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Yamazaki R, Ohno N. The Mouse Model of Internal Capsule Demyelination: A Novel Tool for Investigating Motor Functional Changes Caused by Demyelination and for Evaluating Drugs That Promote Remyelination. Acta Histochem Cytochem 2024; 57:1-5. [PMID: 38463203 PMCID: PMC10918433 DOI: 10.1267/ahc.24-00005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 01/23/2024] [Indexed: 03/12/2024] Open
Abstract
Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system, characterized by remyelination failure and axonal dysfunction. Remyelination by oligodendrocytes is critical for improvement of neurological deficits associated with demyelination. Rodent models of demyelination are frequently used to develop and evaluate therapies for MS. However, a suitable mouse model for assessing remyelination-associated recovery of motor functions is currently unavailable. In this review, we describe the development of the mouse model of internal capsule (IC) demyelination by focal injection of lysolecithin into brain and its application in the evaluation of drugs for demyelinating diseases. This mouse model exhibits motor deficits and subsequent functional recovery accompanying IC remyelination. Notably, this model shows enhancement of functional recovery as well as tissue regeneration when treated with clemastine, a drug that promotes remyelination. The IC demyelination mouse model should contribute to the development of novel drugs that promote remyelination and ameliorate neurological deficits in demyelinating diseases.
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Affiliation(s)
- Reiji Yamazaki
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Nobuhiko Ohno
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
- Division of Ultrastructural Research, National Institute for Physiological Sciences, Okazaki, Japan
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Shulman Y, Finkelstein L, Levi Y, Kovalchuk D, Weksler A, Reichstein A, Kigel-Tsur K, Davidi M, Levi I, Schauder A, Rubin K, Achituv E, Castel D, Meilin S. A Novel Sensory Wave (P25) in Myelin Oligodendrocyte Glycoprotein-induced Experimental Autoimmune Encephalomyelitis Murine Model. J Pain 2024; 25:73-87. [PMID: 37524220 DOI: 10.1016/j.jpain.2023.07.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 07/09/2023] [Accepted: 07/25/2023] [Indexed: 08/02/2023]
Abstract
Myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) is a murine model for multiple sclerosis. This model is characterized by chronic and progressive demyelination, leading to impairment of motor function and paralysis. While the outcomes of the disease, including impaired motor function and immunological changes, are well-characterized, little is known about the impact of EAE on the electrophysiology of the motor and sensory systems. In this study, we assessed evoked potentials as a quantitative marker for in vivo monitoring of nervous system damage. Motor-evoked potentials (MEPs) and sensory-evoked potentials (SEPs) were first standardized in naïve C57BL mice and studied thoroughly in EAE mice. The duration of MEPs and the number of connotative potentials increased significantly alongside an increase in temporal SEP amplitudes. Moreover, a new SEP wave was identified in naïve animals, which significantly increased in MOG-induced EAE animals with no or mild symptoms (clinical score 0-2, 0-5 scale). This wave occurred ∼25 milliseconds poststimulation, thus named p25. P25 was correlated with increased vocalization and was also reduced in amplitude following treatment with morphine. As the EAE score progressed (clinical score 3-4, 0-5 scale), the amplitude of MEPs and SEPs decreased drastically. Our results demonstrate that desynchronized neural motor activity, along with hypersensitivity in the early stages of EAE, leads to a complete loss of motor and sensory functions in the late stages of the disease. The findings also suggest an increase in p25 amplitude before motor deficits appear, indicating SEP as a predictive marker for disease progression. PERSPECTIVE: This article assesses p25, a new sensory electrophysiology wave that correlates with pain-related behavior in MOG-induced EAE mice and appears prior to the clinical symptoms. Motor electrophysiology correlates with traditional motor behavior scoring and histology.
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Affiliation(s)
- Yoav Shulman
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | - Lena Finkelstein
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | - Yakir Levi
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | | | - Ayelet Weksler
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | | | - Keren Kigel-Tsur
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | - Mazal Davidi
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | - Isaac Levi
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | - Avital Schauder
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | - Keren Rubin
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | - Elhanan Achituv
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
| | - David Castel
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel; The Neufeld Cardiac Research Institute and Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Sigal Meilin
- Neurology Division, MD Biosciences Innovalora, Ltd, Rehovot, Israel
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Yamazaki R, Osanai Y, Kouki T, Huang JK, Ohno N. Pharmacological treatment promoting remyelination enhances motor function after internal capsule demyelination in mice. Neurochem Int 2023; 164:105505. [PMID: 36754122 DOI: 10.1016/j.neuint.2023.105505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/17/2023] [Accepted: 02/04/2023] [Indexed: 02/09/2023]
Abstract
Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system characterized by remyelination failure, axonal degeneration, and progressive worsening of motor functions. Animal models of demyelination are frequently used to develop and evaluate therapies for MS. We recently reported that focal internal capsule (IC) demyelination in mice with lysophosphatidylcholine injection induced acute motor deficits followed by recovery through remyelination. However, it remains unknown whether the IC demyelination mouse model can be used to evaluate changes in motor functions caused by pharmacological treatments that promote remyelination using behavioral testing and histological analysis. In this study, we examined the effect of clemastine, an anti-muscarinic drug that promotes remyelination, in the mouse IC demyelination model. Clemastine administration improved motor function and changed forepaw preference in the IC demyelinated mice. Moreover, clemastine-treated mice showed increased mature oligodendrocyte density, reduced axonal injury, an increased number of myelinated axons and thicker myelin in the IC lesions compared with control (PBS-treated) mice. These results suggest that the lysophosphatidylcholine-induced IC demyelination model is useful for evaluating changes in motor functions following pharmacological treatments that promote remyelination.
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Reeves JA, Bergsland N, Dwyer MG, Wilding GE, Jakimovski D, Salman F, Sule B, Meineke N, Weinstock-Guttman B, Zivadinov R, Schweser F. Susceptibility networks reveal independent patterns of brain iron abnormalities in multiple sclerosis. Neuroimage 2022; 261:119503. [PMID: 35878723 PMCID: PMC10097440 DOI: 10.1016/j.neuroimage.2022.119503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/06/2022] [Accepted: 07/21/2022] [Indexed: 11/24/2022] Open
Abstract
Brain iron homeostasis is necessary for healthy brain function. MRI and histological studies have shown altered brain iron levels in the brains of patients with multiple sclerosis (MS), particularly in the deep gray matter (DGM). Previous studies were able to only partially separate iron-modifying effects because of incomplete knowledge of iron-modifying processes and influencing factors. It is therefore unclear to what extent and at which stages of the disease different processes contribute to brain iron changes. We postulate that spatially covarying magnetic susceptibility networks determined with Independent Component Analysis (ICA) reflect, and allow for the study of, independent processes regulating iron levels. We applied ICA to quantitative susceptibility maps for 170 individuals aged 9-81 years without neurological disease ("Healthy Aging" (HA) cohort), and for a cohort of 120 patients with MS and 120 age- and sex-matched healthy controls (HC; together the "MS/HC" cohort). Two DGM-associated "susceptibility networks" identified in the HA cohort (the Dorsal Striatum and Globus Pallidus Interna Networks) were highly internally reproducible (i.e. "robust") across multiple ICA repetitions on cohort subsets. DGM areas overlapping both robust networks had higher susceptibility levels than DGM areas overlapping only a single robust network, suggesting that these networks were caused by independent processes of increasing iron concentration. Because MS is thought to accelerate brain aging, we hypothesized that associations between age and the two robust DGM-associated networks would be enhanced in patients with MS. However, only one of these networks was altered in patients with MS, and it had a null age association in patients with MS rather than a stronger association. Further analysis of the MS/HC cohort revealed three additional disease-related networks (the Pulvinar, Mesencephalon, and Caudate Networks) that were differentially altered between patients with MS and HCs and between MS subtypes. Exploratory regression analyses of the disease-related networks revealed differential associations with disease duration and T2 lesion volume. Finally, analysis of ROI-based disease effects in the MS/HC cohort revealed an effect of disease status only in the putamen ROI and exploratory regression analysis did not show associations between the caudate and pulvinar ROIs and disease duration or T2 lesion volume, showing the ICA-based approach was more sensitive to disease effects. These results suggest that the ICA network framework increases sensitivity for studying patterns of brain iron change, opening a new avenue for understanding brain iron physiology under normal and disease conditions.
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Affiliation(s)
- Jack A Reeves
- Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Niels Bergsland
- Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA; MR Research Laboratory, IRCCS, Don Gnocchi Foundation ONLUS, Milan, Italy
| | - Michael G Dwyer
- Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; Center for Biomedical Imaging, Clinical and Translational Science Institute, Clinical and Translational Research Center, State University of New York at Buffalo, 6045C, 875 Ellicott Street, Buffalo, NY 14203, USA; Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Gregory E Wilding
- Department of Biostatistics, School of Public Health and Health Professions, State University of New York at Buffalo, Buffalo, NY, USA
| | - Dejan Jakimovski
- Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Fahad Salman
- Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Balint Sule
- Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Nicklas Meineke
- Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Bianca Weinstock-Guttman
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA; Jacobs Neurological Institute, Buffalo, NY, USA
| | - Robert Zivadinov
- Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; Center for Biomedical Imaging, Clinical and Translational Science Institute, Clinical and Translational Research Center, State University of New York at Buffalo, 6045C, 875 Ellicott Street, Buffalo, NY 14203, USA; Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Ferdinand Schweser
- Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; Center for Biomedical Imaging, Clinical and Translational Science Institute, Clinical and Translational Research Center, State University of New York at Buffalo, 6045C, 875 Ellicott Street, Buffalo, NY 14203, USA; Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA.
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5
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Beger AW, Hauther KA, Dudzik B, Woltjer RL, Wood PL. Human Brain Lipidomics: Investigation of Formalin Fixed Brains. Front Mol Neurosci 2022; 15:835628. [PMID: 35782380 PMCID: PMC9245516 DOI: 10.3389/fnmol.2022.835628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
Human brain lipidomics have elucidated structural lipids and lipid signal transduction pathways in neurologic diseases. Such studies have traditionally sourced tissue exclusively from brain bank biorepositories, however, limited inventories signal that these facilities may not be able to keep pace with this growing research domain. Formalin fixed, whole body donors willed to academic institutions offer a potential supplemental tissue source, the lipid profiles of which have yet to be described. To determine the potential of these subjects in lipid analysis, the lipid levels of fresh and fixed frontal cortical gray matter of human donors were compared using high resolution electrospray ionization mass spectrometry. Results revealed commensurate levels of specific triacylglycerols, diacylglycerols, hexosyl ceramides, and hydroxy hexosyl ceramides. Baseline levels of these lipid families in human fixed tissue were identified via a broader survey study covering six brain regions: cerebellar gray matter, superior cerebellar peduncle, gray and subcortical white matter of the precentral gyrus, periventricular white matter, and internal capsule. Whole body donors may therefore serve as supplemental tissue sources for lipid analysis in a variety of clinical contexts, including Parkinson's disease, Alzheimer's disease, Lewy body dementia, multiple sclerosis, and Gaucher's disease.
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Affiliation(s)
- Aaron W. Beger
- Department of Anatomy, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, Harrogate, TN, United States
| | - Kathleen A. Hauther
- Metabolomics Unit, College of Veterinary Medicine, Lincoln Memorial University, Harrogate, TN, United States
| | - Beatrix Dudzik
- Department of Anatomy, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, Harrogate, TN, United States
| | - Randall L. Woltjer
- Department of Neurology, Oregon Health Science University, Portland, OR, United States
- Portland VA Medical Center, Portland, OR, United States
| | - Paul L. Wood
- Metabolomics Unit, College of Veterinary Medicine, Lincoln Memorial University, Harrogate, TN, United States
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6
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Ramasamy R, Hardy CC, Crocker SJ, Smith PP. Cuprizone-mediated demyelination reversibly degrades voiding behavior in mice while sparing brainstem reflex. J Neurosci Res 2022; 100:1707-1720. [PMID: 35596557 DOI: 10.1002/jnr.25065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/30/2022] [Accepted: 04/22/2022] [Indexed: 11/12/2022]
Abstract
Multiple sclerosis (MS) is a chronic, progressively debilitating demyelinating disease of the central nervous system (CNS). Nearly 80% of MS patients experience lower urinary tract dysfunction early in their diagnosis. This significantly affects the quality of life, and in latter stages of disease is a leading cause of hospitalization. Previously, animal models have shown that inflammatory demyelination in the CNS causes profound bladder dysfunction, but the confounding influence of systemic inflammation limits the potential interpretation of the contribution of CNS demyelination to bladder dysfunction. Since the micturition circuit has myelinated neuronal connections in the cortex, brainstem, and spinal cord, we examined alterations in bladder function in the cuprizone model characterized by demyelinating lesions in the cortex and corpus callosum that are independent of T-cell-mediated autoimmunity. Herein, we report that a 4-week dietary cuprizone treatment in C57Bl/6J mice induced alterations in voiding behavior with increased micturition frequency and reduced volume voided, similar to human MS bladder dysfunction. Subsequently, recovery from cuprizone treatment restored normal bladder function. Demyelination and remyelination were confirmed by Luxol Fast Blue staining of the corpus callosum. Additionally, we also determined that an 8-week cuprizone treatment, resulting in chronic demyelination lacking spontaneous remyelination potential, is associated with an exacerbated voiding phenotype. Interestingly, while cuprizone-induced CNS demyelination severely affected conscious (cortical) urinary behavior, the brainstem and spinal cord reflex remained unchanged, as confirmed by urethane-anesthetized cystometry. This is the first study to show that cortical demyelination independent of inflammation can negatively impact urinary function.
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Affiliation(s)
- Ramalakshmi Ramasamy
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, Connecticut, USA.,UConn Center on Aging, University of Connecticut School of Medicine, Farmington, Connecticut, USA
| | - Cara C Hardy
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, Connecticut, USA.,UConn Center on Aging, University of Connecticut School of Medicine, Farmington, Connecticut, USA
| | - Stephen J Crocker
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, Connecticut, USA.,UConn Center on Aging, University of Connecticut School of Medicine, Farmington, Connecticut, USA
| | - Phillip P Smith
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, Connecticut, USA.,UConn Center on Aging, University of Connecticut School of Medicine, Farmington, Connecticut, USA.,Department of Surgery, University of Connecticut School of Medicine, Farmington, Connecticut, USA
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7
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Vega-Riquer JM, Campos-Ordonez T, Galvez-Contreras AY, Gonzalez-Castañeda RE, Gonzalez-Perez O. Phenytoin promotes the proliferation of oligodendrocytes and enhances the expression of myelin basic protein in the corpus callosum of mice demyelinated by cuprizone. Exp Brain Res 2022. [PMID: 35362723 DOI: 10.1007/s00221-022-06356-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 03/21/2022] [Indexed: 11/04/2022]
Abstract
Oligodendrocyte loss and myelin sheet destruction are crucial characteristics of demyelinating diseases. Phenytoin promotes the proliferation of endogenous neural precursor cells in the ventricular-subventricular zone in the postnatal brain that help restore the oligodendroglial population. This study aimed to evaluate whether phenytoin promotes myelin recovery of the corpus callosum of demyelinated adult mice. CD1 male mice were exposed to a demyelinating agent (0.2% cuprizone) for 8 weeks. We assembled two groups: the phenytoin-treated group and the control-vehicle group. The treated group received oral phenytoin (10 mg/kg) for 4 weeks. We quantified the number of Olig2 + and NG2 + oligodendrocyte precursor cells (OPCs), Rip + oligodendrocytes, the expression level of myelin basic protein (MBP), and the muscle strength and motor coordination. The oligodendroglial lineage (Olig2 + cells, NG2 + cells, and RIP + cells) significantly increases by the phenytoin administration when compared to the control-vehicle group. The phenytoin-treated group also showed an increased expression of MBP in the corpus callosum and better functional scores in the horizontal bar test. These findings suggest that phenytoin stimulates the proliferation of OPCs, re-establishes the oligodendroglial population, promotes myelin recovery in the corpus callosum, and improves motor coordination and muscle strength.
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8
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Yamazaki R, Ohno N, Huang JK. Acute motor deficit and subsequent remyelination-associated recovery following internal capsule demyelination in mice. J Neurochem 2020; 156:917-928. [PMID: 32750162 PMCID: PMC8048697 DOI: 10.1111/jnc.15142] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 07/22/2020] [Accepted: 07/27/2020] [Indexed: 12/20/2022]
Abstract
Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system (CNS), characterized by accumulated motor disability. However, whether remyelination promotes motor recovery following demyelinating injury remains unclear. Damage to the internal capsule (IC) is known to result in motor impairment in multiple sclerosis and stroke. Here, we induced focal IC demyelination in mice by lysophosphatidylcholine (LPC) injection, and examined its effect on motor behavior. We also compared the effect of LPC-induced IC damage to that produced by endothelin-1 (ET1), a potent vasoconstrictor used in experimental stroke lesions. We found that LPC or ET1 injections induced asymmetric motor deficit at 7 days post-lesion (dpl), and that both lesion types displayed increased microglia/macrophage density, myelin loss, and axonal dystrophy. The motor deficit and lesion pathology remained in ET1-injected mice at 28 dpl. In contrast, LPC-injected mice regained motor function by 28 dpl, with corresponding reduction in activated microglia/macrophage density, and recovery of myelin staining and axonal integrity in lesions. These results suggest that LPC-induced IC demyelination results in acute motor deficit and subsequent recovery through remyelination, and may be used to complement future drug screens to identify drugs for promoting remyelination.
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Affiliation(s)
- Reiji Yamazaki
- Department of Biology and Center for Cell Reprogramming, Georgetown University, Washington, DC, USA.,Division of Histology and Cell Biology, Department of Anatomy, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Nobuhiko Ohno
- Division of Histology and Cell Biology, Department of Anatomy, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Jeffrey K Huang
- Department of Biology and Center for Cell Reprogramming, Georgetown University, Washington, DC, USA
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McGregor M, Richer K, Ananth M, Thanos PK. The functional networks of a novel environment: Neural activity mapping in awake unrestrained rats using positron emission tomography. Brain Behav 2020; 10:e01646. [PMID: 32562468 PMCID: PMC7428510 DOI: 10.1002/brb3.1646] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 11/06/2022] Open
Abstract
INTRODUCTION Novel environment stimulation is thought to have an important role in cognitive development and has been shown to encourage exploratory behavior in rats. However, psychopathology or perceived danger or stress can impede this exploratory drive. The balance between brain circuits controlling the exploratory drive elicited by a novel environment, and the avoidance response to stressors, is not well understood. METHODS Using positron emission tomography (PET) and the glucose analog [18 F]fluorodeoxyglucose (18F-FDG), we assessed awake brain glucose metabolism (BGluM) in rats while in a novel environment (cage of an unfamiliar male rat) and non-novel environment (the animal's home cage). RESULTS Exposure to the novel environment increased BGluM in regions associated with vision (visual cortex), motor function and motivated behavior (striatum and motor cortex), and anxiety (stria terminalis), and decreased BGluM in regions associated with auditory processing (auditory cortex, insular cortex, inferior colliculus), locomotor activity (globus pallidus, striatum, motor cortex, ventral thalamic nucleus), spatial navigation (retrosplenial cortex), and working memory (hippocampus, cingulate cortex, prelimbic cortex, orbitofrontal cortex). CONCLUSION These results suggest that the novel cage is a stressful environment that inhibits activity in brain regions associated with exploratory behavior. Patterns of inhibition in the novel cage also support the proposed rat default mode network, indicating that animals are more cognitively engaged in this environment. Additionally, these data support the unique capability of combining FDG-PET with psychopharmacology experiments to examine novelty seeking and brain activation in the context of decision making, risk taking, and cognitive function more generally, along with response to environmental or stress challenges.
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Affiliation(s)
- Matthew McGregor
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Clinical Research Institute on Addictions, Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biosciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Kaleigh Richer
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Clinical Research Institute on Addictions, Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biosciences, State University of New York at Buffalo, Buffalo, NY, USA.,Department of Psychology, State University of New York at Buffalo, Buffalo, NY, USA
| | - Mala Ananth
- Department of Neurobiology, State University of New York at Stony Brook, Stony Brook, NY, USA
| | - Panayotis K Thanos
- Behavioral Neuropharmacology and Neuroimaging Laboratory on Addictions, Clinical Research Institute on Addictions, Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biosciences, State University of New York at Buffalo, Buffalo, NY, USA.,Department of Psychology, State University of New York at Buffalo, Buffalo, NY, USA
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10
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Adebiyi O, Adigun K, Folarin O, Olopade J, Olayemi F. Administration of ethanolic extract of Erythrophleum ivorense (A Chev.) stem bark to male Wistar rats alters brain areas involved in motor coordination, behavior, and memory. J Ethnopharmacol 2020; 253:112650. [PMID: 32035221 DOI: 10.1016/j.jep.2020.112650] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 01/08/2020] [Accepted: 02/02/2020] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Erythrophleum ivorense (A Chev.) is a common plant in the tropics. Its use as ordeal poison in folklore medicine is controversial. The incoordination and behavioral changes following consumption are often associated with guilt. This study is aimed at dispelling or upholding this belief by investigating the actions of E. ivorense on the brain and behavior using rat model. MATERIALS AND METHODS Sixty male Wistar rats were equally divided into five groups; control group received distilled water, test groups were administered 10, 20, 30 and 40 mg/kg ethanolic extract of E. ivorense in a daily oral dose for 28 days. Cognition (Morris water maze) depression (forced swim test), motor function (hanging wire and inverted wire mesh grid grip tests) and exploratory assessments were done. Brains were stained with H&E, Cresyl violet and immunohistochemistry was done using GFAP, anticalbindin-D28k, Iba-1 and MBP antibodies. RESULTS At all doses, E. ivorense significantly (P ≤ 0.05) increased escape latency in the Morris water maze compared to control. Forced swim test showed a dose-related increase in duration of immobility, significant reduction in hanging latency in hanging wire and wire mesh grid grip test was also observed. Depletion of Purkinje cells of the cerebellum and hippocampal neurons was observed with H&E and cresyl violet. Immuno-staining revealed astrocytic activation in the cerebellum, loss of dendritic spines, cortical microglial activation and demyelination in the cerebellum and dentate gyrus of the hippocampus. CONCLUSION The ethanolic extract of E. ivorense stem bark caused a dose-dependent deficit in learning, memory and motor coordination with evidences of depression in rats. It is concluded that the plant is neurotoxic and induce several neurobehavioral changes.
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Affiliation(s)
- Olamide Adebiyi
- Department of Veterinary Physiology and Biochemistry, University of Ibadan, Nigeria.
| | - Kabirat Adigun
- Department of Veterinary Physiology and Biochemistry, University of Ibadan, Nigeria
| | | | - James Olopade
- Department of Veterinary Anatomy, University of Ibadan, Nigeria
| | - Funsho Olayemi
- Department of Veterinary Physiology and Biochemistry, University of Ibadan, Nigeria
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11
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Swanberg KM, Landheer K, Pitt D, Juchem C. Quantifying the Metabolic Signature of Multiple Sclerosis by in vivo Proton Magnetic Resonance Spectroscopy: Current Challenges and Future Outlook in the Translation From Proton Signal to Diagnostic Biomarker. Front Neurol 2019; 10:1173. [PMID: 31803127 PMCID: PMC6876616 DOI: 10.3389/fneur.2019.01173] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/21/2019] [Indexed: 01/03/2023] Open
Abstract
Proton magnetic resonance spectroscopy (1H-MRS) offers a growing variety of methods for querying potential diagnostic biomarkers of multiple sclerosis in living central nervous system tissue. For the past three decades, 1H-MRS has enabled the acquisition of a rich dataset suggestive of numerous metabolic alterations in lesions, normal-appearing white matter, gray matter, and spinal cord of individuals with multiple sclerosis, but this body of information is not free of seeming internal contradiction. The use of 1H-MRS signals as diagnostic biomarkers depends on reproducible and generalizable sensitivity and specificity to disease state that can be confounded by a multitude of influences, including experiment group classification and demographics; acquisition sequence; spectral quality and quantifiability; the contribution of macromolecules and lipids to the spectroscopic baseline; spectral quantification pipeline; voxel tissue and lesion composition; T1 and T2 relaxation; B1 field characteristics; and other features of study design, spectral acquisition and processing, and metabolite quantification about which the experimenter may possess imperfect or incomplete information. The direct comparison of 1H-MRS data from individuals with and without multiple sclerosis poses a special challenge in this regard, as several lines of evidence suggest that experimental cohorts may differ significantly in some of these parameters. We review the existing findings of in vivo1H-MRS on central nervous system metabolic abnormalities in multiple sclerosis and its subtypes within the context of study design, spectral acquisition and processing, and metabolite quantification and offer an outlook on technical considerations, including the growing use of machine learning, by future investigations into diagnostic biomarkers of multiple sclerosis measurable by 1H-MRS.
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Affiliation(s)
- Kelley M Swanberg
- Department of Biomedical Engineering, Columbia University Fu Foundation School of Engineering and Applied Science, New York, NY, United States
| | - Karl Landheer
- Department of Biomedical Engineering, Columbia University Fu Foundation School of Engineering and Applied Science, New York, NY, United States
| | - David Pitt
- Department of Neurology, Yale University School of Medicine, New Haven, CT, United States
| | - Christoph Juchem
- Department of Biomedical Engineering, Columbia University Fu Foundation School of Engineering and Applied Science, New York, NY, United States.,Department of Radiology, Columbia University College of Physicians and Surgeons, New York, NY, United States
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12
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Hochstrasser T, Rühling S, Hecher K, Fabisch KH, Chrzanowski U, Brendel M, Eckenweber F, Sacher C, Schmitz C, Kipp M. Stereological Investigation of Regional Brain Volumes after Acute and Chronic Cuprizone-Induced Demyelination. Cells 2019; 8:E1024. [PMID: 31484353 DOI: 10.3390/cells8091024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/19/2019] [Accepted: 08/30/2019] [Indexed: 02/03/2023] Open
Abstract
Brain volume measurement is one of the most frequently used biomarkers to establish neuroprotective effects during pre-clinical multiple sclerosis (MS) studies. Furthermore, whole-brain atrophy estimates in MS correlate more robustly with clinical disability than traditional, lesion-based metrics. However, the underlying mechanisms leading to brain atrophy are poorly understood, partly due to the lack of appropriate animal models to study this aspect of the disease. The purpose of this study was to assess brain volumes and neuro-axonal degeneration after acute and chronic cuprizone-induced demyelination. C57BL/6 male mice were intoxicated with cuprizone for up to 12 weeks. Brain volume, as well as total numbers and densities of neurons, were determined using design-based stereology. After five weeks of cuprizone intoxication, despite severe demyelination, brain volumes were not altered at this time point. After 12 weeks of cuprizone intoxication, a significant volume reduction was found in the corpus callosum and diverse subcortical areas, particularly the internal capsule and the thalamus. Thalamic volume loss was accompanied by glucose hypermetabolism, analyzed by [18F]-fluoro-2-deoxy-d-glucose (18F-FDG) positron-emission tomography. This study demonstrates region-specific brain atrophy of different subcortical brain regions after chronic cuprizone-induced demyelination. The chronic cuprizone demyelination model in male mice is, thus, a useful tool to study the underlying mechanisms of subcortical brain atrophy and to investigate the effectiveness of therapeutic interventions.
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13
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Howell BR, Ahn M, Shi Y, Godfrey JR, Hu X, Zhu H, Styner M, Sanchez MM. Disentangling the effects of early caregiving experience and heritable factors on brain white matter development in rhesus monkeys. Neuroimage 2019; 197:625-642. [PMID: 30978495 DOI: 10.1016/j.neuroimage.2019.04.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 03/30/2019] [Accepted: 04/03/2019] [Indexed: 10/27/2022] Open
Abstract
Early social experiences, particularly maternal care, shape behavioral and physiological development in primates. Thus, it is not surprising that adverse caregiving, such as child maltreatment leads to a vast array of poor developmental outcomes, including increased risk for psychopathology across the lifespan. Studies of the underlying neurobiology of this risk have identified structural and functional alterations in cortico-limbic brain circuits that seem particularly sensitive to these early adverse experiences and are associated with anxiety and affective disorders. However, it is not understood how these neurobiological alterations unfold during development as it is very difficult to study these early phases in humans, where the effects of maltreatment experience cannot be disentangled from heritable traits. The current study examined the specific effects of experience ("nurture") versus heritable factors ("nature") on the development of brain white matter (WM) tracts with putative roles in socioemotional behavior in primates from birth through the juvenile period. For this we used a randomized crossfostering experimental design in a naturalistic rhesus monkey model of infant maltreatment, where infant monkeys were randomly assigned at birth to either a mother with a history of maltreating her infants, or a competent mother. Using a longitudinal diffusion tensor imaging (DTI) atlas-based tract-profile approach we identified widespread, but also specific, maturational changes on major brain tracts, as well as alterations in a measure of WM integrity (fractional anisotropy, FA) in the middle longitudinal fasciculus (MdLF) and the inferior longitudinal fasciculus (ILF), of maltreated animals, suggesting decreased structural integrity in these tracts due to early adverse experience. Exploratory voxelwise analyses confirmed the tract-based approach, finding additional effects of early adversity, biological mother, social dominance rank, and sex in other WM tracts. These results suggest tract-specific effects of postnatal maternal care experience versus heritable or biological factors on primate WM microstructural development. Further studies are needed to determine the specific behavioral outcomes and biological mechanisms associated with these alterations in WM integrity.
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Affiliation(s)
- Brittany R Howell
- Department of Psychiatry & Behavioral Sciences, Emory University, Atlanta, GA, USA; Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA; Institute of Child Development, University of Minnesota, Minneapolis, MN, USA.
| | - Mihye Ahn
- Department of Mathematics and Statistics, University of Nevada, Reno, NV, USA; Department of Biostatistics and Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, USA
| | - Yundi Shi
- Department. of Psychiatry and Computer Science, University of North Carolina, Chapel Hill, NC, USA
| | - Jodi R Godfrey
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | - Xiaoping Hu
- Biomedical Imaging Technology Center, Emory University and Georgia Institute of Technology, Atlanta, GA, USA
| | - Hongtu Zhu
- Department of Biostatistics and Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, USA
| | - Martin Styner
- Department. of Psychiatry and Computer Science, University of North Carolina, Chapel Hill, NC, USA
| | - Mar M Sanchez
- Department of Psychiatry & Behavioral Sciences, Emory University, Atlanta, GA, USA; Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
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Zhang X, Kiapour N, Kapoor S, Merrill JR, Xia Y, Ban W, Cohen SM, Midkiff BR, Jewells V, Shih YI, Markovic-Plese S. IL-11 antagonist suppresses Th17 cell-mediated neuroinflammation and demyelination in a mouse model of relapsing-remitting multiple sclerosis. Clin Immunol 2018; 197:45-53. [PMID: 30149119 DOI: 10.1016/j.clim.2018.08.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/12/2018] [Accepted: 08/15/2018] [Indexed: 12/19/2022]
Abstract
IL-11 induced differentiation and expansion of Th17 cells in patients with early relapsing-remitting multiple sclerosis (RRMS). In mice with relapsing-remitting experimental autoimmune encephalomyelitis (RREAE), IL-11 exacerbated disease, induced demyelination in the central nervous system (CNS), increased the percentage of IL-17A+CD4+ Th17 cells in the CNS in the early acute phase, and up-regulated serum IL-17A levels and the percentage of IL-17A+CD4+ Th17 cells in lymph nodes, and IFN-γ+CD4+ T cells in spinal cord in the RR phase. IL-11 antagonist suppressed RREAE disease activities, inhibited IL-17A+CD4+ cell infiltration and demyelination in the CNS, and decreased the percentage of IL-17A+CD4+ T cells in peripheral blood mononuclear cells and ICAM1+CD4+ T cells in brain and SC. Diffusion Tensor Imaging indicated that IL-11 antagonist inhibited demyelination in several brain regions. We conclude that by suppressing Th17 cell-mediated neuroinflammation and demyelination, IL-11 antagonist can be further studied as a potential selective and early therapy for RRMS.
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Chopra S, Shaw M, Shaw T, Sachdev PS, Anstey KJ, Cherbuin N. More highly myelinated white matter tracts are associated with faster processing speed in healthy adults. Neuroimage 2018; 171:332-340. [DOI: 10.1016/j.neuroimage.2017.12.069] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/18/2017] [Accepted: 12/21/2017] [Indexed: 01/23/2023] Open
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Traboulsee A, Dehmeshki J, Peters KR, Griffin CM, Brex PA, Silver N, Ciccarrelli O, Chard DT, Barker GJ, Thompson AJ, Miller DH. Disability in multiple sclerosis is related to normal appearing brain tissue MTR histogram abnormalities. Mult Scler 2016; 9:566-73. [PMID: 14664468 DOI: 10.1191/1352458503ms958oa] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Background: Magnetization transfer ratio (MTR) histogram analysis provides a global measure of disease burden in multiple sclerosis (MS). MTR abnormalities in normal appearing brain tissue (NABT) provide quantitative information on the extent of tissue damage undetected by conventional T2-weighted (T2W) magnetic resonance imaging (MRI). A ims: 1) To compare the MTR histograms from NABT across a broad spectrum of relapse onset MS patients, including relapsing-remitting (RR) MS (including newly diagnosed and benign subgroups) and secondary progressive (SP) MS. 2) To determine the relationship between clinical disability and NA BT MTR histograms. Methods: 2D spin echo magnetization transfer imaging was performed on 70 RRMS and 25 SPMS patients and compared with 63 controls. MTR histograms were acquired for NA BT after extracting lesions and cerebrospinal fluid (C SF). T2W images were used to measure the brain parenchymal fraction (BPF) and T2 lesion load. Results: MS patients had a disease duration ranging from 0.5 to 37 years and an Expanded Disability Status Scale (EDSS) score ranging from 0 to 8.5. There was a significant decrease in NA BT mean MTR (± standard deviation) compared with controls (33.07 pu± 1.06 versus 34.26 pu± 0.47; P < 0.001) with an effect size of 2.56. The reductio n in NA BT mean MTR varied among patient groups from 4.9% for SPMS, 3% for all RRMS, 2.7% for early RRMS and 2.5% for benign MS, compared with controls. NA BT mean MTR correlated significantly with T2 lesion load (r = -0.82) and BPF (r =0.58). EDSS score correlated with NA BT mean MTR (r = -0.43), BPF (r = -0.33) and with T2 lesion load (r =0.59). Multivariate analysis using NA BT MTR peak height, T2 lesion load and BPF combined only accounted for 38% of the variance in the EDSS (r =0.62; P <0.001). Disease duration accounted for an additional 14% of variance in the EDSS (r =0.72; P <0.001). Conclusions: There is evidence of diffuse abnormalities in NA BT in addition to global brain atrophy in relapse onset MS patients, including those with recently diagnosed RRMS and benign MS. The abnormalities are greatest in patients with the more disabling SPMS. A trophy, NA BT and lesion abnormalities are all partly correlated; the processes marked by these MR measures all contribute to disability in MS, providing complementary information relevant to the complex pathological processes that occur in MS.
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Affiliation(s)
- A Traboulsee
- NMR Research Unit, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.
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Burns T, Miers L, Xu J, Man A, Moreno M, Pleasure D, Bannerman P. Neuronopathy in the motor neocortex in a chronic model of multiple sclerosis. J Neuropathol Exp Neurol 2014; 73:335-44. [PMID: 24607968 DOI: 10.1097/nen.0000000000000058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We provide evidence of cortical neuronopathy in myelin oligodendrocyte glycoprotein peptide-induced experimental autoimmune encephalomyelitis, an established model of chronic multiple sclerosis. To investigate phenotypic perturbations in neurons in this model, we used apoptotic markers and immunohistochemistry with antibodies to NeuN and other surrogate markers known to be expressed by adult pyramidal Layer V somas, including annexin V, encephalopsin, and Emx1. We found no consistent evidence of chronic loss of Layer V neurons but detected both reversible and chronic decreases in the expression of these markers in conjunction with evidence of cortical demyelination and presynaptic loss. These phenotypic perturbations were present in, but not restricted to, the neocortical Layer V. We also investigated inflammatory responses in the cortex and subcortical white matter of the corpus callosum and spinal dorsal funiculus and found that those in the cortex and corpus callosum were delayed compared with those in the spinal cord. Inflammatory infiltrates initially included T cells, neutrophils, and Iba1-positive microglia/macrophages in the corpus callosum, whereas only Iba1-positive cells were present in the cortex. These data indicate that we have identified a new temporal pattern of subtle phenotypic perturbations in neocortical neurons in this chronic multiple sclerosis model.
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Affiliation(s)
- Travis Burns
- From the Department of Neurology, University of California Davis, Sacramento (TB, LM, JX, MM, DP); Department of Biomedical Engineering, University of California Davis, Davis (AM); Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Northern California, Sacramento (MM, DP, PB); and Department of Cell Biology and Human Anatomy, University of California Davis, Davis (PB), California
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Narayana PA, Herrera JJ, Bockhorst KH, Esparza-Coss E, Xia Y, Steinberg JL, Moeller FG. Chronic cocaine administration causes extensive white matter damage in brain: diffusion tensor imaging and immunohistochemistry studies. Psychiatry Res 2014; 221:220-30. [PMID: 24507117 PMCID: PMC3943678 DOI: 10.1016/j.pscychresns.2014.01.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 12/21/2013] [Accepted: 01/14/2014] [Indexed: 12/14/2022]
Abstract
The effect of chronic cocaine exposure on multiple white matter structures in rodent brain was examined using diffusion tensor imaging (DTI), locomotor behavior, and end point histology. The animals received either cocaine at a dose of 100mg/kg (N=19), or saline (N=17) for 28 days through an implanted osmotic minipump. The animals underwent serial DTI scans, locomotor assessment, and end point histology for determining the expressions of myelin basic protein (MBP), neurofilament-heavy protein (NF-H), proteolipid protein (PLP), Nogo-A, aquaporin-4 (AQP-4), and growth associated protein-43 (GAP-43). Differences in the DTI measures were observed in the splenium (scc) and genu (gcc) of the corpus callosum (cc), fimbria (fi), and the internal capsule (ic). A significant increase in the activity in the fine motor movements and a significant decrease in the number of rearing events were observed in the cocaine-treated animals. Reduced MBP and Nogo-A and increased GAP-43 expressions were most consistently observed in these structures. A decrease in the NF-H expression was observed in fi and ic. The reduced expression of Nogo-A and the increased expression of GAP-43 may suggest destabilization of axonal connectivity and increased neurite growth with aberrant connections. Increased GAP-43 suggests drug-induced plasticity or a possible repair mechanism response. The findings indicated that multiple white matter tracts are affected following chronic cocaine exposure.
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Affiliation(s)
- Ponnada A Narayana
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| | - Juan J Herrera
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Kurt H Bockhorst
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Emilio Esparza-Coss
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ying Xia
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Joel L Steinberg
- Department of Psychiatry, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - F Gerard Moeller
- Department of Psychiatry, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
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Evangelidou M, Karamita M, Vamvakas SS, Szymkowski DE, Probert L. Altered expression of oligodendrocyte and neuronal marker genes predicts the clinical onset of autoimmune encephalomyelitis and indicates the effectiveness of multiple sclerosis-directed therapeutics. J Immunol 2014; 192:4122-33. [PMID: 24683189 DOI: 10.4049/jimmunol.1300633] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Experimental autoimmune encephalomyelitis (EAE) is a valuable model for studying immunopathology in multiple sclerosis (MS) and for exploring the interface between autoimmune responses and CNS tissue that ultimately leads to lesion development. In this study, we measured gene expression in mouse spinal cord during myelin oligodendrocyte gp35-55 peptide-induced EAE, using quantitative RT-PCR, to identify gene markers that monitor individual hallmark pathological processes. We defined a small panel of genes whose longitudinal expression patterns provided insight into the timing, interrelationships, and mechanisms of individual disease processes and the efficacy of therapeutics for the treatment of MS. Earliest transcriptional changes were upregulation of Il17a and sharp downregulation of neuronal and oligodendrocyte marker genes preceding clinical disease onset, whereas neuroinflammatory markers progressively increased as symptoms and tissue lesions developed. EAE-induced gene-expression changes were not altered in mice deficient in IKKβ in cells of the myeloid lineage compared with controls, but the administration of a selective inhibitor of soluble TNF to mice from the day of immunization delayed changes in the expression of innate inflammation, myelin, and neuron markers from the presymptomatic phase. Proof of principle that the gene panel shows drug screening potential was obtained using a well-established MS therapeutic, glatiramer acetate. Prophylactic treatment of mice with glatiramer acetate normalized gene marker expression, and this correlated with the level of therapeutic success. These results show that neurons and oligodendrocytes are highly sensitive to CNS-directed autoimmunity before the development of clinical symptoms and immunopathology and reveal a role for soluble TNF in mediating the earliest changes in gene expression.
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Affiliation(s)
- Maria Evangelidou
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, 11521 Athens, Greece
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20
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Abstract
Recent years have witnessed impressive advancements in the use of magnetic resonance imaging (MRI) for the assessment of patients with multiple sclerosis (MS). Complementary to the clinical evaluation, conventional MRI (cMRI) provides crucial pieces of information for the diagnosis of MS, the understanding of its natural history, and monitoring the efficacy of experimental treatments. Measures derived from cMRI present clear advantages over the clinical assessment, including their more objective nature and an increased sensitivity to MS-related changes. However, the correlation between these measures and the clinical manifestations of the disease remains weak, and this can be explained, at least partially, by the limited ability of cMRI to characterize and quantify the heterogeneous features of MS pathology. Quantitative MR-based techniques have the potential to overcome the limitations of cMRI. Magnetization transfer MRI, diffusion-weighted and diffusion tensor MRI with fiber tractography, proton magnetic resonance spectroscopy, T1 and T2 relaxation time measurement, and functional MRI are contributing to elucidate the mechanisms that underlie injury, repair, and functional adaptation in patients with MS. All conventional and nonconventional MR techniques will benefit from the use of high-field MR systems (3.0T or more).
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Affiliation(s)
- Massimo Filippi
- Neuroimaging Research Unit, Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
| | - Arnaud Charil
- Neuroimaging Research Unit, Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Marco Rovaris
- Neuroimaging Research Unit, Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Martina Absinta
- Neuroimaging Research Unit, Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Maria Assunta Rocca
- Neuroimaging Research Unit, Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
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von Meyenburg J, Wilm BJ, Weck A, Petersen J, Gallus E, Mathys J, Schaetzle E, Schubert M, Boesiger P, von Meyenburg K, Goebels N, Kollias S. Spinal Cord Diffusion-Tensor Imaging and Motor-evoked Potentials in Multiple Sclerosis Patients: Microstructural and Functional Asymmetry. Radiology 2013; 267:869-79. [DOI: 10.1148/radiol.13112776] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wootla B, Watzlawik JO, Denic A, Rodriguez M. The road to remyelination in demyelinating diseases: current status and prospects for clinical treatment. Expert Rev Clin Immunol 2013; 9:535-49. [PMID: 23730884 DOI: 10.1586/eci.13.37] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Within CNS disorders, demyelinating diseases are among the most devastating and cost intensive due to long-term disabilities affecting relatively young patients. Multiple sclerosis, a chronic inflammatory demyelinating disease in which the persistent inhibitory microenvironment of the resident oligodendrocyte precursor cells abrogates regeneration of myelin sheaths, is the most prominent disease in the spectrum of demyelinating diseases. The essential goal is to stimulate creation of new myelin sheaths on the demyelinated axons, leading to restoration of saltatory conduction and resolving functional deficits. The past few decades witnessed significant efforts to understand the cellular interactions at the lesion site with studies suggesting efficient remyelination as a prerequisite for functional repair. Despite its proven efficacy in experimental models, immunosuppression has not had profound clinical consequences in multiple sclerosis, which argued for a paradigm shift in the design of therapeutics aiming to achieve remyelination. For example, targeting oligodendrocytes themselves may drive remyelination in the CNS. This group and others have demonstrated that natural autoreactive antibodies directed at oligodendrocyte progenitors participate in remyelination. Accordingly, the authors developed a recombinant autoreactive natural human IgM antibody with therapeutic potential for remyelination.
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Affiliation(s)
- Bharath Wootla
- Department of Neurology, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905, USA.
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23
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Boyd A, Zhang H, Williams A. Insufficient OPC migration into demyelinated lesions is a cause of poor remyelination in MS and mouse models. Acta Neuropathol 2013; 125:841-59. [PMID: 23595275 PMCID: PMC3661931 DOI: 10.1007/s00401-013-1112-y] [Citation(s) in RCA: 186] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 03/13/2013] [Accepted: 04/01/2013] [Indexed: 12/14/2022]
Abstract
Failure of remyelination of multiple sclerosis (MS) lesions contributes to neurodegeneration that correlates with chronic disability in patients. Currently, there are no available treatments to reduce neurodegeneration, but one therapeutic approach to fill this unmet need is to promote remyelination. As many demyelinated MS lesions contain plentiful oligodendrocyte precursor cells (OPCs), but no mature myelinating oligodendrocytes, research has previously concentrated on promoting OPC maturation. However, some MS lesions contain few OPCs, and therefore, remyelination failure may also be secondary to OPC recruitment failure. Here, in a series of MS samples, we determined how many lesions contained few OPCs, and correlated this to pathological subtype and expression of the chemotactic molecules Semaphorin (Sema) 3A and 3F. 37 % of MS lesions contained low numbers of OPCs, and these were mostly chronic active lesions, in which cells expressed Sema3A (chemorepellent). To test the hypothesis that differential Sema3 expression in demyelinated lesions alters OPC recruitment and the efficiency of subsequent remyelination, we used a focal myelinotoxic mouse model of demyelination. Adding recombinant (r)Sema3A (chemorepellent) to demyelinated lesions reduced OPC recruitment and remyelination, whereas the addition of rSema3F (chemoattractant), or use of transgenic mice with reduced Sema3A expression increased OPC recruitment and remyelination. We conclude that some MS lesions fail to remyelinate secondary to reduced OPC recruitment, and that chemotactic molecules are involved in the mechanism, providing a new group of drug targets to improve remyelination, with a specific target in the Sema3A receptor neuropilin-1.
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Affiliation(s)
- Amanda Boyd
- MS Centre, MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh Bioquarter, 5 Little France Drive, Edinburgh, EH16 4UU UK
| | - Hui Zhang
- MS Centre, MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh Bioquarter, 5 Little France Drive, Edinburgh, EH16 4UU UK
| | - Anna Williams
- MS Centre, MRC Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh Bioquarter, 5 Little France Drive, Edinburgh, EH16 4UU UK
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Abstract
BACKGROUND Multiple sclerosis (MS) is a chronic disabling disorder histopathologically characterized by inflammation, demyelination and axonal loss. Conventional MRI has made most contributions to the diagnosis of MS. However, it is not sufficiently sensitive and specific to reveal the extent and severity of the damage in the disease. Other nuclear magnetic resonance (NMR) techniques including magnetic resonance spectroscopy, magnetization transfer imaging, diffusion weighted and diffusion tensor imaging, and functional MRI have provided additional information that improves the diagnosis and understanding of MS. Optical techniques including optical coherence tomography (OCT) and coherent anti-Stokes Raman scattering (CARS) microscopy have shown promise in diagnosis and mechanistic study of myelin diseases. OBJECTIVE To review new imaging techniques and their potential in diagnosis of MS. METHOD The principles of three imaging techniques (MRI, OCT and CARS) and their applications to MS studies are described. Their advantages and disadvantages are compared. CONCLUSION Conventional MRI remains a critical tool in the diagnosis of MS. Alternative NMR/MRI techniques have improved specificity for the detection of lesions and provided more quantitative information about MS. Optical techniques including OCT and CARS microscopy are opening up new ways for diagnosis and mechanistic study of myelin diseases.
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Affiliation(s)
- Yan Fu
- Purdue University, Weldon School of Biomedical Engineering, West Lafayette, IN 47907, USA
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Tur C, Wheeler-Kingshott CAM, Altmann DR, Miller DH, Thompson AJ, Ciccarelli O. Spatial variability and changes of metabolite concentrations in the cortico-spinal tract in multiple sclerosis using coronal CSI. Hum Brain Mapp 2012; 35:993-1003. [PMID: 23281189 PMCID: PMC4238834 DOI: 10.1002/hbm.22229] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 10/03/2012] [Accepted: 11/05/2012] [Indexed: 11/07/2022] Open
Abstract
We characterized metabolic changes along the cortico-spinal tract (CST) in multiple sclerosis (MS) patients using a novel application of chemical shift imaging (CSI) and considering the spatial variation of metabolite levels. Thirteen relapsing-remitting (RR) and 13 primary-progressive (PP) MS patients and 16 controls underwent (1)H-MR CSI, which was applied to coronal-oblique scans to sample the entire CST. The concentrations of the main metabolites, i.e., N-acetyl-aspartate, myo-Inositol (Ins), choline containing compounds (Cho) and creatine and phosphocreatine (Cr), were calculated within voxels placed in regions where the CST is located, from cerebral peduncle to corona radiata. Differences in metabolite concentrations between groups and associations between metabolite concentrations and disability were investigated, allowing for the spatial variability of metabolite concentrations in the statistical model. RRMS patients showed higher CST Cho concentration than controls, and higher CST Ins concentration than PPMS, suggesting greater inflammation and glial proliferation in the RR than in the PP course. In RRMS, a significant, albeit modest, association between greater Ins concentration and greater disability suggested that gliosis may be relevant to disability. In PPMS, lower CST Cho and Cr concentrations correlated with greater disability, suggesting that in the progressive stage of the disease, inflammation declines and energy metabolism reduces. Attention to the spatial variation of metabolite concentrations made it possible to detect in patients a greater increase in Cr concentration towards the superior voxels as compared to controls and a stronger association between Cho and disability, suggesting that this step improves our ability to identify clinically relevant metabolic changes.
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Affiliation(s)
- Carmen Tur
- Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom; Department of Medicine, Clinical Neuroimmunology Unit, Multiple Sclerosis Centre of Catalonia (CEM-Cat), Autonomous University of Barcelona, CARM-Vall d'Hebron University Hospital, Barcelona, Spain
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Cambron M, D'Haeseleer M, Laureys G, Clinckers R, Debruyne J, De Keyser J. White-matter astrocytes, axonal energy metabolism, and axonal degeneration in multiple sclerosis. J Cereb Blood Flow Metab 2012; 32:413-24. [PMID: 22214904 PMCID: PMC3293127 DOI: 10.1038/jcbfm.2011.193] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In patients with multiple sclerosis (MS), a diffuse axonal degeneration occurring throughout the white matter of the central nervous system causes progressive neurologic disability. The underlying mechanism is unclear. This review describes a number of pathways by which dysfunctional astrocytes in MS might lead to axonal degeneration. White-matter astrocytes in MS show a reduced metabolism of adenosine triphosphate-generating phosphocreatine, which may impair the astrocytic sodium potassium pump and lead to a reduced sodium-dependent glutamate uptake. Astrocytes in MS white matter appear to be deficient in β(2) adrenergic receptors, which are involved in stimulating glycogenolysis and suppressing inducible nitric oxide synthase (NOS2). Glutamate toxicity, reduced astrocytic glycogenolysis leading to reduced lactate and glutamine production, and enhanced nitric oxide (NO) levels may all impair axonal mitochondrial metabolism, leading to axonal degeneration. In addition, glutamate-mediated oligodendrocyte damage and impaired myelination caused by a decreased production of N-acetylaspartate by axonal mitochondria might also contribute to axonal loss. White-matter astrocytes may be considered as a potential target for neuroprotective MS therapies.
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Affiliation(s)
- Melissa Cambron
- Department of Neurology, Center for Neurosciences, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussel, Belgium
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Dalton CM, Bodini B, Samson RS, Battaglini M, Fisniku LK, Thompson AJ, Ciccarelli O, Miller DH, Chard DT. Brain lesion location and clinical status 20 years after a diagnosis of clinically isolated syndrome suggestive of multiple sclerosis. Mult Scler 2011; 18:322-8. [PMID: 21878451 DOI: 10.1177/1352458511420269] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND/OBJECTIVES The objective of this study was to investigate associations between the spatial distribution of brain lesions and clinical outcomes in a cohort of people followed up 20 years after presentation with a clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS). METHODS Brain lesion probability maps (LPMs) of T1 and T2 lesions were generated from 74 people who underwent magnetic resonance imaging (MRI) and clinical assessment a mean of 19.9 years following a CIS. One-tailed t-test statistics were used to compare LPMs between the following groups: clinically definite (CD) MS and those who remained with CIS, with an abnormal MRI; people with MS and an Expanded Disability Status Scale (EDSS) ≤3 and >3; people with relapsing-remitting (RR) and secondary progressive (SP) MS. The probability of each voxel being lesional was analysed adjusting for age and gender using a multiple linear regression model. RESULTS People with CDMS were significantly more likely than those with CIS and abnormal scan 20 years after onset to have T1 and T2 lesions in the corona radiata, optic radiation, and splenium of the corpus callosum (periventricularly) and T2 lesions in the right fronto-occipital fasciculus. People with MS EDSS >3, compared with those with EDSS ≤3, were more likely to have optic radiation and left internal capsule T2 lesions. No significant difference in lesion distribution was noted between RRMS and SPMS. CONCLUSION This work demonstrates that lesion location characteristics are associated with CDMS and disability after long-term follow-up following a CIS. The lack of lesion spatial distribution differences between RRMS and SPMS suggests focal pathology affects similar regions in both subgroups.
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Affiliation(s)
- C M Dalton
- NMR Research Unit, UCL Institute of Neurology, UCL, London, UK.
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Kern KC, Sarcona J, Montag M, Giesser BS, Sicotte NL. Corpus callosal diffusivity predicts motor impairment in relapsing–remitting multiple sclerosis: A TBSS and tractography study. Neuroimage 2011; 55:1169-77. [DOI: 10.1016/j.neuroimage.2010.10.077] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 10/26/2010] [Accepted: 10/27/2010] [Indexed: 11/15/2022] Open
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Wegner C, Filippi M, Korteweg T, Beckmann C, Ciccarelli O, De Stefano N, Enzinger C, Fazekas F, Agosta F, Gass A, Hirsch J, Johansen-Berg H, Kappos L, Barkhof F, Polman C, Mancini L, Manfredonia F, Marino S, Miller DH, Montalban X, Palace J, Rocca M, Ropele S, Rovira A, Smith S, Thompson A, Thornton J, Yousry T, Matthews PM. Relating functional changes during hand movement to clinical parameters in patients with multiple sclerosis in a multi-centre fMRI study. Eur J Neurol 2008; 15:113-22. [PMID: 18217881 DOI: 10.1111/j.1468-1331.2007.02027.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We performed a prospective multi-centre study using functional magnetic resonance imaging (fMRI) to better characterize the relationships between clinical expression and brain function in patients with multiple sclerosis (MS) at eight European sites (56 MS patients and 60 age-matched, healthy controls). Patients showed greater task-related activation bilaterally in brain regions including the pre- and post-central, inferior and superior frontal, cingulate and superior temporal gyri and insula (P < 0.05, all statistics corrected for multiple comparisons). Both patients and healthy controls showed greater brain activation with increasing age in the ipsilateral pre-central and inferior frontal gyri (P < 0.05). Patients, but not controls, showed greater brain activation in the anterior cingulate gyrus and the bilateral ventral striatum (P < 0.05) with less hand dexterity. An interaction between functional activation changes in MS and age was found. This large fMRI study over a broadly selected MS patient population confirms that movement for patients demands significantly greater cognitive 'resource allocation' and suggests age-related differences in brain responses to the disease. These observations add to evidence that brain functional responses (including potentially adaptive brain plasticity) contribute to modulation of clinical expression of MS pathology and demonstrate the feasibility of a multi-site functional MRI study of MS.
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Affiliation(s)
- C Wegner
- Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford, UK
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Abstract
In multiple sclerosis (MS), the presence of demyelinating plaques has concentrated researchers' minds on the role of the oligodendrocyte in its pathophysiology. Recently, with the rediscovery of early and widespread loss of axons in the disease, new emphasis has been put on the role of axons and axon-oligodendrocyte interactions in MS. Despite the fact that, in 1904, Müller claimed that MS was a disease of astrocytes, more recently, astrocytes have taken a back seat, except as the cells that form the final glial scar after all hope of demyelination is over. However, perhaps it is time for the return of the astrocyte to popularity in the pathogenesis of MS, with recent reports on the dual role of astrocytes in aiding degeneration and demyelination, by promoting inflammation, damage of oligodendrocytes and axons, and glial scarring, but also in creating a permissive environment for remyelination by their action on oligodendrocyte precursor migration, oligodendrocyte proliferation, and differentiation. We review these findings to try to provide a cogent view of astrocytes in the pathology of MS.
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Affiliation(s)
- Anna Williams
- Inserm, U711, Université Pierre and Marie Curie, Faculté de médecine, IFR 70, Paris F-75013, France, and Department of Clinical Neurosciences, Western General Hospital, Edinburgh, UK.
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Reich DS, Smith SA, Zackowski KM, Gordon-Lipkin EM, Jones CK, Farrell JAD, Mori S, van Zijl PCM, Calabresi PA. Multiparametric magnetic resonance imaging analysis of the corticospinal tract in multiple sclerosis. Neuroimage 2007; 38:271-9. [PMID: 17870615 PMCID: PMC2082136 DOI: 10.1016/j.neuroimage.2007.07.049] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2006] [Revised: 07/11/2007] [Accepted: 07/20/2007] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND/PURPOSE Muscle weakness is an important feature of multiple sclerosis and is responsible for much of the disability associated with that condition. Here, we describe the quantitative magnetic resonance imaging (MRI) attributes of the major intracerebral motor pathway--the corticospinal tract--in multiple sclerosis. To do so, we develop an intuitive method for creating and displaying spatially normalized tract-specific imaging data. METHODS In 75 individuals with multiple sclerosis and 29 healthy controls, the corticospinal tracts were reconstructed from diffusion tensor imaging at 3 T. Multiple MRI indices--T2 relaxation time; fractional anisotropy; mean, longitudinal, and transverse diffusivity; and magnetization transfer ratio--were examined within the reconstructed tracts. Spatially normalized tract profiles were created to compare, across subjects, the variation in MRI index as a function of tract position. RESULTS Each index's tract profile had a characteristic shape. Individual subjects had markedly abnormal tract profiles, particularly at lesion sites. On average, tract profiles were different between patients and controls, particularly in the subcortical white matter and corona radiata, for all indices examined except for fractional anisotropy. Magnetization transfer ratio was further decreased in subjects with secondary progressive disease. Tract asymmetry was increased in multiple sclerosis compared to controls. CONCLUSION Multiparametric MRI allows rapid detection, localization, and characterization of tract-specific abnormalities in multiple sclerosis. Tract profiles bridge the gap between whole-brain imaging of neurological disease and the interrogation of individual, functionally relevant subsystems.
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Affiliation(s)
- Daniel S Reich
- Department of Neurology, Johns Hopkins University, 600 N Wolfe St, Baltimore, MD 21287, USA.
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Westerhausen R, Huster RJ, Kreuder F, Wittling W, Schweiger E. Corticospinal tract asymmetries at the level of the internal capsule: Is there an association with handedness? Neuroimage 2007; 37:379-86. [PMID: 17601751 DOI: 10.1016/j.neuroimage.2007.05.047] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Revised: 04/23/2007] [Accepted: 05/29/2007] [Indexed: 12/13/2022] Open
Abstract
The functional integrity of the corticospinal tract (CST) is of crucial importance for fine and independent finger movement. Therefore, it has been frequently speculated that interhemispheric asymmetries in this tract might be associated with handedness. The objective of the present study was to examine this proposed relationship, by studying the effects of handedness on macro- and microstructural properties of the CST. For this purpose, 30 consistently left and 30 consistently right-handed participants of either sex were examined applying a combination of anatomical T1-weighted and diffusion-tensor (DTI) MR imaging. In an automated procedure and based on white matter probability maps as well as on DTI fibre direction information, the left and right hemispheric CST was segmented in the individual brain. Focussing the analysis on the posterior limb of the internal capsule, the size as well as two DTI parameters (mean diffusion and fractional anisotropy) was determined. Although the statistical analysis revealed substantial CST asymmetries regarding size, mean diffusion, and anisotropy, neither of these metrics showed a significant hemisphere-by-handedness interaction. From this it was concluded that handedness might be related to motorcortical asymmetries which seem not to be directly reflected in the corticospinal fibre tract characteristics.
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Affiliation(s)
- René Westerhausen
- Department of Biological and Medical Psychology, University of Bergen Jonas Lies vei 91 N-5009 Bergen, Norway.
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Abstract
Functional MRI (fMRI) has had a major impact in cognitive neuroscience. fMRI now has a small but growing role in clinical neuroimaging, with initial applications to neurosurgical planning. Current clinical research has emphasized novel concepts for clinicians, such as the role of plasticity in recovery and the maintenance of brain functions in a broad range of diseases. There is a wider potential for clinical fMRI in applications ranging from presymptomatic diagnosis, through drug development and individualization of therapies, to understanding functional brain disorders. Realization of this potential will require changes in the way clinical neuroimaging services are planned and delivered.
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Affiliation(s)
- Paul M Matthews
- Centre for Functional Magnetic Resonance Imaging of the Brain, Dept. of Clinical Neurology, University of Oxford, UK.
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Bonfiglio L, Rossi B, Sartucci F. Prolonged intracortical delay of long-latency reflexes: electrophysiological evidence for a cortical dysfunction in multiple sclerosis. Brain Res Bull 2006; 69:606-13. [PMID: 16716826 DOI: 10.1016/j.brainresbull.2006.03.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2005] [Revised: 01/20/2006] [Accepted: 03/04/2006] [Indexed: 11/24/2022]
Abstract
Convincing evidence suggests that long-latency reflexes (LLRs) are capable of testing the transcortical sensorimotor reflex arch. By subtracting the sum of the latencies of N20 (afferent branch) and transcranially elicited motor evoked potentials (MEP; efferent branch) from the LLR II latency, the cortical relay time (CRT) can also be obtained, which is alleged to represent the time required for the cortical sensorimotor integration. The aim of the present study was to investigate if a cortical dysfunction occurs in multiple sclerosis (MS). Median nerve somatosensory evoked potentials (SEPs), MEPs and LLRs were recorded from the upper limbs of 23, not severely disabled MS patients in acute phases of the disease. Eighteen age and sex matched healthy volunteers served as controls. N20, MEP, LLR II latencies were measured, and the CRT was calculated for each limb. The statistical comparison between patients and controls was only weakly significant by taking into account conduction times along either the afferent (N20) or the efferent (MEP) pathways. On the contrary, it turned out to be considerably significant if both branches of the transcortical sensorimotor reflex arch, together with the intracortical pathway, were simultaneously tested by means of the LLRs. Moreover, the patients showed a significantly higher CRT compared with that found in the control subjects. These findings are consistent with a prolonged intracortical delay of LLRs in the MS group and suggest the occurrence of conduction velocity slowing and/or synaptic transmission impairment along the sensorimotor intracortical pathway in MS.
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Affiliation(s)
- Luca Bonfiglio
- Unit of Neurorehabilitation, Department of Neuroscience, University of Pisa, 67 Via Roma, I-56126 Pisa, Italy.
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Abstract
In addition to providing information on tissue structure, magnetic resonance (MR) technology offers the potential to investigate tissue metabolism and function. MR spectroscopy (MRS) offers a wealth of data on the biochemistry of a selected brain tissue volume, which represent potential surrogate markers for the pathology underlying multiple sclerosis (MS). In particular, the N-acetylaspartate peak in an MR spectrum is a putative marker of neuronal and axonal integrity, and the choline peak appears to reflect cell-membrane metabolism. On this basis, a diminished N-acetylaspartate peak is interpreted to represent neuronal/axonal dysfunction or loss, and an elevated choline peak represents heightened cell-membrane turnover, as seen in demyelination, remyelination, inflammation, or gliosis. Therefore, MRS may provide a unique tool to evaluate the severity of MS, establish a prognosis, follow disease evolution, understand its pathogenesis, and evaluate the efficacy of therapeutic interventions, which complements the information obtained from the various forms of assessment made by conventional MR imaging.
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Affiliation(s)
- Ponnada A Narayana
- Department of Interventional Imaging, University of Texas Medical School at Houston, TX 77030, USA.
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Abstract
Meta-analysis was performed on the results of 75 comparisons from the 30 peer-reviewed publications that used proton magnetic resonance spectroscopy (1H-MRS) or spectroscopic imaging to (i) quantify the mean concentrations of total creatine (tCr, found in neurons, astrocytes and oligodendrocytes), and/or total N-acetyl groups (tNA, found only in neurons), in the lesional and/or non-lesional white matter (WM) and/or the grey matter (GM) of patients with multiple sclerosis (MS) and (ii) compare these values with those in the homologous tissues of normal controls (NC). For mean [tNA] values, there was (i) a large-effect-sized overall decrease in patients' lesional WM relative to NC WM (25 comparisons), (ii) a medium-effect-sized overall decrease in patients' non-lesional WM relative to NC WM (36 comparisons) and (iii) a medium-effect-sized overall decrease in patients' GM relative to NC GM (14 comparisons). Patients' mean [tNA] values were sometimes statistically normal but were never statistically increased. For mean [tCr] values, there was (i) no statistically significant overall change in the patients' lesional WM relative to NC WM (24 comparisons), although statistically significant increases and decreases were sometimes found, (ii) a medium-effect-sized overall increase in patients' non-lesional WM relative to NC WM (33 comparisons) and (iii) no statistically significant overall change in patients' GM relative to NC GM (12 comparisons), although a significant decrease was found in one comparison. Of 41 comparisons with statistically significant changes, 38 combined in a way that would probably result in decreased mean [tNA]/[tCr] ratios such that (i) 66% had statistically decreased mean [tNA] and statistically unchanged mean [tCr] values, (ii) 13% had statistically decreased mean [tNA] and statistically increased mean [tCr] values and (iii) 21% had statistically unchanged mean [tNA] values and statistically increased mean [tCr] values. Of the 25 comparisons that came from studies that also analysed [tNA]/[tCr] ratios, the direction of change in mean [tNA] values and mean [tNA]/[tCr] ratios was concordant in 84%. In comparisons that quantified both [tNA] and [tCr], there was a similar amount of variability in both measures in each of the different tissue types studied, both in patients and NCs. Together, these results suggest that within-voxel tNA/tCr ratios can be interpreted as valid and accurate surrogate measures of 'cerebral tissue integrity'-with decreased tNA/tCr ratios indicating some combination of neuroaxonal disturbance, oligodendroglial disturbance, and astrocytic proliferation. These results also suggest that, although within-voxel tNA/tCr ratios are not perfect indicators of [tNA] content, they do represent a practical compromise to acquiring surrogate measures of within-voxel neuroaxonal integrity.
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Affiliation(s)
- Zografos Caramanos
- Magnetic Resonance Spectroscopy Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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Abstract
The classical view of MS as a chronic inflammatory demyelinating disease leading to the formation of focal central nervous system (CNS) white matter (WM) lesions has been recently challenged by pathological studies and by the extensive application of modern MRI-based techniques. There is now overwhelming evidence supporting the following statements: MS causes widespread tissue damage in the normal-appearing white matter (NAWM) of the brain and spinal cord, whose extent and severity is more strictly associated to the clinical manifestations of the disease than the extent of focal pathology. Discrete, macroscopic lesions are just the tip of the iceberg of MS pathology. Grey matter (GM) damage is a consistent feature of all MS phenotypes, which is progressive from the start of the relapsing-remitting phase of the disease. As is the case for WM, GM damage is also a mixture of focal lesions and diffuse pathology. High-field strength MR scanners are improving our ability to image focal GM lesions and modern MR-based techniques are enabling us to quantify in vivo the extent and severity of GM pathology, which have been shown to correlate only moderately with the amount of WM changes. At least part of GM pathology in MS is not secondary to retrograde degeneration of fibers traversing WM lesions. The neurodegenerative component of the disease is not a late phenomenon and it is not completely driven by inflammatory demyelination. In fact, neurodegeneration occurs very early in the course of MS and the correlation between MRI measures of inflammation and neurodegeneration is weak in all disease phases. The interplay of inflammation and neurodegeneration is a complex and still poorly understood phenomenon. At least part of MS-related neurodegeneration is not directly driven by Wallerian degeneration. Functional cortical changes can be seen in virtually all MS patients and are likely to play a central role in the ability of the MS brain to respond to tissue injury and, hence, limit the functional consequences of structural damage. MS disability is not just the result of tissue destruction but rather a balance between tissue destruction, tissue repair and adaptive cortical reorganization. All of this calls for the concept of MS as a focal, inflammatory demyelinating, WM disease to be reexamined and to start viewing MS as a diffuse CNS disease with an important neurodegenerative component. This is central for identifying novel and effective treatment strategies.
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Affiliation(s)
- Massimo Filippi
- Neuroimaging Research Unit, Dept. of Neurology Scientific Institute and University Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy.
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Cooke FJ, Blamire AM, Manners DN, Styles P, Rajagopalan B. Quantitative proton magnetic resonance spectroscopy of the cervical spinal cord. Magn Reson Med 2004; 51:1122-8. [PMID: 15170831 DOI: 10.1002/mrm.20084] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Proton MR spectroscopy ((1)H-MRS) provides indices of neuronal damage in the central nervous system (CNS); however, it has not been extensively applied in the spinal cord. This work describes an optimized proton spectroscopy protocol for examination of the human cervical spinal cord. B(0) field mapping of the cord revealed periodic inhomogeneities due to susceptibility differences with surrounding tissue. By combining field maps and experimental data, we found that the optimum voxel size was 9 x 7 x 35 mm(3) placed with the inferior end of the voxel above vertebral body C2. Metabolite concentrations were determined in the cervical cord in six healthy controls by short-echo point-resolved spectroscopy (PRESS) volume localization. The results were compared with metabolite concentrations in the brainstem, cerebellum, and cortex in the same individuals. The concentrations in the cervical cord were as follows: N-acetyl-aspartate (NAA) 17.3 +/- 0.5, creatine (Cr) 9.5 +/- 0.9, and choline 2.7 +/- 0.5 mmol/l. The NAA concentration was significantly lower in the cord than in the brainstem (Mann-Whitney, P < 0.025), and higher than in the cortex (P < 0.005) and cerebellum (P < 0.005). Cr was significantly lower in the cord than in the cerebellum (P < 0.05). There were no significant differences between Cr concentrations in the spinal cord compared to the cortex and brainstem.
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Affiliation(s)
- F J Cooke
- MRC Biochemical and Clinical Magnetic Resonance Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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Abstract
MR spectroscopy (MRS) of the brain in patients with multiple sclerosis has been well studied. However, in vivo MRS of the spinal cord in patients with MR spectroscopy has not been reported to our knowledge. We performed MRS of normal-appearing cervical spinal cords in multiple sclerosis patients and in healthy controls. N-acetyl aspartate was shown to be reduced within the cervical spinal cord of multiple sclerosis patients when compared with healthy controls. This finding supports axonal loss and damage within even normal-appearing spinal cords of multiple sclerosis patients.
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Abstract
Despite intensive research, the cause and a cure of multiple sclerosis (MS) have remained elusive and many aspects of the pathogenesis are not understood. Immunohistochemical experiments have shown that astrocytic beta(2)-adrenergic receptors are lost in MS. Because norepinephrine mediates important supportive and protective actions of astrocytes via activation of these beta(2)-adrenergic receptors, we postulate that this abnormality may play a prominent role in the pathogenesis of MS. First, it may allow astrocytes to act as facultative antigen-presenting cells, thereby initiating T-cell mediated inflammatory responses that lead to the characteristic demyelinated lesions. Second, it may contribute to inflammatory injury by stimulating the production of nitric oxide and proinflammatory cytokines, and reducing glutamate uptake. Third, it may lead to apoptosis of oligodendrocytes by reducing the astrocytic production of trophic factors, including neuregulin, nerve growth factor and brain-derived neurotrophic factor. Fourth, it may impair astrocytic glycogenolysis, which supplies energy to axons, and this may represent a mechanism underlying axonal degeneration that is hold responsible for the progressive chronic disability.
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Affiliation(s)
- Jacques De Keyser
- Department of Neurology, University Hospital Groningen, Groningen, The Netherlands.
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De Keyser J, Zeinstra E, Mostert J, Wilczak N. Beta 2-adrenoceptor involvement in inflammatory demyelination and axonal degeneration in multiple sclerosis. Trends Pharmacol Sci 2004; 25:67-71. [PMID: 15102491 DOI: 10.1016/j.tips.2003.12.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Relapses of multiple sclerosis (MS) are considered to be the clinical expression of acute T-cell-mediated inflammatory demyelinating lesions disseminated in the CNS, whereas disease progression seems to result from widespread axonal degeneration. The pathophysiology of both disease components is incompletely understood. Astrocytes in MS lack beta(2)-adrenoceptors, which via cAMP-mediated processes inhibit the expression of major histocompatibility (MHC) class II molecules and stimulate glycogenolysis in normal conditions. In a pro-inflammatory CNS environment this beta(2)-adrenoceptor defect might allow astrocytes to transform into facultative antigen-presenting cells that can initiate the inflammatory cascade. The same receptor defect might impair astrocytic glycogenolysis, which normally generates lactate that is transported to axons as an energy source. Failure of axonal energy metabolism might result in axonal degeneration through mechanisms that involve intra-axonal accumulation of Ca(2+) ions and mitochondrial dysfunction. If this hypothesis is correct, therapies designed to elevate cAMP levels in astrocytes should reduce or prevent both relapses and progression of MS.
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Affiliation(s)
- Jacques De Keyser
- Department of Neurology, University Hospital Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
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Audoin B, Ibarrola D, Ranjeva J, Confort‐Gouny S, Malikova I, Ali‐Chérif A, Pelletier J, Cozzone P. Compensatory cortical activation observed by fMRI during a cognitive task at the earliest stage of MS. Hum Brain Mapp 2003; 20:51-8. [PMID: 14505331 PMCID: PMC6872003 DOI: 10.1002/hbm.10128] [Citation(s) in RCA: 190] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent functional magnetic resonance imaging (fMRI) studies have suggested that functional cortical changes seen in patients with early relapsing-remitting multiple sclerosis (MS) can have an adaptive role to limit the clinical impact of tissue injury. To determine whether cortical reorganization occurs during high cognitive processes at the earliest stage of multiple sclerosis (MS), we performed an fMRI experiment using the conventional Paced Auditory Serial Addition Test (PASAT) as paradigm in a population of ten patients with clinically isolated syndrome suggestive of multiple sclerosis (CISSMS). At the time of the fMRI exploration, mean disease duration was 6.8 +/- 3.3 months. We compared these results to those obtained in a group of ten education-, age-, and sex-matched healthy controls. Subjects were explored on a 1.5 T MRI system using single-shot gradient-echo EPI sequence. Performances of the two groups during PASAT recorded inside the MR scanner were not different. Statistical assessment of brain activation was based on the random effect analysis (between-group analysis two-sample t-test P < 0.005 confirmed by individual analyses performed in the surviving regions P < 0.05 Mann Whitney U-test). Compared to controls, patients showed significantly greater activation in the right frontopolar cortex, the bilateral lateral prefrontal cortices, and the right cerebellum. Healthy controls did not show greater activation compared to CISSMS patients. The present study argues in favor of the existence of compensatory cortical activations at the earliest stage of MS mainly located in regions involved in executive processing in patients performing PASAT. It also suggests that fMRI can evidence the active processes of neuroplasticity contributing to mask the clinical cognitive expression of brain pathology at the earliest stage of MS.
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Affiliation(s)
- Bertrand Audoin
- Centre de Résonance Magnétique Biologique et Médicale, UMR CNRS no. 6612, Faculté de Médecine, Marseille, France
- Département de Neurologie, CHU Timone, Marseille, France
| | - Danielle Ibarrola
- Centre de Résonance Magnétique Biologique et Médicale, UMR CNRS no. 6612, Faculté de Médecine, Marseille, France
| | - Jean‐Philippe Ranjeva
- Centre de Résonance Magnétique Biologique et Médicale, UMR CNRS no. 6612, Faculté de Médecine, Marseille, France
| | - Sylviane Confort‐Gouny
- Centre de Résonance Magnétique Biologique et Médicale, UMR CNRS no. 6612, Faculté de Médecine, Marseille, France
| | - Irina Malikova
- Département de Neurologie, CHU Timone, Marseille, France
| | | | - Jean Pelletier
- Centre de Résonance Magnétique Biologique et Médicale, UMR CNRS no. 6612, Faculté de Médecine, Marseille, France
- Département de Neurologie, CHU Timone, Marseille, France
| | - Patrick Cozzone
- Centre de Résonance Magnétique Biologique et Médicale, UMR CNRS no. 6612, Faculté de Médecine, Marseille, France
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Lo AC, Saab CY, Black JA, Waxman SG. Phenytoin protects spinal cord axons and preserves axonal conduction and neurological function in a model of neuroinflammation in vivo. J Neurophysiol 2003; 90:3566-71. [PMID: 12904334 DOI: 10.1152/jn.00434.2003] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Axonal degeneration within the spinal cord contributes substantially to neurological disability in multiple sclerosis (MS). Thus neuroprotective therapies that preserve axons, so that they maintain their integrity and continue to function, might be expected to result in improved neurological outcome. Sodium channels are known to provide a route for sodium influx that can drive calcium influx, via reverse operation of the Na+/Ca2+ exchanger, after injury to axons within the CNS, and sodium channel blockers have been shown to protect CNS axons from degeneration after experimental anoxic, traumatic, and nitric oxide (NO)-induced injury. In this study, we asked whether phenytoin, which is known to block sodium channels, can protect spinal cord axons from degeneration in mice with experimental allergic encephalomyelitis (EAE), which display substantial axonal degeneration and clinical paralysis. We demonstrate that the loss of dorsal corticospinal tract (63%) and dorsal column (cuneate fasciculus; 43%) axons in EAE is significantly ameliorated (corticospinal tract: 28%; cuneate fasciculus: 17%) by treatment with phenytoin. Spinal cord compound action potentials (CAP) were significantly attenuated in untreated EAE, whereas spinal cords from phenytoin-treated EAE had robust CAPs, similar to those from phenytoin-treated control mice. Clinical scores in phenytoin-treated EAE at 28 days were significantly improved (1.5, i.e., minor righting reflex abnormalities) compared with untreated EAE (3.8, i.e., near-complete hindlimb paralysis). Our results demonstrate that phenytoin has a protective effect in vivo on spinal cord axons, preventing their degeneration, maintaining their ability to conduct action potentials, and improving clinical status in a model of neuroinflammation.
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Affiliation(s)
- Albert C Lo
- Department of Neurology and Paralyzed Veterans Association/Eastern Paralyzed Veterans Association of America Neuroscience Research Center, Yale University School of Medicine, New Haven, CT 06510, USA
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Abstract
Conventional MRI can improve accuracy in the diagnosis of multiple sclerosis (MS) and monitor the efficacy of experimental treatments. However, conventional MRI provides only gross estimates of the extent and nature of tissue damage associated with this disease. Other quantitative magnetic-resonance-based techniques have the potential to overcome the limitations of conventional MRI and, as a consequence, to improve our understanding of the natural history of MS. Magnetisation-transfer, diffusion-weighted, and functional MRI--as well as proton magnetic-resonance spectroscopy--are helping us to elucidate the mechanisms that underlie injury, repair, and functional adaptation in patients with MS. These techniques are substantially changing our understanding of how MS causes irreversible disability and should be used more extensively in clinical trials and in studies of disease progression.
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Affiliation(s)
- Massimo Filippi
- Department of Neurology, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
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Abstract
Experimental autoimmune encephalomyelitis reproduces in rodents the features of multiple sclerosis, an immune-mediated, disabling disorder of the human nervous system. No adequate therapy is available for multiple sclerosis, despite anti-inflammatory, immunosuppressive, and immunomodulatory measures. Increasingly glutamate is implicated in the pathogenesis of neurodegenerative diseases. Here we (1) review changes in the glutamatergic system in multiple sclerosis and (2) reveal the effects of glutamate AMPA antagonists in acute and chronic rodent models of multiple sclerosis. Administration of structurally diverse competitive and non-competitive AMPA antagonists reduces neurologic disability in rodents subjected to acute experimental autoimmune encephalomyelitis. In addition, AMPA antagonists are active in both the adoptive transfer and in chronic models of experimental autoimmune encephalomyelitis in rats and mice and affect both the acute and chronic relapsing phases. Moreover, short-term therapy with AMPA antagonists leads to sustained benefit well into the progressive phases. These results imply that therapeutic strategies for multiple sclerosis should be complemented by glutamate AMPA antagonists to reduce neurologic disability.
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MESH Headings
- Animals
- Brain Stem/immunology
- Brain Stem/pathology
- Disease Models, Animal
- Encephalomyelitis, Autoimmune, Experimental/drug therapy
- Encephalomyelitis, Autoimmune, Experimental/etiology
- Encephalomyelitis, Autoimmune, Experimental/physiopathology
- Excitatory Amino Acid Antagonists/immunology
- Excitatory Amino Acid Antagonists/pharmacology
- Excitatory Amino Acid Antagonists/therapeutic use
- Glutamic Acid/metabolism
- Humans
- Mice
- Mice, Inbred Strains
- Multiple Sclerosis/drug therapy
- Multiple Sclerosis/etiology
- Multiple Sclerosis/physiopathology
- Nootropic Agents/pharmacology
- Nootropic Agents/therapeutic use
- Pyrrolidinones/pharmacology
- Pyrrolidinones/therapeutic use
- Quinoxalines/immunology
- Quinoxalines/pharmacology
- Quinoxalines/therapeutic use
- Rats
- Receptors, AMPA/antagonists & inhibitors
- Receptors, AMPA/metabolism
- Spinal Cord/immunology
- Spinal Cord/pathology
- Spinal Cord/ultrastructure
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Affiliation(s)
- Anthony J Groom
- Eisai London Research Laboratories, University College London, Bernard Katz Building, Gower Street, United Kingdom
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Gielen A, Khademi M, Muhallab S, Olsson T, Piehl F. Increased brain-derived neurotrophic factor expression in white blood cells of relapsing-remitting multiple sclerosis patients. Scand J Immunol 2003; 57:493-7. [PMID: 12753507 DOI: 10.1046/j.1365-3083.2003.01260.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Central nervous system (CNS)-autoreactive immune responses can exert neuroprotective effects, possibly mediated via the release of neurotrophic factors from infiltrating leucocytes. Herein, we analysed neurotrophin and cytokine mRNA levels using TaqMan polymerase chain reaction in unstimulated peripheral blood mononuclear cells (PBMCs) from multiple sclerosis (MS) patients in remission and controls. We demonstrate that mRNA for brain-derived neurotrophic factor (BDNF), but not neurotrophin-3 or nerve growth factor (NGF), is readily detectable in PBMC and that levels in MS are increased by approximately 60% compared with patients with other neurological diseases or healthy subjects. These results provide additional evidence that a potentially neuroprotective facet of autoimmune inflammation is present in MS.
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Affiliation(s)
- A Gielen
- Department of Medicine, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.
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49
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Abstract
Conventional magnetic resonance imaging (cMRI) is widely used for diagnosing multiple sclerosis (MS) and for monitoring its activity and evolution. However, the correlation between cMRI and clinical findings of MS is limited, possibly due to the low pathological specificity of the abnormalities seen on cMRI scans and to the inability of cMRI to quantify the extent of the damage of the normal-appearing tissues. Magnetization transfer and diffusion-weighted MRI can quantify the extent and pathological severity of structural changes occurring within and outside cMRI-visible MS lesions. Proton MR spectroscopy can add information on the biochemical nature of such changes. Finally, functional MRI can provide new insights into the role of cortical adaptive changes in limiting the clinical consequences of MS structural damage. The application of quantitative MR-based techniques is changing dramatically our understanding of how MS causes irreversible disability and there is increasing perception that these methodologies should be more extensively employed in clinical trials to derive innovative information.
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Affiliation(s)
- Marco Rovaris
- Neuroimaging Research Unit, Department of Neuroscience, Scientific Institute and University Ospedale San Raffaele, Milan, Italy
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50
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Abstract
Accumulating data support axonal degeneration as the major determinant of irreversible neurological disability in patients with multiple sclerosis (MS). The extent of axonal injury correlates with the degree of inflammation in active MS lesions and occurs at early stages of disease, indicating that inflammatory demyelination is an important factor behind axon pathology at the relapsing-remitting stage of MS. Axonal loss from disease onset can remain clinically silent for many years, and permanent neurological disability develops when a threshold of axonal loss is reached and the CNS compensatory resources are exhausted. Lack of myelin-derived trophic support due to long term demyelination may cause continuous axonal degeneration in chronic inactive lesions at the secondary-progressive stage of MS. Axonal pathology is not limited to demyelinated lesions, but also extends into normal appearing white matter. The concept of MS as a neurodegenerative disorder has important clinical implications: First, proactive anti-inflammatory and immunomodulatory treatment should prevent or delay chronic disability since inflammation influences axonal injury. Second, the pathophysiological mechanisms underlying axonal degeneration in MS need to be clarified in order to develop novel neuroprotective therapeutics. Finally, surrogate markers of axonal pathology, such as N-acetyl aspartate, can be used to monitor axonal dysfunction, axonal loss and treatment efficiency in patients with MS.
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Affiliation(s)
- Carl Bjartmar
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195, USA.
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