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Del Turco D, Paul MH, Schlaudraff J, Muellerleile J, Bozic F, Vuksic M, Jedlicka P, Deller T. Layer-specific changes of KCC2 and NKCC1 in the mouse dentate gyrus after entorhinal denervation. Front Mol Neurosci 2023; 16:1118746. [PMID: 37293543 PMCID: PMC10244516 DOI: 10.3389/fnmol.2023.1118746] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 04/25/2023] [Indexed: 06/10/2023] Open
Abstract
The cation-chloride cotransporters KCC2 and NKCC1 regulate the intracellular Cl- concentration and cell volume of neurons and/or glia. The Cl- extruder KCC2 is expressed at higher levels than the Cl- transporter NKCC1 in mature compared to immature neurons, accounting for the developmental shift from high to low Cl- concentration and from depolarizing to hyperpolarizing currents through GABA-A receptors. Previous studies have shown that KCC2 expression is downregulated following central nervous system injury, returning neurons to a more excitable state, which can be pathological or adaptive. Here, we show that deafferentation of the dendritic segments of granule cells in the outer (oml) and middle (mml) molecular layer of the dentate gyrus via entorhinal denervation in vivo leads to cell-type- and layer-specific changes in the expression of KCC2 and NKCC1. Microarray analysis validated by reverse transcription-quantitative polymerase chain reaction revealed a significant decrease in Kcc2 mRNA in the granule cell layer 7 days post-lesion. In contrast, Nkcc1 mRNA was upregulated in the oml/mml at this time point. Immunostaining revealed a selective reduction in KCC2 protein expression in the denervated dendrites of granule cells and an increase in NKCC1 expression in reactive astrocytes in the oml/mml. The NKCC1 upregulation is likely related to the increased activity of astrocytes and/or microglia in the deafferented region, while the transient KCC2 downregulation in granule cells may be associated with denervation-induced spine loss, potentially also serving a homeostatic role via boosting GABAergic depolarization. Furthermore, the delayed KCC2 recovery might be involved in the subsequent compensatory spinogenesis.
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Affiliation(s)
- Domenico Del Turco
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Mandy H. Paul
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Jessica Schlaudraff
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Julia Muellerleile
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Fran Bozic
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Mario Vuksic
- Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
- Faculty of Medicine, Justus-Liebig-University Giessen, Giessen, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
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2
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De Niear MA, Smith GR, Robinson ML, Moses-Hampton MK, Lakhmani PG, Upright NA, Krause EL, Ramirez JJ. Lesion-induced sprouting promotes neurophysiological integration of septal and entorhinal inputs to granule cells in the dentate gyrus of rats. Neurobiol Learn Mem 2023; 198:107723. [PMID: 36621561 DOI: 10.1016/j.nlm.2023.107723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/03/2023] [Indexed: 01/07/2023]
Abstract
Axonal sprouting of dentate gyrus (DG) afferents after entorhinal cortex (EC) lesion is a model preparation to assess lesion-induced functional reorganization in a denervated target structure. Following a unilateral EC lesion, the surviving contralateral entorhinal projection, termed the crossed temporodentate pathway (CTD), and the heterotypic septal input to the DG, the septodentate pathway (SD), undergo extensive axonal sprouting. We explored whether EC lesion alters the capacity of the SD pathway to influence CTD-evoked granule cell excitability in the DG. We recorded extracellular field excitatory postsynaptic potentials (fEPSPs) after CTD stimulation alone and paired SD-CTD stimulation. Male rats were given unilateral EC lesions or sham operations; evoked fEPSPs in the DG were recorded at 4-, 15-, and 90-days post-entorhinal lesion to assess functional reorganization of the CTD and SD pathways. We found significantly increased fEPSP amplitudes in cases with unilateral lesions compared to sham-operates at 15- and 90-days post lesion. Within each time point, paired SD-CTD stimulation resulted in significantly depressed fEPSP amplitudes compared to amplitudes evoked after CTD stimulation alone and this effect was solely seen in cases with EC lesion. In cases where granule cell discharge was observed, SD stimulation increased discharge amplitude elicited by the CTD stimulation at 90-days postlesion. These findings demonstrate that synaptic remodeling following unilateral cortical lesion results in a synergistic interaction between two established hippocampal afferents that is not seen in uninjured brains. This work may be important for models of neurodegenerative disease and neural injury that target these structures and associated hippocampal circuitry.
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Affiliation(s)
- Matthew A De Niear
- Neuroscience Program, Davidson College, Davidson, NC 28035, USA; Medical Scientist Training Program, Vanderbilt University Medical School, Vanderbilt University, Nashville, TN 37235, USA; Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37235, USA
| | - Garrett R Smith
- Neuroscience Program, Davidson College, Davidson, NC 28035, USA; Department of Psychology, Davidson College, Davidson, NC 28035, USA
| | - Mercedes L Robinson
- Neuroscience Program, Davidson College, Davidson, NC 28035, USA; Department of Psychology, Davidson College, Davidson, NC 28035, USA
| | - Malcolm K Moses-Hampton
- Neuroscience Program, Davidson College, Davidson, NC 28035, USA; Department of Psychology, Davidson College, Davidson, NC 28035, USA
| | - Puneet G Lakhmani
- Neuroscience Program, Davidson College, Davidson, NC 28035, USA; Department of Psychology, Davidson College, Davidson, NC 28035, USA
| | - Nicholas A Upright
- Neuroscience Program, Davidson College, Davidson, NC 28035, USA; Department of Psychology, Davidson College, Davidson, NC 28035, USA
| | - Emma L Krause
- Neuroscience Program, Davidson College, Davidson, NC 28035, USA; Department of Psychology, Davidson College, Davidson, NC 28035, USA
| | - Julio J Ramirez
- Neuroscience Program, Davidson College, Davidson, NC 28035, USA; Department of Psychology, Davidson College, Davidson, NC 28035, USA.
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3
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Conti E, Pavone FS, Allegra Mascaro AL. In Vivo Imaging of the Structural Plasticity of Cortical Neurons After Stroke. Methods Mol Biol 2023; 2616:69-81. [PMID: 36715929 DOI: 10.1007/978-1-0716-2926-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The comprehension of the finest mechanisms underlying experience-dependent plasticity requires the investigation of neurons and synaptic terminals in the intact brain over prolonged periods of time. Longitudinal two-photon imaging together with the expression of fluorescent proteins enables high-resolution imaging of dendritic spines and axonal varicosities of cortical neurons in vivo. Importantly, the study of the mechanisms of structural reorganization is relevant for a deeper understanding of the pathophysiological mechanisms of neurological diseases such as stroke and for the development of new therapeutic approaches. This protocol describes the principal steps for in vivo investigation of neuronal plasticity both in healthy conditions and after an ischemic lesion. First, we give a description of the surgery to perform a stable cranial window that allows optical access to the mouse brain cortex. Then we explain how to perform longitudinal two-photon imaging of dendrites, axonal branches, and synaptic terminals in the mouse brain cortex in vivo, in order to investigate the plasticity of synaptic terminals and orientation of neuronal processes. Finally, we describe how to induce an ischemic lesion in a target region of the mouse brain cortex through a cranial window by applying the photothrombotic stroke model.
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Affiliation(s)
- Emilia Conti
- Neuroscience Institute, National Research Council, Pisa, Italy
- European Laboratory for Non-Linear Spectroscopy, Sesto Fiorentino, Italy
| | - Francesco Saverio Pavone
- European Laboratory for Non-Linear Spectroscopy, Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, Italy
- National Institute of Optics, National Research Council, Sesto Fiorentino, Italy
| | - Anna Letizia Allegra Mascaro
- Neuroscience Institute, National Research Council, Pisa, Italy.
- European Laboratory for Non-Linear Spectroscopy, Sesto Fiorentino, Italy.
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Vergara P, Pino G, Vera J, Arancibia F, Sanhueza M. Heterogeneous CaMKII-Dependent Synaptic Compensations in CA1 Pyramidal Neurons From Acute Hippocampal Slices. Front Cell Neurosci 2022; 16:821088. [PMID: 35431809 PMCID: PMC9005847 DOI: 10.3389/fncel.2022.821088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Prolonged changes in neural activity trigger homeostatic synaptic plasticity (HSP) allowing neuronal networks to operate within functional ranges. Cell-wide or input-specific adaptations can be induced by pharmacological or genetic manipulations of activity, and by sensory deprivation. Reactive functional changes caused by deafferentation may partially share mechanisms with HSP. Acute hippocampal slices are a suitable model to investigate relatively rapid (hours) modifications occurring after denervation and explore the underlying mechanisms. As during slicing many afferents are cut, we conducted whole-cell recordings of miniature excitatory postsynaptic currents (mEPSCs) in CA1 pyramidal neurons to evaluate changes over the following 12 h. As Schaffer collaterals constitute a major glutamatergic input to these neurons, we also dissected CA3. We observed an average increment in mEPSCs amplitude and a decrease in decay time, suggesting synaptic AMPA receptor upregulation and subunit content modifications. Sorting mEPSC by rise time, a correlate of synapse location along dendrites, revealed amplitude raises at two separate domains. A specific frequency increase was observed in the same domains and was accompanied by a global, unspecific raise. Amplitude and frequency increments were lower at sites initially more active, consistent with local compensatory processes. Transient preincubation with a specific Ca2+/calmodulin-dependent kinase II (CaMKII) inhibitor either blocked or occluded amplitude and frequency upregulation in different synapse populations. Results are consistent with the concurrent development of different known CaMKII-dependent HSP processes. Our observations support that deafferentation causes rapid and diverse compensations resembling classical slow forms of adaptation to inactivity. These results may contribute to understand fast-developing homeostatic or pathological events after brain injury.
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Ergen FB, Cosan DT, Kandemir T, Dag İ, Mutlu F, Cosan TE. An Enriched Environment Leads to Increased Synaptic Plasticity-Associated miRNA Levels after Experimental Subarachnoid Hemorrhage. J Stroke Cerebrovasc Dis 2021; 30:105766. [PMID: 33866227 DOI: 10.1016/j.jstrokecerebrovasdis.2021.105766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 02/26/2021] [Accepted: 03/17/2021] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE In subarachnoid hemorrhage (SAH), impairments in motor and cognitive functions may occur and continue in later periods. MicroRNAs (miRNAs) are small non-coding RNAs that can directly or indirectly affect synaptic reconstruction. mir-132, mir-134, and mir-138 are the leading miRNAs that can be effective on some neurological functions through its effects on synaptic plasticity in the relevant brain areas. In our study, it was aimed to determine the levels of miRNAs in the hippocampus and frontal lobe of rats exposed to different environmental conditions after the experimental SAH. METHODS SAH was created using the cisterna magna double blood-injection method. Brain tissues were collected at different times after the last blood injection. Rats were grouped according to the different environmental conditions in which they were kept. Expression levels of miRNAs were performed by qPCR and ultrastructural changes in samples were determined by transmission electron microscopy (TEM). RESULTS After SAH, miR-132, miR-134, and miR-138 expressions in the frontal lobes of rats increased in impoverished environment on the 7th day and in the enriched environment on the 14th day. It was observed that the myelin and microtubule structures in the axons that were disrupted after SAH were more organized and stable in the enriched environment. CONCLUSIONS After SAH, different environmental conditions may affect the miRNA levels associated with synaptic plasticity and microtubule organization in the frontal lobe, and this might have some effects especially on cognitive and motor functions related to this brain area.
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Affiliation(s)
- Fulya Buge Ergen
- Department of Interdisciplinary Neuroscience, Health Science Institute, Eskisehir Osmangazi University, Eskisehir, Turkey.
| | - Didem Turgut Cosan
- Department of Interdisciplinary Neuroscience, Health Science Institute, Eskisehir Osmangazi University, Eskisehir, Turkey; Department of Medical Biology, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Turan Kandemir
- Department of Neurosurgery, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - İlknur Dag
- Central Research Laboratory Application and Research Center, Eskisehir Osmangazi University, Eskisehir, Turkey; Vocational Health Services High School, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Fezan Mutlu
- Department of Biostatistics, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey
| | - Tevfik Erhan Cosan
- Department of Interdisciplinary Neuroscience, Health Science Institute, Eskisehir Osmangazi University, Eskisehir, Turkey; Department of Neurosurgery, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey
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6
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Paul MH, Hildebrandt-Einfeldt L, Beeg Moreno VJ, Del Turco D, Deller T. Maturation-Dependent Differences in the Re-innervation of the Denervated Dentate Gyrus by Sprouting Associational and Commissural Mossy Cell Axons in Organotypic Tissue Cultures of Entorhinal Cortex and Hippocampus. Front Neuroanat 2021; 15:682383. [PMID: 34122019 PMCID: PMC8194403 DOI: 10.3389/fnana.2021.682383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 04/28/2021] [Indexed: 11/30/2022] Open
Abstract
Sprouting of surviving axons is one of the major reorganization mechanisms of the injured brain contributing to a partial restoration of function. Of note, sprouting is maturation as well as age-dependent and strong in juvenile brains, moderate in adult and weak in aged brains. We have established a model system of complex organotypic tissue cultures to study sprouting in the dentate gyrus following entorhinal denervation. Entorhinal denervation performed after 2 weeks postnatally resulted in a robust, rapid, and very extensive sprouting response of commissural/associational fibers, which could be visualized using calretinin as an axonal marker. In the present study, we analyzed the effect of maturation on this form of sprouting and compared cultures denervated at 2 weeks postnatally with cultures denervated at 4 weeks postnatally. Calretinin immunofluorescence labeling as well as time-lapse imaging of virally-labeled (AAV2-hSyn1-GFP) commissural axons was employed to study the sprouting response in aged cultures. Compared to the young cultures commissural/associational sprouting was attenuated and showed a pattern similar to the one following entorhinal denervation in adult animals in vivo. We conclude that a maturation-dependent attenuation of sprouting occurs also in vitro, which now offers the chance to study, understand and influence maturation-dependent differences in brain repair in these culture preparations.
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Affiliation(s)
- Mandy H Paul
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Lars Hildebrandt-Einfeldt
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Viktor J Beeg Moreno
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Domenico Del Turco
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
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7
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Bissen D, Kracht MK, Foss F, Hofmann J, Acker-Palmer A. EphrinB2 and GRIP1 stabilize mushroom spines during denervation-induced homeostatic plasticity. Cell Rep 2021; 34:108923. [PMID: 33789115 PMCID: PMC8028307 DOI: 10.1016/j.celrep.2021.108923] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 12/20/2020] [Accepted: 03/09/2021] [Indexed: 12/03/2022] Open
Abstract
Despite decades of work, much remains elusive about molecular events at the interplay between physiological and structural changes underlying neuronal plasticity. Here, we combined repetitive live imaging and expansion microscopy in organotypic brain slice cultures to quantitatively characterize the dynamic changes of the intracellular versus surface pools of GluA2-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) across the different dendritic spine types and the shaft during hippocampal homeostatic plasticity. Mechanistically, we identify ephrinB2 and glutamate receptor interacting protein (GRIP) 1 as mediating AMPAR relocation to the mushroom spine surface following lesion-induced denervation. Moreover, stimulation with the ephrinB2 specific receptor EphB4 not only prevents the lesion-induced disappearance of mushroom spines but is also sufficient to shift AMPARs to the surface and rescue spine recovery in a GRIP1 dominant-negative background. Thus, our results unravel a crucial role for ephrinB2 during homeostatic plasticity and identify a potential pharmacological target to improve dendritic spine plasticity upon injury.
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Affiliation(s)
- Diane Bissen
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany; Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438 Frankfurt am Main, Germany
| | - Maximilian Ken Kracht
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Franziska Foss
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Jan Hofmann
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany
| | - Amparo Acker-Palmer
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany; Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438 Frankfurt am Main, Germany; Cardio-Pulmonary Institute (CPI), Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany.
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8
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B cells migrate into remote brain areas and support neurogenesis and functional recovery after focal stroke in mice. Proc Natl Acad Sci U S A 2020; 117:4983-4993. [PMID: 32051245 PMCID: PMC7060723 DOI: 10.1073/pnas.1913292117] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Neuroinflammation occurs immediately after stroke onset in the ischemic infarct, but whether neuroinflammation occurs in remote regions supporting plasticity and functional recovery remains unknown. We used advanced imaging to quantify whole-brain diapedesis of B cells, an immune cell capable of producing neurotrophins. We identify bilateral B cell diapedesis into remote regions, outside of the injury, that support motor and cognitive recovery in young male mice. Poststroke depletion of B cells confirms a positive role in neurogenesis, neuronal survival, and recovery of motor coordination, spatial learning, and anxiety. More than 80% of stroke survivors have long-term disability uniquely affected by age and lifestyle factors. Thus, identifying beneficial neuroinflammation during long-term recovery increases the opportunity of therapeutic interventions to support functional recovery. Lymphocytes infiltrate the stroke core and penumbra and often exacerbate cellular injury. B cells, however, are lymphocytes that do not contribute to acute pathology but can support recovery. B cell adoptive transfer to mice reduced infarct volumes 3 and 7 d after transient middle cerebral artery occlusion (tMCAo), independent of changing immune populations in recipient mice. Testing a direct neurotrophic effect, B cells cocultured with mixed cortical cells protected neurons and maintained dendritic arborization after oxygen-glucose deprivation. Whole-brain volumetric serial two-photon tomography (STPT) and a custom-developed image analysis pipeline visualized and quantified poststroke B cell diapedesis throughout the brain, including remote areas supporting functional recovery. Stroke induced significant bilateral B cell diapedesis into remote brain regions regulating motor and cognitive functions and neurogenesis (e.g., dentate gyrus, hypothalamus, olfactory areas, cerebellum) in the whole-brain datasets. To confirm a mechanistic role for B cells in functional recovery, rituximab was given to human CD20+ (hCD20+) transgenic mice to continuously deplete hCD20+-expressing B cells following tMCAo. These mice experienced delayed motor recovery, impaired spatial memory, and increased anxiety through 8 wk poststroke compared to wild type (WT) littermates also receiving rituximab. B cell depletion reduced stroke-induced hippocampal neurogenesis and cell survival. Thus, B cell diapedesis occurred in areas remote to the infarct that mediated motor and cognitive recovery. Understanding the role of B cells in neuronal health and disease-based plasticity is critical for developing effective immune-based therapies for protection against diseases that involve recruitment of peripheral immune cells into the injured brain.
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Del Turco D, Paul MH, Beeg Moreno VJ, Hildebrandt-Einfeldt L, Deller T. Re-innervation of the Denervated Dentate Gyrus by Sprouting Associational and Commissural Mossy Cell Axons in Organotypic Tissue Cultures of Entorhinal Cortex and Hippocampus. Front Mol Neurosci 2019; 12:270. [PMID: 31798410 PMCID: PMC6861856 DOI: 10.3389/fnmol.2019.00270] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 10/22/2019] [Indexed: 12/25/2022] Open
Abstract
Collateral sprouting of surviving axons contributes to the synaptic reorganization after brain injury. To study this clinically relevant phenomenon, we used complex organotypic tissue cultures of mouse entorhinal cortex (EC) and hippocampus (H). Single EC-H cultures were generated to analyze associational sprouting, and double EC-H cultures were used to evaluate commissural sprouting of mossy cells in the dentate gyrus (DG) following entorhinal denervation. Entorhinal denervation (transection of the perforant path) was performed at 14 days in vitro (DIV) and associational/commissural sprouting was assessed at 28 DIV. First, associational sprouting was studied in genetically hybrid EC-H cultures of beta-actin-GFPtg and wild-type mice. Using calretinin as a marker, associational axons were found to re-innervate almost the entire entorhinal target zone. Denervation experiments performed with EC-H cultures of Thy1-YFPtg mice, in which mossy cells are YFP-positive, confirmed that the overwhelming majority of sprouting associational calretinin-positive axons are mossy cell axons. Second, we analyzed associational/commissural sprouting by combining wild-type EC-H cultures with calretinin-deficient EC-H cultures. In these cultures, only wild-type mossy cells contain calretinin, and associational and commissural mossy cell collaterals can be distinguished using calretinin as a marker. Nearly the entire DG entorhinal target zone was re-innervated by sprouting of associational and commissural mossy cell axons. Finally, viral labeling of newly formed associational/commissural axons revealed a rapid post-lesional sprouting response. These findings demonstrate extensive and rapid re-innervation of the denervated DG outer molecular layer by associational and commissural mossy cell axons, similar to what has been reported to occur in juvenile rodent DG in vivo.
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Affiliation(s)
- Domenico Del Turco
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Mandy H Paul
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Viktor J Beeg Moreno
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Lars Hildebrandt-Einfeldt
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt, Germany
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10
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Liu XY, Wei MG, Liang J, Xu HH, Wang JJ, Wang J, Yang XP, Lv FF, Wang KQ, Duan JH, Tu Y, Zhang S, Chen C, Li XH. Injury-preconditioning secretome of umbilical cord mesenchymal stem cells amplified the neurogenesis and cognitive recovery after severe traumatic brain injury in rats. J Neurochem 2019; 153:230-251. [PMID: 31465551 DOI: 10.1111/jnc.14859] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/10/2019] [Accepted: 08/02/2019] [Indexed: 12/14/2022]
Abstract
Traumatic brain injury (TBI) is a dominant cause of death and permanent disability worldwide. Although TBI could significantly increase the proliferation of adult neural stem cells in the hippocampus, the survival and maturation of newborn cells is markedly low. Increasing evidence suggests that the secretome derived from mesenchymal stem cells (MSCs) would be an ideal alternative to MSC transplantation. The successive and microenvironmentally responsive secretion in MSCs may be critical for the functional benefits provided by transplanted MSCs after TBI. Therefore, it is reasonable to hypothesize that the signaling molecules secreted in response to local tissue damage can further facilitate the therapeutic effect of the MSC secretome. To simulate the complex microenvironment in the injured brain well, we used traumatically injured brain tissue extracts to pretreat umbilical cord mesenchymal stem cells (UCMSCs) in vitro and stereotaxically injected the secretome from traumatic injury-preconditioned UCMSCs into the dentate gyrus of the hippocampus in a rat severe TBI model. The results revealed that compared with the normal secretome, the traumatic injury-preconditioned secretome could significantly further promote the differentiation, migration, and maturation of newborn cells in the dentate gyrus and ultimately improve cognitive function after TBI. Cytokine antibody array suggested that the increased benefits of secretome administration were attributable to the newly produced proteins and up-regulated molecules from the MSC secretome preconditioned by a traumatically injured microenvironment. Our study utilized the traumatic injury-preconditioned secretome to amplify neurogenesis and improve cognitive recovery, suggesting this method may be a novel and safer candidate for nerve repair. Cover Image for this issue: doi: 10.1111/jnc.14741.
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Affiliation(s)
- Xiao-Yin Liu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China.,Tianjin Medical University, Tianjin, China
| | - Meng-Guang Wei
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
| | - Jun Liang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Hai-Huan Xu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
| | - Jing-Jing Wang
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
| | - Jing Wang
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
| | - Xi-Ping Yang
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
| | - Fang-Fang Lv
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
| | - Ke-Qiang Wang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Jing-Hao Duan
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Yue Tu
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
| | - Sai Zhang
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
| | - Chong Chen
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
| | - Xiao-Hong Li
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Characteristic Medical Center of People's Armed Police Forces, Tianjin, China
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11
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Pampaloni NP, Rago I, Calaresu I, Cozzarini L, Casalis L, Goldoni A, Ballerini L, Scaini D. Transparent carbon nanotubes promote the outgrowth of enthorino-dentate projections in lesioned organ slice cultures. Dev Neurobiol 2019; 80:316-331. [PMID: 31314946 DOI: 10.1002/dneu.22711] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 12/25/2022]
Abstract
The increasing engineering of carbon-based nanomaterials as components of neuroregenerative interfaces is motivated by their dimensional compatibility with subcellular compartments of excitable cells, such as axons and synapses. In neuroscience applications, carbon nanotubes (CNTs) have been used to improve electronic device performance by exploiting their physical properties. Besides, when manufactured to interface neuronal networks formation in vitro, CNT carpets have shown their unique ability to potentiate synaptic networks formation and function. Due to the low optical transparency of CNTs films, further developments of these materials in neural prosthesis fabrication or in implementing interfacing devices to be paired with in vivo imaging or in vitro optogenetic approaches are currently limited. In the present work, we exploit a new method to fabricate CNTs by growing them on a fused silica surface, which results in a transparent CNT-based substrate (tCNTs). We show that tCNTs favor dissociated primary neurons network formation and function, an effect comparable to the one observed for their dark counterparts. We further adopt tCNTs to support the growth of intact or lesioned entorhinal-hippocampal complex organotypic cultures (EHCs). Through immunocytochemistry and electrophysiological field potential recordings, we show here that tCNTs platforms are suitable substrates for the growth of EHCs and we unmask their ability to significantly increase the signal synchronization and fiber sprouting between the cortex and the hippocampus with respect to Controls. tCNTs transparency and ability to enhance recovery of lesioned brain cultures, make them optimal candidates to implement implantable devices in regenerative medicine and tissue engineering.
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Affiliation(s)
| | - Ilaria Rago
- Elettra Sincrotrone Trieste, Trieste, Italy.,Department of Physics, University of Trieste, Trieste, Italy
| | - Ivo Calaresu
- International School for Advanced Studies (SISSA), Trieste, Italy
| | - Luca Cozzarini
- Elettra Sincrotrone Trieste, Trieste, Italy.,Department of Engineering and Architecture, University of Trieste, Trieste, Italy
| | | | | | - Laura Ballerini
- International School for Advanced Studies (SISSA), Trieste, Italy
| | - Denis Scaini
- International School for Advanced Studies (SISSA), Trieste, Italy.,Elettra Sincrotrone Trieste, Trieste, Italy
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12
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Yamada S, Sakakibara SI. Expression profile of the STAND protein Nwd1 in the developing and mature mouse central nervous system. J Comp Neurol 2018; 526:2099-2114. [PMID: 30004576 DOI: 10.1002/cne.24495] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 06/02/2018] [Accepted: 06/13/2018] [Indexed: 12/12/2022]
Abstract
The orchestrated events required during brain development, as well as the maintenance of adult neuronal plasticity, highly depend on the accurate responses of neuronal cells to various cellular stress or environmental stimuli. Recent studies have defined a previously unrecognized, broad class of multidomain proteins, designated as signal transduction ATPases with numerous domains (STAND), which comprises a large number of proteins, including the apoptotic peptidase activating factor 1 (Apaf1) and nucleotide-binding oligomerization domain-like receptors (NLRs), central players in cell death and innate immune responses, respectively. Although the involvement of STANDs in the central nervous system (CNS) has been postulated in terms of neuronal development and function, it remains largely unclear. Here, we identified Nwd1 (NACHT and WD repeat domain-containing protein 1), as a novel STAND protein, expressed in neural stem/progenitor cells (NSPCs). Structurally, Nwd1 was most analogous to the apoptosis regulator Apaf1, also involved in mitosis and axonal outgrowth regulation in the CNS. Using a specific antibody, we show that, during the embryonic and postnatal period, Nwd1 is expressed in nestin-positive NSPCs in vivo and in vitro, while postnatally it is found in terminally differentiated neurons and blood vessels. At the subcellular level, we demonstrate that Nwd1 is preferentially located in the cytosolic compartment of cultured NSPCs, partially overlapping with cytochrome c. These observations imply that Nwd1 might be involved in the neuronal lineage as a new STAND gene, including having a pro-apoptotic or nonapoptotic role, similar to Apaf1.
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Affiliation(s)
- Seiya Yamada
- Laboratory for Molecular Neurobiology, Graduate School of Human Sciences, Waseda University, Saitama, Japan
| | - Shin-Ichi Sakakibara
- Laboratory for Molecular Neurobiology, Graduate School of Human Sciences, Waseda University, Saitama, Japan
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13
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DeWalt GJ, Mahajan B, Foster AR, Thompson LDE, Marttini AA, Schmidt EV, Mansuri S, D'Souza D, Patel SB, Tenenbaum M, Brandao-Viruet KI, Thompson D, Duong B, Smith DH, Blute TA, Eldred WD. Region-specific alterations in astrocyte and microglia morphology following exposure to blasts in the mouse hippocampus. Neurosci Lett 2017; 664:160-166. [PMID: 29133177 DOI: 10.1016/j.neulet.2017.11.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 11/07/2017] [Accepted: 11/07/2017] [Indexed: 12/28/2022]
Abstract
Traumatic brain injury (TBI) is a serious public health concern, especially injuries from repetitive insults. The main objective of this study was to immunocytochemically examine morphological alterations in astrocytes and microglia in the hippocampus 48h following a single blast versus multiple blasts in adult C57BL/6 mice. The effects of ketamine and xylazine (KX), two common anesthetic agents used in TBI research, were also evaluated due to the confounding effect of anesthetics on injury outcome. Results showed a significant increase in hypertrophic microglia that was limited to the outer molecular layer of the dentate gyrus, but only in the absence of KX. Although the presence or absence of KX had no effect on astrocytes following a single blast, a significant decrease in astrocytic immunoreactivity was observed in the stratum lacunosum moleculare following multiple blasts in the absence of KX. The morphological changes in astrocytes and microglia reported in this study reveal region-specific differences in the absence of KX that could have significant implications for our interpretation of glial alterations in animal models of injury.
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Affiliation(s)
| | | | | | | | | | | | - Sara Mansuri
- Boston University, Department of Biology, United States
| | | | - Shama B Patel
- Boston University, Department of Biology, United States
| | | | | | | | - Bryan Duong
- Boston University, Department of Biology, United States
| | | | - Todd A Blute
- Boston University, Department of Biology, United States
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14
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Brizuela M, Blizzard CA, Chuckowree JA, Pitman KA, Young KM, Dickson T. Mild Traumatic Brain Injury Leads to Decreased Inhibition and a Differential Response of Calretinin Positive Interneurons in the Injured Cortex. J Neurotrauma 2017; 34:2504-2517. [DOI: 10.1089/neu.2017.4977] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Mariana Brizuela
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
| | | | - Jyoti A. Chuckowree
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
| | - Kimberley A. Pitman
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
| | - Kaylene M. Young
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
| | - Tracey Dickson
- Menzies Institute for Medical Research, University of Tasmania, Tasmania, Australia
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15
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Fasulo L, Brandi R, Arisi I, La Regina F, Berretta N, Capsoni S, D'Onofrio M, Cattaneo A. ProNGF Drives Localized and Cell Selective Parvalbumin Interneuron and Perineuronal Net Depletion in the Dentate Gyrus of Transgenic Mice. Front Mol Neurosci 2017; 10:20. [PMID: 28232789 PMCID: PMC5299926 DOI: 10.3389/fnmol.2017.00020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/16/2017] [Indexed: 01/12/2023] Open
Abstract
ProNGF, the precursor of mature Nerve Growth Factor (NGF), is the most abundant NGF form in the brain and increases markedly in the cortex in Alzheimer's Disease (AD), relative to mature NGF. A large body of evidence shows that the actions of ProNGF and mature NGF are often conflicting, depending on the receptors expressed in target cells. TgproNGF#3 mice, expressing furin-cleavage resistant proNGF in CNS neurons, directly reveal consequences of increased proNGF levels on brain homeostasis. Their phenotype clearly indicates that proNGF can be a driver of neurodegeneration, including severe learning and memory behavioral deficits, cholinergic deficits, and diffuse immunoreactivity for A-beta and A-beta-oligomers. In aged TgproNGF#3 mice spontaneous epileptic-like events are detected in entorhinal cortex-hippocampal slices, suggesting occurrence of excitatory/inhibitory (E/I) imbalance. In this paper, we investigate the molecular events linking increased proNGF levels to the epileptiform activity detected in hippocampal slices. The occurrence of spontaneous epileptiform discharges in the hippocampal network in TgproNGF#3 mice suggests an impaired inhibitory interneuron homeostasis. In the present study, we detect the onset of hippocampal epileptiform events at 1-month of age. Later, we observe a regional- and cellular-selective Parvalbumin interneuron and perineuronal net (PNN) depletion in the dentate gyrus (DG), but not in other hippocampal regions of TgproNGF#3 mice. These results demonstrate that, in the hippocampus, the DG is selectively vulnerable to altered proNGF/NGF signaling. Parvalbumin interneuron depletion is also observed in the amygdala, a region strongly connected to the hippocampus and likewise receiving cholinergic afferences. Transcriptome analysis of TgproNGF#3 hippocampus reveals a proNGF signature with broad down-regulation of transcription. The most affected mRNAs modulated at early times belong to synaptic transmission and plasticity and extracellular matrix (ECM) gene families. Moreover, alterations in the expression of selected BDNF splice variants were observed. Our results provide further mechanistic insights into the vicious negative cycle linking proNGF and neurodegeneration, confirming the regulation of E/I homeostasis as a crucial mediating mechanism.
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Affiliation(s)
- Luisa Fasulo
- Bio@SNS Laboratory, Scuola Normale SuperiorePisa, Italy; European Brain Research Institute Rita Levi-MontalciniRome, Italy
| | - Rossella Brandi
- European Brain Research Institute Rita Levi-Montalcini Rome, Italy
| | - Ivan Arisi
- European Brain Research Institute Rita Levi-Montalcini Rome, Italy
| | | | - Nicola Berretta
- Department of Experimental Neurology, Fondazione Santa Lucia IRCCS Rome, Italy
| | - Simona Capsoni
- Bio@SNS Laboratory, Scuola Normale Superiore Pisa, Italy
| | - Mara D'Onofrio
- European Brain Research Institute Rita Levi-Montalcini Rome, Italy
| | - Antonino Cattaneo
- Bio@SNS Laboratory, Scuola Normale SuperiorePisa, Italy; European Brain Research Institute Rita Levi-MontalciniRome, Italy
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16
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Ramos-Languren LE, García-Díaz G, González-Maciel A, Rosas-López LE, Bueno-Nava A, Avila-Luna A, Ramírez-Anguiano H, González-Piña R. Sensorimotor Intervention Recovers Noradrenaline Content in the Dentate Gyrus of Cortical Injured Rats. Neurochem Res 2016; 41:3261-3271. [PMID: 27639395 DOI: 10.1007/s11064-016-2054-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 08/26/2016] [Accepted: 08/31/2016] [Indexed: 11/25/2022]
Abstract
Nowadays, a consensus has been reached that designates the functional and structural reorganization of synapses as the primary mechanisms underlying the process of recovery from brain injury. We have reported that pontine noradrenaline (NA) is increased in animals after cortical ablation (CA). The aim of the present study was to explore the noradrenergic and morphological response after sensorimotor intervention (SMI) in rats injured in the motor cortex. We used male Wistar adult rats allocated in four conditions: sham-operated, injured by cortical ablation, sham-operated with SMI and injured by cortical ablation with SMI. Motor and somatosensory performance was evaluated prior to and 20 days after surgery. During the intervening period, a 15-session, SMI program was implemented. Subsequently, total NA analysis in the pons and dentate gyrus (DG) was performed. All groups underwent histological analysis. Our results showed that NA content in the DG was reduced in the injured group versus control, and this reduction was reverted in the injured group that underwent SMI. Moreover, injured rats showed reduction in the number of granule cells in the DG and decreased dentate granule cell layer thickness. Notably, after SMI, the loss of granule cells was reverted. Locus coeruleus showed turgid cells in the injured rats. These results suggest that SMI elicits biochemical and structural modifications in the hippocampus that could reorganize the system and lead the recovery process, modulating structural and functional plasticity.
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Affiliation(s)
- Laura E Ramos-Languren
- Laboratorio de Neuroplasticidad-División de Neurociencias, Torre de Investigación, Instituto Nacional de Rehabilitacion, Calz. Mexico-Xochimilco 289 Col. Arenal de Guadalupe, Deleg. Tlalpan, C.P. 14389, Mexico City, Mexico
| | - Gabriela García-Díaz
- Laboratorio de Neuroplasticidad-División de Neurociencias, Torre de Investigación, Instituto Nacional de Rehabilitacion, Calz. Mexico-Xochimilco 289 Col. Arenal de Guadalupe, Deleg. Tlalpan, C.P. 14389, Mexico City, Mexico
| | - Angélica González-Maciel
- Instituto Nacional de Pediatría, SSA. Av. Imán 1 Col. Insurgentes Cuicuilco, Coyoacán, C.P. 04530, Mexico City, Mexico
| | - Laura E Rosas-López
- Instituto Nacional de Pediatría, SSA. Av. Imán 1 Col. Insurgentes Cuicuilco, Coyoacán, C.P. 04530, Mexico City, Mexico
| | - Antonio Bueno-Nava
- Laboratorio de Neuroplasticidad-División de Neurociencias, Torre de Investigación, Instituto Nacional de Rehabilitacion, Calz. Mexico-Xochimilco 289 Col. Arenal de Guadalupe, Deleg. Tlalpan, C.P. 14389, Mexico City, Mexico
| | - Alberto Avila-Luna
- Laboratorio de Neuroplasticidad-División de Neurociencias, Torre de Investigación, Instituto Nacional de Rehabilitacion, Calz. Mexico-Xochimilco 289 Col. Arenal de Guadalupe, Deleg. Tlalpan, C.P. 14389, Mexico City, Mexico
| | - Hayde Ramírez-Anguiano
- Laboratorio de Neuroplasticidad-División de Neurociencias, Torre de Investigación, Instituto Nacional de Rehabilitacion, Calz. Mexico-Xochimilco 289 Col. Arenal de Guadalupe, Deleg. Tlalpan, C.P. 14389, Mexico City, Mexico
- Universidad de las Américas AC, Puebla 23 Col. Roma, Deleg. Cuauhtemoc, C.P. 06700, Mexico City, Mexico
| | - Rigoberto González-Piña
- Laboratorio de Neuroplasticidad-División de Neurociencias, Torre de Investigación, Instituto Nacional de Rehabilitacion, Calz. Mexico-Xochimilco 289 Col. Arenal de Guadalupe, Deleg. Tlalpan, C.P. 14389, Mexico City, Mexico.
- Universidad de las Américas AC, Puebla 23 Col. Roma, Deleg. Cuauhtemoc, C.P. 06700, Mexico City, Mexico.
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17
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Schuldt G, Galanis C, Strehl A, Hick M, Schiener S, Lenz M, Deller T, Maggio N, Vlachos A. Inhibition of Protease-Activated Receptor 1 Does not Affect Dendritic Homeostasis of Cultured Mouse Dentate Granule Cells. Front Neuroanat 2016; 10:64. [PMID: 27378862 PMCID: PMC4904007 DOI: 10.3389/fnana.2016.00064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/27/2016] [Indexed: 12/25/2022] Open
Abstract
Protease-activated receptors (PARs) are widely expressed in the central nervous system (CNS). While a firm link between PAR1-activation and functional synaptic and intrinsic neuronal properties exists, studies on the role of PAR1 in neural structural plasticity are scarce. The physiological function of PAR1 in the brain remains not well understood. We here sought to determine whether prolonged pharmacologic PAR1-inhibition affects dendritic morphologies of hippocampal neurons. To address this question we employed live-cell microscopy of mouse dentate granule cell dendrites in 3-week old entorhino-hippocampal slice cultures prepared from Thy1-GFP mice. A subset of cultures were treated with the PAR1-inhibitor SCH79797 (1 μM; up to 3 weeks). No major effects of PAR1-inhibition on static and dynamic parameters of dentate granule cell dendrites were detected under control conditions. Granule cells of PAR1-deficient slice cultures showed unaltered dendritic morphologies, dendritic spine densities and excitatory synaptic strength. Furthermore, we report that PAR1-inhibition does not prevent dendritic retraction following partial deafferentation in vitro. Consistent with this finding, no major changes in PAR1-mRNA levels were detected in the denervated dentate gyrus (DG). We conclude that neural PAR1 is not involved in regulating the steady-state dynamics or deafferentation-induced adaptive changes of cultured dentate granule cell dendrites. These results indicate that drugs targeting neural PAR1-signals may not affect the stability and structural integrity of neuronal networks in healthy brain regions.
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Affiliation(s)
- Gerlind Schuldt
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt Frankfurt, Germany
| | - Christos Galanis
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt Frankfurt, Germany
| | - Andreas Strehl
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt Frankfurt, Germany
| | - Meike Hick
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt Frankfurt, Germany
| | - Sabine Schiener
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt Frankfurt, Germany
| | - Maximilian Lenz
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University FrankfurtFrankfurt, Germany; Institute of Anatomy II, Faculty of Medicine, Heinrich-Heine-University DüsseldorfDüsseldorf, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt Frankfurt, Germany
| | - Nicola Maggio
- Department of Neurology, The Sagol Center for Neurosciences, Sheba Medical Center, Affiliated to the Sackler Faculty of Medicine, Tel Aviv UniversityTel Aviv, Israel; Talpiot Medical Leadership Program, Department of Neurology and J. Sagol Neuroscience Center, The Chaim Sheba Medical CenterTel HaShomer, Israel; Sagol School of Neuroscience, Tel Aviv UniversityTel Aviv, Israel
| | - Andreas Vlachos
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University FrankfurtFrankfurt, Germany; Institute of Anatomy II, Faculty of Medicine, Heinrich-Heine-University DüsseldorfDüsseldorf, Germany
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18
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Wolf JA, Koch PF. Disruption of Network Synchrony and Cognitive Dysfunction After Traumatic Brain Injury. Front Syst Neurosci 2016; 10:43. [PMID: 27242454 PMCID: PMC4868948 DOI: 10.3389/fnsys.2016.00043] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 04/26/2016] [Indexed: 11/13/2022] Open
Abstract
Traumatic brain injury (TBI) is a heterogeneous disorder with many factors contributing to a spectrum of severity, leading to cognitive dysfunction that may last for many years after injury. Injury to axons in the white matter, which are preferentially vulnerable to biomechanical forces, is prevalent in many TBIs. Unlike focal injury to a discrete brain region, axonal injury is fundamentally an injury to the substrate by which networks of the brain communicate with one another. The brain is envisioned as a series of dynamic, interconnected networks that communicate via long axonal conduits termed the "connectome". Ensembles of neurons communicate via these pathways and encode information within and between brain regions in ways that are timing dependent. Our central hypothesis is that traumatic injury to axons may disrupt the exquisite timing of neuronal communication within and between brain networks, and that this may underlie aspects of post-TBI cognitive dysfunction. With a better understanding of how highly interconnected networks of neurons communicate with one another in important cognitive regions such as the limbic system, and how disruption of this communication occurs during injury, we can identify new therapeutic targets to restore lost function. This requires the tools of systems neuroscience, including electrophysiological analysis of ensemble neuronal activity and circuitry changes in awake animals after TBI, as well as computational modeling of the effects of TBI on these networks. As more is revealed about how inter-regional neuronal interactions are disrupted, treatments directly targeting these dysfunctional pathways using neuromodulation can be developed.
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Affiliation(s)
- John A Wolf
- Center for Brain Injury and Repair, Department of Neurosurgery, University of PennsylvaniaPhiladelphia, PA, USA; Corporal Michael J. Crescenz VA Medical CenterPhiladelphia, PA, USA
| | - Paul F Koch
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania Philadelphia, PA, USA
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19
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Li L, Chopp M, Ding G, Qu C, Nejad-Davarani SP, Davoodi-Bojd E, Li Q, Mahmood A, Jiang Q. Diffusion-Derived Magnetic Resonance Imaging Measures of Longitudinal Microstructural Remodeling Induced by Marrow Stromal Cell Therapy after Traumatic Brain Injury. J Neurotrauma 2016; 34:182-191. [PMID: 26993214 DOI: 10.1089/neu.2015.4315] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Using magnetic resonance imaging (MRI) and an animal model of traumatic brain injury (TBI), we investigated the capacity and sensitivity of diffusion-derived measures, fractional anisotropy (FA), and diffusion entropy, to longitudinally identify structural plasticity in the injured brain in response to the transplantation of human bone marrow stromal cells (hMSCs). Male Wistar rats (300-350g, n = 30) were subjected to controlled cortical impact TBI. At 6 h or 1 week post-injury, these rats were intravenously injected with 1 mL of saline (at 6 h or 1 week, n = 5/group) or with hMSCs in suspension (∼3 × 106 hMSCs, at 6 h or 1 week, n = 10/group). In vivo MRI measurements and sensorimotor function estimates were performed on all animals pre-injury, 1 day post-injury, and weekly for 3 weeks post-injury. Bielschowsky's silver and Luxol fast blue staining were used to reveal the axon and myelin status, respectively, with and without cell treatment after TBI. Based on image data and histological observation, regions of interest encompassing the structural alterations were made and the values of FA and entropy were monitored in these specific brain regions. Our data demonstrate that administration of hMSCs after TBI leads to enhanced white matter reorganization particularly along the boundary of contusional lesion, which can be identified by both FA and entropy. Compared with the therapy performed at 1 week post-TBI, cell intervention executed at 6 h expedites the brain remodeling process and results in an earlier functional recovery. Although FA and entropy present a similar capacity to dynamically detect the microstructural changes in the tissue regions with predominant orientation of fiber tracts, entropy exhibits a sensitivity superior to that of FA, in probing the structural alterations in the tissue areas with complex fiber patterns.
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Affiliation(s)
- Lian Li
- 1 Department of Neurology, Henry Ford Hospital , Detroit, Michigan
| | - Michael Chopp
- 1 Department of Neurology, Henry Ford Hospital , Detroit, Michigan.,2 Department of Physics, Oakland University , Rochester, Michigan
| | - Guangliang Ding
- 1 Department of Neurology, Henry Ford Hospital , Detroit, Michigan
| | - Changsheng Qu
- 3 Department of Neurosurgery, Henry Ford Hospital , Detroit, Michigan
| | | | | | - Qingjiang Li
- 1 Department of Neurology, Henry Ford Hospital , Detroit, Michigan
| | - Asim Mahmood
- 3 Department of Neurosurgery, Henry Ford Hospital , Detroit, Michigan
| | - Quan Jiang
- 1 Department of Neurology, Henry Ford Hospital , Detroit, Michigan.,2 Department of Physics, Oakland University , Rochester, Michigan
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20
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Willems LM, Zahn N, Ferreirós N, Scholich K, Maggio N, Deller T, Vlachos A. Sphingosine-1-phosphate receptor inhibition prevents denervation-induced dendritic atrophy. Acta Neuropathol Commun 2016; 4:28. [PMID: 27036416 PMCID: PMC4818430 DOI: 10.1186/s40478-016-0303-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 03/16/2016] [Indexed: 11/10/2022] Open
Abstract
A hallmark of several major neurological diseases is neuronal cell death. In addition to this primary pathology, secondary injury is seen in connected brain regions in which neurons not directly affected by the disease are denervated. These transneuronal effects on the network contribute considerably to the clinical symptoms. Since denervated neurons are viable, they are attractive targets for intervention. Therefore, we studied the role of Sphingosine-1-phosphate (S1P)-receptor signaling, the target of Fingolimod (FTY720), in denervation-induced dendritic atrophy. The entorhinal denervation in vitro model was used to assess dendritic changes of denervated mouse dentate granule cells. Live-cell microscopy of GFP-expressing granule cells in organotypic entorhino-hippocampal slice cultures was employed to follow individual dendritic segments for up to 6 weeks after deafferentation. A set of slice cultures was treated with FTY720 or the S1P-receptor (S1PR) antagonist VPC23019. Lesion-induced changes in S1P (mass spectrometry) and S1PR-mRNA levels (laser microdissection and qPCR) were determined. Denervation caused profound changes in dendritic stability. Dendritic elongation and retraction events were markedly increased, resulting in a net reduction of total dendritic length (TDL) during the first 2 weeks after denervation, followed by a gradual recovery in TDL. These changes were accompanied by an increase in S1P and S1PR1- and S1PR3-mRNA levels, and were not observed in slice cultures treated with FTY720 or VPC23019. We conclude that inhibition of S1PR signaling prevents dendritic destabilization and denervation-induced dendrite loss. These results suggest a novel neuroprotective effect for pharmaceuticals targeting neural S1PR pathways.
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21
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Platschek S, Cuntz H, Vuksic M, Deller T, Jedlicka P. A general homeostatic principle following lesion induced dendritic remodeling. Acta Neuropathol Commun 2016; 4:19. [PMID: 26916562 PMCID: PMC4766619 DOI: 10.1186/s40478-016-0285-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 02/06/2016] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Neuronal death and subsequent denervation of target areas are hallmarks of many neurological disorders. Denervated neurons lose part of their dendritic tree, and are considered "atrophic", i.e. pathologically altered and damaged. The functional consequences of this phenomenon are poorly understood. RESULTS Using computational modelling of 3D-reconstructed granule cells we show that denervation-induced dendritic atrophy also subserves homeostatic functions: By shortening their dendritic tree, granule cells compensate for the loss of inputs by a precise adjustment of excitability. As a consequence, surviving afferents are able to activate the cells, thereby allowing information to flow again through the denervated area. In addition, action potentials backpropagating from the soma to the synapses are enhanced specifically in reorganized portions of the dendritic arbor, resulting in their increased synaptic plasticity. These two observations generalize to any given dendritic tree undergoing structural changes. CONCLUSIONS Structural homeostatic plasticity, i.e. homeostatic dendritic remodeling, is operating in long-term denervated neurons to achieve functional homeostasis.
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22
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Xu A, Matushewski B, Nygard K, Hammond R, Frasch MG, Richardson BS. Brain Injury and Inflammatory Response to Umbilical Cord Occlusions Is Limited With Worsening Acidosis in the Near-Term Ovine Fetus. Reprod Sci 2015; 23:858-70. [DOI: 10.1177/1933719115623640] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Alex Xu
- Department of Obstetrics and Gynecology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Brad Matushewski
- Department of Obstetrics and Gynecology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Karen Nygard
- Biotron Experimental Climate Change Research Centre, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Robert Hammond
- Department of Pathology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Martin G. Frasch
- Department of Obstetrics and Gynaecology and Department of Neurosciences, CHU Ste-Justine Research Center, Université de Montréal, Montreal, Québec, Canada
- Centre de Recherche en Reproduction Animale, Université de Montréal, St-Hyacinthe, Québec, Canada
| | - Bryan S. Richardson
- Department of Obstetrics and Gynecology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
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23
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Jones TA, Adkins DL. Motor System Reorganization After Stroke: Stimulating and Training Toward Perfection. Physiology (Bethesda) 2015; 30:358-70. [PMID: 26328881 PMCID: PMC4556825 DOI: 10.1152/physiol.00014.2015] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Stroke instigates regenerative responses that reorganize connectivity patterns among surviving neurons. The new connectivity patterns can be suboptimal for behavioral function. This review summarizes current knowledge on post-stroke motor system reorganization and emerging strategies for shaping it with manipulations of behavior and cortical activity to improve functional outcome.
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Affiliation(s)
- Theresa A Jones
- Psychology Department, Neuroscience Institute, University of Texas at Austin, Austin, Texas; and
| | - DeAnna L Adkins
- Neurosciences Department, and Health Sciences & Research Department, Colleges of Medicine & Health Professions, Medical University of South Carolina, Charleston, South Carolina
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24
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Baratz R, Tweedie D, Wang JY, Rubovitch V, Luo W, Hoffer BJ, Greig NH, Pick CG. Transiently lowering tumor necrosis factor-α synthesis ameliorates neuronal cell loss and cognitive impairments induced by minimal traumatic brain injury in mice. J Neuroinflammation 2015; 12:45. [PMID: 25879458 PMCID: PMC4352276 DOI: 10.1186/s12974-015-0237-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 01/06/2015] [Indexed: 11/30/2022] Open
Abstract
Background The treatment of traumatic brain injury (TBI) represents an unmet medical need, as no effective pharmacological treatment currently exists. The development of such a treatment requires a fundamental understanding of the pathophysiological mechanisms that underpin the sequelae resulting from TBI, particularly the ensuing neuronal cell death and cognitive impairments. Tumor necrosis factor-alpha (TNF-α) is a cytokine that is a master regulator of systemic and neuroinflammatory processes. TNF-α levels are reported to become rapidly elevated post TBI and, potentially, can lead to secondary neuronal damage. Methods To elucidate the role of TNF-α in TBI, particularly as a drug target, the present study evaluated (i) time-dependent TNF-α levels and (ii) markers of apoptosis and gliosis within the brain and related these to behavioral measures of ‘well being’ and cognition in a mouse closed head 50 g weight drop mild TBI (mTBI) model in the presence and absence of post-treatment with an experimental TNF-α synthesis inhibitor, 3,6′-dithiothalidomide. Results mTBI elevated brain TNF-α levels, which peaked at 12 h post injury and returned to baseline by 18 h. This was accompanied by a neuronal loss and an increase in astrocyte number (evaluated by neuronal nuclei (NeuN) and glial fibrillary acidic protein (GFAP) immunostaining), as well as an elevation in the apoptotic death marker BH3-interacting domain death agonist (BID) at 72 h. Selective impairments in measures of cognition, evaluated by novel object recognition and passive avoidance paradigms - without changes in well being, were evident at 7 days after injury. A single systemic treatment with the TNF-α synthesis inhibitor 3,6′-dithiothalidomide 1 h post injury prevented the mTBI-induced TNF-α elevation and fully ameliorated the neuronal loss (NeuN), elevations in astrocyte number (GFAP) and BID, and cognitive impairments. Cognitive impairments evident at 7 days after injury were prevented by treatment as late as 12 h post mTBI but were not reversed when treatment was delayed until 18 h. Conclusions These results implicate that TNF-α in mTBI induced secondary brain damage and indicate that pharmacologically limiting the generation of TNF-α post mTBI may mitigate such damage, defining a time-dependent window of up to 12 h to achieve this reversal.
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Affiliation(s)
- Renana Baratz
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
| | - David Tweedie
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, BRC Room 05C220, 251 Bayview Blvd., Baltimore, MD, 21224, USA.
| | - Jia-Yi Wang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Vardit Rubovitch
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
| | - Weiming Luo
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, BRC Room 05C220, 251 Bayview Blvd., Baltimore, MD, 21224, USA.
| | - Barry J Hoffer
- Department of Neurosurgery, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
| | - Nigel H Greig
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, BRC Room 05C220, 251 Bayview Blvd., Baltimore, MD, 21224, USA.
| | - Chaim G Pick
- Department of Anatomy and Anthropology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
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25
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Hayley S. The neuroimmune-neuroplasticity interface and brain pathology. Front Cell Neurosci 2014; 8:419. [PMID: 25538568 PMCID: PMC4255592 DOI: 10.3389/fncel.2014.00419] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 11/19/2014] [Indexed: 01/01/2023] Open
Affiliation(s)
- Shawn Hayley
- Hayley Lab, Neuroscience, Carleton University Ottawa, ON, Canada
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26
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Becker D, Ikenberg B, Schiener S, Maggio N, Vlachos A. NMDA-receptor inhibition restores Protease-Activated Receptor 1 (PAR1) mediated alterations in homeostatic synaptic plasticity of denervated mouse dentate granule cells. Neuropharmacology 2014; 86:212-8. [DOI: 10.1016/j.neuropharm.2014.07.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Revised: 06/30/2014] [Accepted: 07/21/2014] [Indexed: 12/27/2022]
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27
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Marc R, Pfeiffer R, Jones B. Retinal prosthetics, optogenetics, and chemical photoswitches. ACS Chem Neurosci 2014; 5:895-901. [PMID: 25089879 PMCID: PMC4210130 DOI: 10.1021/cn5001233] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
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Three
technologies have emerged as therapies to restore light sensing to
profoundly blind patients suffering from late-stage retinal degenerations:
(1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches.
Prosthetics are the most mature and the only approach in clinical
practice. Prosthetic implants require complex surgical intervention
and provide only limited visual resolution but can potentially restore
navigational ability to many blind patients. Optogenetics uses viral
delivery of type 1 opsin genes from prokaryotes or eukaryote algae
to restore light responses in survivor neurons. Targeting and expression
remain major problems, but are potentially soluble. Importantly, optogenetics
could provide the ultimate in high-resolution vision due to the long
persistence of gene expression achieved in animal models. Nevertheless,
optogenetics remains challenging to implement in human eyes with large
volumes, complex disease progression, and physical barriers to viral
penetration. Now, a new generation of photochromic ligands or chemical
photoswitches (azobenzene-quaternary ammonium derivatives) can be
injected into a degenerated mouse eye and, in minutes to hours, activate
light responses in neurons. These photoswitches offer the potential
for rapidly and reversibly screening the vision restoration expected
in an individual patient. Chemical photoswitch variants that persist
in the cell membrane could make them a simple therapy of choice, with
resolution and sensitivity equivalent to optogenetics approaches.
A major complexity in treating retinal degenerations is retinal remodeling:
pathologic network rewiring, molecular reprogramming, and cell death
that compromise signaling in the surviving retina. Remodeling forces
a choice between upstream and downstream targeting, each engaging
different benefits and defects. Prosthetics and optogenetics can be
implemented in either mode, but the use of chemical photoswitches
is currently limited to downstream implementations. Even so, given
the high density of human foveal ganglion cells, the ultimate chemical
photoswitch treatment could deliver cost-effective, high-resolution
vision for the blind.
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Affiliation(s)
- Robert Marc
- Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City, Utah 84132, United States
| | - Rebecca Pfeiffer
- Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City, Utah 84132, United States
| | - Bryan Jones
- Department of Ophthalmology, University of Utah School of Medicine, Salt Lake City, Utah 84132, United States
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28
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Jonas P, Lisman J. Structure, function, and plasticity of hippocampal dentate gyrus microcircuits. Front Neural Circuits 2014; 8:107. [PMID: 25309334 PMCID: PMC4159971 DOI: 10.3389/fncir.2014.00107] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 08/18/2014] [Indexed: 12/31/2022] Open
Affiliation(s)
- Peter Jonas
- IST Austria (Institute of Science and Technology Austria) Klosterneuburg, Austria
| | - John Lisman
- Biology, Volen National Center for Complex Systems, Brandeis University Waltham, MA, USA
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29
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Ogundele OM, Omoaghe AO, Ajonijebu DC, Ojo AA, Fabiyi TD, Olajide OJ, Falode DT, Adeniyi PA. Glia activation and its role in oxidative stress. Metab Brain Dis 2014; 29:483-93. [PMID: 24218104 DOI: 10.1007/s11011-013-9446-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Accepted: 10/21/2013] [Indexed: 12/24/2022]
Abstract
Glia activation and neuroinflamation are major factors implicated in the aetiology of most neurodegenerative diseases (NDDs). Several agents and toxins have been known to be capable of inducing glia activation an inflammatory response; most of which are active substances that can cause oxidative stress by inducing production of reactive oxygen species (ROS). Neurogenesis on the other hand involves metabolic and structural interaction between neurogenic and glia cells of the periventricular zone (PVZ); a region around the third ventricle. This study investigates glia activation (GFAP), cell proliferation (Ki-67) and neuronal metabolism (NSE) during neurogenesis and oxidative stress by comparing protein expression in the PVZ against that of the parietal cortex. Adult Wistar Rats were treated with normal saline and 20 mg/Kg KCN for 7 days. The tissue sections were processed for immunohistochemistry to demonstrate glia cells (anti Rat-GFAP), cell proliferation (anti Rat-Ki-67) and neuronal metabolism (anti Rat-NSE) using the antigen retrieval method. The sections from Rats treated with cyanide showed evidence of neurodegeneration both in the PVZ and cortex. The distribution of glia cells (GFAP), Neuron specific Enolase (NSE) and Ki-67 increased with cyanide treatment, although the increases were more pronounced in the neurogenic cell area (PVZ) when compared to the cortex. This suggests the close link between neuronal metabolism and glia activation both in neurogenesis and oxidative stress.
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Affiliation(s)
- Olalekan Michael Ogundele
- Department of Anatomy, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti, Nigeria,
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30
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Yeung ST, Myczek K, Kang AP, Chabrier MA, Baglietto-Vargas D, Laferla FM. Impact of hippocampal neuronal ablation on neurogenesis and cognition in the aged brain. Neuroscience 2014; 259:214-22. [PMID: 24316470 PMCID: PMC4438704 DOI: 10.1016/j.neuroscience.2013.11.054] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 11/22/2013] [Accepted: 11/25/2013] [Indexed: 11/29/2022]
Abstract
Neuronal loss is the most common and critical feature of a spectrum of brain traumas and neurodegenerative disorders such as Alzheimer's disease (AD). The capacity to generate new neurons in the central nervous system diminishes early during brain development and is restricted mainly to two brain areas in the mature brain: subventricular zone and subgranular zone. Extensive research on the impact of brain injury on endogenous neurogenesis and cognition has been conducted primarily using young animals, when neurogenesis is most active. However, a critical question remains to elucidate the effect of brain injury on endogenous neurogenesis and cognition in older animals, which is far more relevant for age-related neurodegenerative disorders such as AD. Therefore, we examined the impact of neuronal loss on endogenous neurogenesis in aged animals using CaM/Tet-DTA mice, a transgenic model of hippocampal cell loss. Additionally, we investigated whether the upregulation of adult neurogenesis could mitigate cognitive deficits following substantial hippocampal neuronal loss. Our findings demonstrate that aged CaM/Tet-DTA mice that sustain severe neuronal loss exhibit an upregulation of endogenous neurogenesis. However, despite this significant upregulation, neurogenesis alone is not able to mitigate the cognitive deficits observed. Our studies suggest that the aged brain has the capacity to stimulate neurogenesis post-injury; however, multiple therapeutic approaches, including upregulation of endogenous neurogenesis, will be necessary to recover brain function after severe neurodegeneration.
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Affiliation(s)
- S T Yeung
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697-4545, USA
| | - K Myczek
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697-4545, USA
| | - A P Kang
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697-4545, USA
| | - M A Chabrier
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697-4545, USA
| | - D Baglietto-Vargas
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697-4545, USA
| | - F M Laferla
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697-4545, USA.
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31
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Vlachos A, Helias M, Becker D, Diesmann M, Deller T. NMDA-receptor inhibition increases spine stability of denervated mouse dentate granule cells and accelerates spine density recovery following entorhinal denervation in vitro. Neurobiol Dis 2013; 59:267-76. [PMID: 23932917 DOI: 10.1016/j.nbd.2013.07.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 07/19/2013] [Accepted: 07/29/2013] [Indexed: 12/22/2022] Open
Abstract
Neuronal networks are reorganized following brain injury. At the structural level this is in part reflected by changes in the spine turnover of the denervated neurons. Using the entorhinal cortex lesion in vitro model, we recently showed that mouse dentate granule cells respond to entorhinal denervation with coordinated functional and structural changes: During the early phase after denervation spine density decreases, while excitatory synaptic strength increases in a homeostatic manner. At later stages spine density increases again, and synaptic strength decreases back to baseline. In the present study, we have addressed the question of whether the denervation-induced homeostatic strengthening of excitatory synapses could not only be a result of the deafferentation, but could, in turn, affect the dynamics of the spine reorganization process following entorhinal denervation in vitro. Using a computational approach, time-lapse imaging of neurons in organotypic slice cultures prepared from Thy1-GFP mice, and patch-clamp recordings we provide experimental evidence which suggests that the strengthening of surviving synapses can lead to the destabilization of spines formed after denervation. This activity-dependent pruning of newly formed spines requires the activation of N-methyl-d-aspartate receptors (NMDA-Rs), since pharmacological inhibition of NMDA-Rs resulted in a stabilization of spines and in an accelerated spine density recovery after denervation. Thus, NMDA-R inhibitors may restore the ability of neurons to form new stable synaptic contacts under conditions of denervation-induced homeostatic synaptic up-scaling, which may contribute to their beneficial effect seen in the context of some neurological diseases.
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Affiliation(s)
- Andreas Vlachos
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt 60590, Germany.
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