scholarly journals Schwann cell remyelination of the central nervous system: why does it happen and what are the benefits?

Open Biology ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 200352
Author(s):  
Civia Z. Chen ◽  
Björn Neumann ◽  
Sarah Förster ◽  
Robin J. M. Franklin
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Current Knowledge ◽  
Oligodendrocyte Progenitor Cells ◽  
Neuronal Function ◽  
Lesion Area ◽  
Myelin Sheaths ◽  
The Central Nervous System ◽  
Review Current ◽  
Surprising Finding

Myelin sheaths, by supporting axonal integrity and allowing rapid saltatory impulse conduction, are of fundamental importance for neuronal function. In response to demyelinating injuries in the central nervous system (CNS), oligodendrocyte progenitor cells (OPCs) migrate to the lesion area, proliferate and differentiate into new oligodendrocytes that make new myelin sheaths. This process is termed remyelination. Under specific conditions, demyelinated axons in the CNS can also be remyelinated by Schwann cells (SCs), the myelinating cell of the peripheral nervous system. OPCs can be a major source of these CNS-resident SCs—a surprising finding given the distinct embryonic origins, and physiological compartmentalization of the peripheral and central nervous system. Although the mechanisms and cues governing OPC-to-SC differentiation remain largely undiscovered, it might nevertheless be an attractive target for promoting endogenous remyelination. This article will (i) review current knowledge on the origins of SCs in the CNS, with a particular focus on OPC to SC differentiation, (ii) discuss the necessary criteria for SC myelination in the CNS and (iii) highlight the potential of using SCs for myelin regeneration in the CNS.

scholarly journals R-Ras GTPases Signaling Role in Myelin Neurodegenerative Diseases

2020 ◽  
Vol 21 (16) ◽  
pp. 5911
Author(s):  
Berta Alcover-Sanchez ◽  
Gonzalo Garcia-Martin ◽  
Francisco Wandosell ◽  
Beatriz Cubelos
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Synaptic Transmission ◽  
Neurodegenerative Diseases ◽  
Progenitor Cells ◽  
Oligodendrocyte Progenitor Cells ◽  
Myelin Sheaths ◽  
Ras Gtpases ◽  
Complex Process ◽  
The Central Nervous System

Myelination is required for fast and efficient synaptic transmission in vertebrates. In the central nervous system, oligodendrocytes are responsible for creating myelin sheaths that isolate and protect axons, even throughout adulthood. However, when myelin is lost, the failure of remyelination mechanisms can cause neurodegenerative myelin-associated pathologies. From oligodendrocyte progenitor cells to mature myelinating oligodendrocytes, myelination is a highly complex process that involves many elements of cellular signaling, yet many of the mechanisms that coordinate it, remain unknown. In this review, we will focus on the three major pathways involved in myelination (PI3K/Akt/mTOR, ERK1/2-MAPK, and Wnt/β-catenin) and recent advances describing the crosstalk elements which help to regulate them. In addition, we will review the tight relation between Ras GTPases and myelination processes and discuss its potential as novel elements of crosstalk between the pathways. A better understanding of the crosstalk elements orchestrating myelination mechanisms is essential to identify new potential targets to mitigate neurodegeneration.

scholarly journals Plant Species of Sub-Family Valerianaceae—A Review on Its Effect on the Central Nervous System

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 846
Author(s):  
Gitishree Das ◽  
Han-Seung Shin ◽  
Rosa Tundis ◽  
Sandra Gonçalves ◽  
Ourlad Alzeus G. Tantengco ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Plant Species ◽  
Current Knowledge ◽  
Biological Properties ◽  
In Vivo Studies ◽  
Food Species ◽  
The Central Nervous System ◽  
Preclinical And Clinical Studies

Valerianaceae, the sub-family of Caprifoliaceae, contains more than 300 species of annual and perennial herbs, worldwide distributed. Several species are used for their biological properties while some are used as food. Species from the genus Valeriana have been used for their antispasmodic, relaxing, and sedative properties, which have been mainly attributed to the presence of valepotriates, borneol derivatives, and isovalerenic acid. Among this genus, the most common and employed species is Valerianaofficinalis. Although valerian has been traditionally used as a mild sedative, research results are still controversial regarding the role of the different active compounds, the herbal preparations, and the dosage used. The present review is designed to summarize and critically describe the current knowledge on the different plant species belonging to Valerianaceae, their phytochemicals, their uses in the treatment of different diseases with particular emphasis on the effects on the central nervous system. The available information on this sub-family was collected from scientific databases up until year 2020. The following electronic databases were used: PubMed, Scopus, Sci Finder, Web of Science, Science Direct, NCBI, and Google Scholar. The search terms used for this review included Valerianaceae, Valeriana, Centranthus, Fedia, Patrinia, Nardostachys, Plectritis, and Valerianella, phytochemical composition, in vivo studies, Central Nervous System, neuroprotective, antidepressant, antinociceptive, anxiolytic, anxiety, preclinical and clinical studies.

scholarly journals Biology of the repair of central nervous system demyelinated lesions: an appraisal

1996 ◽  
Vol 54 (2) ◽  
pp. 331-334 ◽  
Author(s):  
L. A. V Peireira ◽  
M. A. Cruz-Höfling ◽  
M. S. J. Dertkigil ◽  
D. L. Graça
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Schwann Cells ◽  
Demyelinating Disease ◽  
Experimental Models ◽  
Primitive Cell ◽  
Marked Influence ◽  
Myelin Sheaths ◽  
Human Material ◽  
The Central Nervous System

The integrity of myelin sheaths is maintained by oligodendrocytes and Schwann cells respectively in the central nervous system (CNS) and in the peripheral nervous system. The process of demyelination consisting of the withdrawal of myelin sheaths from their axons is a characteristic feature of multiple sclerosis, the most common human demyelinating disease. Many experimental models have been designed to study the biology of demyelination and remyelination (repair of the lost myelin) in the CNS, due to the difficulties in studying human material. In the ethidium bromide (an intercalating gliotoxic drug) model of demyelination, CNS remyelination may be carried out by surviving oligodendrocytes and/or by cells differentiated from the primitive cell lines or either by Schwann cells that invade the CNS. However, some factors such as the age of the experimental animals, intensity and time of exposure to the intercalating chemical and the topography of the lesions have marked influence on the repair of the tissue.

Nogo-A Represses Anatomical and Synaptic Plasticity in the Central Nervous System

Physiology ◽  
2013 ◽  
Vol 28 (3) ◽  
pp. 151-163 ◽  
Author(s):  
Anissa Kempf ◽  
Martin E. Schwab
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Synaptic Plasticity ◽  
Axonal Regeneration ◽  
Current Knowledge ◽  
Cns Injury ◽  
Inhibitory Protein ◽  
Growth Inhibitory ◽  
The Central Nervous System ◽  
Regulation Of Growth

Nogo-A was initially discovered as a myelin-associated growth inhibitory protein limiting axonal regeneration after central nervous system (CNS) injury. This review summarizes current knowledge on how myelin and neuronal Nogo-A and its receptors exert physiological functions ranging from the regulation of growth suppression to synaptic plasticity in the developing and adult intact CNS.

Flaviviruses and the Central Nervous System: Revisiting Neuropathological Concepts

2018 ◽  
Vol 5 (1) ◽  
pp. 255-272 ◽  
Author(s):  
Olga A. Maximova ◽  
Alexander G. Pletnev
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Current Knowledge ◽  
Global Scale ◽  
Encephalitis Virus ◽  
Host Responses ◽  
Human Pathogens ◽  
Virus West Nile ◽  
The Central Nervous System ◽  
Tick Borne Encephalitis Virus

Flaviviruses are major emerging human pathogens on a global scale. Some flaviviruses can infect the central nervous system of the host and therefore are regarded as neurotropic. The most clinically relevant classical neurotropic flaviviruses include Japanese encephalitis virus, West Nile virus, and tick-borne encephalitis virus. In this review, we focus on these flaviviruses and revisit the concepts of flaviviral neurotropism, neuropathogenicity, neuroinvasion, and resultant neuropathogenesis. We attempt to synthesize the current knowledge about interactions between the central nervous system and flaviviruses from the neuroanatomical and neuropathological perspectives and address some misconceptions and controversies. We hope that revisiting these neuropathological concepts will improve the understanding of flaviviral neuroinfections. This, in turn, may provide further guiding foundations for relevant studies of other emerging or geographically expanding flaviviruses with neuropathogenic potential, such as Zika virus and dengue virus, and pave the way for intelligent therapeutic strategies harnessing potentially beneficial, protective host responses to interfere with disease progression and outcome.

scholarly journals You Talking to Me? Says the Enteric Nervous System (ENS) to the Microbe. How Intestinal Microbes Interact with the ENS

2020 ◽  
Vol 9 (11) ◽  
pp. 3705
Author(s):  
Mauro Giuffrè ◽  
Rita Moretti ◽  
Giuseppina Campisciano ◽  
Alexandre Barcelos Morais da Silveira ◽  
Vincenzo Maria Monda ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Enteric Nervous System ◽  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Intestinal Microbes ◽  
The Central Nervous System ◽  
Gut Microorganisms ◽  
Future Concepts ◽  
Suitable Environment

Mammalian organisms form intimate interfaces with commensal and pathogenic gut microorganisms. Increasing evidence suggests a close interaction between gut microorganisms and the enteric nervous system (ENS), as the first interface to the central nervous system. Each microorganism can exert a different effect on the ENS, including phenotypical neuronal changes or the induction of chemical transmitters that interact with ENS neurons. Some pathogenic bacteria take advantage of the ENS to create a more suitable environment for their growth or to promote the effects of their toxins. In addition, some commensal bacteria can affect the central nervous system (CNS) by locally interacting with the ENS. From the current knowledge emerges an interesting field that may shape future concepts on the pathogen–host synergic interaction. The aim of this narrative review is to report the current findings regarding the inter-relationships between bacteria, viruses, and parasites and the ENS.

scholarly journals Organization of GABA-Containing Neurons in Some Extrapyramidal Nuclei

1980 ◽  
Vol 7 (3) ◽  
pp. 251-252 ◽  
Author(s):  
H.C. Fibiger
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Glutamic Acid ◽  
Glutamic Acid Decarboxylase ◽  
Current Knowledge ◽  
Gabaergic Neurons ◽  
Acid Decarboxylase ◽  
Extrapyramidal System ◽  
The Central Nervous System ◽  
The Subject

SUMMARY:Nuclei of the extrapyramidal system contain among the highest levels of GABA and its synthesizing enzyme glutamic acid decarboxylase (GA D) in the central nervous system. In recent years the anatomical organization of GABAergic neurons in the extrapyramidal system has been the subject of considerable experimental enquiry. In this note, current knowledge concerning the origin and projections of GABAergic neurons in certain extrapyramidal nuclei is briefly reviewed.

scholarly journals Neuroinflammation as Fuel for Axonal Regeneration in the Injured Vertebrate Central Nervous System

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Ilse Bollaerts ◽  
Jessie Van houcke ◽  
Lien Andries ◽  
Lies De Groef ◽  
Lieve Moons
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Axonal Regeneration ◽  
Current Knowledge ◽  
Cord Injury ◽  
The Central Nervous System ◽  
Novel Therapeutic Strategies ◽  
The Impact ◽  
Vertebrate Central Nervous System

Damage to the central nervous system (CNS) is one of the leading causes of morbidity and mortality in elderly, as repair after lesions or neurodegenerative disease usually fails because of the limited capacity of CNS regeneration. The causes underlying this limited regenerative potential are multifactorial, but one critical aspect is neuroinflammation. Although classically considered as harmful, it is now becoming increasingly clear that inflammation can also promote regeneration, if the appropriate context is provided. Here, we review the current knowledge on how acute inflammation is intertwined with axonal regeneration, an important component of CNS repair. After optic nerve or spinal cord injury, inflammatory stimulation and/or modification greatly improve the regenerative outcome in rodents. Moreover, the hypothesis of a beneficial role of inflammation is further supported by evidence from adult zebrafish, which possess the remarkable capability to repair CNS lesions and even restore functionality. Lastly, we shed light on the impact of aging processes on the regenerative capacity in the CNS of mammals and zebrafish. As aging not only affects the CNS, but also the immune system, the regeneration potential is expected to further decline in aged individuals, an element that should definitely be considered in the search for novel therapeutic strategies.

scholarly journals A STRUCTURAL ANALYSIS OF THE MYELIN SHEATH IN THE CENTRAL NERVOUS SYSTEM

1967 ◽  
Vol 34 (2) ◽  
pp. 555-567 ◽  
Author(s):  
Asao Hirano ◽  
Herbert M. Dembitzer
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Electron Microscope ◽  
Myelin Sheath ◽  
Cerebral White Matter ◽  
Experimental Conditions ◽  
Myelin Sheaths ◽  
Basic Theme ◽  
Cell Processes ◽  
The Central Nervous System

The cerebral white matter of rats subjected to a variety of noxious experimental conditions was examined in the electron microscope. Several unusual configurations of the myelin sheath are identified in addition to the usual configuration. These variations include the presence of (a) formed organelles within the inner and outer loops, (b) isolated islands of cytoplasm in unfused portions of the major dense lines, (c) apparently unconnected cell processes between the sheath and the axon, and (d) concentric, double myelin sheaths. A generalized model of the myelin sheath based on a hypothetical unrolling of the sheath is described. It consists of a shovel-shaped myelin sheet surrounded by a continuous thickened rim of cytoplasm. Most of the unusual myelin configurations are explained as simple variations on this basic theme. With the help of this model, an explanation of the formation of the myelin sheath is offered. This explanation involves the concept that myelin formation can occur at all cytoplasmic areas adjacent to the myelin proper and that adjacent myelin lamellae can move in relation to each other.

Preferential localization of prostamide/prostaglandin F synthase in myelin sheaths of the central nervous system

2011 ◽  
Vol 1367 ◽  
pp. 22-32 ◽  
Author(s):  
Keisuke Yoshikawa ◽  
Shiro Takei ◽  
Sanae Hasegawa-Ishii ◽  
Yoichi Chiba ◽  
Ayako Furukawa ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Myelin Sheaths ◽  
Preferential Localization ◽  
Prostaglandin F ◽  
The Central Nervous System
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