An H, Zhang F, Jiang H, Wan T, Wen Y, Han N, Zhang P. Prospects of Using Chitosan-Based Biopolymers in the Treatment of Peripheral Nerve Injuries. Int J Mol Sci 2023; 24:12956. [PMID: 37629137 PMCID: PMC10454829 DOI: 10.3390/ijms241612956] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/10/2023] [Accepted: 08/12/2023] [Indexed: 08/27/2023] Open
Abstract
Peripheral nerve injuries are common neurological disorders, and the available treatment options, such as conservative management and surgical repair, often yield limited results. However, there is growing interest in the potential of using chitosan-based biopolymers as a novel therapeutic approach to treating these injuries. Chitosan-based biopolymers possess unique characteristics, including biocompatibility, biodegradability, and the ability to stimulate cell proliferation, making them highly suitable for repairing nerve defects and promoting nerve regeneration and functional recovery. Furthermore, these biopolymers can be utilized in drug delivery systems to control the release of therapeutic agents and facilitate the growth of nerve cells. This comprehensive review focuses on the latest advancements in utilizing chitosan-based biopolymers for peripheral nerve regeneration. By harnessing the potential of chitosan-based biopolymers, we can pave the way for innovative treatment strategies that significantly improve the outcomes of peripheral nerve injury repair, offering renewed hope and better prospects for patients in need.
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Affiliation(s)
- Meng Zhang
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing 100044, China; (M.Z.)
- Key Laboratory of Trauma and Neural Regeneration, Ministry of Education, Beijing 100044, China
| | - Heng An
- Beijing Key Laboratory for Bioengineering and Sensing Technology, Daxing Research Institute, School of Chemistry & Biological Engineering, University of Science & Technology Beijing, Beijing 100083, China; (H.A.)
| | - Fengshi Zhang
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing 100044, China; (M.Z.)
- Key Laboratory of Trauma and Neural Regeneration, Ministry of Education, Beijing 100044, China
| | - Haoran Jiang
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing 100044, China; (M.Z.)
- Key Laboratory of Trauma and Neural Regeneration, Ministry of Education, Beijing 100044, China
| | - Teng Wan
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing 100044, China; (M.Z.)
- Key Laboratory of Trauma and Neural Regeneration, Ministry of Education, Beijing 100044, China
| | - Yongqiang Wen
- Beijing Key Laboratory for Bioengineering and Sensing Technology, Daxing Research Institute, School of Chemistry & Biological Engineering, University of Science & Technology Beijing, Beijing 100083, China; (H.A.)
| | - Na Han
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing 100044, China; (M.Z.)
- Key Laboratory of Trauma and Neural Regeneration, Ministry of Education, Beijing 100044, China
| | - Peixun Zhang
- Department of Orthopedics and Trauma, Peking University People’s Hospital, Beijing 100044, China; (M.Z.)
- Key Laboratory of Trauma and Neural Regeneration, Ministry of Education, Beijing 100044, China
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5
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Hu X, Geng P, Zhao X, Wang Q, Liu C, Guo C, Dong W, Jin X. The NG2-glia is a potential target to maintain the integrity of neurovascular unit after acute ischemic stroke. Neurobiol Dis 2023; 180:106076. [PMID: 36921779 DOI: 10.1016/j.nbd.2023.106076] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/07/2023] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
The neurovascular unit (NVU) plays a critical role in health and disease. In the current review, we discuss the critical role of a class of neural/glial antigen 2 (NG2)-expressing glial cells (NG2-glia) in regulating NVU after acute ischemic stroke (AIS). We first introduce the role of NG2-glia in the formation of NVU during development as well as aging-induced damage to NVU and accompanying NG2-glia change. We then discuss the reciprocal interactions between NG2-glia and the other component cells of NVU, emphasizing the factors that could influence NG2-glia. Damage to the NVU integrity is the pathological basis of edema and hemorrhagic transformation, the most dreaded complication after AIS. The role of NG2-glia in AIS-induced NVU damage and the effect of NG2-glia transplantation on AIS-induced NVU damage are summarized. We next discuss the role of NG2-glia and the effect of NG2-glia transplantation in oligodendrogenesis and white matter repair as well as angiogenesis which is associated with the outcome of the patients after AIS. Finally, we review the current strategies to promote NG2-glia proliferation and differentiation and propose to use the dental pulp stem cells (DPSC)-derived exosome as a promising strategy to reduce AIS-induced injury and promote repair through maintaining the integrity of NVU by regulating endogenous NG2-glia proliferation and differentiation.
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Affiliation(s)
- Xiaoyan Hu
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Department of Histology and Embryology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
| | - Panpan Geng
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Department of Histology and Embryology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
| | - Xiaoyun Zhao
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Department of Histology and Embryology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
| | - Qian Wang
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Department of Histology and Embryology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
| | - Changqing Liu
- Department of Neurosurgery, Beijing Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Chun Guo
- School of Biosciences, University of Sheffield, Firth Court, Western Bank, Sheffield, UK
| | - Wen Dong
- China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
| | - Xinchun Jin
- Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Department of Histology and Embryology, School of Basic Medical Sciences, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; Institute of Neuroscience, The Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
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6
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Reed CB, Feltri ML, Wilson ER. Peripheral glia diversity. J Anat 2022; 241:1219-1234. [PMID: 34131911 PMCID: PMC8671569 DOI: 10.1111/joa.13484] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/20/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
Recent years have seen an evolving appreciation for the role of glial cells in the nervous system. As we move away from the typical neurocentric view of neuroscience, the complexity and variability of central nervous system glia is emerging, far beyond the three main subtypes: astrocytes, oligodendrocytes, and microglia. Yet the diversity of the glia found in the peripheral nervous system remains rarely discussed. In this review, we discuss the developmental origin, morphology, and function of the different populations of glia found in the peripheral nervous system, including: myelinating Schwann cells, Remak Schwann cells, repair Schwann cells, satellite glia, boundary cap-derived glia, perineurial glia, terminal Schwann cells, glia found in the skin, olfactory ensheathing cells, and enteric glia. The morphological and functional heterogeneity of glia found in the periphery reflects the diverse roles the nervous system performs throughout the body. Further, it highlights a complexity that should be appreciated and considered when it comes to a complete understanding of the peripheral nervous system in health and disease.
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Affiliation(s)
- Chelsey B Reed
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences State, University of New York at Buffalo, Buffalo, New York, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - M Laura Feltri
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences State, University of New York at Buffalo, Buffalo, New York, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Emma R Wilson
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences State, University of New York at Buffalo, Buffalo, New York, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
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7
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Arena KA, Zhu Y, Kucenas S. Transforming growth factor-beta signaling modulates perineurial glial bridging following peripheral spinal motor nerve injury in zebrafish. Glia 2022; 70:1826-1849. [PMID: 35616185 PMCID: PMC9378448 DOI: 10.1002/glia.24220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 05/06/2022] [Accepted: 05/11/2022] [Indexed: 11/12/2022]
Abstract
Spinal motor nerves are necessary for organismal locomotion and survival. In zebrafish and most vertebrates, these peripheral nervous system structures are composed of bundles of axons that naturally regenerate following injury. However, the cellular and molecular mechanisms that mediate this process are still only partially understood. Perineurial glia, which form a component of the blood-nerve barrier, are necessary for the earliest regenerative steps by establishing a glial bridge across the injury site as well as phagocytosing debris. Without perineurial glial bridging, regeneration is impaired. In addition to perineurial glia, Schwann cells, the cells that ensheath and myelinate axons within the nerve, are essential for debris clearance and axon guidance. In the absence of Schwann cells, perineurial glia exhibit perturbed bridging, demonstrating that these two cell types communicate during the injury response. While the presence and importance of perineurial glial bridging is known, the molecular mechanisms that underlie this process remain a mystery. Understanding the cellular and molecular interactions that drive perineurial glial bridging is crucial to unlocking the mechanisms underlying successful motor nerve regeneration. Using laser axotomy and in vivo imaging in zebrafish, we show that transforming growth factor-beta (TGFβ) signaling modulates perineurial glial bridging. Further, we identify connective tissue growth factor-a (ctgfa) as a downstream effector of TGF-β signaling that works in a positive feedback loop to mediate perineurial glial bridging. Together, these studies present a new signaling pathway involved in the perineurial glial injury response and further characterize the dynamics of the perineurial glial bridge.
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Affiliation(s)
- Kimberly A. Arena
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
- Program in Fundamental NeuroscienceUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Yunlu Zhu
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Sarah Kucenas
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
- Program in Fundamental NeuroscienceUniversity of VirginiaCharlottesvilleVirginiaUSA
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Ye Z, Wei J, Zhan C, Hou J. Role of Transforming Growth Factor Beta in Peripheral Nerve Regeneration: Cellular and Molecular Mechanisms. Front Neurosci 2022; 16:917587. [PMID: 35769702 PMCID: PMC9234557 DOI: 10.3389/fnins.2022.917587] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/11/2022] [Indexed: 11/24/2022] Open
Abstract
Peripheral nerve injury (PNI) is one of the most common concerns in trauma patients. Despite significant advances in repair surgeries, the outcome can still be unsatisfactory, resulting in morbidities such as loss of sensory or motor function and reduced quality of life. This highlights the need for more supportive strategies for nerve regrowth and adequate recovery. Multifunctional cytokine transforming growth factor-β (TGF-β) is essential for the development of the nervous system and is known for its neuroprotective functions. Accumulating evidence indicates its involvement in multiple cellular and molecular responses that are critical to peripheral nerve repair. Following PNI, TGF-β is released at the site of injury where it can initiate a series of phenotypic changes in Schwann cells (SCs), modulate immune cells, activate neuronal intrinsic growth capacity, and regulate blood nerve barrier (BNB) permeability, thus enhancing the regeneration of the nerves. Notably, TGF-β has already been applied experimentally in the treatment of PNI. These treatments with encouraging outcomes further demonstrate its regeneration-promoting capacity. Herein, we review the possible roles of TGF-β in peripheral nerve regeneration and discuss the underlying mechanisms, thus providing new cues for better treatment of PNI.
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Affiliation(s)
- Zhiqian Ye
- The First School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Junbin Wei
- The First School of Clinical Medicine, Southern Medical University, Guangzhou, China
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Chaoning Zhan
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jin Hou
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
- *Correspondence: Jin Hou,
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9
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Habicher J, Manuel R, Pedroni A, Ferebee C, Ampatzis K, Boije H. A new transgenic reporter line reveals expression of protocadherin 9 at a cellular level within the zebrafish central nervous system. Gene Expr Patterns 2022; 44:119246. [DOI: 10.1016/j.gep.2022.119246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/07/2022] [Accepted: 04/09/2022] [Indexed: 11/16/2022]
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10
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Fu H, Hu D, Chen J, Wang Q, Zhang Y, Qi C, Yu T. Repair of the Injured Spinal Cord by Schwann Cell Transplantation. Front Neurosci 2022; 16:800513. [PMID: 35250447 PMCID: PMC8891437 DOI: 10.3389/fnins.2022.800513] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 01/27/2022] [Indexed: 01/12/2023] Open
Abstract
Spinal cord injury (SCI) can result in sensorimotor impairments or disability. Studies of the cellular response to SCI have increased our understanding of nerve regenerative failure following spinal cord trauma. Biological, engineering and rehabilitation strategies for repairing the injured spinal cord have shown impressive results in SCI models of both rodents and non-human primates. Cell transplantation, in particular, is becoming a highly promising approach due to the cells’ capacity to provide multiple benefits at the molecular, cellular, and circuit levels. While various cell types have been investigated, we focus on the use of Schwann cells (SCs) to promote SCI repair in this review. Transplantation of SCs promotes functional recovery in animal models and is safe for use in humans with subacute SCI. The rationales for the therapeutic use of SCs for SCI include enhancement of axon regeneration, remyelination of newborn or sparing axons, regulation of the inflammatory response, and maintenance of the survival of damaged tissue. However, little is known about the molecular mechanisms by which transplanted SCs exert a reparative effect on SCI. Moreover, SC-based therapeutic strategies face considerable challenges in preclinical studies. These issues must be clarified to make SC transplantation a feasible clinical option. In this review, we summarize the recent advances in SC transplantation for SCI, and highlight proposed mechanisms and challenges of SC-mediated therapy. The sparse information available on SC clinical application in patients with SCI is also discussed.
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Affiliation(s)
- Haitao Fu
- Department of Sports Medicine, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Die Hu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao Eye Hospital, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China
| | - Jinli Chen
- Department of Sports Medicine, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Qizun Wang
- Department of Orthopedics, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yingze Zhang
- Key Laboratory of Biomechanics of Hebei Province, Department of Trauma Emergency Center, The Third Hospital of Hebei Medical University, Orthopaedics Research Institution of Hebei Province, Shijiazhuang, China
| | - Chao Qi
- Department of Sports Medicine, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
- *Correspondence: Chao Qi,
| | - Tengbo Yu
- Department of Sports Medicine, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
- Tengbo Yu,
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11
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Garrett A, Rakhilin N, Wang N, McKey J, Cofer G, Anderson RB, Capel B, Johnson GA, Shen X. Mapping the peripheral nervous system in the whole mouse via compressed sensing tractography. J Neural Eng 2021; 18. [PMID: 33979784 DOI: 10.1088/1741-2552/ac0089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 05/12/2021] [Indexed: 11/12/2022]
Abstract
Objective.The peripheral nervous system (PNS) connects the central nervous system with the rest of the body to regulate many physiological functions and is therapeutically targeted to treat diseases such as epilepsy, depression, intestinal dysmotility, chronic pain, and more. However, we still lack understanding of PNS innervation in most organs because the large span, diffuse nature, and small terminal nerve bundle fibers have precluded whole-organism, high resolution mapping of the PNS. We sought to produce a comprehensive peripheral nerve atlas for use in future interrogation of neural circuitry and selection of targets for neuromodulation.Approach.We used diffusion tensor magnetic resonance imaging (DT-MRI) with high-speed compressed sensing to generate a tractogram of the whole mouse PNS. The tractography generated from the DT-MRI data is validated using lightsheet microscopy on optically cleared, antibody stained tissue.Main results.Herein we demonstrate the first comprehensive PNS tractography in a whole mouse. Using this technique, we scanned the whole mouse in 28 h and mapped PNS innervation and fiber network in multiple organs including heart, lung, liver, kidneys, stomach, intestines, and bladder at 70µm resolution. This whole-body PNS tractography map has provided unparalleled information; for example, it delineates the innervation along the gastrointestinal tract by multiple sacral levels and by the vagal nerves. The map enabled a quantitative tractogram that revealed relative innervation of the major organs by each vertebral foramen as well as the vagus nerve.Significance.This novel high-resolution nerve atlas provides a potential roadmap for future neuromodulation therapies and other investigations into the neural circuits which drive homeostasis and disease throughout the body.
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Affiliation(s)
- Aliesha Garrett
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States of America
| | - Nikolai Rakhilin
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States of America
| | - Nian Wang
- Duke Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States of America
| | - Jennifer McKey
- Department of Cell Biology, School of Medicine, Duke University, Durham, NC, United States of America
| | - Gary Cofer
- Duke Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States of America
| | - Robert Bj Anderson
- Duke Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States of America
| | - Blanche Capel
- Department of Cell Biology, School of Medicine, Duke University, Durham, NC, United States of America
| | - G Allan Johnson
- Duke Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States of America
| | - Xiling Shen
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States of America
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12
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Current Advances in Comprehending Dynamics of Regenerating Axons and Axon-Glia Interactions after Peripheral Nerve Injury in Zebrafish. Int J Mol Sci 2021; 22:ijms22052484. [PMID: 33801205 PMCID: PMC7957880 DOI: 10.3390/ijms22052484] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/11/2021] [Accepted: 02/22/2021] [Indexed: 12/13/2022] Open
Abstract
Following an injury, axons of both the central nervous system (CNS) and peripheral nervous system (PNS) degenerate through a coordinated and genetically conserved mechanism known as Wallerian degeneration (WD). Unlike central axons, severed peripheral axons have a higher capacity to regenerate and reinnervate their original targets, mainly because of the favorable environment that they inhabit and the presence of different cell types. Even though many aspects of regeneration in peripheral nerves have been studied, there is still a lack of understanding regarding the dynamics of axonal degeneration and regeneration, mostly due to the inherent limitations of most animal models. In this scenario, the use of zebrafish (Danio rerio) larvae combined with time-lapse microscopy currently offers a unique experimental opportunity to monitor the dynamics of the regenerative process in the PNS in vivo. This review summarizes the current knowledge and advances made in understanding the dynamics of the regenerative process of PNS axons. By using different tools available in zebrafish such as electroablation of the posterior lateral line nerve (pLLn), and laser-mediated transection of motor and sensory axons followed by time-lapse microscopy, researchers are beginning to unravel the complexity of the spatiotemporal interactions among different cell types during the regenerative process. Thus, understanding the cellular and molecular mechanisms underlying the degeneration and regeneration of peripheral nerves will open new avenues in the treatment of acute nerve trauma or chronic conditions such as neurodegenerative diseases.
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Fontenas L, Kucenas S. Spinal cord precursors utilize neural crest cell mechanisms to generate hybrid peripheral myelinating glia. eLife 2021; 10:64267. [PMID: 33554855 PMCID: PMC7886336 DOI: 10.7554/elife.64267] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 02/05/2021] [Indexed: 12/11/2022] Open
Abstract
During development, oligodendrocytes and Schwann cells myelinate central and peripheral nervous system axons, respectively, while motor exit point (MEP) glia are neural tube-derived, peripheral glia that myelinate axonal territory between these populations at MEP transition zones. From which specific neural tube precursors MEP glia are specified, and how they exit the neural tube to migrate onto peripheral motor axons, remain largely unknown. Here, using zebrafish, we found that MEP glia arise from lateral floor plate precursors and require foxd3 to delaminate and exit the spinal cord. Additionally, we show that similar to Schwann cells, MEP glial development depends on axonally derived neuregulin1. Finally, our data demonstrate that overexpressing axonal cues is sufficient to generate additional MEP glia in the spinal cord. Overall, these studies provide new insight into how a novel population of hybrid, peripheral myelinating glia are generated from neural tube precursors and migrate into the periphery.
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Affiliation(s)
- Laura Fontenas
- Department of Biology, University of Virginia, Charlottesville, United States
| | - Sarah Kucenas
- Department of Biology, University of Virginia, Charlottesville, United States
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14
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Establishment of a Convenient System for the Culture and Study of Perineurium Barrier In Vitro. Cell Mol Neurobiol 2020; 42:807-816. [PMID: 33026550 DOI: 10.1007/s10571-020-00978-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/29/2020] [Indexed: 10/23/2022]
Abstract
The perineurium serves as a selective, metabolically active diffusion barrier in the peripheral nervous system, which is composed of perineurial cells joined together by tight junctions (TJs). Not only are these junctions known to play an essential role in maintaining cellular polarity and tissue integrity, but also limit the paracellular diffusion of certain molecules and ions, whereas loss of TJs barrier function is imperative for tumour growth, invasion and metastasis. Hence, a detailed study on the barrier function of perineurial cells may provide insights into the molecular mechanism of perineural invasion (PNI). In this study, we aimed to develop an efficient procedure for the establishment of perineurial cell lines as a tool for investigating the physiology and pathophysiology of the peripheral nerve barriers. Herein, the isolation, expansion, characterization and maintenance of perineurial cell lines under favourable conditions are presented. Furthermore, the analysis of the phenotypic features of these perineurial cells as well as the barrier function for the study of PNI are described. Such techniques may provide a valuable means for the functional and molecular investigation of perineurial cells, and in particular may elucidate the pathogenesis and progression of PNI, and other peripheral nerve disorders.
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15
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Lee DW, Kim E, Jeong I, Kim HK, Kim S, Park HC. Schwann cells selectively myelinate primary motor axons via neuregulin-ErbB signaling. Glia 2020; 68:2585-2600. [PMID: 32589818 DOI: 10.1002/glia.23871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 05/20/2020] [Accepted: 05/26/2020] [Indexed: 11/06/2022]
Abstract
Spinal motor neurons project their axons out of the spinal cord via the motor exit point (MEP) and regulate their target muscle fibers for diverse behaviors. Several populations of glial cells including Schwann cells, MEP glia, and perineurial glia are tightly associated with spinal motor axons in nerve fascicles. Zebrafish have two types of spinal motor neurons, primary motor neurons (PMNs) and secondary motor neurons (SMNs). PMNs are implicated in the rapid response, whereas SMNs are implicated in normal and slow movements. However, the precise mechanisms mediating the distinct functions of PMNs and SMNs in zebrafish are unclear. In this study, we found that PMNs were myelinated by MEP glia and Schwann cells, whereas SMNs remained unmyelinated at the examined stages. Immunohistochemical analysis revealed that myelinated PMNs solely innervated fast muscle through a distributed neuromuscular junction (NMJ), whereas unmyelinated SMNs innervated both fast and slow muscle through distributed and myoseptal NMJs, respectively, indicating that myelinated PMNs could provide rapid responses for startle and escape movements, while unmyelinated SMNs regulated normal, slow movement. Further, we demonstrate that neuregulin 1 (Nrg1) type III-ErbB signaling provides a key instructive signal that determines the myelination of primary motor axons by MEP glia and Schwann cells. Perineurial glia ensheathed unmyelinated secondary motor axons and myelinated primary motor nerves. Ensheathment required interaction with both MEP glia and Schwann cells. Collectively, these data suggest that primary and secondary motor neurons contribute to the regulation of movement in zebrafish with distinct patterns of myelination.
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Affiliation(s)
- Dong-Won Lee
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Eunmi Kim
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Inyoung Jeong
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Hwan-Ki Kim
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Suhyun Kim
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
| | - Hae-Chul Park
- Department of Biomedical Sciences, College of Medicine, Korea University, Ansan, Republic of Korea
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16
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Fontenas L, Welsh TG, Piller M, Coughenour P, Gandhi AV, Prober DA, Kucenas S. The Neuromodulator Adenosine Regulates Oligodendrocyte Migration at Motor Exit Point Transition Zones. Cell Rep 2020; 27:115-128.e5. [PMID: 30943395 DOI: 10.1016/j.celrep.2019.03.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/27/2019] [Accepted: 03/02/2019] [Indexed: 12/30/2022] Open
Abstract
During development, oligodendrocyte progenitor cells (OPCs) migrate extensively throughout the spinal cord. However, their migration is restricted at transition zones (TZs). At these specialized locations, unique glial cells in both zebrafish and mice play a role in preventing peripheral OPC migration, but the mechanisms of this regulation are not understood. To elucidate the mechanisms that mediate OPC segregation at motor exit point (MEP) TZs, we performed an unbiased small-molecule screen. Using chemical screening and in vivo imaging, we discovered that inhibition of A2a adenosine receptors (ARs) causes ectopic OPC migration out of the spinal cord. We provide in vivo evidence that neuromodulation, partially mediated by adenosine, influences OPC migration specifically at the MEP TZ. This work opens exciting possibilities for understanding how OPCs reach their final destinations during development and identifies mechanisms that could promote their migration in disease.
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Affiliation(s)
- Laura Fontenas
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Taylor G Welsh
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22904, USA
| | - Melanie Piller
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Patricia Coughenour
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
| | - Avni V Gandhi
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - David A Prober
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Sarah Kucenas
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA; Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22904, USA.
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17
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Reinhold AK, Rittner HL. Characteristics of the nerve barrier and the blood dorsal root ganglion barrier in health and disease. Exp Neurol 2020; 327:113244. [PMID: 32057794 DOI: 10.1016/j.expneurol.2020.113244] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/17/2020] [Accepted: 02/09/2020] [Indexed: 12/14/2022]
Abstract
A variety of barriers ensures the protection of the peripheral nervous system from noxious blood-borne or surrounding stimuli. In this review, anatomy and functioning of the blood nerve barrier (BNB) and the blood DRG barrier (BDB) will be presented and key tight junction proteins described: ZO-1, claudin-1, -3, -5, -11, -12, -19, occludin, and tricellulin. Different diseases can lead to or be accompanied by nerve barrier disruption; impairment of nerve barriers in turn worsens pathology. Peripheral nerve injury, diabetic neuropathy and inflammatory polyneuropathy cause an increased permeability of BNB and BDB. Knowledge and understanding of these mechanisms might ultimately lead to the invention of drugs to control barrier function and help ameliorating neurological diseases.
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Affiliation(s)
- A K Reinhold
- Dept Anesthesiology, Center for Interdisciplinary Pain Medicine, University Hospitals Wuerzburg, Germany
| | - H L Rittner
- Dept Anesthesiology, Center for Interdisciplinary Pain Medicine, University Hospitals Wuerzburg, Germany.
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18
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Fontenas L, Kucenas S. Motor Exit Point (MEP) Glia: Novel Myelinating Glia That Bridge CNS and PNS Myelin. Front Cell Neurosci 2018; 12:333. [PMID: 30356886 PMCID: PMC6190867 DOI: 10.3389/fncel.2018.00333] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 09/11/2018] [Indexed: 12/12/2022] Open
Abstract
Oligodendrocytes (OLs) and Schwann cells (SCs) have traditionally been thought of as the exclusive myelinating glial cells of the central and peripheral nervous systems (CNS and PNS), respectively, for a little over a century. However, recent studies demonstrate the existence of a novel, centrally-derived peripheral glial population called motor exit point (MEP) glia, which myelinate spinal motor root axons in the periphery. Until recently, the boundaries that exist between the CNS and PNS, and the cells permitted to cross them, were mostly described based on fixed histological collections and static lineage tracing. Recent work in zebrafish using in vivo, time-lapse imaging has shed light on glial cell interactions at the MEP transition zone and reveals a more complex picture of myelination both centrally and peripherally.
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Affiliation(s)
- Laura Fontenas
- Department of Biology, University of Virginia, Charlottesville, VA, United States
| | - Sarah Kucenas
- Department of Biology, University of Virginia, Charlottesville, VA, United States
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19
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Liu Q, Wang X, Yi S. Pathophysiological Changes of Physical Barriers of Peripheral Nerves After Injury. Front Neurosci 2018; 12:597. [PMID: 30210280 PMCID: PMC6119778 DOI: 10.3389/fnins.2018.00597] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 08/08/2018] [Indexed: 12/11/2022] Open
Abstract
Peripheral nerves are composed of complex layered anatomical structures, including epineurium, perineurium, and endoneurium. Perineurium and endoneurium contain many physical barriers, including the blood-nerve barrier at endoneurial vessels and the perineurial barrier. These physical barriers help to eliminate flux penetration and thus contribute to the establishment of a stable microenvironment. In the current review, we introduce the anatomical compartments and physical barriers of peripheral nerves and then describe the cellular and molecular basis of peripheral physical barriers. We also specifically explore peripheral nerve injury-induced changes of peripheral physical barriers, including elevated endoneurial fluid pressure, increased leakage of tracer, decreased barrier-type endothelial cell ratio, and altered distributions and expressions of cellular junctional proteins. The understanding of the pathophysiological changes of physical barriers following peripheral nerve injury may provide a clue for the treatment of peripheral nerve injury.
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Affiliation(s)
- Qianyan Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xinghui Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Sheng Yi
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
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20
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Wen J, Han Y, Guo S, Yang M, Li L, Sun G, Wang J, Hu F, Liang J, Wei L, Zhou Q, Zhang W, Tan J. Recovery of respiratory function and autonomic diaphragm movement following unilateral recurrent laryngeal nerve to phrenic nerve anastomosis in rabbits. J Neurosurg Spine 2018; 29:470-480. [PMID: 29979142 DOI: 10.3171/2017.12.spine17849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The authors studied restoration of respiratory function in rabbits, using the recurrent laryngeal nerve to restore function after the phrenic nerve had been severed. The results of this animal study are encouraging and suggest that a similar technique could possibly be used to help patients with severe cervical spinal cord injuries.
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Affiliation(s)
- Junxiang Wen
- 1Department of Orthopaedics, Ruijin Hospital, Shanghai Jiaotong University School of Medicine.,Departments of3Spine Surgery and
| | | | - Song Guo
- Departments of3Spine Surgery and
| | | | - Lijun Li
- Departments of3Spine Surgery and
| | - Guixin Sun
- 4Traumatology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Jun Wang
- 2Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Orthopedics and Traumatology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine; and
| | - Fangqiong Hu
- 2Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Orthopedics and Traumatology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine; and
| | - Jing Liang
- 2Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Orthopedics and Traumatology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine; and
| | - Li Wei
- 2Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Orthopedics and Traumatology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine; and
| | - Qi Zhou
- 2Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Orthopedics and Traumatology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine; and
| | - Weibin Zhang
- 1Department of Orthopaedics, Ruijin Hospital, Shanghai Jiaotong University School of Medicine.,2Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Orthopedics and Traumatology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine; and
| | - Jun Tan
- Departments of3Spine Surgery and
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21
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Bączyk M, Jankowska E. Long-term effects of direct current are reproduced by intermittent depolarization of myelinated nerve fibers. J Neurophysiol 2018; 120:1173-1185. [PMID: 29924713 DOI: 10.1152/jn.00236.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Direct current (DC) potently increases the excitability of myelinated afferent fibers in the dorsal columns, both during DC polarization of these fibers and during a considerable (>1 h) postpolarization period. The aim of the present study was to investigate whether similarly long-lasting changes in the excitability of myelinated nerve fibers in the dorsal columns may be evoked by field potentials following stimulation of peripheral afferents and by subthreshold epidurally applied current pulses. The experiments were performed in deeply anesthetized rats. The effects were monitored by changes in nerve volleys evoked in epidurally stimulated hindlimb afferents and in the synaptic actions of these afferents. Both were found to be facilitated during as well as following stimulation of a skin nerve and during as well as following epidurally applied current pulses of 5- to 10-ms duration. The facilitation occurring ≤2 min after skin nerve stimulation could be linked to both primary afferent depolarization and large dorsal horn field potentials, whereas the subsequent changes (up to 1 h) were attributable to effects of the field potentials. The findings lead to the conclusion that the modulation of spinal activity evoked by DC does not require long-lasting polarization and that relatively short current pulses and intrinsic field potentials may contribute to plasticity in spinal activity. These results suggest the possibility of enhancing the effects of epidural stimulation in human subjects by combining it with polarizing current pulses and peripheral afferent stimulation and not only with continuous DC. NEW & NOTEWORTHY The aim of this study was to define conditions under which a long-term increase is evoked in the excitability of myelinated nerve fibers. The results demonstrate that a potent and long-lasting increase in the excitability of afferent fibers traversing the dorsal columns may be induced by synaptically evoked intrinsic field as well as by epidurally applied intermittent current pulses. They thus provide a new means for the facilitation of the effects of epidural stimulation.
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Affiliation(s)
- M Bączyk
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden.,Department of Neurobiology, Poznań University of Physical Education , Poznań , Poland
| | - E Jankowska
- Department of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
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22
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Livin' On The Edge: glia shape nervous system transition zones. Curr Opin Neurobiol 2017; 47:44-51. [PMID: 28957729 DOI: 10.1016/j.conb.2017.09.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 09/11/2017] [Indexed: 11/21/2022]
Abstract
The vertebrate nervous system is divided into two functional halves; the central nervous system (CNS), which includes the brain and spinal cord, and the peripheral nervous system (PNS), which consists of nerves and ganglia. Incoming peripheral stimuli transmitted from the periphery to the CNS and subsequent motor responses created because of this information, require efficient communication between the two halves that make up this organ system. Neurons and glial cells of each half of the nervous system, which are the main actors in this communication, segregate across nervous system transition zones and never mix, allowing for efficient neurotransmission. Studies aimed at understanding the cellular and molecular mechanisms governing the development and maintenance of these transition zones have predominantly focused on mammalian models. However, zebrafish has emerged as a powerful model organism to study these structures and has allowed researchers to identify novel glial cells and mechanisms essential for nervous system assembly. This review will highlight recent advances into the important role that glial cells play in building and maintaining the nervous system and its boundaries.
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