251
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Tomlinson L, Leiton CV, Colognato H. Behavioral experiences as drivers of oligodendrocyte lineage dynamics and myelin plasticity. Neuropharmacology 2015; 110:548-562. [PMID: 26415537 DOI: 10.1016/j.neuropharm.2015.09.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 09/10/2015] [Accepted: 09/12/2015] [Indexed: 12/28/2022]
Abstract
Many behavioral experiences are known to promote hippocampal neurogenesis. In contrast, the ability of behavioral experiences to influence the production of oligodendrocytes and myelin sheath formation remains relatively unknown. However, several recent studies indicate that voluntary exercise and environmental enrichment can positively influence both oligodendrogenesis and myelination, and that, in contrast, social isolation can negatively influence myelination. In this review we summarize studies addressing the influence of behavioral experiences on oligodendrocyte lineage cells and myelin, and highlight potential mechanisms including experience-dependent neuronal activity, metabolites, and stress effectors, as well as both local and systemic secreted factors. Although more study is required to better understand the underlying mechanisms by which behavioral experiences regulate oligodendrocyte lineage cells, this exciting and newly emerging field has already revealed that oligodendrocytes and their progenitors are highly responsive to behavioral experiences and suggest the existence of a complex network of reciprocal interactions among oligodendrocyte lineage development, behavioral experiences, and brain function. Achieving a better understanding of these relationships may have profound implications for human health, and in particular, for our understanding of changes in brain function that occur in response to experiences. This article is part of the Special Issue entitled 'Oligodendrocytes in Health and Disease'.
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252
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Krogsrud SK, Fjell AM, Tamnes CK, Grydeland H, Mork L, Due-Tønnessen P, Bjørnerud A, Sampaio-Baptista C, Andersson J, Johansen-Berg H, Walhovd KB. Changes in white matter microstructure in the developing brain--A longitudinal diffusion tensor imaging study of children from 4 to 11years of age. Neuroimage 2015; 124:473-486. [PMID: 26375208 PMCID: PMC4655940 DOI: 10.1016/j.neuroimage.2015.09.017] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 08/19/2015] [Accepted: 09/07/2015] [Indexed: 01/08/2023] Open
Abstract
The purpose of the present study was to detail the childhood developmental course of different white matter (WM) characteristics. In a longitudinal diffusion tensor imaging (DTI) study of 159 healthy children between 4 and 11years scanned twice, we used tract-based spatial statistics as well as delineation of 15 major WM tracts to characterize the regional pattern of change in fractional anisotropy (FA), mean (MD), radial (RD) and axial diffusivity (AD). We tested whether there were decelerations of change with increasing age globally and tract-wise, and also illustrated change along medial-to-lateral, posterior-to-anterior and inferior-to-superior gradients. We found a significant linear increase in global FA, and decrease in MD and RD over time. For mean AD, a weak decrease was observed. The developmental changes in specific WM tracts showed regional differences. Eight WM tracts showed non-linear development patterns for one or several DTI metrics, with a deceleration in change with age. Sex did not affect change in any DTI metric. Overall, greater rate of change was found in the left hemisphere. Spatially, there was a posterior-to-anterior gradient of change with greater change in frontal regions for all metrics. The current study provides a comprehensive characterization of the regional patters of change in WM microstructure across pre-adolescence childhood.
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Affiliation(s)
- Stine K Krogsrud
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway.
| | - Anders M Fjell
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway; Department of Physical Medicine and Rehabilitation, Unit of Neuropsychology, Oslo University Hospital, Norway
| | - Christian K Tamnes
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway
| | - Håkon Grydeland
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway
| | - Lia Mork
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway
| | - Paulina Due-Tønnessen
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway; Department of Radiology, Rikshospitalet, Oslo University Hospital, Norway
| | - Atle Bjørnerud
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway; The Interventional Centre, Rikshospitalet, Oslo University Hospital, Norway
| | - Cassandra Sampaio-Baptista
- The Oxford Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Jesper Andersson
- The Oxford Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Heidi Johansen-Berg
- The Oxford Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Kristine B Walhovd
- Research Group for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway; Department of Physical Medicine and Rehabilitation, Unit of Neuropsychology, Oslo University Hospital, Norway
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253
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Miras-Portugal MT, Gomez-Villafuertes R, Gualix J, Diaz-Hernandez JI, Artalejo AR, Ortega F, Delicado EG, Perez-Sen R. Nucleotides in neuroregeneration and neuroprotection. Neuropharmacology 2015; 104:243-54. [PMID: 26359530 DOI: 10.1016/j.neuropharm.2015.09.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/01/2015] [Accepted: 09/02/2015] [Indexed: 02/03/2023]
Abstract
Brain injury generates the release of a multitude of factors including extracellular nucleotides, which exhibit bi-functional properties and contribute to both detrimental actions in the acute phase and also protective and reparative actions in the later recovery phase to allow neuroregeneration. A promising strategy toward restoration of neuronal function is based on activation of endogenous adult neural stem/progenitor cells. The implication of purinergic signaling in stem cell biology, including regulation of proliferation, differentiation, and cell death has become evident in the last decade. In this regard, current strategies of acute transplantation of ependymal stem/progenitor cells after spinal cord injury restore altered expression of P2X4 and P2X7 receptors and improve functional locomotor recovery. The expression of both receptors is transcriptionally regulated by Sp1 factor, which plays a key role in the startup of the transcription machinery to induce regeneration-associated genes expression. Finally, general signaling pathways triggered by nucleotide receptors in neuronal populations converge on several intracellular kinases, such as PI3K/Akt, GSK3 and ERK1,2, as well as the Nrf-2/heme oxigenase-1 axis, which specifically link them to neuroprotection. In this regard, regulation of dual specificity protein phosphatases can become novel mechanism of actions for nucleotide receptors that associate them to cell homeostasis regulation. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
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Affiliation(s)
- M Teresa Miras-Portugal
- Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain
| | - Rosa Gomez-Villafuertes
- Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain.
| | - Javier Gualix
- Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain
| | - Juan Ignacio Diaz-Hernandez
- Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain
| | - Antonio R Artalejo
- Department of Toxicology and Pharmacology, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain
| | - Felipe Ortega
- Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain
| | - Esmerilda G Delicado
- Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain
| | - Raquel Perez-Sen
- Department of Biochemistry and Molecular Biology IV, Veterinary School, Universidad Complutense of Madrid, 28040 Madrid, Spain
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254
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Abstract
Neonatal hypoxia-ischemia (H-I) is the leading cause of brain damage resulting from birth complications. Studies in neonatal rats have shown that H-I acutely expands the numbers of neural precursors (NPs) within the subventricular zone (SVZ). The aim of these studies was to establish which NPs expand after H-I and to determine how leukemia inhibitory factor (LIF) insufficiency affects their response. During recovery from H-I, the number of Ki67(+) cells in the medial SVZ of the injured hemisphere increased. Similarly, the number and size of primary neurospheres produced from the injured SVZ increased approximately twofold versus controls, and, upon differentiation, more than twice as many neurospheres from the damaged brain were tripotential, suggesting an increase in neural stem cells (NSCs). However, multimarker flow cytometry for CD133/LeX/NG2/CD140a combined with EdU incorporation revealed that NSC frequency diminished after H-I, whereas that of two multipotential progenitors and three unique glial-restricted precursors expanded, attributable to changes in their proliferation. By quantitative PCR, interleukin-6, LIF, and CNTF mRNA increased but with significantly different time courses, with LIF expression correlating best with NP expansion. Therefore, we evaluated the NP response to H-I in LIF-haplodeficient mice. Flow cytometry revealed that one subset of multipotential and bipotential intermediate progenitors did not increase after H-I, whereas another subset was amplified. Altogether, our studies demonstrate that neonatal H-I alters the composition of the SVZ and that LIF is a key regulator for a subset of intermediate progenitors that expand during acute recovery from neonatal H-I.
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255
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Wake H, Ortiz FC, Woo DH, Lee PR, Angulo MC, Fields RD. Nonsynaptic junctions on myelinating glia promote preferential myelination of electrically active axons. Nat Commun 2015; 6:7844. [PMID: 26238238 PMCID: PMC4532789 DOI: 10.1038/ncomms8844] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 06/18/2015] [Indexed: 11/16/2022] Open
Abstract
The myelin sheath on vertebrate axons is critical for neural impulse transmission, but whether electrically active axons are preferentially myelinated by glial cells, and if so, whether axo-glial synapses are involved, are long-standing questions of significance to nervous system development, plasticity and disease. Here we show using an in vitro system that oligodendrocytes preferentially myelinate electrically active axons, but synapses from axons onto myelin-forming oligodendroglial cells are not required. Instead, vesicular release at nonsynaptic axo-glial junctions induces myelination. Axons releasing neurotransmitter from vesicles that accumulate in axon varicosities induces a local rise in cytoplasmic calcium in glial cell processes at these nonsynaptic functional junctions, and this signalling stimulates local translation of myelin basic protein to initiate myelination. The myelin sheath on vertebrate axons is critical for neural impulse transmission, but whether electrically active axons are preferentially myelinated by glial cells, is not clear. Here the authors show that cultured oligodendrocytes preferentially myelinate electrically active axons via a mechanism dependent on nonsynaptic vesicular release of glutamate.
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Affiliation(s)
- Hiroaki Wake
- Section on Nervous System Development and Plasticity, National Institutes of Health, National Institute of Child Health and Human Development, Building 35, Room 2A211, MSC 3713, 35 Lincoln Drive, Bethesda, Maryland 20892, USA
| | - Fernando C Ortiz
- 1] INSERM U1128, 75006 Paris, France [2] Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France
| | - Dong Ho Woo
- Section on Nervous System Development and Plasticity, National Institutes of Health, National Institute of Child Health and Human Development, Building 35, Room 2A211, MSC 3713, 35 Lincoln Drive, Bethesda, Maryland 20892, USA
| | - Philip R Lee
- Section on Nervous System Development and Plasticity, National Institutes of Health, National Institute of Child Health and Human Development, Building 35, Room 2A211, MSC 3713, 35 Lincoln Drive, Bethesda, Maryland 20892, USA
| | - María Cecilia Angulo
- 1] INSERM U1128, 75006 Paris, France [2] Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France
| | - R Douglas Fields
- Section on Nervous System Development and Plasticity, National Institutes of Health, National Institute of Child Health and Human Development, Building 35, Room 2A211, MSC 3713, 35 Lincoln Drive, Bethesda, Maryland 20892, USA
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256
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Wilhelm CJ, Hashimoto JG, Roberts ML, Bloom SH, Andrew MR, Wiren KM. Astrocyte Dysfunction Induced by Alcohol in Females but Not Males. Brain Pathol 2015; 26:433-51. [PMID: 26088166 DOI: 10.1111/bpa.12276] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/10/2015] [Indexed: 01/08/2023] Open
Abstract
Chronic alcohol abuse is associated with brain damage in a sex-specific fashion, but the mechanisms involved are poorly described and remain controversial. Previous results have suggested that astrocyte gene expression is influenced by ethanol intoxication and during abstinence in vivo. Here, bioinformatic analysis of astrocyte-enriched ethanol-regulated genes in vivo revealed ubiquitin pathways as an ethanol target, but with sexually dimorphic cytokine signaling and changes associated with brain aging in females and not males. Consistent with this result, astrocyte activation was observed after exposure in female but not male animals, with reduced S100β levels in the anterior cingulate cortex and increased GFAP(+) cells in the hippocampus. In primary culture, the direct effects of chronic ethanol exposure followed by recovery on sex-specific astrocyte function were examined. Male astrocyte responses were consistent with astrocyte deactivation with reduced GFAP expression during ethanol exposure. In contrast, female astrocytes exhibited increased expression of Tnf, reduced expression of the neuroprotective cytokine Tgfb1, disrupted bioenergetics and reduced excitatory amino acid uptake following exposure or recovery. These results indicate widespread astrocyte dysfunction in ethanol-exposed females and suggest a mechanism that may underlie increased vulnerability to ethanol-induced neurotoxicity in females.
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Affiliation(s)
- Clare J Wilhelm
- VA Portland Health Care System, Portland, OR.,Department of Psychiatry, Oregon Health & Science University, Portland, OR
| | - Joel G Hashimoto
- VA Portland Health Care System, Portland, OR.,Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR
| | | | | | - Melissa R Andrew
- Cincinnati Center for Growth Disorders, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Kristine M Wiren
- VA Portland Health Care System, Portland, OR.,Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR
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257
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Improved differentiation of oligodendrocyte precursor cells and neurological function after spinal cord injury in rats by oscillating field stimulation. Neuroscience 2015; 303:346-51. [PMID: 26166729 DOI: 10.1016/j.neuroscience.2015.07.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 07/03/2015] [Accepted: 07/04/2015] [Indexed: 12/29/2022]
Abstract
Oscillating field stimulation (OFS) has been used in attempts to treat spinal cord injury (SCI) and has been shown to improve remyelination after SCI in rats. However, some controversies regarding the effects of OFS have been presented in previous papers. Oligodendrocytes (OLs) are the main cell for remyelination and are derived from the differentiation of oligodendrocyte precursor cells (OPCs). To date, it has been unclear whether the differentiation of OPCs can be regulated by OFS. The goal of this study was to determine if OFS can improve the differentiation of OPCs and promote the recovery of neurological function after SCI in rats. Immature and mature OLs were observed in spinal cord slices through immunofluorescence staining. Levels of adenosine triphosphate (ATP) and the cytokine leukemia inhibitory factor (LIF) were detected by enzyme-linked immunosorbent assay (ELISA). Basso-Beattie-Bresnahan (BBB) scores and transcranial magnetic motor-evoked potentials (tcMMEPs) were used to evaluate the locomotor outcomes of rats after SCI. Our results showed a significant improvement in the differentiation of OPCs and the content of ATP and LIF in the injured spinal cord in the OFS group. Furthermore, BBB scores and tcMMEPs were significantly improved in the rats stimulated by OFS. These findings suggest that OFS can improve the differentiation of OPCs and promote the recovery of neurological function following SCI in rats.
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258
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Fields RD, Woo DH, Basser PJ. Glial Regulation of the Neuronal Connectome through Local and Long-Distant Communication. Neuron 2015; 86:374-86. [PMID: 25905811 DOI: 10.1016/j.neuron.2015.01.014] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
If "the connectome" represents a complete map of anatomical and functional connectivity in the brain, it should also include glia. Glia define and regulate both the brain's anatomical and functional connectivity over a broad range of length scales, spanning the whole brain to subcellular domains of synaptic interactions. This Perspective article examines glial interactions with the neuronal connectome (including long-range networks, local circuits, and individual synaptic connections) and highlights opportunities for future research. Our understanding of the structure and function of the neuronal connectome would be incomplete without an understanding of how all types of glia contribute to neuronal connectivity and function, from single synapses to circuits.
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Affiliation(s)
- R Douglas Fields
- Nervous System Development and Plasticity Section, The Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA.
| | - Dong Ho Woo
- Nervous System Development and Plasticity Section, The Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Peter J Basser
- Section on Tissue Biophysics and Biomimetics, Program on Pediatric Imaging and Tissue Sciences, The Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
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259
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Partridge MA, Gopinath S, Myers SJ, Coorssen JR. An initial top-down proteomic analysis of the standard cuprizone mouse model of multiple sclerosis. J Chem Biol 2015; 9:9-18. [PMID: 26855677 DOI: 10.1007/s12154-015-0138-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Accepted: 05/28/2015] [Indexed: 11/29/2022] Open
Abstract
An initial proteomic analysis of the cuprizone mouse model to characterise the breadth of toxicity by assessing cortex, skeletal muscle, spleen and peripheral blood mononuclear cells. Cuprizone treated vs. control mice for an initial characterisation. Select tissues from each group were pooled, analysed in triplicate using two-dimensional gel electrophoresis (2DE) and deep imaging and altered protein species identified using liquid chromatography tandem mass spectrometry (LC/MS/MS). Forty-three proteins were found to be uniquely detectable or undetectable in the cuprizone treatment group across the tissues analysed. Protein species identified in the cortex may potentially be linked to axonal damage in this model, and those in the spleen and peripheral blood mononuclear cells to the minimal peripheral immune cell infiltration into the central nervous system during cuprizone mediated demyelination. Primary oligodendrocytosis has been observed in type III lesions in multiple sclerosis. However, the underlying mechanisms are poorly understood. Cuprizone treatment results in oligodendrocyte apoptosis and secondary demyelination. This initial analysis identified proteins likely related to axonal damage; these may link primary oligodendrocytosis and secondary axonal damage. Furthermore, this appears to be the first study of the cuprizone model to also identify alterations in the proteomes of skeletal muscle, spleen and peripheral blood mononuclear cells. Notably, protein disulphide isomerase was not detected in the cuprizone cohort; its absence has been linked to reduced major histocompatibility class I assembly and reduced antigen presentation. Overall, the results suggest that, like experimental autoimmune encephalomyelitis, results from the standard cuprizone model should be carefully considered relative to clinical multiple sclerosis.
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Affiliation(s)
- Melissa A Partridge
- Department of Molecular Physiology, School of Medicine, University of Western Sydney, Penrith, NSW Australia ; Molecular Medicine Research Group, School of Medicine, University of Western Sydney, Penrith, NSW Australia
| | - Sumana Gopinath
- Molecular Medicine Research Group, School of Medicine, University of Western Sydney, Penrith, NSW Australia ; Department of Neurology, Campbelltown Hospital, Campbelltown, NSW Australia
| | - Simon J Myers
- Molecular Medicine Research Group, School of Medicine, University of Western Sydney, Penrith, NSW Australia ; Neuro-Cell Biology Laboratory, School of Science and Health, University of Western Sydney, Penrith, NSW Australia
| | - Jens R Coorssen
- Department of Molecular Physiology, School of Medicine, University of Western Sydney, Penrith, NSW Australia ; Molecular Medicine Research Group, School of Medicine, University of Western Sydney, Penrith, NSW Australia
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260
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Burnstock G. An introduction to the roles of purinergic signalling in neurodegeneration, neuroprotection and neuroregeneration. Neuropharmacology 2015; 104:4-17. [PMID: 26056033 DOI: 10.1016/j.neuropharm.2015.05.031] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 05/19/2015] [Accepted: 05/20/2015] [Indexed: 12/21/2022]
Abstract
Purinergic signalling appears to play important roles in neurodegeneration, neuroprotection and neuroregeneration. Initially there is a brief summary of the background of purinergic signalling, including release of purines and pyrimidines from neural and non-neural cells and their ectoenzymatic degradation, and the current characterisation of P1 (adenosine), and P2X (ion channel) and P2Y (G protein-coupled) nucleotide receptor subtypes. There is also coverage of the localization and roles of purinoceptors in the healthy central nervous system. The focus is then on the roles of purinergic signalling in trauma, ischaemia, stroke and in neurodegenerative diseases, including Alzheimer's, Parkinson's and Huntington's diseases, as well as multiple sclerosis and amyotrophic lateral sclerosis. Neuroprotective mechanisms involving purinergic signalling are considered and its involvement in neuroregeneration, including the role of adult neural stem/progenitor cells. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London NW3 2PF, UK; Department of Pharmacology and Therapeutics, The University of Melbourne, Australia.
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261
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Olude MA, Mustapha OA, Aderounmu OA, Olopade JO, Ihunwo AO. Astrocyte morphology, heterogeneity, and density in the developing African giant rat (Cricetomys gambianus). Front Neuroanat 2015; 9:67. [PMID: 26074782 PMCID: PMC4443027 DOI: 10.3389/fnana.2015.00067] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/11/2015] [Indexed: 01/22/2023] Open
Abstract
Astrocyte morphologies and heterogeneity were described in male African giant rats (AGR; Cricetomys gambianus, Waterhouse) across three age groups (five neonates, five juveniles, and five adults) using Silver impregnation method and immunohistochemistry against glial fibrillary acidic protein. Immunopositive cell signaling, cell size and population were least in neonates, followed by adults and juveniles, respectively. In neonates, astrocyte processes were mostly detected within the glia limitans of the mid and hind brain; their cell bodies measuring 32 ± 4.8 μm in diameter against 91 ± 5.4 μm and 75 ± 1.9 μm in juveniles and adults, respectively. Astrocyte heterogeneity in juvenile and adult groups revealed eight subtypes to include fibrous astrocytes chiefly in the corpus callosum and brain stem, protoplasmic astrocytes in the cortex and dentate gyrus (DG); radial glia were found along the olfactory bulb (OB) and subventricular zone (SVZ); velate astrocytes were mainly found in the cerebellum and hippocampus; marginal astrocytes close to the pia mater; Bergmann glia in the molecular layer of the cerebellum; perivascular and periventricular astrocytes in the cortex and third ventricle, respectively. Cell counts from twelve anatomical regions of the brain were significantly higher in juveniles than in adults (p ≤ 0.01) using unpaired student t-test in the cerebral cortex, pia, corpus callosum, rostral migratory stream, DG, and cerebellum. Highest astrocyte count was found in the DG, while the least count was in the brain stem and sub cortex. Astrocytes along the periventricular layer of the OB are believed to be part of the radial glia system that transport newly formed cells towards the hippocampus and play roles in neurogenesis migration and homeostasis in the AGR. Therefore, astrocyte heterogeneity was examined across age groups in the AGR to determine whether age influences astrocytes population in different regions of the AGR brain and discuss possible functional roles.
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Affiliation(s)
- Matthew A Olude
- Neuroscience Unit, Department of Veterinary Anatomy, Federal University of Agriculture Abeokuta, Nigeria ; Neuroscience Unit, Department of Veterinary Anatomy, University of Ibadan Ibadan, Nigeria ; School of Anatomical Sciences, Neuroscience Unit, University of the Witwatersrand Johannesburg, South Africa
| | - Oluwaseun A Mustapha
- Neuroscience Unit, Department of Veterinary Anatomy, Federal University of Agriculture Abeokuta, Nigeria ; Neuroscience Unit, Department of Veterinary Anatomy, University of Ibadan Ibadan, Nigeria
| | - Oluwatunde A Aderounmu
- Neuroscience Unit, Department of Veterinary Anatomy, Federal University of Agriculture Abeokuta, Nigeria ; Neuroscience Unit, Department of Veterinary Anatomy, University of Ibadan Ibadan, Nigeria
| | - James O Olopade
- Neuroscience Unit, Department of Veterinary Anatomy, Federal University of Agriculture Abeokuta, Nigeria
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Neuroscience Unit, University of the Witwatersrand Johannesburg, South Africa
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262
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Takebayashi H, Ikenaka K. Oligodendrocyte generation during mouse development. Glia 2015; 63:1350-6. [PMID: 26013243 DOI: 10.1002/glia.22863] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 04/30/2015] [Indexed: 12/15/2022]
Abstract
Oligodendrocytes (OLs) are glial cells, which generate myelin in the central nervous system. Their interesting developmental features attract many neurobiologists eager to study cell differentiation, gene expression regulation, or dynamic morphogenesis. Their primary role in protecting the axons has major impacts in the medical research field: in multiple sclerosis, a demyelinating disease in which remyelination is blocked. Oligodendrogenesis is involved in higher brain function including motor skill learning and cognitive function. Here, we review advances in the research on OL development and highlight areas where questions remain to be answered in both developmental biology and neurobiology related aspects.
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Affiliation(s)
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan
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263
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Roe C. Can neurotrophic cytokines help to regenerate the mammalian central nervous system? Int J Neurosci 2015; 126:669-70. [PMID: 26000915 DOI: 10.3109/00207454.2015.1049266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Cieron Roe
- a Brighton and Sussex Medical School , Brighton , United Kingdom
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264
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Social Experience-Dependent Myelination: An Implication for Psychiatric Disorders. Neural Plast 2015; 2015:465345. [PMID: 26078885 PMCID: PMC4452491 DOI: 10.1155/2015/465345] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/05/2015] [Accepted: 05/06/2015] [Indexed: 12/02/2022] Open
Abstract
Myelination is one of the strategies to promote the conduction velocity of axons in order to adjust to evolving environment in vertebrates. It has been shown that myelin formation depends on genetic programing and experience, including multiple factors, intracellular and extracellular molecules, and neuronal activities. Recently, accumulating studies have shown that myelination in the central nervous system changes more dynamically in response to neuronal activities and experience than expected. Among experiences, social experience-dependent myelination draws attention as one of the critical pathobiologies of psychiatric disorders. In this review, we summarize the mechanisms of neuronal activity-dependent and social experience-dependent myelination and discuss the contribution of social experience-dependent myelination to the pathology of psychiatric disorders.
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265
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Lindner M, Thümmler K, Arthur A, Brunner S, Elliott C, McElroy D, Mohan H, Williams A, Edgar JM, Schuh C, Stadelmann C, Barnett SC, Lassmann H, Mücklisch S, Mudaliar M, Schaeren-Wiemers N, Meinl E, Linington C. Fibroblast growth factor signalling in multiple sclerosis: inhibition of myelination and induction of pro-inflammatory environment by FGF9. Brain 2015; 138:1875-93. [PMID: 25907862 PMCID: PMC7185739 DOI: 10.1093/brain/awv102] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 02/14/2015] [Indexed: 12/18/2022] Open
Abstract
Remyelination failure plays an important role in the pathophysiology of multiple sclerosis, but the underlying cellular and molecular mechanisms remain poorly understood. We now report actively demyelinating lesions in patients with multiple sclerosis are associated with increased glial expression of fibroblast growth factor 9 (FGF9), which we demonstrate inhibits myelination and remyelination in vitro. This inhibitory activity is associated with the appearance of multi-branched ‘pre-myelinating’ MBP+/PLP+ oligodendrocytes that interact with axons but fail to assemble myelin sheaths; an oligodendrocyte phenotype described previously in chronically demyelinated multiple sclerosis lesions. This inhibitory activity is not due to a direct effect of FGF9 on cells of the oligodendrocyte lineage but is mediated by factors secreted by astrocytes. Transcriptional profiling and functional validation studies demonstrate that these include effects dependent on increased expression of tissue inhibitor of metalloproteinase-sensitive proteases, enzymes more commonly associated with extracellular matrix remodelling. Further, we found that FGF9 induces expression of Ccl2 and Ccl7, two pro-inflammatory chemokines that contribute to recruitment of microglia and macrophages into multiple sclerosis lesions. These data indicate glial expression of FGF9 can initiate a complex astrocyte-dependent response that contributes to two distinct pathogenic pathways involved in the development of multiple sclerosis lesions. Namely, induction of a pro-inflammatory environment and failure of remyelination; a combination of effects predicted to exacerbate axonal injury and loss in patients.
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Affiliation(s)
- Maren Lindner
- 1 Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Katja Thümmler
- 1 Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Ariel Arthur
- 1 Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Sarah Brunner
- 2 Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Christina Elliott
- 1 Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Daniel McElroy
- 1 Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Hema Mohan
- 3 Institute of Clinical Neuroimmunology, Ludwig-Maximilians-Universität, Munich, Germany
| | - Anna Williams
- 4 MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - Julia M Edgar
- 1 Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Cornelia Schuh
- 5 Centre for Brain Research, Medical University of Vienna, Vienna, Austria
| | | | - Susan C Barnett
- 1 Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Hans Lassmann
- 5 Centre for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Steve Mücklisch
- 7 Department of Computer Science, Chemnitz University of Technology, Chemnitz, Germany
| | - Manikhandan Mudaliar
- 8 Glasgow Polyomics, College of Medical, Veterinary and Life Science, University of Glasgow, UK
| | - Nicole Schaeren-Wiemers
- 2 Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Edgar Meinl
- 3 Institute of Clinical Neuroimmunology, Ludwig-Maximilians-Universität, Munich, Germany
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266
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Dietrich S, Hertrich I, Kumar V, Ackermann H. Experience-related structural changes of degenerated occipital white matter in late-blind humans - a diffusion tensor imaging study. PLoS One 2015; 10:e0122863. [PMID: 25830371 PMCID: PMC4382192 DOI: 10.1371/journal.pone.0122863] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 02/16/2015] [Indexed: 12/21/2022] Open
Abstract
Late-blind humans can learn to understand speech at ultra-fast syllable rates (ca. 20 syllables/s), a capability associated with hemodynamic activation of the central-visual system. Thus, the observed functional cross-modal recruitment of occipital cortex might facilitate ultra-fast speech processing in these individuals. To further elucidate the structural prerequisites of this skill, diffusion tensor imaging (DTI) was conducted in late-blind subjects differing in their capability of understanding ultra-fast speech. Fractional anisotropy (FA) was determined as a quantitative measure of the directionality of water diffusion, indicating fiber tract characteristics that might be influenced by blindness as well as the acquired perceptual skills. Analysis of the diffusion images revealed reduced FA in late-blind individuals relative to sighted controls at the level of the optic radiations at either side and the right-hemisphere dorsal thalamus (pulvinar). Moreover, late-blind subjects showed significant positive correlations between FA and the capacity of ultra-fast speech comprehension within right-hemisphere optic radiation and thalamus. Thus, experience-related structural alterations occurred in late-blind individuals within visual pathways that, presumably, are linked to higher order frontal language areas.
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Affiliation(s)
- Susanne Dietrich
- Department of General Neurology—Center for Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany
- * E-mail:
| | - Ingo Hertrich
- Department of General Neurology—Center for Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany
| | - Vinod Kumar
- Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital, RWTH, Aachen University, Aachen, Germany
| | - Hermann Ackermann
- Department of General Neurology—Center for Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Str. 3, D-72076, Tübingen, Germany
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267
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Thompson DM, Koppes AN, Hardy JG, Schmidt CE. Electrical stimuli in the central nervous system microenvironment. Annu Rev Biomed Eng 2015; 16:397-430. [PMID: 25014787 DOI: 10.1146/annurev-bioeng-121813-120655] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Electrical stimulation to manipulate the central nervous system (CNS) has been applied as early as the 1750s to produce visual sensations of light. Deep brain stimulation (DBS), cochlear implants, visual prosthetics, and functional electrical stimulation (FES) are being applied in the clinic to treat a wide array of neurological diseases, disorders, and injuries. This review describes the history of electrical stimulation of the CNS microenvironment; recent advances in electrical stimulation of the CNS, including DBS to treat essential tremor, Parkinson's disease, and depression; FES for the treatment of spinal cord injuries; and alternative electrical devices to restore vision and hearing via neuroprosthetics (retinal and cochlear implants). It also discusses the role of electrical cues during development and following injury and, importantly, manipulation of these endogenous cues to support regeneration of neural tissue.
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Affiliation(s)
- Deanna M Thompson
- Department of Biomedical Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180;
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268
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Jukkola P, Gu C. Regulation of neurovascular coupling in autoimmunity to water and ion channels. Autoimmun Rev 2015; 14:258-67. [PMID: 25462580 PMCID: PMC4303502 DOI: 10.1016/j.autrev.2014.11.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 11/15/2014] [Indexed: 12/27/2022]
Abstract
Much progress has been made in understanding autoimmune channelopathies, but the underlying pathogenic mechanisms are not always clear due to broad expression of some channel proteins. Recent studies show that autoimmune conditions that interfere with neurovascular coupling in the central nervous system (CNS) can lead to neurodegeneration. Cerebral blood flow that meets neuronal activity and metabolic demand is tightly regulated by local neural activity. This process of reciprocal regulation involves coordinated actions of a number of cell types, including neurons, glia, and vascular cells. In particular, astrocytic endfeet cover more than 90% of brain capillaries to assist blood-brain barrier (BBB) function, and wrap around synapses and nodes of Ranvier to communicate with neuronal activity. In this review, we highlight four types of channel proteins that are expressed in astrocytes, regarding their structures, biophysical properties, expression and distribution patterns, and related diseases including autoimmune disorders. Water channel aquaporin 4 (AQP4) and inwardly rectifying potassium (Kir4.1) channels are concentrated in astrocytic endfeet, whereas some voltage-gated Ca(2+) and two-pore domain K(+) channels are expressed throughout the cell body of reactive astrocytes. More channel proteins are found in astrocytes under normal and abnormal conditions. This research field will contribute to a better understanding of pathogenic mechanisms underlying autoimmune disorders.
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Affiliation(s)
- Peter Jukkola
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH 43210, USA
| | - Chen Gu
- Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH 43210, USA; Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA.
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269
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Razavi S, Nazem G, Mardani M, Esfandiari E, Salehi H, Esfahani SHZ. Neurotrophic factors and their effects in the treatment of multiple sclerosis. Adv Biomed Res 2015; 4:53. [PMID: 25802822 PMCID: PMC4361963 DOI: 10.4103/2277-9175.151570] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 04/24/2014] [Indexed: 12/24/2022] Open
Abstract
Neurotrophins are small molecules of polypeptides, which include nerve growth factor (NGF) family, glial cell line–derived neurotrophic factor (GDNF) family ligands, and neuropoietic cytokines. These factors have an important role in neural regeneration, remyelination, and regulating the development of the peripheral and central nervous systems (PNS and CNS, respectively) by intracellular signaling through specific receptors. It has been suggested that the pathogenesis of human neurodegenerative disorders may be due to an alteration in the neurotrophic factors and their receptors. The use of neurotrophic factors as therapeutic agents is a novel strategy for restoring and maintaining neuronal function during neurodegenerative disorders such as multiple sclerosis. Innate and adaptive immune responses contribute to pathology of neurodegenerative disorders. Furthermore, autoimmune and mesenchymal stem cells, by the release of neurotrophic factors, have the ability to protect neuronal population and can efficiently suppress the formation of new lesions. So, these cells may be an alternative source for delivering neurotrophic factors into the CNS.
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Affiliation(s)
- Shahnaz Razavi
- Department of Anatomical Sciences and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ghasemi Nazem
- Department of Anatomical Sciences and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Mardani
- Department of Anatomical Sciences and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ebrahim Esfandiari
- Department of Anatomical Sciences and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hossein Salehi
- Department of Anatomical Sciences and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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270
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Pituch KC, Moyano AL, Lopez-Rosas A, Marottoli FM, Li G, Hu C, van Breemen R, Månsson JE, Givogri MI. Dysfunction of platelet-derived growth factor receptor α (PDGFRα) represses the production of oligodendrocytes from arylsulfatase A-deficient multipotential neural precursor cells. J Biol Chem 2015; 290:7040-53. [PMID: 25605750 DOI: 10.1074/jbc.m115.636498] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The membrane-bound receptor for platelet-derived growth factor A (PDGFRα) is crucial for controlling the production of oligodendrocytes (OLs) for myelination, but regulation of its activity during OL differentiation is largely unknown. We have examined the effect of increased sulfated content of galactosylceramides (sulfatides) on the regulation of PDGFRα in multipotential neural precursors (NPs) that are deficient in arylsulfatase A (ASA) activity. This enzyme is responsible for the lysosomal hydrolysis of sulfatides. We show that sulfatide accumulation significantly impacts the formation of OLs via deregulation of PDGFRα function. PDGFRα is less associated with detergent-resistant membranes in ASA-deficient cells and showed a significant decrease in AKT phosphorylation. Rescue experiments with ASA showed a normalization of the ratio of long versus short sulfatides, restored PDGFRα levels, corrected its localization to detergent-resistant membranes, increased AKT phosphorylation, and normalized the production of OLs in ASA-deficient NPs. Moreover, our studies identified a novel mechanism that regulates the secretion of PDGFRα in NPs, in glial cells, and in the brain cortex via exosomal shedding. Our study provides a first step in understanding the role of sulfatides in regulating PDGFRα levels in OLs and its impact in myelination.
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Affiliation(s)
- Katarzyna C Pituch
- From the Department of Anatomy and Cell Biology, College of Medicine, and
| | - Ana L Moyano
- From the Department of Anatomy and Cell Biology, College of Medicine, and
| | - Aurora Lopez-Rosas
- From the Department of Anatomy and Cell Biology, College of Medicine, and
| | | | - Guannan Li
- the Department of Medical Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois, Chicago, Illinois 60612 and
| | - Chenqi Hu
- the Department of Medical Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois, Chicago, Illinois 60612 and
| | - Richard van Breemen
- the Department of Medical Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois, Chicago, Illinois 60612 and
| | - Jan E Månsson
- the Department of Clinical Chemistry, Sahlgren Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden
| | - Maria I Givogri
- From the Department of Anatomy and Cell Biology, College of Medicine, and
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271
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Schlegel A, Alexander P, Fogelson SV, Li X, Lu Z, Kohler PJ, Riley E, Tse PU, Meng M. The artist emerges: Visual art learning alters neural structure and function. Neuroimage 2015; 105:440-51. [DOI: 10.1016/j.neuroimage.2014.11.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 10/19/2014] [Accepted: 11/07/2014] [Indexed: 12/21/2022] Open
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272
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Bierer LM, Ivanov I, Carpenter DM, Wong EW, Golier JA, Tang CY, Yehuda R. White matter abnormalities in Gulf War veterans with posttraumatic stress disorder: A pilot study. Psychoneuroendocrinology 2015; 51:567-76. [PMID: 25465169 DOI: 10.1016/j.psyneuen.2014.11.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 10/01/2014] [Accepted: 11/10/2014] [Indexed: 11/16/2022]
Abstract
BACKGROUND Gulf War veterans were exposed to environmental toxins not present in other combat theaters resulting in a unique biological signature that only partially resembles that seen in other combat veterans with PTSD. Thus it is important to determine if brain abnormalities seen in non-Gulf War veterans with PTSD are also present in Gulf War veterans. In this pilot study, diffusion tensor imaging (DTI) tractography was used to assess the ultra-structural integrity of fronto-limbic white matter connections in Gulf War veterans with and without PTSD. The effects of chronic multisymptom illness on DTI measures was also evaluated. METHODS Subjects were 20 previously studied Gulf War veterans on whom MRIs had been obtained. Mean diffusivity (MD) and fractional anisotropy (FA) were determined for left and right cingulum bundle by DTI tractography and compared in separate analyses for 12 veterans with, and 8 without PTSD. The effect of chronic multisymptom illness and it's interaction with PTSD, were similarly investigated using multivariate ACOVA. Partial correlations were used to test the associations of both DTI indices with PTSD severity and plasma cortisol, controlling for whole brain volume. RESULTS Significantly lower MD was demonstrated in the right cingulum bundle among Gulf War veterans with PTSD. There were no significant differences in MD or FA in the left cingulum bundle. The presence of chronic multisymptom illness significantly attenuated the PTSD associated decrement in right cingulum MD. Clinician and self-rated PTSD symptom severity scores were significantly associated with reduced MD and increased FA in the right cingulum. Similar associations were observed for 8am plasma cortisol in a subset of participants. CONCLUSIONS The preliminary findings indicate increased structural integrity - supporting enhanced connectivity - between right amygdala and anterior cingulate cortex in PTSD. This effect was strongest among Gulf War veterans without chronic multisymptom illness. The association of both MD and FA in the right cingulum with PTSD severity, and with heightened glucocorticoid responsivity, suggests that these DTI findings are a reflection of current PTSD illness expression. Although based on a small sample, these microstructural observations are consistent with a functional model suggesting increased amygdala responsivity in association with anterior cingulate modulation in PTSD.
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Affiliation(s)
- Linda M Bierer
- Department of Psychiatry, Traumatic Stress Studies Division, Icahn School of Medicine at Mount Sinai, United States; Traumatic Stress Studies Division, James J. Peters VA Medical Center, United States.
| | - Iliyan Ivanov
- Department of Psychiatry, Traumatic Stress Studies Division, Icahn School of Medicine at Mount Sinai, United States; Traumatic Stress Studies Division, James J. Peters VA Medical Center, United States
| | - David M Carpenter
- Department of Radiology, Icahn School of Medicine at Mount Sinai, United States
| | - Edmund W Wong
- Department of Radiology, Icahn School of Medicine at Mount Sinai, United States
| | - Julia A Golier
- Department of Psychiatry, Traumatic Stress Studies Division, Icahn School of Medicine at Mount Sinai, United States; Traumatic Stress Studies Division, James J. Peters VA Medical Center, United States
| | - Cheuk Y Tang
- Department of Radiology, Icahn School of Medicine at Mount Sinai, United States
| | - Rachel Yehuda
- Department of Psychiatry, Traumatic Stress Studies Division, Icahn School of Medicine at Mount Sinai, United States; Traumatic Stress Studies Division, James J. Peters VA Medical Center, United States
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273
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Matejko AA, Ansari D. Drawing connections between white matter and numerical and mathematical cognition: A literature review. Neurosci Biobehav Rev 2015; 48:35-52. [DOI: 10.1016/j.neubiorev.2014.11.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 11/05/2014] [Accepted: 11/08/2014] [Indexed: 10/24/2022]
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274
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275
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Nowak LG, Rosay B, Czégé D, Fonta C. Tetramisole and Levamisole Suppress Neuronal Activity Independently from Their Inhibitory Action on Tissue Non-specific Alkaline Phosphatase in Mouse Cortex. Subcell Biochem 2015. [PMID: 26219715 DOI: 10.1007/978-94-017-7197-9_12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tissue non-specific alkaline phosphatase (TNAP) may be involved in the synthesis of GABA and adenosine, which are the main inhibitory neurotransmitters in cortex. We explored this putative TNAP function through electrophysiological recording (local field potential ) in slices of mouse somatosensory cortex maintained in vitro. We used tetramisole, a well documented TNAP inhibitor, to block TNAP activity. We expected that inhibiting TNAP with tetramisole would lead to an increase of neuronal response amplitude, owing to a diminished availability of GABA and/or adenosine. Instead, we found that tetramisole reduced neuronal response amplitude in a dose-dependent manner. Tetramisole also decreased axonal conduction velocity. Levamisole had identical effects. Several control experiments demonstrated that these actions of tetramisole were independent from this compound acting on TNAP. In particular, tetramisole effects were not stereo-specific and they were not mimicked by another inhibitor of TNAP, MLS-0038949. The decrease of axonal conduction velocity and preliminary intracellular data suggest that tetramisole blocks voltage-dependent sodium channels. Our results imply that levamisole or tetramisole should not be used with the sole purpose of inhibiting TNAP in living excitable cells as it will also block all processes that are activity-dependent. Our data and a review of the literature indicate that tetramisole may have at least four different targets in the nervous system. We discuss these results with respect to the neurological side effects that were observed when levamisole and tetramisole were used for medical purposes, and that may recur nowadays due to the recent use of levamisole and tetramisole as cocaine adulterants.
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Affiliation(s)
- Lionel G Nowak
- Centre de Recherche Cerveau et Cognition (CerCo), Université de Toulouse UPS; CNRS UMR 5549 , Toulouse, France,
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276
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P2X and P2Y receptors—role in the pathophysiology of the nervous system. Int J Mol Sci 2014; 15:23672-704. [PMID: 25530618 PMCID: PMC4284787 DOI: 10.3390/ijms151223672] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 12/03/2014] [Accepted: 12/06/2014] [Indexed: 12/16/2022] Open
Abstract
Purinergic signalling plays a crucial role in proper functioning of the nervous system. Mechanisms depending on extracellular nucleotides and their P2 receptors also underlie a number of nervous system dysfunctions. This review aims to present the role of purinergic signalling, with particular focus devoted to role of P2 family receptors, in epilepsy, depression, neuropathic pain, nervous system neoplasms, such as glioma and neuroblastoma, neurodegenerative diseases like Parkinson’s disease, Alzheimer’s disease and multiple sclerosis. The above-mentioned conditions are associated with changes in expression of extracellular ectonucleotidases, P2X and P2Y receptors in neurons and glial cells, as well as releasing considerable amounts of nucleotides from activated or damaged nervous tissue cells into the extracellular space, which contributes to disturbance in purinergic signalling. The numerous studies indicate a potential possibility of using synthetic agonists/antagonists of P2 receptors in treatment of selected nervous system diseases. This is of particular significance, since numerous available agents reveal a low effectiveness and often produce side effects.
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277
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Chen HJ, Chen R, Yang M, Teng GJ, Herskovits EH. Identification of minimal hepatic encephalopathy in patients with cirrhosis based on white matter imaging and Bayesian data mining. AJNR Am J Neuroradiol 2014; 36:481-7. [PMID: 25500314 DOI: 10.3174/ajnr.a4146] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE White matter abnormalities have been demonstrated to play an important role in minimal hepatic encephalopathy. In this study, we aimed to evaluate whether WM diffusion tensor imaging can be used to identify minimal hepatic encephalopathy among patients with cirrhosis. MATERIALS AND METHODS Our study included 65 patients with cirrhosis with covert hepatic encephalopathy (29 with minimal hepatic encephalopathy and 36 without hepatic encephalopathy). Participants underwent DTI, from which we generated mean diffusivity and fractional anisotropy maps. We used a Bayesian machine-learning technique, called Graphical-Model-based Multivariate Analysis, to determine WM regions that characterize group differences. To further test the clinical significance of these potential biomarkers, we performed Cox regression analysis to assess the potential of these WM regions in predicting survival. RESULTS In mean diffusivity or fractional anisotropy maps, 2 spatially distributed WM regions (predominantly located in the bilateral frontal lobes, corpus callosum, and parietal lobes) were consistently identified as differentiating minimal hepatic encephalopathy from no hepatic encephalopathy and yielded 75.4%-81.5% and 83.1%-92.3% classification accuracy, respectively. We were able to follow 55 of 65 patients (median = 18 months), and 15 of these patients eventually died of liver-related causes. Survival analysis indicated that mean diffusivity and fractional anisotropy values in WM regions were predictive of survival, in addition to the Child-Pugh score. CONCLUSIONS Our findings indicate that WM DTI can provide useful biomarkers differentiating minimal hepatic encephalopathy from no hepatic encephalopathy, which would be helpful for minimal hepatic encephalopathy detection and subsequent treatment.
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Affiliation(s)
- H-J Chen
- From the Jiangsu Key Laboratory of Molecular and Functional Imaging (H.-J.C., M.Y., G.-J.T.), Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China Department of Radiology (H.-J.C.), The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - R Chen
- Department of Diagnostic Radiology and Nuclear Medicine (R.C., E.H.H.), University of Maryland School of Medicine, Baltimore, Maryland
| | - M Yang
- From the Jiangsu Key Laboratory of Molecular and Functional Imaging (H.-J.C., M.Y., G.-J.T.), Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China
| | - G-J Teng
- From the Jiangsu Key Laboratory of Molecular and Functional Imaging (H.-J.C., M.Y., G.-J.T.), Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, China
| | - E H Herskovits
- Department of Diagnostic Radiology and Nuclear Medicine (R.C., E.H.H.), University of Maryland School of Medicine, Baltimore, Maryland
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Mohan H, Friese A, Albrecht S, Krumbholz M, Elliott CL, Arthur A, Menon R, Farina C, Junker A, Stadelmann C, Barnett SC, Huitinga I, Wekerle H, Hohlfeld R, Lassmann H, Kuhlmann T, Linington C, Meinl E. Transcript profiling of different types of multiple sclerosis lesions yields FGF1 as a promoter of remyelination. Acta Neuropathol Commun 2014; 2:168. [PMID: 25589163 PMCID: PMC4359505 DOI: 10.1186/s40478-014-0168-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 11/25/2014] [Indexed: 01/17/2023] Open
Abstract
Chronic demyelination is a pathological hallmark of multiple sclerosis (MS). Only a minority of MS lesions remyelinates completely. Enhancing remyelination is, therefore, a major aim of future MS therapies. Here we took a novel approach to identify factors that may inhibit or support endogenous remyelination in MS. We dissected remyelinated, demyelinated active, and demyelinated inactive white matter MS lesions, and compared transcript levels of myelination and inflammation-related genes using quantitative PCR on customized TaqMan Low Density Arrays. In remyelinated lesions, fibroblast growth factor (FGF) 1 was the most abundant of all analyzed myelination-regulating factors, showed a trend towards higher expression as compared to demyelinated lesions and was significantly higher than in control white matter. Two MS tissue blocks comprised lesions with adjacent de- and remyelinated areas and FGF1 expression was higher in the remyelinated rim compared to the demyelinated lesion core. In functional experiments, FGF1 accelerated developmental myelination in dissociated mixed cultures and promoted remyelination in slice cultures, whereas it decelerated differentiation of purified primary oligodendrocytes, suggesting that promotion of remyelination by FGF1 is based on an indirect mechanism. The analysis of human astrocyte responses to FGF1 by genome wide expression profiling showed that FGF1 induced the expression of the chemokine CXCL8 and leukemia inhibitory factor, two factors implicated in recruitment of oligodendrocytes and promotion of remyelination. Together, this study presents a transcript profiling of remyelinated MS lesions and identified FGF1 as a promoter of remyelination. Modulation of FGF family members might improve myelin repair in MS.
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279
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Enriquez-Geppert S, Huster RJ, Figge C, Herrmann CS. Self-regulation of frontal-midline theta facilitates memory updating and mental set shifting. Front Behav Neurosci 2014; 8:420. [PMID: 25538585 PMCID: PMC4257088 DOI: 10.3389/fnbeh.2014.00420] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/17/2014] [Indexed: 11/13/2022] Open
Abstract
Frontal-midline (fm) theta oscillations as measured via the electroencephalogram (EEG) have been suggested as neural "working language" of executive functioning. Their power has been shown to increase when cognitive processing or task performance is enhanced. Thus, the question arises whether learning to increase fm-theta amplitudes would functionally impact the behavioral performance in tasks probing executive functions (EFs). Here, the effects of neurofeedback (NF), a learning method to self-up-regulate fm-theta over fm electrodes, on the four most representative EFs, memory updating, set shifting, conflict monitoring, and motor inhibition are presented. Before beginning and after completing an individualized, eight-session gap-spaced NF intervention, the three-back, letter/number task-switching, Stroop, and stop-signal tasks were tested while measuring the EEG. Self-determined up-regulation of fm-theta and its putative role for executive functioning were compared to an active control group, the so-called pseudo-neurofeedback group. Task-related fm-theta activity after training differed significantly between groups. More importantly, though, after NF significantly enhanced behavioral performance was observed. The training group showed higher accuracy scores in the three-back task and reduced mixing and shifting costs in letter/number task-switching. However, this specific protocol type did not affect performance in tasks probing conflict monitoring and motor inhibition. Thus, our results suggest a modulation of proactive but not reactive mechanisms of cognitive control. Furthermore, task-related EEG changes show a distinct pattern for fm-theta after training between the NF and the pseudo-neurofeedback group, which indicates that NF training indeed tackles EFs-networks. In sum, the modulation of fm-theta via NF may serve as potent treatment approach for executive dysfunctions.
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Affiliation(s)
- Stefanie Enriquez-Geppert
- Experimental Psychology Laboratory, Department of Psychology, European Medical School, Carl von Ossietzky University of Oldenburg Oldenburg, Germany ; Karl-Jaspers Clinic, European Medical School Oldenburg-Groningen Oldenburg, Germany
| | - René J Huster
- Experimental Psychology Laboratory, Department of Psychology, European Medical School, Carl von Ossietzky University of Oldenburg Oldenburg, Germany ; Research Center Neurosensory Science, Carl von Ossietzky University Oldenburg, Germany
| | - Christian Figge
- Karl-Jaspers Clinic, European Medical School Oldenburg-Groningen Oldenburg, Germany
| | - Christoph S Herrmann
- Experimental Psychology Laboratory, Department of Psychology, European Medical School, Carl von Ossietzky University of Oldenburg Oldenburg, Germany ; Research Center Neurosensory Science, Carl von Ossietzky University Oldenburg, Germany ; Center for Excellence 'Hearing4all', Carl von Ossietzky University of Oldenburg Oldenburg, Germany
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280
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de Hoz L, Simons M. The emerging functions of oligodendrocytes in regulating neuronal network behaviour. Bioessays 2014; 37:60-9. [PMID: 25363888 DOI: 10.1002/bies.201400127] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Myelin is required for efficient nerve conduction, but not all axons are myelinated to the same extent. Here we review recent studies that have revealed distinct myelination patterns of different axonal paths, suggesting that myelination is not an all or none phenomenon and that its presence is finely regulated in central nervous system networks. Whereas powerful reductionist biology has led to important knowledge of how oligodendrocytes function by themselves, little is known about their role in neuronal networks. We still do not understand how oligodendrocytes integrate information from neurons to adapt their function to the need of the system. An intricate cross talk between neurons and glia is likely to exist and to determine how neuronal circuits operate as a whole. Dissecting these mechanisms by using integrative systems biology approaches is one of the major challenges ahead.
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Affiliation(s)
- Livia de Hoz
- Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
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281
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Prosperini L, Fanelli F, Petsas N, Sbardella E, Tona F, Raz E, Fortuna D, De Angelis F, Pozzilli C, Pantano P. Multiple Sclerosis: Changes in Microarchitecture of White Matter Tracts after Training with a Video Game Balance Board. Radiology 2014; 273:529-38. [DOI: 10.1148/radiol.14140168] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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282
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Reichert P, Kiełbowicz Z, DziĘgiel P, Puła B, Kuryszko J, Gosk J, Bocheńska A. The Rabbit Brachial Plexus as a Model for Nerve Repair Surgery-Histomorphometric Analysis. Anat Rec (Hoboken) 2014; 298:444-54. [DOI: 10.1002/ar.23058] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 06/26/2014] [Accepted: 08/04/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Paweł Reichert
- Department of Traumatology; Clinic of Traumatology and Hand Surgery, Wroclaw Medical University; ul. Borowska 213 50-556 Wrocław Poland
| | - Zdzisław Kiełbowicz
- Department of Surgery; the Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences; pl. Grunwaldzki 51 50-366 Wrocław Poland
| | - Piotr DziĘgiel
- Department of Histology and Embryology; Wroclaw Medical University; ul. Chałubińskiego 6a 50-368 Wrocław Poland
| | - Bartosz Puła
- Department of Histology and Embryology; Wroclaw Medical University; ul. Chałubińskiego 6a 50-368 Wrocław Poland
| | - Jan Kuryszko
- Department of Animal Physiology and Biostructure; Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences; ul. Norwida 31 50-373 Wroclaw Poland
| | - Jerzy Gosk
- Department of Traumatology; Clinic of Traumatology and Hand Surgery, Wroclaw Medical University; ul. Borowska 213 50-556 Wrocław Poland
| | - Aneta Bocheńska
- Department of Internal Medicine; Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn; ul. Oczapowskiego 14 10-718 Olsztyn Poland
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283
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McLean NA, Popescu BF, Gordon T, Zochodne DW, Verge VMK. Delayed nerve stimulation promotes axon-protective neurofilament phosphorylation, accelerates immune cell clearance and enhances remyelination in vivo in focally demyelinated nerves. PLoS One 2014; 9:e110174. [PMID: 25310564 PMCID: PMC4195712 DOI: 10.1371/journal.pone.0110174] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/17/2014] [Indexed: 01/19/2023] Open
Abstract
Rapid and efficient axon remyelination aids in restoring strong electrochemical communication with end organs and in preventing axonal degeneration often observed in demyelinating neuropathies. The signals from axons that can trigger more effective remyelination in vivo are still being elucidated. Here we report the remarkable effect of delayed brief electrical nerve stimulation (ES; 1 hour @ 20 Hz 5 days post-demyelination) on ensuing reparative events in a focally demyelinated adult rat peripheral nerve. ES impacted many parameters underlying successful remyelination. It effected increased neurofilament expression and phosphorylation, both implicated in axon protection. ES increased expression of myelin basic protein (MBP) and promoted node of Ranvier re-organization, both of which coincided with the early reappearance of remyelinated axons, effects not observed at the same time points in non-stimulated demyelinated nerves. The improved ES-associated remyelination was accompanied by enhanced clearance of ED-1 positive macrophages and attenuation of glial fibrillary acidic protein expression in accompanying Schwann cells, suggesting a more rapid clearance of myelin debris and return of Schwann cells to a nonreactive myelinating state. These benefits of ES correlated with increased levels of brain derived neurotrophic factor (BDNF) in the acute demyelination zone, a key molecule in the initiation of the myelination program. In conclusion, the tremendous impact of delayed brief nerve stimulation on enhancement of the innate capacity of a focally demyelinated nerve to successfully remyelinate identifies manipulation of this axis as a novel therapeutic target for demyelinating pathologies.
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Affiliation(s)
- Nikki A. McLean
- CMSNRC (Cameco MS Neuroscience Research Center) and Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Bogdan F. Popescu
- CMSNRC (Cameco MS Neuroscience Research Center) and Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Tessa Gordon
- Department of Surgery, Division of Plastic Reconstructive Surgery, University of Toronto, Toronto, ON, Canada
| | - Douglas W. Zochodne
- Department of Medicine, Division of Neurology, University of Alberta, Edmonton, AB, Canada
| | - Valerie M. K. Verge
- CMSNRC (Cameco MS Neuroscience Research Center) and Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK, Canada
- * E-mail:
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284
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García-Díaz B, Riquelme R, Varela-Nieto I, Jiménez AJ, de Diego I, Gómez-Conde AI, Matas-Rico E, Aguirre JÁ, Chun J, Pedraza C, Santín LJ, Fernández O, Rodríguez de Fonseca F, Estivill-Torrús G. Loss of lysophosphatidic acid receptor LPA1 alters oligodendrocyte differentiation and myelination in the mouse cerebral cortex. Brain Struct Funct 2014; 220:3701-20. [PMID: 25226845 DOI: 10.1007/s00429-014-0885-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 09/08/2014] [Indexed: 12/16/2022]
Abstract
Lysophosphatidic acid (LPA) is an intercellular signaling lipid that regulates multiple cellular functions, acting through specific G-protein coupled receptors (LPA(1-6)). Our previous studies using viable Malaga variant maLPA1-null mice demonstrated the requirement of the LPA1 receptor for normal proliferation, differentiation, and survival of the neuronal precursors. In the cerebral cortex LPA1 is expressed extensively in differentiating oligodendrocytes, in parallel with myelination. Although exogenous LPA-induced effects have been investigated in myelinating cells, the in vivo contribution of LPA1 to normal myelination remains to be demonstrated. This study identified a relevant in vivo role for LPA1 as a regulator of cortical myelination. Immunochemical analysis in adult maLPA1-null mice demonstrated a reduction in the steady-state levels of the myelin proteins MBP, PLP/DM20, and CNPase in the cerebral cortex. The myelin defects were confirmed using magnetic resonance spectroscopy and electron microscopy. Stereological analysis limited the defects to adult differentiating oligodendrocytes, without variation in the NG2+ precursor cells. Finally, a possible mechanism involving oligodendrocyte survival was demonstrated by the impaired intracellular transport of the PLP/DM20 myelin protein which was accompanied by cellular loss, suggesting stress-induced apoptosis. These findings describe a previously uncharacterized in vivo functional role for LPA1 in the regulation of oligodendrocyte differentiation and myelination in the CNS, underlining the importance of the maLPA1-null mouse as a model for the study of demyelinating diseases.
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Affiliation(s)
- Beatriz García-Díaz
- Laboratorio de Investigación, UGC Intercentros de Neurociencias, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospitales Universitarios Regional de Málaga y Virgen de la Victoria, Hospital Civil, Pabellón 5, Planta Sótano, Plaza del Hospital Civil s/n, 29009, Málaga, Spain.,Department of Neurology, H. Houston Merritt Clinical Research Center, Columbia University Medical Center, New York, NY, 10032, USA
| | - Raquel Riquelme
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), 28029, Madrid, Spain
| | - Isabel Varela-Nieto
- Instituto de Investigaciones Biomédicas 'Alberto Sols', Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), 28029, Madrid, Spain
| | - Antonio Jesús Jiménez
- Departamento de Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29071, Málaga, Spain
| | - Isabel de Diego
- Departamento de Anatomía y Medicina Legal, Universidad de Málaga, 29071, Málaga, Spain
| | - Ana Isabel Gómez-Conde
- ECAI de Microscopía, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospitales Universitarios Regional de Málaga y Virgen de la Victoria, 29010, Málaga, Spain
| | - Elisa Matas-Rico
- Laboratorio de Investigación, UGC Intercentros de Neurociencias, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospitales Universitarios Regional de Málaga y Virgen de la Victoria, Hospital Civil, Pabellón 5, Planta Sótano, Plaza del Hospital Civil s/n, 29009, Málaga, Spain.,Division of Cell Biology I, The Netherlands Cancer Institute, 1066CX, Amsterdam, The Netherlands
| | - José Ángel Aguirre
- Departamento de Fisiología Humana y Educación Físico Deportiva, Universidad de Málaga, 29071, Málaga, Spain
| | - Jerold Chun
- Department of Molecular and Cellular Neuroscience, Dorris Neuroscience Centre, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Carmen Pedraza
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29071, Málaga, Spain
| | - Luis Javier Santín
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29071, Málaga, Spain
| | - Oscar Fernández
- Neurology Service, UGC Intercentros de Neurociencias, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospitales Universitarios Regional de Málaga y Virgen de la Victoria, Universidad de Málaga, 29010, Málaga, Spain
| | - Fernando Rodríguez de Fonseca
- Laboratorio de Medicina Regenerativa, UGC de Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Universitario Regional de Málaga, 29010, Málaga, Spain
| | - Guillermo Estivill-Torrús
- Laboratorio de Investigación, UGC Intercentros de Neurociencias, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospitales Universitarios Regional de Málaga y Virgen de la Victoria, Hospital Civil, Pabellón 5, Planta Sótano, Plaza del Hospital Civil s/n, 29009, Málaga, Spain. .,ECAI de Microscopía, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospitales Universitarios Regional de Málaga y Virgen de la Victoria, 29010, Málaga, Spain.
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285
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Yeatman JD, Wandell BA, Mezer AA. Lifespan maturation and degeneration of human brain white matter. Nat Commun 2014; 5:4932. [PMID: 25230200 PMCID: PMC4238904 DOI: 10.1038/ncomms5932] [Citation(s) in RCA: 277] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 08/08/2014] [Indexed: 12/16/2022] Open
Abstract
Properties of human brain tissue change across the lifespan. Here we model these changes in the living human brain by combining quantitative magnetic resonance imaging (MRI) measurements of R1 (1/T1) with diffusion MRI and tractography (N=102, ages 7-85). The amount of R1 change during development differs between white-matter fascicles, but in each fascicle the rate of development and decline are mirror-symmetric; the rate of R1 development as the brain approaches maturity predicts the rate of R1 degeneration in aging. Quantitative measurements of macromolecule tissue volume (MTV) confirm that R1 is an accurate index of the growth of new brain tissue. In contrast to R1, diffusion development follows an asymmetric time-course with rapid childhood changes but a slow rate of decline in old age. Together, the time-courses of R1 and diffusion changes demonstrate that multiple biological processes drive changes in white-matter tissue properties over the lifespan.
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Affiliation(s)
- Jason D. Yeatman
- Stanford University Department of Psychology, Stanford, CA, USA
- Stanford University Center for Cognitive and Neurobiological Imaging, Stanford, CA, USA
| | - Brian A. Wandell
- Stanford University Department of Psychology, Stanford, CA, USA
- Stanford University Center for Cognitive and Neurobiological Imaging, Stanford, CA, USA
| | - Aviv A. Mezer
- Stanford University Department of Psychology, Stanford, CA, USA
- Stanford University Center for Cognitive and Neurobiological Imaging, Stanford, CA, USA
- Hebrew University Edmond and Lily Safra Center for Brain Sciences (ELSC), Jerusalm, Israel
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286
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Myers CA, Vandermosten M, Farris EA, Hancock R, Gimenez P, Black JM, Casto B, Drahos M, Tumber M, Hendren RL, Hulme C, Hoeft F. White matter morphometric changes uniquely predict children's reading acquisition. Psychol Sci 2014; 25:1870-83. [PMID: 25212581 DOI: 10.1177/0956797614544511] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This study examined whether variations in brain development between kindergarten and Grade 3 predicted individual differences in reading ability at Grade 3. Structural MRI measurements indicated that increases in the volume of two left temporo-parietal white matter clusters are unique predictors of reading outcomes above and beyond family history, socioeconomic status, and cognitive and preliteracy measures at baseline. Using diffusion MRI, we identified the left arcuate fasciculus and superior corona radiata as key fibers within the two clusters. Bias-free regression analyses using regions of interest from prior literature revealed that volume changes in temporo-parietal white matter, together with preliteracy measures, predicted 56% of the variance in reading outcomes. Our findings demonstrate the important contribution of developmental differences in areas of left dorsal white matter, often implicated in phonological processing, as a sensitive early biomarker for later reading abilities, and by extension, reading difficulties.
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Affiliation(s)
- Chelsea A Myers
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco
| | | | - Emily A Farris
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco Department of Psychology, University of Texas of the Permian Basin
| | - Roeland Hancock
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco
| | - Paul Gimenez
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco
| | - Jessica M Black
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco Graduate School of Social Work, Boston College
| | - Brandi Casto
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco Pacific Graduate School of Psychology, Palo Alto University
| | - Miroslav Drahos
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco
| | - Mandeep Tumber
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco Pacific Graduate School of Psychology, Palo Alto University
| | - Robert L Hendren
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco
| | - Charles Hulme
- Division of Psychology and Language Sciences, University College London
| | - Fumiko Hoeft
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, University of California, San Francisco Haskins Laboratories, Yale University Department of Neuropsychiatry, Keio University School of Medicine
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287
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Dubois J, Dehaene-Lambertz G, Kulikova S, Poupon C, Hüppi PS, Hertz-Pannier L. The early development of brain white matter: A review of imaging studies in fetuses, newborns and infants. Neuroscience 2014; 276:48-71. [PMID: 24378955 DOI: 10.1016/j.neuroscience.2013.12.044] [Citation(s) in RCA: 477] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 12/12/2013] [Accepted: 12/16/2013] [Indexed: 12/13/2022]
Affiliation(s)
- J Dubois
- INSERM, U992, Cognitive Neuroimaging Unit, Gif-sur-Yvette, France; CEA, NeuroSpin Center, UNICOG, Gif-sur-Yvette, France; University Paris Sud, Orsay, France.
| | - G Dehaene-Lambertz
- INSERM, U992, Cognitive Neuroimaging Unit, Gif-sur-Yvette, France; CEA, NeuroSpin Center, UNICOG, Gif-sur-Yvette, France; University Paris Sud, Orsay, France
| | - S Kulikova
- CEA, NeuroSpin Center, UNIACT, Gif-sur-Yvette, France; INSERM, U663, Child epilepsies and brain plasticity, Paris, France; University Paris Descartes, Paris, France
| | - C Poupon
- CEA, NeuroSpin Center, UNIRS, Gif-sur-Yvette, France
| | - P S Hüppi
- Geneva University Hospitals, Department of Pediatrics, Division of Development and Growth, Geneva, Switzerland; Harvard Medical School, Children's Hospital, Department of Neurology, Boston, MA, USA
| | - L Hertz-Pannier
- CEA, NeuroSpin Center, UNIACT, Gif-sur-Yvette, France; INSERM, U663, Child epilepsies and brain plasticity, Paris, France; University Paris Descartes, Paris, France
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288
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Pathological potential of astroglial purinergic receptors. ADVANCES IN NEUROBIOLOGY 2014; 11:213-56. [PMID: 25236731 DOI: 10.1007/978-3-319-08894-5_11] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Acute brain injury and neurodegenerative disorders may result in astroglial activation. Astrocytes are able to determine the progression and outcome of these neuropathologies in a beneficial or detrimental way. Nucleotides, e.g. adenosine 5'-triphosphate (ATP), released after acute or chronic neuronal injury, are important mediators of glial activation and astrogliosis.Acute injury may cause significant changes in ATP balance, resulting in (1) a decline of intracellular ATP levels and (2) an increase in extracellular ATP concentrations via efflux from the intracellular space. The released ATP may have trophic effects, but can also act as a proinflammatory mediator or cytotoxic factor, inducing necrosis/apoptosis as a universal "danger" signal. Furthermore, ATP, primarily released from astrocytes, is a means of communication between neurons, glial cells, and intracerebral blood vessels.Astrocytes express a heterogeneous battery of purinergic ionotropic and metabotropic receptors (P2XRs and P2YRs, respectively) to respond to extracellular nucleotides.In this chapter, we summarize the contemporary knowledge on the pathological potential of P2Rs in relation to changes of astrocytic functions, determined by distinct molecular signaling cascades, in a variety of diseases. We discuss specific aspects of reactive astrogliosis, with respect to the involvement of prominent receptor subtypes, such as the P2X7 and P2Y1/2Rs. Examples of purinergic signaling of microglia, oligodendrocytes, and blood vessels under pathophysiological conditions will also be presented.The understanding of the pathological potential of purinergic signaling in "controlling and fine-tuning" of astrocytic responses is important for identifying possible therapeutic principles to treat acute and chronic central nervous system diseases.
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289
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Yuen TJ, Silbereis JC, Griveau A, Chang SM, Daneman R, Fancy SPJ, Zahed H, Maltepe E, Rowitch DH. Oligodendrocyte-encoded HIF function couples postnatal myelination and white matter angiogenesis. Cell 2014; 158:383-396. [PMID: 25018103 DOI: 10.1016/j.cell.2014.04.052] [Citation(s) in RCA: 275] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 03/13/2014] [Accepted: 04/22/2014] [Indexed: 12/30/2022]
Abstract
Myelin sheaths provide critical functional and trophic support for axons in white matter tracts of the brain. Oligodendrocyte precursor cells (OPCs) have extraordinary metabolic requirements during development as they differentiate to produce multiple myelin segments, implying that they must first secure adequate access to blood supply. However, mechanisms that coordinate myelination and angiogenesis are unclear. Here, we show that oxygen tension, mediated by OPC-encoded hypoxia-inducible factor (HIF) function, is an essential regulator of postnatal myelination. Constitutive HIF1/2α stabilization resulted in OPC maturation arrest through autocrine activation of canonical Wnt7a/7b. Surprisingly, such OPCs also show paracrine activity that induces excessive postnatal white matter angiogenesis in vivo and directly stimulates endothelial cell proliferation in vitro. Conversely, OPC-specific HIF1/2α loss of function leads to insufficient angiogenesis in corpus callosum and catastrophic axon loss. These findings indicate that OPC-intrinsic HIF signaling couples postnatal white matter angiogenesis, axon integrity, and the onset of myelination in mammalian forebrain.
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Affiliation(s)
- Tracy J Yuen
- Department of Pediatrics, Eli and Edythe Broad Institute for Stem Cell Research and Regeneration Medicine and Howard Hughes Medical Institute, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - John C Silbereis
- Department of Pediatrics, Eli and Edythe Broad Institute for Stem Cell Research and Regeneration Medicine and Howard Hughes Medical Institute, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA; Neuroscience Graduate Program, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Amelie Griveau
- Department of Pediatrics, Eli and Edythe Broad Institute for Stem Cell Research and Regeneration Medicine and Howard Hughes Medical Institute, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Sandra M Chang
- Department of Pediatrics, Eli and Edythe Broad Institute for Stem Cell Research and Regeneration Medicine and Howard Hughes Medical Institute, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Richard Daneman
- Department of Anatomy, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Stephen P J Fancy
- Department of Pediatrics, Eli and Edythe Broad Institute for Stem Cell Research and Regeneration Medicine and Howard Hughes Medical Institute, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Hengameh Zahed
- Department of Pediatrics, Eli and Edythe Broad Institute for Stem Cell Research and Regeneration Medicine and Howard Hughes Medical Institute, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA; Medical Science Training Program, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Emin Maltepe
- Division of Neonatology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
| | - David H Rowitch
- Department of Pediatrics, Eli and Edythe Broad Institute for Stem Cell Research and Regeneration Medicine and Howard Hughes Medical Institute, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA; Division of Neonatology, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA.
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290
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A new approach to corpus callosum anomalies in idiopathic scoliosis using diffusion tensor magnetic resonance imaging. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2014; 23:2643-9. [DOI: 10.1007/s00586-014-3435-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 06/21/2014] [Accepted: 06/21/2014] [Indexed: 11/25/2022]
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291
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Segura B, Melo AI, Fleming AS, Mendoza-Garrido ME, González del Pliego M, Aguirre-Benitez EL, Hernández-Falcón J, Jiménez-Estrada I. Early social isolation provokes electrophysiological and structural changes in cutaneous sensory nerves of adult male rats. Dev Neurobiol 2014; 74:1184-93. [DOI: 10.1002/dneu.22197] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 05/14/2014] [Accepted: 06/02/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Bertha Segura
- Department of Biology, FES Iztacala; UNAM. Av. de los Barrios 1 Col. Los Reyes Iztacala; Tlanepantla de Baz Estado de México CP 54090 México
| | - Angel I. Melo
- Centro de Investigación en Reproducción Animal; CINVESTAV Laboratorio Tlaxcala. Universidad Autónoma de Tlaxcala; A.P. 62. C.P. 90000 Tlaxcala México
| | - Alison S. Fleming
- Department of Psychology; University of Toronto at Mississauga; Mississauga, Ontario 5L 1C6 Canada
| | - Maria Eugenia Mendoza-Garrido
- Department of Physiology, Biophysics and Neurosciences; CINVESTAV, IPN Av. Instituto Politécnico Nacional 2508 Col. San Pedro Zacatenco, Del. Gustavo A. Madero; C.P. 07360 México D.F México
| | | | | | - Jesús Hernández-Falcón
- Laboratorio de Redes Neuronales, Departamento de Fisiología; Facultad de Medicina, UNAM; Mexico
| | - Ismael Jiménez-Estrada
- Department of Physiology, Biophysics and Neurosciences; CINVESTAV, IPN Av. Instituto Politécnico Nacional 2508 Col. San Pedro Zacatenco, Del. Gustavo A. Madero; C.P. 07360 México D.F México
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292
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Miller DJ, Lackey EP, Hackett TA, Kaas JH. Development of myelination and cholinergic innervation in the central auditory system of a prosimian primate (Otolemur garnetti). J Comp Neurol 2014; 521:3804-16. [PMID: 23749337 DOI: 10.1002/cne.23379] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 11/07/2022]
Abstract
Change in the timeline of neurobiological growth is an important source of biological variation, and thus phenotypic evolution. However, no study has to date investigated sensory system development in any of the prosimian primates that are thought to most closely resemble our earliest primate ancestors. Acetylcholine (ACh) is a neurotransmitter critical to normal brain function by regulating synaptic plasticity associated with attention and learning. Myelination is an important structural component of the brain because it facilitates rapid neuronal communication. In this work we investigated the expression of acetylcholinesterase (AChE) and the density of myelinated axons throughout postnatal development in the inferior colliculus (IC), medial geniculate complex (MGC), and auditory cortex (auditory core, belt, and parabelt) in Garnett's greater galago (Otolemur garnetti). We found that the IC and MGC exhibit relatively high myelinated fiber length density (MFLD) values at birth and attain adult-like values by the species-typical age at weaning. In contrast, neocortical auditory fields are relatively unmyelinated at birth and only attain adult-like MFLD values by the species-typical age at puberty. Analysis of AChE expression indicated that, in contrast to evidence from rodent samples, the adult-like distribution of AChE in the core area of auditory cortex, dense bands in layers I, IIIb/IV, and Vb/VI, is present at birth. These data indicate the differential developmental trajectory of central auditory system structures and demonstrate the early onset of adult-like AChE expression in primary auditory cortex in O. garnetti, suggesting the auditory system is more developed at birth in primates compared to rodents.
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Affiliation(s)
- Daniel J Miller
- Department of Psychology, Vanderbilt University, Nashville, Tennessee, 37205
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293
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Abstract
BACKGROUND An increasing number of studies have examined the effects of training of cognitive and other tasks on brain structure, using magnetic resonance imaging. METHODS Studies combining cognitive and other tasks training with longitudinal imaging designs were reviewed, with a view to identify paradigms potentially applicable to treatment of cognitive impairment. RESULTS We identified 36 studies, employing training as variable as juggling, working memory, meditation, learning abstract information, and aerobic exercise. There were training-related structural changes, increases in gray matter volume, decreases, increases and decreases in different regions, or no change at all. There was increased integrity in white matter following training, but other patterns of results were also reported. CONCLUSIONS Questions still to be answered are: Are changes due to use-dependent effects or are they specific to learning? What are the underlying neural correlates of learning, the temporal dynamics of changes, the relations between structure and function, and the upper limits of improvement? How can gains be maintained? The question whether neuroplasticity will contribute to the treatment of dementia will need to be posed again at that stage.
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294
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Differential conduction velocity regulation in ipsilateral and contralateral collaterals innervating brainstem coincidence detector neurons. J Neurosci 2014; 34:4914-9. [PMID: 24695710 DOI: 10.1523/jneurosci.5460-13.2014] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Information processing in the brain relies on precise timing of signal propagation. The highly conserved neuronal network for computing spatial representations of acoustic signals resolves microsecond timing of sounds processed by the two ears. As such, it provides an excellent model for understanding how precise temporal regulation of neuronal signals is achieved and maintained. The well described avian and mammalian brainstem circuit for computation of interaural time differences is composed of monaural cells in the cochlear nucleus (CN; nucleus magnocellularis in birds) projecting to binaurally innervated coincidence detection neurons in the medial superior olivary nucleus (MSO) in mammals or nucleus laminaris (NL) in birds. Individual axons from CN neurons issue a single axon that bifurcates into an ipsilateral branch and a contralateral branch that innervate segregated dendritic regions of the MSO/NL coincidence detector neurons. We measured conduction velocities of the ipsilateral and contralateral branches of these bifurcating axon collaterals in the chicken by antidromic stimulation of two sites along each branch and whole-cell recordings in the parent neurons. At the end of each experiment, the individual CN neuron and its axon collaterals were filled with dye. We show that the two collaterals of a single axon adjust the conduction velocities individually to achieve the specific conduction velocities essential for precise temporal integration of information from the two ears, as required for sound localization. More generally, these results suggest that individual axonal segments in the CNS interact locally with surrounding neural structures to determine conduction velocity.
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295
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Li S, Clements R, Sulak M, Gregory R, Freeman E, McDonough J. Decreased NAA in gray matter is correlated with decreased availability of acetate in white matter in postmortem multiple sclerosis cortex. Neurochem Res 2014; 38:2385-96. [PMID: 24078261 DOI: 10.1007/s11064-013-1151-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 08/02/2013] [Accepted: 09/05/2013] [Indexed: 01/31/2023]
Abstract
Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS) which leads to progressive neurological disability. Our previous studies have demonstrated mitochondrial involvement in MS cortical pathology and others have documented decreased levels of the neuronal mitochondrial metabolite N-acetyl aspartate (NAA) in the MS brain. While NAA is synthesized in neurons, it is broken down in oligodendrocytes into aspartate and acetate. The resulting acetate is incorporated into myelin lipids, linking neuronal mitochondrial function to oligodendrocyte-mediated elaboration of myelin lipids in the CNS. In the present study we show that treating human SH-SY5Y neuroblastoma cells with the electron transport chain inhibitor antimycin A decreased levels of NAA as measured by HPLC. To better understand the significance of the relationship between mitochondrial function and levels of NAA and its breakdown product acetate on MS pathology we then quantitated the levels of NAA and acetate in MS and control postmortem tissue blocks. Regardless of lesion status, we observed that levels of NAA were decreased 25 and 32 % in gray matter from parietal and motor cortex in MS, respectively, compared to controls. Acetate levels in adjacent white matter mirrored these decreases as evidenced by the 36 and 45 % reduction in acetate obtained from parietal and motor cortices. These data suggest a novel mechanism whereby mitochondrial dysfunction and reduced NAA levels in neurons may result in compromised myelination by oligodendrocytes due to decreased availability of acetate necessary for the synthesis of myelin lipids.
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296
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Ioannidou K, Anderson KI, Strachan D, Edgar JM, Barnett SC. Astroglial-axonal interactions during early stages of myelination in mixed cultures using in vitro and ex vivo imaging techniques. BMC Neurosci 2014; 15:59. [PMID: 24886503 PMCID: PMC4024314 DOI: 10.1186/1471-2202-15-59] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 04/24/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND [corrected] Myelination is a very complex process that requires the cross talk between various neural cell types. Previously, using cytosolic or membrane associated GFP tagged neurospheres, we followed the interaction of oligodendrocytes with axons using time-lapse imaging in vitro and ex vivo and demonstrated dynamic changes in cell morphology. In this study we focus on GFP tagged astrocytes differentiated from neurospheres and their interactions with axons. RESULTS We show the close interaction of astrocyte processes with axons and with oligodendrocytes in mixed mouse spinal cord cultures with formation of membrane blebs as previously seen for oligodendrocytes in the same cultures. When GFP-tagged neurospheres were transplanted into the spinal cord of the dysmyelinated shiverer mouse, confirmation of dynamic changes in cell morphology was provided and a prevalence for astrocyte differentiation compared with oligodendroglial differentiation around the injection site. Furthermore, we were able to image GFP tagged neural cells in vivo after transplantation and the cells exhibited similar membrane changes as cells visualised in vitro and ex vivo. CONCLUSION These data show that astrocytes exhibit dynamic cell process movement and changes in their membrane topography as they interact with axons and oligodendrocytes during the process of myelination, with the first demonstration of bleb formation in astrocytes.
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Affiliation(s)
| | | | | | - Julia M Edgar
- Institute of Infection, Immunity and inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK.
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297
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Butt AM, Fern RF, Matute C. Neurotransmitter signaling in white matter. Glia 2014; 62:1762-79. [PMID: 24753049 DOI: 10.1002/glia.22674] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 03/04/2014] [Accepted: 03/31/2014] [Indexed: 12/16/2022]
Abstract
White matter (WM) tracts are bundles of myelinated axons that provide for rapid communication throughout the CNS and integration in grey matter (GM). The main cells in myelinated tracts are oligodendrocytes and astrocytes, with small populations of microglia and oligodendrocyte precursor cells. The prominence of neurotransmitter signaling in WM, which largely exclude neuronal cell bodies, indicates it must have physiological functions other than neuron-to-neuron communication. A surprising aspect is the diversity of neurotransmitter signaling in WM, with evidence for glutamatergic, purinergic (ATP and adenosine), GABAergic, glycinergic, adrenergic, cholinergic, dopaminergic and serotonergic signaling, acting via a wide range of ionotropic and metabotropic receptors. Both axons and glia are potential sources of neurotransmitters and may express the respective receptors. The physiological functions of neurotransmitter signaling in WM are subject to debate, but glutamate and ATP-mediated signaling have been shown to evoke Ca(2+) signals in glia and modulate axonal conduction. Experimental findings support a model of neurotransmitters being released from axons during action potential propagation acting on glial receptors to regulate the homeostatic functions of astrocytes and myelination by oligodendrocytes. Astrocytes also release neurotransmitters, which act on axonal receptors to strengthen action potential propagation, maintaining signaling along potentially long axon tracts. The co-existence of multiple neurotransmitters in WM tracts suggests they may have diverse functions that are important for information processing. Furthermore, the neurotransmitter signaling phenomena described in WM most likely apply to myelinated axons of the cerebral cortex and GM areas, where they are doubtless important for higher cognitive function.
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Affiliation(s)
- Arthur M Butt
- Institute of Biomedical and Biomolecular Sciences, School of Pharmacy and Biomedical Sciences, University of Portsmouth, United Kingdom
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298
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Hill RA, Nishiyama A. NG2 cells (polydendrocytes): listeners to the neural network with diverse properties. Glia 2014; 62:1195-210. [PMID: 24753030 PMCID: PMC4282324 DOI: 10.1002/glia.22664] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 02/18/2014] [Accepted: 03/11/2014] [Indexed: 01/23/2023]
Abstract
NG2 cells (polydendrocytes) are the fourth major non-neuronal cell type in the central nervous system parenchyma. They exhibit diverse properties, ranging from their well-established role as oligodendrocyte precursors to their ability to respond to neurotransmitters released by synaptic and non-synaptic mechanisms. The functional diversity of NG2 cells has prompted the question of whether they represent a single cellular entity or multiple distinct cell populations. This review first summarizes recent findings on the nature and mechanism underlying the diversity of NG2 cells with regard to their proliferative and differentiation behavior. This will be followed by a synopsis of observations on how their microenvironment, particularly neuronal activity, influences their dynamic behavior, and how these changes in NG2 cells could in turn influence neural function and animal behavior.
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Affiliation(s)
- Robert A Hill
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut; Department of Neurology, Yale University School of Medicine, New Haven, Connecticut
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299
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Gibson EM, Purger D, Mount CW, Goldstein AK, Lin GL, Wood LS, Inema I, Miller SE, Bieri G, Zuchero JB, Barres BA, Woo PJ, Vogel H, Monje M. Neuronal activity promotes oligodendrogenesis and adaptive myelination in the mammalian brain. Science 2014; 344:1252304. [PMID: 24727982 DOI: 10.1126/science.1252304] [Citation(s) in RCA: 913] [Impact Index Per Article: 91.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Myelination of the central nervous system requires the generation of functionally mature oligodendrocytes from oligodendrocyte precursor cells (OPCs). Electrically active neurons may influence OPC function and selectively instruct myelination of an active neural circuit. In this work, we use optogenetic stimulation of the premotor cortex in awake, behaving mice to demonstrate that neuronal activity elicits a mitogenic response of neural progenitor cells and OPCs, promotes oligodendrogenesis, and increases myelination within the deep layers of the premotor cortex and subcortical white matter. We further show that this neuronal activity-regulated oligodendrogenesis and myelination is associated with improved motor function of the corresponding limb. Oligodendrogenesis and myelination appear necessary for the observed functional improvement, as epigenetic blockade of oligodendrocyte differentiation and myelin changes prevents the activity-regulated behavioral improvement.
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Affiliation(s)
- Erin M Gibson
- Departments of Neurology, Neurosurgery, and Pediatrics, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
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300
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Franklin RJM, Gallo V. The translational biology of remyelination: past, present, and future. Glia 2014; 62:1905-15. [PMID: 24446279 DOI: 10.1002/glia.22622] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/07/2013] [Accepted: 12/10/2013] [Indexed: 01/01/2023]
Abstract
Amongst neurological diseases, multiple sclerosis (MS) presents an attractive target for regenerative medicine. This is because the primary pathology, the loss of myelin-forming oligodendrocytes, can be followed by a spontaneous and efficient regenerative process called remyelination. While cell transplantation approaches have been explored as a means of replacing lost oligodendrocytes, more recently therapeutic approaches that target the endogenous regenerative process have been favored. This is in large part due to our increasing understanding of (1) the cell types within the adult brain that are able to generate new oligodendrocytes, (2) the mechanisms and pathways by which this achieved, and (3) an emerging awareness of the reasons why remyelination efficiency eventually fails. Here we review some of these advances and also highlight areas where questions remain to be answered in both the biology and translational potential of this important regenerative process.
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Affiliation(s)
- Robin J M Franklin
- Wellcome Trust-MRC Cambridge Stem Cell Institute and Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES, United Kingdom
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