The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem.
MYELIN-specific proteins that play a structural or regulatory role in the genesis and maintenance of the lamellar MYELIN SHEATH structure.
An abundant cytosolic protein that plays a critical role in the structure of multilamellar myelin. Myelin basic protein binds to the cytosolic sides of myelin cell membranes and causes a tight adhesion between opposing cell membranes.
A protein that accounts for more than half of the peripheral nervous system myelin protein. The extracellular domain of this protein is believed to engage in adhesive interactions and thus hold the myelin membrane compact. It can behave as a homophilic adhesion molecule through interactions with its extracellular domains. (From J Cell Biol 1994;126(4):1089-97)
A class of large neuroglial (macroglial) cells in the central nervous system. Oligodendroglia may be called interfascicular, perivascular, or perineuronal (not the same as SATELLITE CELLS, PERINEURONAL of GANGLIA) according to their location. They form the insulating MYELIN SHEATH of axons in the central nervous system.
Neuroglial cells of the peripheral nervous system which form the insulating myelin sheaths of peripheral axons.
A myelin protein that is the major component of the organic solvent extractable lipoprotein complexes of whole brain. It has been the subject of much study because of its unusual physical properties. It remains soluble in chloroform even after essentially all of its bound lipids have been removed. (From Siegel et al., Basic Neurochemistry, 4th ed, p122)
A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves.
A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.
Diseases characterized by loss or dysfunction of myelin in the central or peripheral nervous system.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
The nerves outside of the brain and spinal cord, including the autonomic, cranial, and spinal nerves. Peripheral nerves contain non-neuronal cells and connective tissue as well as axons. The connective tissue layers include, from the outside to the inside, the epineurium, the perineurium, and the endoneurium.
Regularly spaced gaps in the myelin sheaths of peripheral axons. Ranvier's nodes allow saltatory conduction, that is, jumping of impulses from node to node, which is faster and more energetically favorable than continuous conduction.
The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.
Neoplasms which arise from nerve sheaths formed by SCHWANN CELLS in the PERIPHERAL NERVOUS SYSTEM or by OLIGODENDROCYTES in the CENTRAL NERVOUS SYSTEM. Malignant peripheral nerve sheath tumors, NEUROFIBROMA, and NEURILEMMOMA are relatively common tumors in this category.
A phosphodiesterase that specifically cleaves the 3'-phosphate linkage of 2',3'-cyclic nucleotides. It is found at high level in the cytoplasm of cells that form the MYELIN SHEATH.
A myelin protein found in the periaxonal membrane of both the central and peripheral nervous systems myelin sheaths. It binds to cells surface receptors found on AXONS and may regulate cellular interactions between MYELIN and AXONS.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.
Degeneration of distal aspects of a nerve axon following injury to the cell body or proximal portion of the axon. The process is characterized by fragmentation of the axon and its MYELIN SHEATH.
A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.
The outermost cytoplasmic layer of the SCHWANN CELLS covering NERVE FIBERS.
Renewal or physiological repair of damaged nerve tissue.
Myelin-deficient mutants which are from the inbred Tabby-Jimpy strain.
The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.
The nervous system outside of the brain and spinal cord. The peripheral nervous system has autonomic and somatic divisions. The autonomic nervous system includes the enteric, parasympathetic, and sympathetic subdivisions. The somatic nervous system includes the cranial and spinal nerves and their ganglia and the peripheral sensory receptors.
GLYCOSPHINGOLIPIDS with a sulfate group esterified to one of the sugar groups.
Catalyzes the final step in the galactocerebroside biosynthesis pathway.
A hereditary motor and sensory neuropathy transmitted most often as an autosomal dominant trait and characterized by progressive distal wasting and loss of reflexes in the muscles of the legs (and occasionally involving the arms). Onset is usually in the second to fourth decade of life. This condition has been divided into two subtypes, hereditary motor and sensory neuropathy (HMSN) types I and II. HMSN I is associated with abnormal nerve conduction velocities and nerve hypertrophy, features not seen in HMSN II. (Adams et al., Principles of Neurology, 6th ed, p1343)
Nucleoside-2',3'-cyclic phosphate nucleotidohydrolase. Enzymes that catalyze the hydrolysis of the 2'- or 3'- phosphate bonds of 2',3'-cyclic nucleotides. Also hydrolyzes nucleoside monophosphates. Includes EC 3.1.4.16 and EC 3.1.4.37. EC 3.1.4.-.
A branch of the tibial nerve which supplies sensory innervation to parts of the lower leg and foot.
Mice which carry mutant genes for neurologic defects or abnormalities.
An autoimmune disorder mainly affecting young adults and characterized by destruction of myelin in the central nervous system. Pathologic findings include multiple sharply demarcated areas of demyelination throughout the white matter of the central nervous system. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia, and bladder dysfunction. The usual pattern is one of recurrent attacks followed by partial recovery (see MULTIPLE SCLEROSIS, RELAPSING-REMITTING), but acute fulminating and chronic progressive forms (see MULTIPLE SCLEROSIS, CHRONIC PROGRESSIVE) also occur. (Adams et al., Principles of Neurology, 6th ed, p903)
Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
An early growth response transcription factor that controls the formation of the MYELIN SHEATH around peripheral AXONS by SCHWANN CELLS. Mutations in EGR2 transcription factor have been associated with HEREDITARY MOTOR AND SENSORY NEUROPATHIES such as CHARCOT-MARIE-TOOTH DISEASE.
Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways.
The non-neuronal cells of the nervous system. They not only provide physical support, but also respond to injury, regulate the ionic and chemical composition of the extracellular milieu, participate in the BLOOD-BRAIN BARRIER and BLOOD-RETINAL BARRIER, form the myelin insulation of nervous pathways, guide neuronal migration during development, and exchange metabolites with neurons. Neuroglia have high-affinity transmitter uptake systems, voltage-dependent and transmitter-gated ion channels, and can release transmitters, but their role in signaling (as in many other functions) is unclear.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
A transmembrane protein present in the MYELIN SHEATH of the CENTRAL NERVOUS SYSTEM. It is one of the main autoantigens implicated in the pathogenesis of MULTIPLE SCLEROSIS.
Neutral glycosphingolipids that contain a monosaccharide, normally glucose or galactose, in 1-ortho-beta-glycosidic linkage with the primary alcohol of an N-acyl sphingoid (ceramide). In plants the monosaccharide is normally glucose and the sphingoid usually phytosphingosine. In animals, the monosaccharide is usually galactose, though this may vary with the tissue and the sphingoid is usually sphingosine or dihydrosphingosine. (From Oxford Dictionary of Biochemistry and Molecular Biology, 1st ed)
An experimental animal model for central nervous system demyelinating disease. Inoculation with a white matter emulsion combined with FREUND'S ADJUVANT, myelin basic protein, or purified central myelin triggers a T cell-mediated immune response directed towards central myelin. The pathologic features are similar to MULTIPLE SCLEROSIS, including perivascular and periventricular foci of inflammation and demyelination. Subpial demyelination underlying meningeal infiltrations also occurs, which is also a feature of ENCEPHALOMYELITIS, ACUTE DISSEMINATED. Passive immunization with T-cells from an afflicted animal to a normal animal also induces this condition. (From Immunol Res 1998;17(1-2):217-27; Raine CS, Textbook of Neuropathology, 2nd ed, p604-5)
Methods of preparing tissue for examination and study of the origin, structure, function, or pathology.
A group of slowly progressive inherited disorders affecting motor and sensory peripheral nerves. Subtypes include HMSNs I-VII. HMSN I and II both refer to CHARCOT-MARIE-TOOTH DISEASE. HMSN III refers to hypertrophic neuropathy of infancy. HMSN IV refers to REFSUM DISEASE. HMSN V refers to a condition marked by a hereditary motor and sensory neuropathy associated with spastic paraplegia (see SPASTIC PARAPLEGIA, HEREDITARY). HMSN VI refers to HMSN associated with an inherited optic atrophy (OPTIC ATROPHIES, HEREDITARY), and HMSN VII refers to HMSN associated with retinitis pigmentosa. (From Adams et al., Principles of Neurology, 6th ed, p1343)
Paired bundles of NERVE FIBERS entering and leaving the SPINAL CORD at each segment. The dorsal and ventral nerve roots join to form the mixed segmental spinal nerves. The dorsal roots are generally afferent, formed by the central projections of the spinal (dorsal root) ganglia sensory cells, and the ventral roots are efferent, comprising the axons of spinal motor and PREGANGLIONIC AUTONOMIC FIBERS.
A peptide factor originally identified by its ability to stimulate the phosphorylation the erbB-2 receptor (RECEPTOR, ERBB-2). It is a ligand for the erbB-3 receptor (RECEPTOR, ERBB-3) and the erbB-4 receptor. Variant forms of NEUREGULIN-1 occur through alternative splicing of its mRNA.
Diseases of the peripheral nerves external to the brain and spinal cord, which includes diseases of the nerve roots, ganglia, plexi, autonomic nerves, sensory nerves, and motor nerves.
Refers to animals in the period of time just after birth.
Sensory ganglia located on the dorsal spinal roots within the vertebral column. The spinal ganglion cells are pseudounipolar. The single primary branch bifurcates sending a peripheral process to carry sensory information from the periphery and a central branch which relays that information to the spinal cord or brain.
The use of statistical and mathematical methods to analyze biological observations and phenomena.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.
Broad plate of dense myelinated fibers that reciprocally interconnect regions of the cortex in all lobes with corresponding regions of the opposite hemisphere. The corpus callosum is located deep in the longitudinal fissure.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.
Type III intermediate filament proteins that assemble into neurofilaments, the major cytoskeletal element in nerve axons and dendrites. They consist of three distinct polypeptides, the neurofilament triplet. Types I, II, and IV intermediate filament proteins form other cytoskeletal elements such as keratins and lamins. It appears that the metabolism of neurofilaments is disturbed in Alzheimer's disease, as indicated by the presence of neurofilament epitopes in the neurofibrillary tangles, as well as by the severe reduction of the expression of the gene for the light neurofilament subunit of the neurofilament triplet in brains of Alzheimer's patients. (Can J Neurol Sci 1990 Aug;17(3):302)
Cerebrosides which contain as their polar head group a galactose moiety bound in glycosidic linkage to the hydroxyl group of ceramide. Their accumulation in tissue, due to a defect in beta-galactosidase, is the cause of galactosylceramide lipidosis or globoid cell leukodystrophy.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.
A class of large neuroglial (macroglial) cells in the central nervous system - the largest and most numerous neuroglial cells in the brain and spinal cord. Astrocytes (from "star" cells) are irregularly shaped with many long processes, including those with "end feet" which form the glial (limiting) membrane and directly and indirectly contribute to the BLOOD-BRAIN BARRIER. They regulate the extracellular ionic and chemical environment, and "reactive astrocytes" (along with MICROGLIA) respond to injury.
Surface ligands that mediate cell-to-cell adhesion and function in the assembly and interconnection of the vertebrate nervous system. These molecules promote cell adhesion via a homophilic mechanism. These are not to be confused with NEURAL CELL ADHESION MOLECULES, now known to be expressed in a variety of tissues and cell types in addition to nervous tissue.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
Neoplasms which arise from peripheral nerve tissue. This includes NEUROFIBROMAS; SCHWANNOMAS; GRANULAR CELL TUMORS; and malignant peripheral NERVE SHEATH NEOPLASMS. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp1750-1)
A long flat muscle that extends along the whole length of both sides of the abdomen. It flexes the vertebral column, particularly the lumbar portion; it also tenses the anterior abdominal wall and assists in compressing the abdominal contents. It is frequently the site of hematomas. In reconstructive surgery it is often used for the creation of myocutaneous flaps. (From Gray's Anatomy, 30th American ed, p491)
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Elements of limited time intervals, contributing to particular results or situations.
A moderately firm, benign, encapsulated tumor resulting from proliferation of SCHWANN CELLS and FIBROBLASTS that includes portions of nerve fibers. The tumors usually develop along peripheral or cranial nerves and are a central feature of NEUROFIBROMATOSIS 1, where they may occur intracranially or involve spinal roots. Pathologic features include fusiform enlargement of the involved nerve. Microscopic examination reveals a disorganized and loose cellular pattern with elongated nuclei intermixed with fibrous strands. (From Adams et al., Principles of Neurology, 6th ed, p1016)
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
The posterior filiform portion of the spermatozoon (SPERMATOZOA) that provides sperm motility.
A technique of culturing mixed cell types in vitro to allow their synergistic or antagonistic interactions, such as on CELL DIFFERENTIATION or APOPTOSIS. Coculture can be of different types of cells, tissues, or organs from normal or disease states.
The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.

Prior exposure to neurotrophins blocks inhibition of axonal regeneration by MAG and myelin via a cAMP-dependent mechanism. (1/2525)

MAG is a potent inhibitor of axonal regeneration. Here, inhibition by MAG, and myelin in general, is blocked if neurons are exposed to neurotrophins before encountering the inhibitor; priming cerebellar neurons with BDNF or GDNF, but not NGF, or priming DRG neurons with any of these neurotrophins blocks inhibition by MAG/myelin. Dibutyryl cAMP also overcomes inhibition by MAG/myelin, and cAMP is elevated by neurotrophins. A PKA inhibitor present during priming abrogates the block of inhibition. Finally, if neurons are exposed to MAG/myelin and neurotrophins simultaneously, but with the Gi protein inhibitor, inhibition is blocked. We suggest that priming neurons with particular neurotrophins elevates cAMP and activates PKA, which blocks subsequent inhibition of regeneration and that priming is required because MAG/myelin activates a Gi protein, which blocks increases in cAMP. This is important for encouraging axons to regrow in vivo.  (+info)

Disproportionate recruitment of CD8+ T cells into the central nervous system by professional antigen-presenting cells. (2/2525)

Inappropriate immune responses, thought to exacerbate or even to initiate several types of central nervous system (CNS) neuropathology, could arise from failures by either the CNS or the immune system. The extent that the inappropriate appearance of antigen-presenting cell (APC) function contributes to CNS inflammation and pathology is still under debate. Therefore, we characterized the response initiated when professional APCs (dendritic cells) presenting non-CNS antigens were injected into the CNS. These dendritic cells expressed numerous T-cell chemokines, but only in the presence of antigen did leukocytes accumulate in the ventricles, meninges, sub-arachnoid spaces, and injection site. Within the CNS parenchyma, the injected dendritic cells migrated preferentially into the white matter tracts, yet only a small percentage of the recruited leukocytes entered the CNS parenchyma, and then only in the white matter tracts. Although T-cell recruitment was antigen specific and thus mediated by CD4+ T cells in the models used here, CD8+ T cells accumulated in numbers equal to or greater than that of CD4+ T cells. Few of the recruited T cells expressed activation markers (CD25 and VLA-4), and those that did were primarily in the meninges, injection site, ventricles, and perivascular spaces but not in the parenchyma. These results indicate that 1) the CNS modulates the cellular composition and activation states of responding T-cell populations and that 2) myelin-restricted inflammation need not be initiated by a myelin-specific antigen.  (+info)

A new X linked neurodegenerative syndrome with mental retardation, blindness, convulsions, spasticity, mild hypomyelination, and early death maps to the pericentromeric region. (3/2525)

We report on a family with an X linked neurodegenerative disorder consisting of mental retardation, blindness, convulsions, spasticity, and early death. Neuropathological examination showed mild hypomyelination. By linkage analysis, the underlying genetic defect could be assigned to the pericentromeric region of the X chromosome with a maximum lod score of 3.30 at theta=0.0 for the DXS1204 locus with DXS337 and PGK1P1 as flanking markers.  (+info)

Myelin and collapsin-1 induce motor neuron growth cone collapse through different pathways: inhibition of collapse by opposing mutants of rac1. (4/2525)

Precise growth cone guidance is the consequence of a continuous reorganization of actin filament structures within filopodia and lamellipodia in response to inhibitory and promoting cues. The small GTPases rac1, cdc42, and rhoA are critical for regulating distinct actin structures in non-neuronal cells and presumably in growth cones. Collapse, a retraction of filopodia and lamellipodia, is a typical growth cone behavior on contact with inhibitory cues and is associated with depolymerization and redistribution of actin filaments. We examined whether small GTPases mediate the inhibitory properties of CNS myelin or collapsin-1, a soluble semaphorin, in chick embryonic motor neuron cultures. As demonstrated for collapsin-1, CNS myelin-evoked growth cone collapse was accompanied by a reduction of rhodamine-phalloidin staining most prominent in the growth cone periphery, suggesting actin filament disassembly. Specific mutants of small GTPases were capable of desensitizing growth cones to CNS myelin or collapsin-1. Adenoviral-mediated expression of constitutively active rac1 or rhoA abolished CNS myelin-induced collapse and allowed remarkable neurite extension on a CNS myelin substrate. In contrast, expression of dominant negative rac1 or cdc42 negated collapsin-1-induced growth cone collapse and promoted neurite outgrowth on a collapsin-1 substrate. These findings suggest that small GTPases can modulate the signaling pathways of inhibitory stimuli and, consequently, allow the manipulation of growth cone behavior. However, the fact that opposite mutants of rac1 were effective against different inhibitory stimuli speaks against a universal signaling pathway underlying growth cone collapse.  (+info)

Structural maturation of neural pathways in children and adolescents: in vivo study. (5/2525)

Structural maturation of fiber tracts in the human brain, including an increase in the diameter and myelination of axons, may play a role in cognitive development during childhood and adolescence. A computational analysis of structural magnetic resonance images obtained in 111 children and adolescents revealed age-related increases in white matter density in fiber tracts constituting putative corticospinal and frontotemporal pathways. The maturation of the corticospinal tract was bilateral, whereas that of the frontotemporal pathway was found predominantly in the left (speech-dominant) hemisphere. These findings provide evidence for a gradual maturation, during late childhood and adolescence, of fiber pathways presumably supporting motor and speech functions.  (+info)

Rapid induction of functional and morphological continuity between severed ends of mammalian or earthworm myelinated axons. (6/2525)

The inability to rapidly restore the loss of function that results from severance (cutting or crushing) of PNS and CNS axons is a severe clinical problem. As a novel strategy to help alleviate this problem, we have developed in vitro procedures using Ca2+-free solutions of polyethylene glycol (PEG solutions), which within minutes induce functional and morphological continuity (PEG-induced fusion) between the cut or crushed ends of myelinated sciatic or spinal axons in rats. Using a PEG-based hydrogel that binds to connective tissue to provide mechanical strength at the lesion site and is nontoxic to nerve tissues in earthworms and mammals, we have also developed in vivo procedures that permanently maintain earthworm myelinated medial giant axons whose functional and morphological integrity has been restored by PEG-induced fusion after axonal severance. In all these in vitro or in vivo procedures, the success of PEG-induced fusion of sciatic or spinal axons and myelinated medial giant axons is measured by the restored conduction of action potentials through the lesion site, the presence of intact axonal profiles in electron micrographs taken at the lesion site, and/or the intra-axonal diffusion of fluorescent dyes across the lesion site. These and other data suggest that the application of polymeric fusiogens (such as our PEG solutions), possibly combined with a tissue adherent (such as our PEG hydrogels), could lead to in vivo treatments that rapidly and permanently repair cut or crushed axons in the PNS and CNS of adult mammals, including humans.  (+info)

Synthesis and turnover of cerebrosides and phosphatidylserine of myelin and microsomal fractions of adult and developing rat brain. (7/2525)

The synthesis and turnover of cerebrosides and phospholipids was followed in microsomal and myelin fractions of developing and adult rat brains after an intracerebral injection of [U-14C]serine. The kinetics of incorporation of radioactivity into microsomal and myelin cerebrosides indicate the possibility of a precursor-product relationship between cerebrosides of these membranes. The specific radioactivity of myelin cerebrosides was corrected for the deposition of newly formed cerebrosides in myelin. Multiphasic curves were obtained for the decline in specific radioactivity of myelin and microsomal cerebrosides, suggesting different cerebroside pools in these membranes. The half-life of the fast turning-over pool of cerebrosides of myelin was 7 and 22 days for the developing and adult rat brain respectively. The half-life of the slowly turning-over pool of myelin cerebrosides was about 145 days for both groups of animals. The half-life of the rapidly turning-over microsomal cerebrosides was calculated to be 20 and 40 h for the developing and adult animals respectively. The half-life of the intermediate and slowly turning-over microsomal cerebrosides was 11 and 60 days respectively, for both groups of animals. The amount of incorporation of radioactivity into microsomal cerebrosides from L-serine was greatly decreased in the adult animals, and greater amounts of the precursor were directed towards the synthesis of phosphatidylserine. In the developing animals, considerable amounts of cerebrosides were synthesized from L-serine, besides phosphatidylserine. The time-course of incorporation indicated that a precursor-product relationship exists between microsomal and myelin phosphatidylserine. The half-life of microsomal phosphatidylserine was calculated to be about 8 h for the fast turning-over pool in both groups of animals.  (+info)

Adult brain retains the potential to generate oligodendroglial progenitors with extensive myelination capacity. (8/2525)

Remyelination of focal areas of the central nervous system (CNS) in animals can be achieved by transplantation of glial cells, yet the source of these cells in humans to similarly treat myelin disorders is limited at present to fetal tissue. Multipotent precursor cells are present in the CNS of adult as well as embryonic and neonatal animals and can differentiate into lineage-restricted progenitors such as oligodendroglial progenitors (OPs). The OPs present in adults have a different phenotype from those seen in earlier life, and their potential role in CNS repair remains unknown. To gain insights into the potential to manipulate the myelinating capacity of these precursor and/or progenitor cells, we generated a homogenous culture of OPs from neural precursor cells isolated from adult rat subependymal tissues. Phenotypic characterization indicated that these OPs resembled neonatal rather than adult OPs and produced robust myelin after transplantation. The ability to generate such cells from the adult brain therefore opens an avenue to explore the potential of these cells for repairing myelin disorders in adulthood.  (+info)

BACKGROUND: Traumatic injury to axons produces breakdown of axons and myelin at the site of the lesion and then further distal to this where Wallerian degeneration develops. The rapid removal of degenerated myelin by phagocytosis is advantageous for repair since molecules in myelin impede regeneration of severed axons. Thus, revealing mechanisms that regulate myelin phagocytosis by macrophages and microglia is important. We hypothesize that myelin regulates its own phagocytosis by simultaneous activation and down-regulation of microglial and macrophage responses. Activation follows myelin binding to receptors that mediate its phagocytosis (e.g. complement receptor-3), which has been previously studied. Down-regulation, which we test here, follows binding of myelin CD47 to the immune inhibitory receptor SIRPalpha (signal regulatory protein-alpha) on macrophages and microglia.. METHODS: CD47 and SIRPalpha expression was studied by confocal immunofluorescence microscopy, and myelin phagocytosis by ...
Some of the myelin sheaths in the cerebellum of normal adult toads exhibit extensive evaginations of their full thickness. These redundant flaps of myelin are collapsed; i.e., they contain no axon and have no lumen. They extend away from the parent axonal myelin sheaths and tend to enfold other myelinated fibers or granule cell perikarya, producing bizarre configurations of myelin and what appear to be partially or completely myelinated cell bodies. In some instances, only the redundant flap of myelin appears in the plane of section, and its attachment to an axonal myelin sheath in another plane is only inferred. Single lamellae of myelin also tend to invest cerebellar granule cells and other processes, and these too appear to fold on themselves producing two- or four-layered segments. It is suggested that there are two phases of myelinogenesis: an initial wrapping phase, followed by a prolonged second phase during which internodes of myelin increase in both length and girth by a process other ...
TY - JOUR. T1 - Involvement of CD45 in central nervous system myelination. AU - Nakahara, Jin. AU - Seiwa, Chika. AU - Tan-Takeuchi, Kyoko. AU - Gotoh, Mari. AU - Kishihara, Kenji. AU - Ogawa, Masaharu. AU - Asou, Hiroaki. AU - Aiso, Sadakazu. N1 - Funding Information: J.N. is a research fellow of the Japan Society for the Promotion of Science (JSPS). This work is supported by the Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (for JSPS research fellows; #16-7637) to J.N., and in part by the JSPSs 21st century COE program at Keio University. The authors are grateful to Drs. T. Yagi, T. Takai, Y. Matsuda, D.H. Rowitch, and K. Senzaki for providing experimental materials.. PY - 2005/5/6. Y1 - 2005/5/6. N2 - Myelin is a multi-layered membranous lipid insulator surrounding axons that allows the rapid conduction of neuronal impulses. In the central nervous system (CNS), myelin is produced by oligodendrocytes. During development, ...
Author: Velanac, Viktorija; Genre: Thesis; Open Access; Title: BACE1 dependent function of neuregulin1 in peripheral nervous system myelination
TY - JOUR. T1 - A conditionally immortalized glial cell line that expresses mature myelin proteins and functional GABA(A) receptors. AU - Bronstein, J M. AU - Hales, T G. AU - Tyndale, R F. AU - Charles, A C. PY - 1998/2. Y1 - 1998/2. N2 - We have isolated and characterized a conditionally immortalized glial cell line that expresses mature myelin proteins, as well as functional GABA(A) receptors. Glial cells were isolated from postnatal day 1 H-2Kb-tsA58 transgenic mice that contain the temperature-sensitive SV40 large T antigen oncogene under the control of an interferon-gamma-inducible promoter. A clonal line was isolated that grew rapidly under permissive conditions (33 degrees C in the presence of interferon-gamma), but not under nonpermissive conditions (37 degrees C in the absence of interferon-gamma). Cells expressed mRNAs of mature myelin proteins (myelin basic proteins and proteolipid protein) when grown under either permissive or nonpermissive conditions, but myelin basic proteins were ...
The thickness of the myelin sheath that insulates axons is fitted for optimal nerve conduction velocity. Here, we show that, in Schwann cells, mammalian disks large homolog 1 (Dlg1) interacts with PTEN (phosphatase and tensin homolog deleted on chromosome 10) to inhibit axonal stimulation of myelination. This mechanism limits myelin sheath thickness and prevents overmyelination in mouse sciatic nerves. Removing this brake results also in myelin outfoldings and demyelination, characteristics of some peripheral neuropathies. Indeed, the Dlg1 brake is no longer functional in a mouse model of Charcot-Marie-Tooth disease. Therefore, negative regulation of myelination appears to be essential for optimization of nerve conduction velocity and myelin maintenance.. ...
TY - JOUR. T1 - The formation of paranodal spirals at the ends of CNS myelin sheaths requires the planar polarity protein Vangl2. AU - Jarjour, Andrew. AU - Velichkova, Atanaska. AU - Boyd, Amanda. AU - Lord, Kathryn M.. AU - Torsney, Carole. AU - Henderson, Deborah J. AU - Ffrench-Constant, Charles. PY - 2020/3/3. Y1 - 2020/3/3. N2 - During axonal ensheathment, noncompact myelin channels formed at lateral edges of the myelinating process become arranged into tight paranodal spirals that resemble loops when cut in cross section. These adhere to the axon, concentrating voltage‐dependent sodium channels at nodes of Ranvier and patterning the surrounding axon into distinct molecular domains. The signals responsible for forming and maintaining the complex structure of paranodal myelin are poorly understood. Here, we test the hypothesis that the planar cell polarity determinant Vangl2 organizes paranodal myelin. We show that Vangl2 is concentrated at paranodes and that, following conditional ...
In the human demyelinating central nervous system (CNS) disease multiple sclerosis, remyelination promotes recovery and limits neurodegeneration, but this is inefficient and always ultimately fails. Furthermore, these regenerated myelin sheaths are thinner and shorter than the original, leaving the underlying axons potentially vulnerable. In rodent models, CNS remyelination is more efficient, so that in young animals (but not old) the number of myelinated axons is efficiently restored to normal, but in both young and old rodents, regenerated myelin sheaths are still short and thin. The reasons for these differences in remyelination efficiency, the thinner remyelinated myelin sheaths compared to developmental myelin and the subsequent effect on the underlying axon are unclear. We studied CNS remyelination in the highly regenerative adult zebrafish (Danio rerio), to better understand mechanisms of what we hypothesised would be highly efficient remyelination, and to identify differences to mammalian CNS
Myelin protein zero (P0), a type I transmembrane protein, is the most abundant protein in peripheral nervous system (PNS) myelin—the lipid-rich, periodic structure of membrane pairs that concentrically encloses long axonal segments. Schwann cells, the myelinating glia of the PNS, express P0 throughout their development until the formation of mature myelin. In the intramyelinic compartment, the immunoglobulin-like domain of P0 bridges apposing membranes via homophilic adhesion, forming, as revealed by electron microscopy, the electron-dense, double “intraperiod line” that is split by a narrow, electron-lucent space corresponding to the extracellular space between membrane pairs. The C-terminal tail of P0 adheres apposing membranes together in the narrow cytoplasmic compartment of compact myelin, much like myelin basic protein (MBP). In mouse models, the absence of P0, unlike that of MBP or P2, severely disturbs myelination. Therefore, P0 is the executive molecule of PNS myelin
The myelin sheath is found surrounding axons of the both the central and peripheral nervous system. Axons may be myelinated or unmyelinated. In myelinated axons the sheath is arranged with small gaps known as the nodes of Ranvier, this is where the action potentials are generated as this is where the majority of the axons ion channels are located. This article shall discuss the myelin sheath, its affect on transmission of signals in the nervous system and relevant clinical conditions.
We show here that β1 integrins are required for the myelination of axonal tracts in the CNS and we establish a link between β1 integrins and AKT in oligodendrocyte function. Myelin thickness was reduced in the spinal cord, cerebellum and optic nerve of Itgb1-CNSko mice without a reduction in oligodendrocyte numbers. These findings suggest that the myelination defects in mutant mice were caused by perturbations in the formation of myelin membrane sheaths. Consistent with this finding, myelin outgrowth was substantially impaired in cultured β1-deficient oligodendrocytes. Myelination was also affected in the spinal cord of Itgb1-OL-ko mice, providing additional evidence that β1 integrins act, at least in part, cell-autonomously in oligodendrocytes to regulate myelination. Interestingly, activation of AKT signaling was affected in cultured β1-deficient oligodendrocytes. Furthermore, myelin membrane sheet formation in the β1-mutant cultured cells was restored by inhibiting PTEN or by ...
We report a large family with a multigenerational pedigree of HMSN with focally folded myelin sheaths. The family studied allowed us to uncover the genetic findings, clinical spectrum, and natural history of HMSN with focally folded myelin sheaths, and to highlight the significant intrafamily uniformity of clinical presentation.. Focally folded myelin sheaths are the pathologic hallmark of certain hereditary neuropathies of wide clinical spectrum. 11-14,21-26 Of the 23 cases reported, 10 patients came from five families, whereas 13 cases were sporadic. In two cases, an autosomal-dominant mode of inheritance was postulated. 24 The reports of Dayan et al., 27 Nordborg et a1., 28 and Lutschg et al. 29 were not included because published pathologic data were not detailed enough for a comparison with ours.. In our family, the genealogic study showing the high consanguinity rate represents strong evidence in favor of an autosomal-recessive pattern of inheritance, confirming the hypothesis postulated ...
Oligodendrocytes in the central nervous system (CNS) produce myelin sheaths that insulate axons to ensure fast propagation of action potentials. beta1 integrins regulate the myelination of peripheral nerves, but their function during the myelination of axonal tracts in the CNS is unclear. Here we show that genetically modified mice lacking beta1 integrins in the CNS present a deficit in myelination but no defects in the development of the oligodendroglial lineage. Instead, in vitro data show that beta1 integrins regulate the outgrowth of myelin sheaths. Oligodendrocytes derived from mutant mice are unable to efficiently extend myelin sheets and fail to activate AKT (also known as AKT1), a kinase that is crucial for axonal ensheathment. The inhibition of PTEN, a negative regulator of AKT, or the expression of a constitutively active form of AKT restores myelin outgrowth in cultured beta1-deficient oligodendrocytes. Our data suggest that beta1 integrins play an instructive role in CNS myelination ...
Bekijk Stockfoto van Cryofracture Preparation Of A Sciatic Nerve Crosssection Showing The Myelin Sheaths Around Nerve Fibers The Myelin Sheath Is Formed From Successive Wrapping Of The Schwann Cell Plasma Membrane Around The Axon. Ga voor hoogwaardige fotos met een hoge resolutie naar Getty Images.
The main myelin sheath function is:. It acts as an electrical insulator for the neuron - it prevents the penetration of electrical impulses through the shield.. In myelin sheath function, The sheath prevents ion migration to or from the neuron / prevents depolarization.. Accelerates the transmission of the electrical impulse in the neuron - impulses cannot pass through the shield (the shield acts as an electrical insulator), instead, the pulses jump from the gap in the myelin sheath to another gap (it jumps from one Ranvier node to another).. ...
Myelin sheath serves as an insulator that surrounds the nerves. This includes the nerves in the brain and spinal cord. This layer is made up of fatty substances, as well as protein. Its purpose is to allow impulses to transfer quickly and efficiently along the nerve cells. If the myelin sheath layer is damages the impulses will slow down and it can cause diseases such as multiple sclerosis. In addition, Myelin Sheath is roughly 200 and 800 μm thick and diseases can also thin out the layer causing the level of protection to obviously decrease. ...
The myelination of central nervous system (CNS) axons by oligodendrocytes enables fast and energy‐efficient propagation of action potentials as well as axonal support [[1], [2]]. The absence of the second most abundant CNS myelin protein MBP results in severe hypomyelination, shivering symptoms and premature death in rodents [[3]]. MBP compacts myelin membranes, binds to cytoskeletal proteins and is involved in oligodendroglial calcium signalling [[4], [5]]. Moreover, it regulates the molecular composition of the glial plasma membrane, facilitating the formation of lipid‐rich myelin domains required for effective axon insulation [[6], [7]]. Therefore, appropriate MBP levels are important to maintain oligodendroglial homeostasis as well as functional myelin membrane formation. During oligodendrocyte maturation, MBP transcription precedes translation by about 1 day [[8], [9]], but the mechanisms underlying this translational repression of MBP remain poorly understood. Axon-glial signalling ...
Myelination drastically speeds up action potential propagation along axons, which is fundamental for the correct function of neuronal circuits. However, axon-oligodendrocyte interactions regulating the onset of myelin formation remain unclear. I sought to determine how reticulospinal axons control myelination, as they are the first myelinated in the zebrafish spinal cord. I genetically manipulated zebrafish in order to either remove such axons from a region of the spinal cord, or to increase their number, and characterized oligodendrocyte-lineage cells following this axonal loss- or gain-of-function. In kinesin-binding protein (kbp) mutants, reticulospinal hindbrain neurons start axonogenesis but axons fail to grow along the entire spinal cord as in wildtype, providing an axon-deficient posterior spinal cord and an intact anterior region. I found that early stages of oligodendrocyte development, such as the specification of oligodendrocyte precursors, their distribution and migration were not ...
TY - CHAP. T1 - Myelin and Myelination. AU - Aschner, Michael. AU - Toews, A. D.. PY - 2010/8/12. Y1 - 2010/8/12. N2 - A compound may be neurotoxic by virtue of being targeted to perturb some metabolic, structural, or functional property characteristic of myelin or myelinating cells. Myelin and myelination are described in this section, with emphasis on points relevant to understanding neurotoxic mechanisms. More information is readily available in collections of more specialized reviews of subtopics relevant to myelin.. AB - A compound may be neurotoxic by virtue of being targeted to perturb some metabolic, structural, or functional property characteristic of myelin or myelinating cells. Myelin and myelination are described in this section, with emphasis on points relevant to understanding neurotoxic mechanisms. More information is readily available in collections of more specialized reviews of subtopics relevant to myelin.. UR - ...
The mechanisms that regulate myosin II activity in SC and OL during myelination are not yet known. In SC, phosphorylation of the regulatory chain of myosin II (MLC2) is up-regulated at the onset of myelination and then down-regulated (Melendez-Vasquez et al., 2004), following the same pattern of Rho activation in peripheral nerve extracts (unpublished data). Our previous studies revealed an important role for ROCK during the initial events of PNS myelination, possibly by regulating the phosphorylation status of MLC (Melendez-Vasquez et al., 2004). However, inhibition of ROCK did not interfere with the wrapping of the axon, which suggests that another ROCK-independent mechanism controls the actual motor of SC adaxonal membrane progression around the axon. Our current study extends these initial observations and provides further evidence of the important role of polarized actomyosin contraction for SC myelin formation. Similar to our previous results with a ROCK-specific pharmacological inhibitor, ...
Remyelination is the process of propagating oligodendrocyte precursor cells to form oligodendrocytes to create new myelin sheaths on demyelinated axons in the CNS. This is a process naturally regulated in the body and tends to be very efficient in a healthy CNS. The process creates a thinner myelin sheath than normal, but it helps to protect the axon from further damage, from overall degeneration, and proves to increase conductance once again. Demyelinating diseases, such as Multiple Sclerosis, have been of utmost interest within the last couple of decades. Recent research is uncovering some of the many unknown pathways involved with remyelination in hopes of battling demyelinating diseases like MS which can ultimately cripple a person. While no treatment exists yet in preventing remyelination failure in the chronic stages of these diseases, future research may yet prove to unlock key pathways that can be targeted. Remyelination is activated and regulated by a variety of factors surrounding ...
Myelin is a dielectric (electrically insulating) material that forms a layer, the myelin sheath, usually around only the axon of a neuron. It is essential for the proper functioning of the nervous system. Myelin is an outgrowth of a glial cell. The production of the myelin sheath is called myelination. The production of myelin occurs in the fourteenth week of fetal development, while very little amounts of myelin exist in the brain at the time of birth. During infancy myelination occurs quickly and does not stop until the adolescent stages of life. Because of this rapid myelination, it is essential that children under the age of two receive a diet higher in fats than one of an adult.. Schwann cells supply the myelin for peripheral neurons, whereas oligodendrocytes, specifically of the interfascicular type, myelinate the axons of the central nervous system. Myelin is considered a defining characteristic of the (gnathostome) vertebrates, but it has also arisen by parallel evolution in some ...
The myelin membrane synthesised by oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS) provides electric insulation to axons thus enabling the fast saltatory impulse conduction essential for vertebrate nervous system function. Moreover, myelinating glial cells provide trophic support to neurons which is not understood in molecular terms. Myelin is produced and maintained in response to bidirectional communication between neurons and glial cells. Abnormal axon-glia interaction and defects in myelin formation result in demyelinating diseases such as leukodystrophies and hereditary neuropathies, which are characterized by severe neurodegeneration resulting in long term disability and in severe cases premature death. In the common demyelinating disease Multiple Sclerosis similar symptoms arise due to destruction of the myelin sheath by invading immune cells.. We are studying the properties of oligodendrocyte precursor cells (OPC) and the ...
Marie Bechler, a senior researcher in the ffrench-Constant laboratory at the MRC Centre for Regenerative Medicine, said: The aligned Mimetix scaffold fibres from AMSBIO have been an invaluable tool, allowing us to answer fundamental questions regarding how oligodendrocytes form central nervous system (CNS) myelin sheaths. The suppliers of the Mimetix fibres worked with us to create customised three-dimensional fibres, facilitating the development of an oligodendrocyte culture assay. The culture system we developed permits the examination of myelin sheath formation in the absence of neurons. The aligned microfibres used in our research have enabled us to examine both the physical and molecular signals sufficient to drive CNS myelin sheath formation, which could not be assessed in other culture models. This has opened new opportunities to examine the role of physical cues, heterogeneity due to oligodendrocyte origin, and the sufficiency of molecules to control the number and size of myelin ...
We set up the Cambridge Centre for Myelin Repair in 2005, with the aim of developing treatments that promote myelin repair for people with MS.. Since it opened the Cambridge Centre has created a world-class research environment involving researchers from all around the UK - most notably at our Edinburgh Centre for MS Research.. Scientists at both centres have worked together to show that a molecule called RXR-gamma could encourage the brains own stem cells to repair myelin in animal models of MS. Researchers will now test the benefits of a drug that targets RXR-gamma, called bexarotene, in a phase 2 clinical trial.. We announced four more years of funding for the Cambridge Centre in 2016. Researchers will continue to investigate the fundamental mechanisms behind myelin repair, with the hope of developing new treatments.. They will focus on understanding more about the cells capable of repairing myelin, and the impact ageing and lifestyle factors (such as diet and exercise) can have on these ...
Research Grant Recipient: Mi-Hyeon Jang, PhD. Grant Period: 2017-2019. Award Value: $249,998. Site: University of Minnesota. Summary: Multiple sclerosis and other diseases attack the myelin, a sheath that insulates the nerves. Dr. Jang is investigating the underlying molecular mechanisms of myelin regeneration in an effort to develop a therapy to help patients.. Mi-Hyeon Jang, PhD, is an Assistant Professor of Biochemistry and Molecular Biology and Assistant Professor of Neurosurgery at Mayo Clinic.. ...
Glial cells produce myelin and contribute to axonal morphology in the nervous system. Two myelin membrane proteolipids, PLP and DM20, were shown to be essential for the integrity of myelinated axons. In the absence of PLP-DM20, mice assembled compact myelin sheaths but subsequently developed widespread axonal swellings and degeneration, associated predominantly with small-caliber nerve fibers. Similar swellings were absent in dysmyelinated shiverer mice, which lack myelin basic protein (MBP), but recurred in MBP*PLP double mutants. Thus, fiber degeneration, which was probably secondary to impaired axonal transport, could indicate that myelinated axons require local oligodendroglial support. ...
Antiglycolipid IgM antibodies are recognized to induce formation of extended or wide-spaced myelin, a distinctive type of dysmylination seen as a a repeat period ~2X or 3X regular, observed in diseases including multiple sclerosis also. to look at. Wide spacing tended to involve the external layers from the sheath and perhaps alternated with normally spaced lamellae. An attribute not noticed previously includes multiple extended myelin lamellae in a single sector of the sheath constant with normally spaced lamellae in another, leading to variant in sheath width across the axonal circumference. This unequal distribution of wide-spaced lamellae can be most simply described predicated on incorporation of IgM substances into immature sheaths during myelin development and indicates a style of CNS myelinogenesis more technical than basic spiraling. The periaxonal space under no circumstances shows widening of the kind, but the interface with adjacent myelin sheaths or oligodendrocytes may. Thus, wide ...
Multiple sclerosis is a debilitating condition that is characterized by damage to the myelin sheath, the insulating layer that protect nerve fibers in the brain to enable efficient communication between the nerve cells and the brain in the central nervous system. A possible MS treatment that researchers look into aim to identify ways to repair the damaged myelin sheath. A promising method being looked into is trying to make use of stem cells to help in myelin repair in people with MS. The potential use of stem cells for myelin repair has recently found a breakthrough as researchers from the Universities of Cambridge and Edinburgh have identified a biological switch that would enable stem cells to regenerate myelin in lab rats. The findings of the said study was published in the journal Nature Neuroscience. In the said study, the researchers looked at how the stem cells of MS patients repair myelin. During the course of the study, they have been able to identify a specific type of molecule called RXR
Myelinogenesis is generally the proliferation of myelin sheaths throughout the nervous system, and specifically the progressive myelination of nerve axon fibers in the central nervous system. This is a non-simultaneous process that occurs primarily postnatally in mammalian species, beginning in the embryo during the midst of early development and finishing after birth. The myelination process allows neuronal signals to propagate down an axon more swiftly without the loss of signal. This enables better connectivity within specific brain regions and also improves broader neuronal pathways connecting spatially separate regions required for many sensory, cognitive, and motor functions. Some scientists consider myelination to be a key human evolutionary advantage, enabling greater processing speeds that lead to further brain specialization. Myelination continues for at least another 10 to 12 years after birth before an individual is fully developed. While the rate at which individual children develop ...
Central nervous system (CNS) myelination is important for proper nervous system function in vertebrates. In demyelinating diseases such as multiple sclerosis, autoimmune-mediated myelin destruction results in neurological impairment; and although remyelination does occur spontaneously, it is poorly understood and insufficient in humans. Zebrafish (Danio rerio) are known to harbour tremendous regenerative capacity of various CNS tissues; however, there is presently only little knowledge of their myelin repair efficiency. An experimental model of myelin injury in zebrafish would permit study of the mechanisms involved in successful remyelination and could potentially guide the development of novel therapeutic agents for mammalian remyelination. This doctoral thesis describes the characterisation of the novel myelin protein Claudin k in zebrafish, demonstrates the establishment of adult zebrafish as an experimental model for CNS de- and remyelination and explores some mechanisms underlying myelin ...
1. The lipids of whole brain and subcellular fractions of the rat were analysed during development. 2. The deposition of cholesterol occurred in two phases, one related to increasing wet weight of the brain and the second to myelination. Cerebroside accumulation was related only to myelination. 3. The composition of myelin isolated from 12-day-old rat brain was different in some respects from that of the adult. In the former there was an increase of phospholipid in relation to cholesterol and a marked deficiency in cerebroside. 4. It is suggested that early myelin is extruded glial plasma membrane, which only later becomes mature myelin.. ...
Myelin sheaths in the vertebrate nervous system enable faster impulse propagation, while myelinating glia provide vital support to axons. Once considered a static insulator, converging evidence now suggests that myelin in the central nervous system can be dynamically regulated by neuronal activity and continues to participate in nervous system plasticity beyond development. While the link between experience and myelination gains increased recognition, it is still unclear what role such adaptive myelination plays in facilitating and shaping behaviour. Additionally, fundamental mechanisms and principles underlying myelin remodelling remain poorly understood. In this review, we will discuss new insights into the link between myelin plasticity and behaviour, as well as mechanistic aspects of myelin remodelling that may help to elucidate this intriguing process.
Research on myelination offers centered on identifying molecules capable of inducing oligodendrocyte (OL) differentiation in an effort to develop strategies that promote functional myelin regeneration in demyelinating disorders. of and gene manifestation, mediated from the connection of SMAD3/4 with Sp1 and FoxO1 transcription factors. Our study is the 1st to demonstrate an autonomous and important part of TGF signaling in OL development and CNS myelination, and may provide new avenues in the treatment of demyelinating diseases. studies have shown that O-2A progenitor cells express TGF1 and that TGF signaling activation exerts an anti-mitogenic effect countering PDGFR signaling, in turn promoting cell cycle arrest (McKinnon et al., 1993). Moreover, Activin-A, a member of the TGF superfamily, has been proposed as one of the cytokines secreted by microglial cells that plays a role in OL regeneration and remyelination (Miron et al., 2013). These scholarly research claim that TGF signaling could be ...
Kelton, D E., Myelin degeneration in the central nervous system of dilute-lethal mice. Abstr. (1961). Subject Strain Bibliography 1961. 484 ...
Interested in MS myelin sheath repair? Chat to the MS community and watch multiple sclerosis researchers explain their work on repairing damaged myelin.
FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] This gene encodes a transcription factor that is required for central nervous system myelination and may regulate oligodendrocyte differentiation. It is thought to act by increasing the expression of genes that effect myelin production but may also directly promote myelin gene expression. Loss of a similar gene in mouse models results in severe demyelination. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2014 ...
An innovative funding scheme generates ground-breaking progress in understanding the genetic changes in MS as well as myelin repair.
Discover what role the myelin sheath plays in our day-to-day lives, how it works, and how it can become damaged by certain conditions (multiple sclerosis).
TY - JOUR. T1 - Dysglobulinemic neuropathy. T2 - Absence of immunoglobulin within myelin sheaths. AU - Rodriguez, M.. AU - Powell, H. C.. PY - 1986. Y1 - 1986. UR - http://www.scopus.com/inward/record.url?scp=0022636706&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0022636706&partnerID=8YFLogxK. M3 - Article. VL - 19. SP - 204. EP - 206. JO - Annals of Neurology. JF - Annals of Neurology. SN - 0364-5134. IS - 2. ER - ...
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Although myelin is composed of mostly lipids, the pathological role of myelin lipids in demyelinating diseases remains elusive. The principal lipid of the myelin sheath is β-galactosylceramide (β-Galcer). Its α-anomer (α-Galcer) has been demonstrated to be antigenically presented by macrophages via CD1d, a MHC class I-like molecule. Myelin, which is mostly composed of β-Galcer, has been long considered as an immunologically-inert neuron insulator, because the antigen-binding cleft of CD1d is highly α-form-restricted. Here, we report that CD1d-mediated antigenic presentation of myelin-derived galactosylceramide (Mye-GalCer) by macrophages contributed significantly to the progression of experimental autoimmune encephalomyelitis (EAE). Surprisingly, this presentation was recognizable by α-Galcer:CD1d-specific antibody (clone L363), but incapable of triggering expansion of NKT cells and production of NKT signature cytokines (IFNγ and IL-4). Likewise, a synthesized analog of Mye-Galcer, ...
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In MS, myelin in the brain and spinal cord is destroyed. Though HEALTHY human systems have the natural ability to repair myelin damage, in MS where damage occurs, SCARS of hardened sclerotic tissue INHIBIT and/or PREVENT that process from taking place. There is no cure for MS. Myelin loss has also been linked to a number of other neurological diseases including Parkinsons disease, Alzheimers disease, and depression ...
Using a refined MRI technique, researchers have found that patients with multiple sclerosis (MS) lose myelin in the gray matter of their brains in relative amounts equal to or greater than myelin loss in the brains white matter. Myelin content in gray matter is extremely important to proper function. The results showed that gray matter demyelination was much more advanced in patients with secondary-progressive MS, and was strongly related to patients disability.
Myelin Sheaths is not front women Cassandra Ward. However, Cassandra Ward is the front women of Myelin Sheaths, the phenomenal garage four piece straight from Canada. I know (honestly I do), how constantly blogs these are gushing about the latest garage flash-in-the-pan, who release a very awesome single only to be ignored next releases time. Well Myelin Sheaths are the real deal. These are tunes from their brand Get On Your Nerves LP of of South Paw Records (who have brought us other lovely release from Young Governor, and The White Wires), are pure Jay Reatard worship and its wonderful. Gloves/Mutations in particular is a great ode to Blood Visions, and the way the band manages to pull of instrumental intro into the chantey main song is proof of their garage-punk hybrid perfection ...
Our results provide direct evidence that the mechanism of Hes5‐dependent regulation of gene expression is dependent on the developmental stage and cellular context and therefore extend our understanding on the mechanism of action of this important transcription factor. In mammalian cells, Hes family members (Hes1, Hes3 and Hes5) have been implicated as modulators of neural (Ohtsuka et al, 1999; Cau et al, 2000; Hatakeyama et al, 2004) and astrocytic (Wu et al, 2003) differentiation during embryonic development. A previous study in embryonic neuroepithelial cells isolated from the murine spinal cord, suggested that Hes5 expression was transient and confined to precursors or very early progenitors and thereby questioned its possible role as direct regulator of myelin gene expression (Wu et al, 2003). Our results in immortalized murine cortical neonatal progenitors are in agreement with several other studies reporting the expression of Hes5 in the postnatal brain (Stump et al, 2002) and in ...
I thought multiple sclerosis sufferers suffer from damaged myelin sheath, and this leads to inflammation and the immune system begins to attack the myelin. I think you are getting confused with the terms. Multiple sclerosis is the disease by which people are diagnosed with it if their immune system attacks the myelin sheath(when it is damaged), thus a weaker nervous system(because the nerve cells can no longer conduct the impulses). Myelin sheath provides protection of the axon and electrical insulation ...
The inner mesaxon (Terminologia histologica: Mesaxon internum) is the connection between the myelin sheath and the inner part ... "The Myelin Sheath". Basic Neurochemistry: Molecular, Cellular and Medical Aspects. 6th edition. v t e (All stub articles, ... is the connection of the outer cell membrane to the compact myelin sheath. ...
Morell, Pierre; Quarles, Richard H. (1999). "The Myelin Sheath". Basic Neurochemistry: Molecular, Cellular and Medical Aspects ... The lysosome breaks down acid ceramidase; the fatty acid component is then used to produce myelin. Myelin is an insulating ... The lack of myelin resulting from the lack of acid ceramidase breakdown leads to nerve cell dysfunction.[citation needed] ...
It occurs when the myelin sheath of the nerve cells becomes damaged. As the myelin sheath is responsible for protecting the ... "Myelin Sheath - Definition and Function , Biology Dictionary". Biology Dictionary. 2017-02-10. Retrieved 2018-10-19. " ...
The axon is insulated by a myelin sheath. Myelin is composed of either Schwann cells (in the peripheral nervous system) or ... certain neuronal axons are covered with myelin sheaths. Myelin is a multilamellar membrane that enwraps the axon in segments ... Myelin sheath reduces membrane capacitance and increases membrane resistance in the inter-node intervals, thus allowing a fast ... To be specific, myelin wraps multiple times around the axonal segment, forming a thick fatty layer that prevents ions from ...
They are not attached to neurons via myelin sheaths and, therefore, do not contribute to insulation. They remain opposed to ... A single oligodendrocyte can extend its processes to 50 axons, wrapping approximately 1 μm of myelin sheath around each axon; ... Oligodendrocytes do this by creating the myelin sheath. ... Mammalian nervous systems depend crucially on myelin sheaths, ... Myelin also increases impulse speed, as saltatory propagation of action potentials occurs at the nodes of Ranvier in between ...
This is the provision of an insulating layer, called a myelin sheath. The myelin membrane is unique in its relatively high ... Oligodendrocytes form the insulating myelin in the CNS. Along myelinated nerve fibers, gaps in the myelin sheath known as nodes ... and in the PNS it is myelin basic protein. Nodes of Ranvier (also known as myelin sheath gaps) are short unmyelinated segments ... Hsu K, Terakawa S (July 1996). "Fenestration in the myelin sheath of nerve fibers of the shrimp: a novel node of excitation for ...
Kursula P (Feb 2008). "Structural properties of proteins specific to the myelin sheath". Amino Acids. 34 (2): 175-85. doi: ... phosphate CNPase is a myelin-associated enzyme that makes up 4% of total CNS myelin protein, and is thought to undergo ... Stricker R, Kalbacher H, Reiser G (Aug 1997). "The epitope recognized by a monoclonal antibody in the myelin-associated protein ... Thompson RJ (Aug 1992). "2',3'-cyclic nucleotide-3'-phosphohydrolase and signal transduction in central nervous system myelin ...
In myelinated axons, Schwann cells form the myelin sheath. The sheath is not continuous. Individual myelinating Schwann cells ... Myelinating Schwann cells wrap around axons of motor and sensory neurons to form the myelin sheath. The Schwann cell promoter ... The vertebrate nervous system relies on the myelin sheath for insulation and as a method of decreasing membrane capacitance in ... Myelinating Schwann cells begin to form the myelin sheath in mammals during fetal development and work by spiraling around the ...
Peterson, Edith R.; Murray, Margaret R. (1955). "Myelin sheath formation in cultures of avian spinal ganglia". American Journal ... Murray and collaborators reported in1940 that peripheral nerve sheath tumors originate from Schwann cells. In 1947, Drs. Murray ... Bornstein, Murray B.; Murray, Margaret R. (1958). "Serial Observations on Patterns of Growth, Myelin Formation, Maintenance and ... "Schwann cell versus fibroblast as the origin of the specific nerve sheath tumor". American J. of Pathology. 16: 41-60. Murray, ...
... myelin does not form a single long sheath over the entire length of the axon. Rather, myelin sheaths the nerve in segments: in ... These myelin-like sheaths share several structural features with the sheaths found in vertebrates including multiplicity of ... When a peripheral fiber is severed, the myelin sheath provides a track along which regrowth can occur. However, the myelin ... The MS Information Sourcebook, Myelin H & E Histology Luxol Fast Blue: Modified Kluver's Method to stain for Myelin Sheath (CS1 ...
The myelin sheath allows nerve cells to conduct signals faster. When the myelin sheath is damaged, nerve signals are slower, ... Nerve signals are conducted by an axon with a myelin sheath wrapped around it. Most mutations in CMT affect the myelin sheath, ... CMT2 types are a result of damage to the nerve axons rather than damage to the myelin sheath (as is the case with CMT1). ... Schwann cells create the myelin sheath, by wrapping its plasma membrane around the axon. Neurons, Schwann cells, and ...
"Topographical arrangement of membrane proteins in the intact myelin sheath. Lactoperoxidase incorproation of iodine into myelin ...
The oligodendrocytes that originally formed a myelin sheath cannot completely rebuild a destroyed myelin sheath. However, the ... The newly formed myelin sheaths are thinner and often not as effective as the original ones. Repeated attacks lead to ... Myelin sheaths are still intact but swollen. Small increase in microglia and T cells. Active layer: Phagocytic demyelinating ... MS lesions mainly consist in demyelination and scarring in the fatty myelin sheaths around the axons of the brain and spinal ...
Nerve impulses are transmitted by myelin, a fatty material that grows around a cell. White matter has a myelin sheath (a ... The myelin sheath isn't fully formed until around ages 24-26. This means that adolescents and young adults typically learn ... collection of myelin) while gray matter doesn't, which efficiently allows neural impulses to move swiftly along the fiber. ...
... eventually destroying the myelin sheath of the nervous system. The myelin sheath is a fatty covering that protects nerve fibers ... The Myelin Project Multiple sclerosis "metachromatic leukodystrophy" at Dorland's Medical Dictionary Le, Tao; Bhushan, Vikas; ... Leukodystrophies affect the growth and/or development of myelin, the fatty covering which acts as an insulator around nerve ...
Damage occurs to the myelin sheath in the peripheral nervous system. As doctors at the Mayo Clinic were beginning to note, the ... Physiological testing indicated signature antibodies in the mouse model at 100% in potassium channel antibodies and myelin ...
Myelin is an insulating sheath around neurons in the spinal cord. One proposed cause of degenerative myelopathy is that the ... immune system attacks this sheath, breaking it down. This results in a loss of communication between nerves in lower body of ...
Demyelinating plaques attack the myelin sheaths on neurons. This decreases the conduction velocity of the neurons, making the ...
... on the myelin sheath of the CNS to provide the structural integrity of the myelin sheath." MOG's cDNA coding region in humans ... While the primary molecular function of MOG is not yet known, its likely role with the myelin sheath is either in sheath " ... It is speculated to serve as a necessary "adhesion molecule" to provide structural integrity to the myelin sheath and is known ... "very late on oligodendrocytes and the myelin sheath". Interest in MOG has centered on its role in demyelinating diseases. Some ...
While in Japan, he studied vertebrate nerve fibers and discovered the insulating function of the myelin sheath, a material that ... Tasaki is credited with discovering the insulating function of the myelin sheath. His discoveries provided the foundation for a ... between the breaks in the myelin wrapping, called nodes of Ranvier. This process, termed saltatory conduction, is featured in a ... better understanding of diseases such as multiple sclerosis, in which myelin is lost or damaged. In 1910, Tasaki was born in ...
In this disease, the immune system attacks the myelin sheath surrounding neurons. Deterioration of the myelin sheath ...
The spinal cord becomes thinner and nerve cells lose some myelin sheath. The diameter of the spinal cord is smaller than that ... The spinal cord becomes thinner, and nerve cells lose some myelin sheath. No effective treatment is known, but several ...
Myelin forms a layer, the myelin sheath, around the axons and neurons. When this sheath is damaged the transport of action ...
Axons are wrapped in a sheath of Schwann cells that contain myelin. Between Schwann cells are gaps (nodes of Ranvier) where the ... The demyelinating variant (AIDP, see below) features damage to the myelin sheath by white blood cells (T lymphocytes and ... Myelin disorders, Peripheral nervous system disorders, Syndromes affecting the nervous system, Wikipedia medicine articles ... an autoimmune disorder in which the body's immune system mistakenly attacks the peripheral nerves and damages their myelin ...
... s containing a sulfuric ester (sulfate) group, known as sulfatides, also occur in the myelin sheath of nerves. These ... Monogalactosylceramide is the largest single component of the myelin sheath of nerves. Cerebroside synthesis can therefore give ... a measurement of myelin formation or remyelination. The sugar moiety is linked glycosidically to the C-1 hydroxyl group of ...
For example, sphingomyelin is part of the myelin sheath of nerve fibers. Sphingolipids are formed from ceramides that consist ...
... but in white matter the principal barrier is the myelin sheath of axons. Bundles of axons provide a barrier to perpendicular ... Conditions where the myelin or the structure of the axon are disrupted, such as trauma, tumors, and inflammation reduce ... Barriers can be many things: cell membranes, axons, myelin, etc.; ...
PMP22/gas-3, called peripheral myelin protein, is located in the myelin sheath. The expression of this protein is associated ... In the central and peripheral nervous system are TJ localized between a glia and an axon and within myelin sheaths, where they ... Together they form and compact myelin sheaths of nerve cells. Plaque proteins are molecules, that are required for the ... OAP-1/TSPAN-3 cooperates with β1-integrin and OSP/Claudin11 within myelin sheaths of oligodendrocytes, thereby affects the ...
In MS lesions, the myelin sheath around the axons is deteriorated by inflammation. Alcohol use disorders are associated with a ... The white matter is white because of the fatty substance (myelin) that surrounds the nerve fibers (axons). This myelin is found ... Myelin acts as an insulator, which allows electrical signals to jump, rather than coursing through the axon, increasing the ... However, the tissue of the freshly cut brain appears pinkish-white to the naked eye because myelin is composed largely of lipid ...
"Evolution of myelin sheaths: both lamprey and hagfish lack myelin". Neuroscience Letters. 48 (2): 145-148. doi:10.1016/0304- ... A common feature of both cyclostomes is the absence of myelin in neurons. The brain of a hagfish has specific parts similar to ... They have cartilaginous skulls (although the part surrounding the brain is composed primarily of a fibrous sheath) and tooth- ... The nasal capsule is considerably expanded in hagfish, comprising a fibrous sheath lined with cartilage rings. In contrast to ...
MAG is localized on the inner membrane of the myelin sheath and interacts with axonal membrane proteins to attach the myelin ... Myelin Myelinogenesis NgR Myelin oligodendrocyte glycoprotein Anti-MAG peripheral neuropathy Myelin-associated+glycoprotein at ... MAG is a critical protein in the formation and maintenance of myelin sheaths. ... "Identification of myelin-associated glycoprotein as a major myelin-derived inhibitor of neurite growth". Neuron. 13 (4): 805-11 ...
... is a disorder of the myelin sheath, which is a primary actor in the central nervous system. It has been ... v t e (Central nervous system disorders, Myelin disorders, All stub articles, Nervous system disease stubs). ...
The axon and myelin sheath are affected, but all of the connective tissues (endoneurium, perineurium, and epineurium) remain ... The axons of myelinated nerves have a myelin sheath made up of Schwann cells that coat the axon. Classification of nerve damage ...
... which in turn triggers autoimmunity and degeneration of the nerve's myelin sheath. While the initial article on CCSVI claimed ... Simka M (May 2009). "Blood brain barrier compromise with endothelial inflammation may lead to autoimmune loss of myelin during ...
A myelinated axon is wrapped in a fatty insulating sheath of myelin, which serves to greatly increase the speed of signal ... There are also unmyelinated axons). Myelin is white, making parts of the brain filled exclusively with nerve fibers appear as ...
In demyelinating polyneuropathies, the myelin sheath around axons is damaged, which affects the ability of the axons to conduct ... Expression of peripheral myelin protein 22 in Charcot-Marie-Tooth disease type 1A and hereditary neuropathy with liability to ...
It belongs to a group of genetic disorders known as leukodystrophies, where the growth and maintenance of myelin sheath in the ... However, it has been shown that spongy degeneration is not directly caused by the disrupted synthesis of myelin. Animal models ... NAA-derived acetates are involved in the synthesis of fatty acids, which are subsequently incorporated into myelin lipids. It ... January 2009). "Myelin lipid abnormalities in the aspartoacylase-deficient tremor rat". Neurochemical Research. 34 (1): 138-48 ...
Leukodystrophy: In this condition, the myelin sheath does not develop in a normal way, causing white matter in the brain to ...
Because the A-delta fiber is thicker than the C fiber, and is thinly sheathed in an electrically insulating material (myelin), ...
... a copper phthalocyanine dye that is soluble in alcohol and is attracted to bases found in the lipoproteins of the myelin sheath ... Under the stain, myelin fibers appear blue, neuropil appears pink, and nerve cells appear purple. Tissues sections are treated ... Luxol fast blue stain, abbreviated LFB stain or simply LFB, is a commonly used stain to observe myelin under light microscopy, ...
Myelin proteins make up the myelin sheath that functions in protecting nerve axons, maintaining structural integrity, and ... They can also stimulate local progenitor cells to produce replacement cells for rebuilding the myelin sheath. Neuroregeneration ... autoreactive lymphocytes such as T and B cells cause damage to the central nervous system by attacking myelin proteins. ...
... connective tissue around the neck's vascular compartment Myelin sheath, an insulating layer over the axon of a neuron Preputial ... Look up sheath in Wiktionary, the free dictionary. Sheath pronounced as /ʃiːθ/, may refer to: Scabbard, a sheath for holding a ... a penis sheath worn by some natives of New Guinea Sheath (album), a 2003 techno album by LFO Sheath dress, a type of dress ... the laminas around abdominal muscles Root sheath, the inner or epidermic coat around the root of a hair follicle Tendon sheath ...
Multiple sclerosis - an inflammatory disease in which the myelin sheaths around the axons of the brain and spinal cord are ...
Myelin sheaths are formed by oligodendrocytes in the CNS that wrap around segments of axons to increase their firing speed. ... Myelin is formed in the early stages of development and progresses in waves, with brain areas of later phylogenetic development ... Myelin is known to bind many different axonal growth inhibitors that prevent plasticity seen in critical periods. The Nogo ... In all, myelin and its associated receptors bind several important axonal growth inhibitors which help close the critical ...
... which destroy the myelin sheath that protects axons Multiple sclerosis, which causes inflammation, myelin damage, and lesions ...
Imaging studies reveal a widespread absence of the myelin sheaths of the neurons in the white matter of the brain and general ...
Puchtler, H; Waldrop, FS (Aug 1979). "On the mechanism of Verhoeff's elastica stain: a convenient stain for myelin sheaths". ...
... with synthetic analogs of the molecules in the myelin sheath of the brain which are capable of provoking the disease. He is ...
... and/or the integrity of the myelin sheath. Threshold tracking allows for the strength of a test stimulus to be adjusted by a ...
The posterolateral tract consists of fine fibers which do not receive their myelin sheaths until toward the close of fetal life ...
Conversely, grain alcohol acts locally and degrades the myelin sheaths of the nerves so that the horse cannot move its tail. ...
Inflammation of the optic nerve causes loss of vision most usually by the swelling and destruction of the myelin sheath ...
... parietal bones parietal cell parietal lobe parotid bed parotid duct parotid gland parturition parotid papilla parotid sheath ... spindle muscle tissue muscles of the thorax muscular atrophy muscular system muscular triangle mydriasis myelencephalon myelin ... system carina carotid carotid bifurcation carotid body carotid canal carotid groove carotid plexus carotid sheath carotid sinus ... rectus abdominis muscle rectus capitis anterior muscle rectus capitis lateralis muscle rectus femoris muscle rectus sheath ...
A peripheral nerve fiber contains an axon (Or long dendrite), myelin sheath (if existence), their schwann cells, and the ... It involves loss of the relative continuity of the axon and its covering of myelin, but preservation of the connective tissue ...
... called the myelin sheath. And this sheath is often compared to the insulation on an electrical wire. When that covering is ... The body can repair damage to the myelin sheath, but its not perfect. The resulting damage leaves lesions or scars, and this ... Myelin damage and the nervous system. Myelin damage and the nervous system. In multiple sclerosis, the protective coating on ... In MS, the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems ...
Definition of Myelin sheath at Free-Translator.com ... "Myelin sheath" : case, axolemma, medullated nerve fiber, sheath ... A layer of myelin encasing (and insulating) the axons of medullated nerve fibers. Synonym: medullary sheath. ... oligodendria, medulla, myelin, myelinated nerve fiber, nodes of Ranvier, oligodendroglia, Ranviers nodes, myeline ...
The myelin sheath forms by the spiral wrapping of a glial membrane around the axon. The mechanisms responsible for this process ... The reduction in myelin formation was corroborated by significantly decreased amounts of myelin proteins (MBP, P0, and myelin- ... cultures were fixed and stained for myelin basic protein (MBP) to identify compact myelin sheaths. ... Myosin II has distinct functions in PNS and CNS myelin sheath formation Haibo Wang, Haibo Wang ...
Myelin is the electrically-insulating phospholipid sheath that surrounds the axons of many neurons and enables impulses to hop ... Myelin Sheaths of Neurons Myelin is the electrically-insulating phospholipid sheath that surrounds the axons of many neurons ...
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While investigating healthcare options, many people will have noticed that there is a great variety of health insurance options. Dickerson was arrested for public intoxication and possession of drug paraphernalia, according to WAAY. Use of social media is not only expanding among medical professionals but patients as well. According to the National Research Corp. survey one in five Americans utilize social media (Facebook, YouTube, Twitter, MySpace and FourSquare) as a source of healthcare information. "This could help reduce Medicare costs by identifying poorly performing devices more quickly, which could also protect beneficiaries from unnecessary costs and improve their chances of receiving appropriate follow-up care more quickly," the report said. sciencefile You dont need us to tell you that living through an unprecedented time period is stressful, confusing and exhausting. What you may need is a gentle reminder that fitting into last years jeans doesnt need to be a priority right now; ...
Tag Archives: myelin sheath FAT and CHOLESTROL -FACTS and MYTHS.. Posted on August 4, 2022 by sctri48 ... myelin sheath, Nuts, oestrogen, Oily fishes, poly- unsaturated fats, Progesteron, saturated fat, Sunflower .Avocadoes, ...
The synthesizer allows you to play many bioresonant frequencies on conventional audio devices connected to a computer or built into a smartphone. It is accompanied by a database of bio frequencies developed by the famous scientists R. Rife, H. Clark, P. Schmidt, and some modern authors
Posts about myelin sheath repair written by Helen White ... myelin sheath repair Getting on (with) your nerves. January 10 ... some good sensations and the building blocks for creating myelin, we help to repair it and get so much closer to enjoying a " ...
When the myelin sheath thickens, it allows information to pass along the axon at a faster rate, improving recall and processing ... However, if you practice the task a number of times for a set period each day, you will increase the amount of myelin being ... The more you repeat any learning this sheath thickens stabilising the pathway and helping people to remember what they have ...
What impact does mold have on the myelin sheath? This article explores the possible links between mold and Multiple Sclerosis. ... The bodys nerves are protected by an insulating coating around the nerve cells called the myelin sheath. Myelin is a fatty ... Does Mold Impact The Myelin Sheath?. Could Mold Be A Possible Cause Of Multiple Sclerosis?. Could Mold Be A Possible Cause Of ... The purpose of this article is to explore what impact mold can have on the myelin sheath, whose degeneration leads to Multiple ...
Multiple profiles within a single myelin sheath in the spinal trigeminal tract and subnucleus oralis of the rat. / Sugimoto, T ... Sugimoto T, Sakai A, Shigenaga Y. Multiple profiles within a single myelin sheath in the spinal trigeminal tract and subnucleus ... Sugimoto, T, Sakai, A & Shigenaga, Y 1978, Multiple profiles within a single myelin sheath in the spinal trigeminal tract and ... Sugimoto, T. ; Sakai, A. ; Shigenaga, Y. / Multiple profiles within a single myelin sheath in the spinal trigeminal tract and ...
Naturally Protect Myelin Sheath to Support Your Aging Brain. Posted by Daily Health Alerts in Diet & Fitness, Free Reports, ... Naturally protect the myelin sheath to support your aging brain with these tips to get you going. Stay on top of your health ... Learn some ways to naturally protect myelin sheath to support your aging brain and you just may be able to get ahead of the ... Over time, as a result of trauma or being afflicted with a particular disease, this myelin sheath can deteriorate and result in ...
Myelin Sheaths. w/ The Shrapnelles, TimeCopz & Student Teacher. November 18, 2010. Gobble Gobble. w/ Watermelon & JDH ...
Some may limit harm to the myelin sheath. Others stop the blood cells in lymph nodes from moving to the brain and spine. These ...
nowiki,neurona; Taugafruma; Neuron; neuron; newron; Неврон; Neuron; عصبون; Nerônina; neurón; Neuròna; Neurono; Nervenzelle; 신경 세포; Жүйке жасушалары; neŭrono; неврон; Neiron; Neurona; স্নায়ুকোষ; neurone; Sèl Saraf; Neuron; נייראן; चेतापेशी; nơron; ნეირონი; neuron; неурон; Neuron; neurônio; Нейрон; nervecelle; nevron; Sél saraf; دەمارەخانە; neuron; عصبون; Neuron; Neurona; нэўрон; 神經元; idegsejt; ચેતાપેશી; Neuron; Нейрон; نيورون; Neurona; نورون; Nervenzelle; Nervenzelle; Niwron; Нейрон; նեյրոն; 神經元; neuron; ნეირონი; 神経細胞; nervcell; Sinir hücresi; خليه عصبيه; Nevron; תא עצב; Neuronum; Neuron; न्यूरॉन; 神经元; Neuroni; neuron; neuron; Sel saraf; நரம்பணு; neurone; Cillín néarach; нейрон; Newòn; Neuron; نیوران; ਨਰਵ ...
Our goal was to determine if myelin water imaging a … ... Myelin water imaging (MWI) promises to be invaluable in ... Myelin Sheath / chemistry * Myelin Sheath / pathology* * Tissue Embedding * Tissue Fixation * Water / chemistry* ... Myelin water imaging of multiple sclerosis at 7 T: correlations with histopathology Neuroimage. 2008 May 1;40(4):1575-80. doi: ... Myelin water imaging (MWI) promises to be invaluable in understanding neurological diseases like MS. However, a limitation of ...
Damage to the myelin sheath (eg, by injury or Guillain-Barré syndrome) can often be repaired by surviving Schwann cells in ... The myelin sheath enhances impulse conduction. The largest and most heavily myelinated fibers conduct quickly; they convey ... Damage to the myelin sheath (demyelination) slows nerve conduction. Demyelination affects mainly heavily myelinated fibers, ... Disorders can result from damage to or dysfunction of the cell body, myelin sheath, axons, muscle or neuromuscular junction. ...
MS is caused by damage to the myelin sheath. This sheath is the protective covering that surrounds nerve cells. When this nerve ...
Home All issues 2020, Vol 10 Issue 1 Bio-capacitor consist of insulated myelin-sheath and uninsulated node of Ranvier: a bio- ... Bio-capacitor consist of insulated myelin-sheath and uninsulated node of Ranvier: a bio-nano-antenna. Majid Monajjemi 1, ... Bio-capacitor consist of insulated myelin-sheath and uninsulated node of Ranvier: a bio-nano-antenna ... Bio-capacitor consist of insulated myelin-sheath and uninsulated node of Ranvier: a bio-nano-antenna ...
JBI Evidence Implementation as the myelin sheath to the action potential of implementation science. Lockwood, Craig; Khalil, ...
Myelin Sheaths. Myrrh. Mystery Girls. Mystic Tide. Mystick Crewe of Clearlight. Mystick Krewe of Clearlight. Myty Konkeror. N.i ...
Destruction of the myelin sheath. Spina bifida. Congenital abnormality of spinal column. ...
It is important in maintaining the myelin sheath of nerve cells.[16] A deficiency may not be manifested for several years, ...
Each nerve has insulation (a myelin sheath) and a power station called a Neuron. At one end the filaments, dendrites, connect ...
myelin sheath. Fatty, white covering over the axon of a nerve cell. ... Glial (neuroglial) cell that forms the myelin sheath covering the axon of a neuron. ...
Defective structure and function of myelin sheaths. Dysmyelination is distinguished from demyleination where there is ...
Pigment-producing stem cells can regenerate myelin sheath: Mouse study. Skin-related stem cells may be key to helping restore ... the myelin sheath in patients with multiple sclerosis. Using mouse models, researchers discovered melanocyte stem cells can, ... under the right conditions, function as cells that create myelin.. Read More ...
  • A layer of myelin encasing (and insulating) the axons of medullated nerve fibers. (free-translator.com)
  • Myelin is a highly specialized membrane that wraps around axons in the peripheral (PNS) and central (CNS) nervous systems. (rupress.org)
  • Myelin is the electrically-insulating phospholipid sheath that surrounds the axons of many neurons and enables impulses to hop or "propagate by saltation. (alexanderandturner.com)
  • Myelin consists of fatty molecules (lipids) which are located in the CNC (central nervous system) and as an insulator around nerve cell axons increases the velocities information to transit from one nerve cell to another tissue like an electrical wire (the axon) with insulating material (myelin) around it. (biointerfaceresearch.com)
  • Myelin is the sheath that surrounds the neurons' axons. (webpronews.com)
  • Nerves are made up of axons (nerve fibers) surrounded by a myelin sheath. (medicalnewstoday.com)
  • An insulating sheath spirally wrapped around the axons increases the speed of the electrical impulses enormously. (mpg.de)
  • In most axons, the myelin sheath is interrupted at intervals of about 1 millimeter or more. (studyinnovations.com)
  • The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM . (bvsalud.org)
  • The multilayered myelin sheath wrapping around nerve axons is essential for proper functioning of the central nervous system. (duke.edu)
  • The present work demonstrated that loss of myelin in the central nervous system of the shiverer mouse results in a dramatic reduction of magnetic susceptibility in white matter axons. (duke.edu)
  • The myelin sheath forms by the spiral wrapping of a glial membrane around the axon. (rupress.org)
  • Although the function of myelin in facilitating the efficient and rapid propagation of nerve impulses by saltatory conduction has long been known, the basic mechanisms that drive the extension and wrapping of the glial membrane around the axon remain poorly understood. (rupress.org)
  • When the myelin sheath thickens, it allows information to pass along the axon at a faster rate, improving recall and processing speed. (globalbia.org)
  • Students will be able to label and draw a neuron and all of the parts of a neuron--the axon, dendrite, axon terminal, cell body, myelin sheath, and nucleus. (cdc.gov)
  • Each axon contains multiple long myelinated parts separated from each other through short gaps called "Nodes of Ranvier" or myelin-sheath gaps. (biointerfaceresearch.com)
  • So this covering, this insulation, at different intervals around the axon, this is called the myelin sheath. (khanacademy.org)
  • So there I was, partially destroyed, needing to regenerate nerve tissue, whether it is simply the myelin sheath covering the nerve, or the axon cable inside the sheath, or the entire end of the nerve depending on the area. (movnat.com)
  • This electron micrograph is a cross section through a portion of an axon and its associated myelin wrap from the cochlear nerve of the cat. (ucsd.edu)
  • Your brain uses fat to make cell membranes and the protective myelin sheath that insulates your neurons. (allabouthabits.com)
  • Evidence suggests alterations in synaptology, neurons, myelin sheaths, glial cells, and morphology of cerebrum and cerebellum in severe iodine deficiency. (who.int)
  • MS occurs when the immune system attacks myelin, leaving scars or lesions in the demyelinated areas of the brain and spinal cord. (medicalnewstoday.com)
  • 30, 2012) - Researchers studying Multiple Sclerosis (MS) have long been looking for the specific molecules in the body that cause lesions in myelin, the fatty, insulating cells that sheathe the nerves. (blogspot.com)
  • A thinner myelin sheath and decreased postsynaptic density length were also observed. (medsci.org)
  • However, if you practice the task a number of times for a set period each day, you will increase the amount of myelin being added, and the brain will purpose that pathway for the task increasing competency and creating a habit or unconscious competence in achieving a job or action. (globalbia.org)
  • The net amount of myelin may peak somewhere around the age of 50, but it always continues to function and enhance our neural pathways, so we can keep learning and developing skills, no matter our age. (rdellatraining.com)
  • Multiple sclerosis is a disorder in which the body's immune system attacks the protective covering of the nerve cells in the brain, optic nerve and spinal cord, called the myelin sheath. (mayoclinic.org)
  • The affected spinal cord had regional rarefaction of both gray and white matter and marked variation in myelin sheath size. (cdc.gov)
  • The body's nerves are protected by an insulating coating around the nerve cells called the myelin sheath . (valormold.com)
  • Myelin is a fatty substance that insulates the nerves, helping them send electrical signals that control movement, speech, and other functions. (valormold.com)
  • When the myelin sheath is damaged, nerves do not conduct electrical impulses normally. (msdmanuals.com)
  • Damage to myelin disrupts the ability of nerves to transmit information to nerve cells, resulting in neurological disability. (medicalnewstoday.com)
  • Without inflammation there is no Multiple Sclerosis (MS), the inflammation of the myelin sheath that covers nerves, and no Crohn's disease either, inflammation in the gut. (healthfully.net)
  • PLP [proteolipid protein] and MBP [myelin basic protein] levels were highest in the group that exercised and consumed a high-fat diet. (dailyhealthalerts.com)
  • The Kallikrein 6 neutralizing antibody had reduced inflammatory white blood cells and slowed the depletion of myelin basic protein, a key component of the myelin sheath. (blogspot.com)
  • Multiple sclerosis is a chronic disease in which the immune system attacks myelin. (webpronews.com)
  • In MS, the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems between your brain and the rest of your body. (tsijournals.com)
  • These RNA transcripts hinted at disruptions in the expression of genes related to neurodegenerative disease, including dysregulation of a class of brain cells responsible for producing the myelin sheath critical for proper neuronal communication. (tritonsindustries.com)
  • The quality and detail of 7 T myelin water maps were far superior to that previously seen at 1.5 T, allowing for visualization of fine structures such as the normal prominent myelination of the deeper cortical layers, the alveus of the hippocampus and rings of preserved myelin in a concentric Balo's lesion. (nih.gov)
  • The sheath is formed by the cell membranes of glial cells ( SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). (bvsalud.org)
  • This leads to production of abnormal fatty acids and elevated levels of Methylmalonic acid, which are toxic to myelin. (ispub.com)
  • They are caused by genetic defects that affect growth or formation of the myelin sheath, which is soft, white, fatty material that acts as insulation surrounding nerve fibers. (chop.edu)
  • Oligodendrocyte precursor cells (OPCs) are the major cells that help produce myelin. (dailyhealthalerts.com)
  • New myelin can be formed only when undifferentiated oligodendrocyte precursor cells (OPCs) are transplanted. (mpg.de)
  • You have a naturally protective covering around your nerve cells called myelin. (dailyhealthalerts.com)
  • This sheath is the protective covering that surrounds nerve cells. (medlineplus.gov)
  • And then these little spaces between the myelin sheath-- just so we have all of the terminology from-- so we know the entire anatomy of the neuron-- these are called the nodes of Ranvier. (khanacademy.org)
  • The insulating sheath consists of a lipid-rich membrane called myelin and is formed by so-called oligodendrocytes. (mpg.de)
  • And this sheath is often compared to the insulation on an electrical wire. (mayoclinic.org)
  • Much like the insulation around an electrical wire, the myelin sheath enables nerve signals (electrical impulses) to be conducted along the nerve fiber with speed and accuracy. (msdmanuals.com)
  • Myelin is the sheath (or insulation) around the nerve cells in our nervous system. (rdellatraining.com)
  • According to a paper posted by the Mayo Clinic, "High-fat diet alone or in combination with exercise has the greatest effect on myelin-related protein expression. (dailyhealthalerts.com)
  • they are caused by a point mutation in the myelin P0 protein ( MPZ ) gene (chromosome band 1q22). (medscape.com)
  • Myelin water imaging (MWI) promises to be invaluable in understanding neurological diseases like MS. However, a limitation of MWI is signal to noise ratio. (nih.gov)
  • And, as we make more myelin, the neurological signals travel faster. (rdellatraining.com)
  • We have found that inhibition of myosin II, a key regulator of actin cytoskeleton dynamics, has remarkably opposite effects on myelin formation by Schwann cells (SC) and oligodendrocytes (OL). (rupress.org)
  • During their development and differentiation into myelin-forming cells, oligodendrocytes (OL) in the CNS and Schwann cells (SC) in the PNS undergo striking morphological changes that involve the active remodeling of their cytoskeleton. (rupress.org)
  • So these are called Schwann cells and they're covering-- they make up the myelin sheath. (khanacademy.org)
  • So Schwann cells make up the myelin sheath. (khanacademy.org)
  • La vaina está constituida por las membranas celulares de células gliales (CÉLULAS DE SCHWANN en los nervios periféricos y OLIGODENDROGLÍA en el sistema nervioso central). (bvsalud.org)
  • The purpose of this article is to explore what impact mold can have on the myelin sheath, whose degeneration leads to Multiple Sclerosis (MS). (valormold.com)
  • MS is caused by the degeneration of the myelin sheath. (valormold.com)
  • It involves accumulation of sulfatides in the nervous system, leading to progressive degeneration of myelin sheaths. (cdc.gov)
  • Scientists worldwide are exploring various cell-based strategies to regenerate the myelin sheath. (mpg.de)
  • Elite level athletes become elite through the habits of practice and now the science of myelin growth supports the benefits of practice for skill development. (rdellatraining.com)
  • While the science and research is still in the early stages, there definitely appears to be strong links to myelin growth and peak performance . (rdellatraining.com)
  • The cochlea are now developed, though the myelin sheaths in the neural portion of the auditory system will continue to develop until 18 months after birth. (wikidoc.org)
  • Over time, as a result of trauma or being afflicted with a particular disease, this myelin sheath can deteriorate and result in misfired nerve signals. (dailyhealthalerts.com)
  • Myelin is tremendously important for the correct and rapid transmission of electrical signals in the brain. (mpg.de)
  • The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. (bvsalud.org)
  • Recently, a number of investigators have performed MWI at field strengths higher than 1.5 T. Our goal was to determine if myelin water imaging at increased SNR, arising from the use of a small bore 7 T MR system with optimized coil geometry, enables the production of superior myelin water maps with increased spatial detail and enables better correlations with histology. (nih.gov)
  • If the myelin sheath is damaged, as is the case in demyelinating diseases, electrical conduction is lost. (mpg.de)
  • Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem. (bvsalud.org)
  • As an autosomal recessive mutation, shiverer is characterized by an almost total lack of central nervous system myelin. (duke.edu)
  • Without this, it is believed that over the years the myelin degenerates and may lead to cognitive compromise. (dailyhealthalerts.com)
  • We first provide an overview of white matter development and discuss the role of white matter and myelin in cognitive function. (umn.edu)
  • The body can repair damage to the myelin sheath, but it's not perfect. (mayoclinic.org)
  • Can You Repair Myelin Sheath With Diet? (mylifescoop.net)
  • By Herbalist Alan Tillotson……Protocol for using Planetary Formula's CNS Myelin Sheath Repair…(for 130-160 pound person)…1. (planetherbs.com)
  • You don't often come across a high fat diet recommendation but if you are in a high risk category, over age 65 or have a family history of dementia, then getting more good, natural fats could help support myelin production and brain function. (dailyhealthalerts.com)
  • Multiple profiles within a single myelin sheath in the spinal trigeminal tract and subnucleus oralis of the rat. (elsevier.com)
  • A nerve is an organ composed of multiple nerve fibers bound together by sheaths of connective tissue. (medscape.com)
  • Learn some ways to naturally protect myelin sheath to support your aging brain and you just may be able to get ahead of the curve and avoid this health compromise altogether. (dailyhealthalerts.com)
  • Naturally protect the myelin sheath to support your aging brain with these tips to get you going. (dailyhealthalerts.com)
  • Ten formalin-fixed MS brain samples underwent a 32-echo T(2) relaxation experiment which measured myelin water fraction (MWF) on a 7-T animal MRI scanner. (nih.gov)
  • Most nerve fibers inside and outside the brain are wrapped with many layers of tissue composed of a fat (lipoprotein) called myelin. (msdmanuals.com)
  • Coronal section of rat brain triple-labeled with fluoromyelin (green), DiI (red), and TO-PRO3 (blue) which stain for myelin, blood vessels, and cell bodies, respectively. (cellimagelibrary.org)
  • In contrast, OL branching, differentiation, and myelin formation are potentiated by inhibition of myosin II. (rupress.org)
  • The formation of the myelin sheath around a nerve fiber . (medicinenet.com)
  • Pyruvate carboxylase catalyzes the conversion of pyruvate into oxaloacetate, an important reaction in energy metabolism, neurotransmitter biosynthesis, and myelin sheath formation. (medicalhomeportal.org)
  • Non-invasive imaging of myelin content is of great clinical importance. (duke.edu)
  • It is referred to as an autoimmune disease because MS causes the body to attack the myelin sheath. (valormold.com)
  • It kills the insulating myelin sheath, resulting in progressive loss of the ability to control limbs. (futurism.com)
  • In other words, the more we practice a skill, a lift, or a movement pattern, the more myelin we make. (rdellatraining.com)
  • Our data provide new evidences indicating that myelin is the predominant source of susceptibility differences between deep gray and white matter observed in magnetic resonance imaging. (duke.edu)
  • I decided to use this data and also add a myelin sheath remedy and give this to Sara in her program. (rita-kara-robinson.com)
  • The sheath adjacent to the neurilemma is the endoneurium, which houses blood capillaries that feed nutrients and oxygen to the nerve. (medscape.com)
  • [ 16 ] It is important in maintaining the myelin sheath of nerve cells. (medscape.com)
  • Nursing Central , nursing.unboundmedicine.com/nursingcentral/view/Tabers-Dictionary/767168/0/myelin. (unboundmedicine.com)
  • Thus, by controlling the spatial and localized activation of actin polymerization, myosin II regulates SC polarization and OL branching, and by extension their ability to form myelin. (rupress.org)