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Keleher F, Lindsey HM, Kerestes R, Amiri H, Asarnow RF, Babikian T, Bartnik-Olson B, Bigler ED, Caeyenberghs K, Esopenko C, Ewing-Cobbs L, Giza CC, Goodrich-Hunsaker NJ, Hodges CB, Hoskinson KR, Irimia A, Königs M, Max JE, Newsome MR, Olsen A, Ryan NP, Schmidt AT, Stein DJ, Suskauer SJ, Ware AL, Wheeler AL, Zielinski BA, Thompson PM, Harding IH, Tate DF, Wilde EA, Dennis EL. Multimodal Analysis of Secondary Cerebellar Alterations After Pediatric Traumatic Brain Injury. JAMA Netw Open 2023; 6:e2343410. [PMID: 37966838 PMCID: PMC10652147 DOI: 10.1001/jamanetworkopen.2023.43410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 10/04/2023] [Indexed: 11/16/2023] Open
Abstract
Importance Traumatic brain injury (TBI) is known to cause widespread neural disruption in the cerebrum. However, less is known about the association of TBI with cerebellar structure and how such changes may alter executive functioning. Objective To investigate alterations in subregional cerebellum volume and cerebral white matter microstructure after pediatric TBI and examine subsequent changes in executive function. Design, Setting, and Participants This retrospective cohort study combined 12 data sets (collected between 2006 and 2020) from 9 sites in the Enhancing Neuroimaging Genetics Through Meta-Analysis Consortium Pediatric TBI working group in a mega-analysis of cerebellar structure. Participants with TBI or healthy controls (some with orthopedic injury) were recruited from trauma centers, clinics, and institutional trauma registries, some of which were followed longitudinally over a period of 0.7 to 1.9 years. Healthy controls were recruited from the surrounding community. Data analysis occurred from October to December 2022. Exposure Accidental mild complicated-severe TBI (msTBI) for those in the TBI group. Some controls received a diagnosis of orthopedic injury. Main Outcomes and Measures Volume of 18 cerebellar lobules and vermal regions were estimated from 3-dimensional T1-weighted magnetic resonance imaging (MRI) scans. White matter organization in 28 regions of interest was assessed with diffusion tensor MRI. Executive function was measured by parent-reported scores from the Behavior Rating Inventory of Executive Functioning. Results A total of 598 children and adolescents (mean [SD] age, 14.05 [3.06] years; range, 5.45-19.70 years; 386 male participants [64.5%]; 212 female participants [35.5%]) were included in the study, with 314 participants in the msTBI group, and 284 participants in the non-TBI group (133 healthy individuals and 151 orthopedically injured individuals). Significantly smaller total cerebellum volume (d = -0.37; 95% CI, -0.52 to -0.22; P < .001) and subregional cerebellum volumes (eg, corpus medullare; d = -0.43; 95% CI, -0.58 to -0.28; P < .001) were observed in the msTBI group. These alterations were primarily seen in participants in the chronic phase (ie, >6 months postinjury) of injury (total cerebellar volume, d = -0.55; 95% CI, -0.75 to -0.35; P < .001). Smaller cerebellum volumes were associated with higher scores on the Behavior Rating Inventory of Executive Functioning Global Executive Composite score (β = -208.9 mm3; 95% CI, -319.0 to -98.0 mm3; P = .008) and Metacognition Index score (β = -202.5 mm3; 95% CI, -319.0 to -85.0 mm3; P = .02). In a subset of 185 participants with longitudinal data, younger msTBI participants exhibited cerebellum volume reductions (β = 0.0052 mm3; 95% CI, 0.0013 to 0.0090 mm3; P = .01), and older participants slower growth rates. Poorer white matter organization in the first months postinjury was associated with decreases in cerebellum volume over time (β=0.52 mm3; 95% CI, 0.19 to 0.84 mm3; P = .005). Conclusions and Relevance In this cohort study of pediatric msTBI, our results demonstrated robust cerebellar volume alterations associated with pediatric TBI, localized to the posterior lobe. Furthermore, longitudinal cerebellum changes were associated with baseline diffusion tensor MRI metrics, suggesting secondary cerebellar atrophy. These results provide further understanding of secondary injury mechanisms and may point to new opportunities for intervention.
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Affiliation(s)
- Finian Keleher
- TBI and Concussion Center, Department of Neurology, University of Utah School of Medicine, Salt Lake City
| | - Hannah M. Lindsey
- TBI and Concussion Center, Department of Neurology, University of Utah School of Medicine, Salt Lake City
- George E. Wahlen Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Rebecca Kerestes
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Houshang Amiri
- Institute of Neuropharmacology, Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Robert F. Asarnow
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles
- Brain Research Institute, University of California, Los Angeles
- Department of Psychology, University of California, Los Angeles
| | - Talin Babikian
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles
- Steve Tisch BrainSPORT Program, University of California, Los Angeles
| | - Brenda Bartnik-Olson
- Department of Radiology, Loma Linda University Medical Center, Loma Linda, California
| | - Erin D. Bigler
- TBI and Concussion Center, Department of Neurology, University of Utah School of Medicine, Salt Lake City
- Department of Psychology, Brigham Young University, Provo, Utah
- Neuroscience Center, Brigham Young University, Provo, Utah
| | - Karen Caeyenberghs
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Victoria, Australia
| | - Carrie Esopenko
- Department of Rehabilitation and Human Performance, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Linda Ewing-Cobbs
- Children’s Learning Institute, Department of Pediatrics, University of Texas Health Science Center at Houston
| | - Christopher C. Giza
- Steve Tisch BrainSPORT Program, University of California, Los Angeles
- Division of Neurology, Department of Pediatrics, Mattel Children’s Hospital University of California, Los Angeles
- Department of Neurosurgery, David Geffen School of Medicine at the University of California, Los Angeles
| | - Naomi J. Goodrich-Hunsaker
- TBI and Concussion Center, Department of Neurology, University of Utah School of Medicine, Salt Lake City
- George E. Wahlen Veterans Affairs Medical Center, Salt Lake City, Utah
- Department of Psychology, Brigham Young University, Provo, Utah
| | - Cooper B. Hodges
- Department of Psychology, Brigham Young University, Provo, Utah
- School of Social and Behavioral Sciences, Andrews University, Berrien Springs, Michigan
| | - Kristen R. Hoskinson
- Center for Biobehavioral Health, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus
| | - Andrei Irimia
- Ethel Percy Andrus Gerontology Center, Leonard Davis School of Gerontology, University of Southern California, Los Angeles
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles
| | - Marsh Königs
- Emma Neuroscience Group, Emma Children’s Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands
| | - Jeffrey E. Max
- Department of Psychiatry, University of California, San Diego, La Jolla
- Department of Psychiatry, Rady Children’s Hospital, San Diego, California
| | - Mary R. Newsome
- H. Ben Taub Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, Texas
| | - Alexander Olsen
- Department of Psychology, Norwegian University of Science and Technology, Trondheim, Norway
- Clinic of Rehabilitation, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
- NorHEAD-Norwegian Centre for Headache Research, Trondheim, Norway
| | - Nicholas P. Ryan
- Cognitive Neuroscience Unit, School of Psychology, Deakin University, Geelong, Victoria, Australia
- Department of Clinical Sciences, Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, Victoria, Australia
| | - Adam T. Schmidt
- Department of Psychological Sciences, Texas Tech University, Lubbock
| | - Dan J. Stein
- South African Medical Research Council Unit on Risk and Resilience in Mental Disorders, Department of Psychiatry, Cape Town University, Cape Town, South Africa
- South African Medical Research Council Unit on Risk and Resilience in Mental Disorders, Neuroscience Institute, Cape Town University, Cape Town, South Africa
| | - Stacy J. Suskauer
- Kennedy Krieger Institute, Baltimore, Maryland
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ashley L. Ware
- TBI and Concussion Center, Department of Neurology, University of Utah School of Medicine, Salt Lake City
- Department of Psychology, Georgia State University, Atlanta
| | - Anne L. Wheeler
- Neuroscience and Mental Health Program, Hospital for Sick Children, Toronto, Ontario, Canada
- Physiology Department, University of Toronto, Toronto, Ontario, Canada
| | - Brandon A. Zielinski
- TBI and Concussion Center, Department of Neurology, University of Utah School of Medicine, Salt Lake City
- Department of Pediatrics, University of Florida, Gainesville
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City
- Department of Neurology, University of Florida, Gainesville
| | - Paul M. Thompson
- Imaging Genetics Center, Stevens Neuroimaging & Informatics Institute, Keck School of Medicine of the University of Southern California, Marina del Rey
- Department of Neurology, University of Southern California, Los Angeles
- Department of Pediatrics, University of Southern California, Los Angeles
- Department of Psychiatry, University of Southern California, Los Angeles
- Department of Radiology, University of Southern California, Los Angeles
- Department of Engineering, University of Southern California, Los Angeles
- Department of Ophthalmology, University of Southern California, Los Angeles
| | - Ian H. Harding
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Monash Biomedical Imaging, Monash University, Melbourne, Victoria, Australia
| | - David F. Tate
- TBI and Concussion Center, Department of Neurology, University of Utah School of Medicine, Salt Lake City
- George E. Wahlen Veterans Affairs Medical Center, Salt Lake City, Utah
- Department of Psychology, Brigham Young University, Provo, Utah
| | - Elisabeth A. Wilde
- TBI and Concussion Center, Department of Neurology, University of Utah School of Medicine, Salt Lake City
- George E. Wahlen Veterans Affairs Medical Center, Salt Lake City, Utah
- H. Ben Taub Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, Texas
| | - Emily L. Dennis
- TBI and Concussion Center, Department of Neurology, University of Utah School of Medicine, Salt Lake City
- George E. Wahlen Veterans Affairs Medical Center, Salt Lake City, Utah
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Dündar AS, Oruç M, Celbiş O, Şamdancı ET, Akatlı AN, Okumuş H, Taşkapan Ç, Özhan O, Parlakpınar H. An experimental rat model of electric shock injury with isolated electric shock and water conduction: the histopathological changes on the skin and internal organs and the effect on biochemical parameters. Int J Legal Med 2023; 137:215-226. [PMID: 35524806 DOI: 10.1007/s00414-022-02834-w] [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: 11/02/2021] [Accepted: 04/25/2022] [Indexed: 01/10/2023]
Abstract
It is difficult to determine the cause of death in electric shock injuries when no trace can be determined on the skin, and this is accepted as a reason for negative autopsy. We aimed to determine useful parameters in the definition of the cause of deaths associated with electric shock and particularly those formed with water conduction. This study used a total of 42 rats, applied with fatal electric shock formed of isolated electric shock at 220 V and with water conduction. The serum NT-ProBNP and H-FABP levels were examined together with histopathological changes in the brain, cerebellum, brainstem, heart, liver and skin and the Bax, caspase-3 and HSP-60 antibody status in these tissues. A statistically significant difference was determined between the groups in respect of the serum H-FABP values and the immunohistochemical staining of the samples taken from the organs. In conclusion, this study is the first in literature with an experimental model of electric shock with water conduction. Using immunohistochemical and biochemical markers in deaths associated with isolated electric shock and electric shock with water conduction, the results of this study can contribute to the clarification of one of the reasons for negative autopsy in forensic medicine.
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Affiliation(s)
| | - Mucahit Oruç
- Department of Forensic Medicine, Inonu University Faculty of Medicine, Malatya, Turkey
| | - Osman Celbiş
- Department of Forensic Medicine, Inonu University Faculty of Medicine, Malatya, Turkey
| | - Emine Türkmen Şamdancı
- Department of Medical Pathology Malatya, Inonu University Faculty of Medicine, Malatya, Turkey
| | - Ayşe Nur Akatlı
- Department of Medical Pathology Malatya, Inonu University Faculty of Medicine, Malatya, Turkey
| | - Hasan Okumuş
- Council of Forensic Medicine, Gebze-Kocaeli, Turkey
| | - Çağatay Taşkapan
- Department of Biochemistry, Inonu University Faculty of Medicine, Malatya, Turkey
| | - Onural Özhan
- Department of Pharmacology, Inonu University Faculty of Medicine, Malatya, Turkey
| | - Hakan Parlakpınar
- Department of Pharmacology, Inonu University Faculty of Medicine, Malatya, Turkey
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Purkinje cell vulnerability induced by diffuse traumatic brain injury is linked to disruption of long-range neuronal circuits. Acta Neuropathol Commun 2022; 10:129. [PMID: 36064443 PMCID: PMC9446851 DOI: 10.1186/s40478-022-01435-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/22/2022] [Indexed: 11/10/2022] Open
Abstract
Cerebellar dysfunction is commonly observed following traumatic brain injury (TBI). While direct impact to the cerebellum by TBI is rare, cerebellar pathology may be caused by indirect injury via cortico-cerebellar pathways. To address the hypothesis that degeneration of Purkinje cells (PCs), which constitute the sole output from the cerebellum, is linked to long-range axonal injury and demyelination, we used the central fluid percussion injury (cFPI) model of widespread traumatic axonal injury in mice. Compared to controls, TBI resulted in early PC loss accompanied by alterations in the size of pinceau synapses and levels of non-phosphorylated neurofilament in PCs. A combination of vDISCO tissue clearing technique and immunohistochemistry for vesicular glutamate transporter type 2 show that diffuse TBI decreased mossy and climbing fiber synapses on PCs. At 2 days post-injury, numerous axonal varicosities were found in the cerebellum supported by fractional anisotropy measurements using 9.4 T MRI. The disruption and demyelination of the cortico-cerebellar circuits was associated with poor performance of brain-injured mice in the beam-walk test. Despite a lack of direct input from the injury site to the cerebellum, these findings argue for novel long-range mechanisms causing Purkinje cell injury that likely contribute to cerebellar dysfunction after TBI.
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Yeh FC, Irimia A, Bastos DCDA, Golby AJ. Tractography methods and findings in brain tumors and traumatic brain injury. Neuroimage 2021; 245:118651. [PMID: 34673247 PMCID: PMC8859988 DOI: 10.1016/j.neuroimage.2021.118651] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 10/05/2021] [Accepted: 10/11/2021] [Indexed: 12/31/2022] Open
Abstract
White matter fiber tracking using diffusion magnetic resonance imaging (dMRI) provides a noninvasive approach to map brain connections, but improving anatomical accuracy has been a significant challenge since the birth of tractography methods. Utilizing tractography in brain studies therefore requires understanding of its technical limitations to avoid shortcomings and pitfalls. This review explores tractography limitations and how different white matter pathways pose different challenges to fiber tracking methodologies. We summarize the pros and cons of commonly-used methods, aiming to inform how tractography and its related analysis may lead to questionable results. Extending these experiences, we review the clinical utilization of tractography in patients with brain tumors and traumatic brain injury, starting from tensor-based tractography to more advanced methods. We discuss current limitations and highlight novel approaches in the context of these two conditions to inform future tractography developments.
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Affiliation(s)
- Fang-Cheng Yeh
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
| | - Andrei Irimia
- Ethel Percy Andrus Gerontology Center, Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California, USA; Corwin D. Denney Research Center, Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California, USA
| | | | - Alexandra J Golby
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA; Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Stelfa G, Vavers E, Svalbe B, Serzants R, Miteniece A, Lauberte L, Grinberga S, Gukalova B, Dambrova M, Zvejniece L. Reduced GFAP Expression in Bergmann Glial Cells in the Cerebellum of Sigma-1 Receptor Knockout Mice Determines the Neurobehavioral Outcomes after Traumatic Brain Injury. Int J Mol Sci 2021; 22:11611. [PMID: 34769042 PMCID: PMC8584110 DOI: 10.3390/ijms222111611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/19/2021] [Accepted: 10/23/2021] [Indexed: 11/17/2022] Open
Abstract
Neuroprotective effects of Sigma-1 receptor (S1R) ligands have been observed in multiple animal models of neurodegenerative diseases. Traumatic brain injury (TBI)-related neurodegeneration can induce long-lasting physical, cognitive, and behavioral disabilities. The aim of our study was to evaluate the role of S1R in the development of neurological deficits after TBI. Adult male wild-type CD-1 (WT) and S1R knockout (S1R-/-) mice were subjected to lateral fluid percussion injury, and behavioral and histological outcomes were assessed for up to 12 months postinjury. Neurological deficits and motor coordination impairment were less pronounced in S1R-/- mice with TBI than in WT mice with TBI 24 h after injury. TBI-induced short-term memory impairments were present in WT but not S1R-/- mice 7 months after injury. Compared to WT animals, S1R-/- mice exhibited better motor coordination and less pronounced despair behavior for up to 12 months postinjury. TBI induced astrocyte activation in the cortex of WT but not S1R-/- mice. S1R-/- mice presented a significantly reduced GFAP expression in Bergmann glial cells in the molecular layer of the cerebellum compared to WT mice. Our findings suggest that S1R deficiency reduces TBI-induced motor coordination impairments by reducing GFAP expression in Bergmann glial cells in the cerebellum.
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Affiliation(s)
- Gundega Stelfa
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (E.V.); (B.S.); (R.S.); (A.M.); (L.L.); (M.D.); (L.Z.)
- Faculty of Veterinary Medicine, Latvia University of Life Sciences and Technologies, K Helmana Str. 8, LV-3001 Jelgava, Latvia
| | - Edijs Vavers
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (E.V.); (B.S.); (R.S.); (A.M.); (L.L.); (M.D.); (L.Z.)
| | - Baiba Svalbe
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (E.V.); (B.S.); (R.S.); (A.M.); (L.L.); (M.D.); (L.Z.)
| | - Rinalds Serzants
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (E.V.); (B.S.); (R.S.); (A.M.); (L.L.); (M.D.); (L.Z.)
- Department of Pharmaceutical Chemistry, Riga Stradins University, Dzirciema Str. 16, LV-1007 Riga, Latvia
| | - Anna Miteniece
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (E.V.); (B.S.); (R.S.); (A.M.); (L.L.); (M.D.); (L.Z.)
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ, UK
| | - Lasma Lauberte
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (E.V.); (B.S.); (R.S.); (A.M.); (L.L.); (M.D.); (L.Z.)
| | - Solveiga Grinberga
- Laboratory of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (S.G.); (B.G.)
| | - Baiba Gukalova
- Laboratory of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (S.G.); (B.G.)
| | - Maija Dambrova
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (E.V.); (B.S.); (R.S.); (A.M.); (L.L.); (M.D.); (L.Z.)
- Department of Pharmaceutical Chemistry, Riga Stradins University, Dzirciema Str. 16, LV-1007 Riga, Latvia
| | - Liga Zvejniece
- Laboratory of Pharmaceutical Pharmacology, Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, LV-1006 Riga, Latvia; (E.V.); (B.S.); (R.S.); (A.M.); (L.L.); (M.D.); (L.Z.)
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Dolenec P, Pilipović K, Janković T, Župan G. Pattern of Neuronal and Axonal Damage, Glial Response, and Synaptic Changes in Rat Cerebellum within the First Week following Traumatic Brain Injury. J Neuropathol Exp Neurol 2021; 79:1163-1182. [PMID: 33057716 DOI: 10.1093/jnen/nlaa111] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We examined damage and repair processes in the rat cerebellum within the first week following moderate traumatic brain injury (TBI) induced by lateral fluid percussion injury (LFPI) over the left parietal cortex. Rats were killed 1, 3, or 7 days after the injury or sham procedure. Fluoro-Jade B staining revealed 2 phases of neurodegenerative changes in the cell bodies and fibers: first, more focal, 1 day after the LFPI, and second, widespread, starting on post-injury day 3. Purkinje cell loss was detected in posterior lobule IX 1 day following LFPI. Apoptosis was observed in the cerebellar cortex, on days 1 and 7 following LFPI, and was not caspase- or apoptosis-inducing factor (AIF)-mediated. AIF immunostaining indicated axonal damage in the cerebellar white matter tracts 3- and 7-days post-injury. Significant astrocytosis and microgliosis were noticed on day 7 following LFPI at the sites of neuronal damage and loss. Immunohistochemical labeling with the presynaptic markers synaptophysin and growth-associated protein-43 revealed synaptic perturbations already on day 1 that were more pronounced at later time points following LFPI. These results provide new insights into pathophysiological alterations in the cerebellum and their mechanisms following cerebral TBI.
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Affiliation(s)
- Petra Dolenec
- Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Kristina Pilipović
- Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Tamara Janković
- Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Gordana Župan
- Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
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Fairless R, Williams SK, Diem R. Calcium-Binding Proteins as Determinants of Central Nervous System Neuronal Vulnerability to Disease. Int J Mol Sci 2019; 20:ijms20092146. [PMID: 31052285 PMCID: PMC6539299 DOI: 10.3390/ijms20092146] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 04/26/2019] [Accepted: 04/27/2019] [Indexed: 12/14/2022] Open
Abstract
Neuronal subpopulations display differential vulnerabilities to disease, but the factors that determine their susceptibility are poorly understood. Toxic increases in intracellular calcium are a key factor in several neurodegenerative processes, with calcium-binding proteins providing an important first line of defense through their ability to buffer incoming calcium, allowing the neuron to quickly achieve homeostasis. Since neurons expressing different calcium-binding proteins have been reported to be differentially susceptible to degeneration, it can be hypothesized that rather than just serving as markers of different neuronal subpopulations, they might actually be a key determinant of survival. In this review, we will summarize some of the evidence that expression of the EF-hand calcium-binding proteins, calbindin, calretinin and parvalbumin, may influence the susceptibility of distinct neuronal subpopulations to disease processes.
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Affiliation(s)
- Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
| | - Sarah K Williams
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
| | - Ricarda Diem
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
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Electrophysiological Correlates of Blast-Wave Induced Cerebellar Injury. Sci Rep 2018; 8:13633. [PMID: 30206255 PMCID: PMC6134123 DOI: 10.1038/s41598-018-31728-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 08/24/2018] [Indexed: 12/17/2022] Open
Abstract
Understanding the mechanisms underlying traumatic neural injury and the sequelae of events in the acute phase is important for deciding on the best window of therapeutic intervention. We hypothesized that evoked potentials (EP) recorded from the cerebellar cortex can detect mild levels of neural trauma and provide a qualitative assessment tool for progression of cerebellar injury in time. The cerebellar local field potentials evoked by a mechanical tap on the hand and collected with chronically implanted micro-ECoG arrays on the rat cerebellar cortex demonstrated substantial changes both in amplitude and timing as a result of blast-wave induced injury. The results revealed that the largest EP changes occurred within the first day of injury, and partial recoveries were observed from day-1 to day-3, followed by a period of gradual improvements (day-7 to day-14). The mossy fiber (MF) and climbing fiber (CF) mediated components of the EPs were affected differentially. The behavioral tests (ladder rung walking) and immunohistological analysis (calbindin and caspase-3) did not reveal any detectable changes at these blast pressures that are typically considered as mild (100-130 kPa). The results demonstrate the sensitivity of the electrophysiological method and its use as a tool to monitor the progression of cerebellar injuries in longitudinal animal studies.
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Facilitated acquisition of the classically conditioned eyeblink response in active duty military expressing posttraumatic stress disorder symptoms. Behav Brain Res 2018; 339:106-113. [DOI: 10.1016/j.bbr.2017.11.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/17/2017] [Accepted: 11/12/2017] [Indexed: 11/18/2022]
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Drijkoningen D, Chalavi S, Sunaert S, Duysens J, Swinnen SP, Caeyenberghs K. Regional Gray Matter Volume Loss Is Associated with Gait Impairments in Young Brain-Injured Individuals. J Neurotrauma 2017; 34:1022-1034. [DOI: 10.1089/neu.2016.4500] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- David Drijkoningen
- University Medical Center Utrecht, Utrecht, the Netherlands
- Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium
| | - Sima Chalavi
- Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium
| | - Stefan Sunaert
- Department of Radiology, University Hospital, Leuven, Belgium
| | - Jacques Duysens
- Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium
| | - Stephan P. Swinnen
- Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium
- Leuven Research Institute for Neuroscience and Disease, Leuven, Belgium
| | - Karen Caeyenberghs
- Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium
- Australian Catholic University, Melbourne, Australia
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Kandeel S, Elhosary NM, El-Noor MMA, Balaha M. Electric injury-induced Purkinje cell apoptosis in rat cerebellum: Histological and immunohistochemical study. J Chem Neuroanat 2017; 81:87-96. [PMID: 28254550 DOI: 10.1016/j.jchemneu.2017.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 02/25/2017] [Accepted: 02/26/2017] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Electrical injury is a prominent problem in low income countries with increased morbidity and mortality rate. Nervous system is one of the most susceptible systems to electrical current because of its low resistance. There were different studies demonstrated electrocution effect on the nervous system, however little was made on the cerebellum. AIM This study was conducted to produce an experimental suggestion concerning injury of the nervous system through evaluating Purkinje cell apoptosis and number in rat cerebellum by fatal and non-fatal electric current using histological and immunohistochemical study. Also to support the diagnosis of electrocution as a probable cause of death and delayed neurological damage as well as disability. MATERIALS & METHODS Fifty male Wistar rats were divided into five groups (10 rats each); control group: normal rats that were sacrificed without exposure to electric current, groups 1-3 (non-fatal electrocution groups): rats were exposed to alternating electric current (220v, 50Hz) for one minute then were sacrificed immediately, after 2h, and after 4h respectively, and group 4 (fatal electrocution group): rats were sacrificed after being electrified up to death (153±27s). Sections from cerebellum were processed for histological and caspase-3 immunohistochemical study. RESULTS Purkinje cells showed marked histopathological changes in the form of shrunken dark stained cells with significant reduction of their number in H &E stained sections when compared to control, widespread argyrophilia, and degenerated organelles along with shrunken irregular nuclei. For caspase-3 staining, there was significantly increased number of caspase-3 positive cells in groups 1-3 (non-fatal electrocution groups) and markedly increased in group 4 (fatal electrocution group) in comparison to control group. These changes were gradually increased with the increased duration after exposure to the electric current. CONCLUSION Apoptosis and loss of Purkinje cells were involved in the pathogenesis of immediate and long term effect of electrical injury on Purkinje cells, which will be an aid to the forensic pathologist to determine the cause of death and residual damage as well as disability after electric shock.
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Affiliation(s)
- Samah Kandeel
- Histology Department, Faculty of Medicine, Tanta University, Egypt.
| | - Naema Mahmoud Elhosary
- Department of Forensic Medicine & Clinical Toxicology, Faculty of Medicine, Tanta University, Egypt
| | - Mona Mohamed Abo El-Noor
- Department of Forensic Medicine & Clinical Toxicology, Faculty of Medicine, Tanta University, Egypt
| | - Mohamed Balaha
- Pharmacology Department, Faculty of Medicine, Tanta University, Egypt
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Caeyenberghs K, Verhelst H, Clemente A, Wilson PH. Mapping the functional connectome in traumatic brain injury: What can graph metrics tell us? Neuroimage 2016; 160:113-123. [PMID: 27919750 DOI: 10.1016/j.neuroimage.2016.12.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 11/25/2016] [Accepted: 12/01/2016] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE Traumatic brain injury (TBI) is associated with cognitive and motor deficits, and poses a significant personal, societal, and economic burden. One mechanism by which TBI is thought to affect cognition and behavior is through changes in functional connectivity. Graph theory is a powerful framework for quantifying topological features of neuroimaging-derived functional networks. The objective of this paper is to review studies examining functional connectivity in TBI with an emphasis on graph theoretical analysis that is proving to be valuable in uncovering network abnormalities in this condition. METHODS We review studies that have examined TBI-related alterations in different properties of the functional brain network, including global integration, segregation, centrality and resilience. We focus on functional data using task-related fMRI or resting-state fMRI in patients with TBI of different severity and recovery phase, and consider how graph metrics may inform rehabilitation and enhance efficacy. Moreover, we outline some methodological challenges associated with the examination of functional connectivity in patients with brain injury, including the sample size, parcellation scheme used, node definition and subgroup analyses. RESULTS The findings suggest that TBI is associated with hyperconnectivity and a suboptimal global integration, characterized by increased connectivity degree and strength and reduced efficiency of functional networks. This altered functional connectivity, also evident in other clinical populations, is attributable to diffuse white matter pathology and reductions in gray and white matter volume. These functional alterations are implicated in post-concussional symptoms, posttraumatic stress and neurocognitive dysfunction after TBI. Finally, the effects of focal lesions have been found to depend critically on topological position and their role in the network. CONCLUSION Graph theory is a unique and powerful tool for exploring functional connectivity in brain-injured patients. One limitation is that its results do not provide specific measures about the biophysical mechanism underlying TBI. Continued work in this field will hopefully see graph metrics used as biomarkers to provide more accurate diagnosis and help guide treatment at the individual patient level.
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Affiliation(s)
- Karen Caeyenberghs
- School of Psychology, Faculty of Health Sciences, Australian Catholic University, Victoria, Australia.
| | - Helena Verhelst
- Department of Experimental Psychology, Faculty of Psychology and Educational Sciences, Ghent University, Ghent, Belgium
| | - Adam Clemente
- School of Psychology, Faculty of Health Sciences, Australian Catholic University, Victoria, Australia
| | - Peter H Wilson
- School of Psychology, Faculty of Health Sciences, Australian Catholic University, Victoria, Australia
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Drijkoningen D, Leunissen I, Caeyenberghs K, Hoogkamer W, Sunaert S, Duysens J, Swinnen SP. Regional volumes in brain stem and cerebellum are associated with postural impairments in young brain-injured patients. Hum Brain Mapp 2015; 36:4897-909. [PMID: 26441014 DOI: 10.1002/hbm.22958] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/19/2015] [Accepted: 08/20/2015] [Indexed: 01/08/2023] Open
Abstract
Many patients with traumatic brain injury (TBI) suffer from postural control impairments that can profoundly affect daily life. The cerebellum and brain stem are crucial for the neural control of posture and have been shown to be vulnerable to primary and secondary structural consequences of TBI. The aim of this study was to investigate whether morphometric differences in the brain stem and cerebellum can account for impairments in static and dynamic postural control in TBI. TBI patients (n = 18) and healthy controls (n = 30) completed three challenging postural control tasks on the EquiTest® system (Neurocom). Infratentorial grey matter (GM) and white matter (WM) volumes were analyzed with cerebellum-optimized voxel-based morphometry using the spatially unbiased infratentorial toolbox. Volume loss in TBI patients was revealed in global cerebellar GM, global infratentorial WM, middle cerebellar peduncles, pons and midbrain. In the TBI group and across both groups, lower postural control performance was associated with reduced GM volume in the vermal/paravermal regions of lobules I-IV, V and VI. Moreover, across all participants, worse postural control performance was associated with lower WM volume in the pons, medulla, midbrain, superior and middle cerebellar peduncles and cerebellum. This is the first study in TBI patients to demonstrate an association between postural impairments and reduced volume in specific infratentorial brain areas. Volumetric measures of the brain stem and cerebellum may be valuable prognostic markers of the chronic neural pathology, which complicates rehabilitation of postural control in TBI.
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Affiliation(s)
- David Drijkoningen
- KU Leuven, Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium
| | - Inge Leunissen
- KU Leuven, Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium
| | - Karen Caeyenberghs
- School of Psychology, Faculty of Health Sciences, Australian Catholic University, Melbourne, Victoria, Australia
| | - Wouter Hoogkamer
- KU Leuven, Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium
| | - Stefan Sunaert
- KU Leuven, Department of Radiology, University Hospital, Leuven, Belgium
| | - Jacques Duysens
- KU Leuven, Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium
| | - Stephan P Swinnen
- KU Leuven, Movement Control and Neuroplasticity Research Group, Group Biomedical Sciences, Leuven, Belgium.,KU Leuven, Leuven Research Institute for Neuroscience & Disease (LIND), Belgium
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Training-induced improvements in postural control are accompanied by alterations in cerebellar white matter in brain injured patients. NEUROIMAGE-CLINICAL 2014; 7:240-51. [PMID: 25610786 PMCID: PMC4300016 DOI: 10.1016/j.nicl.2014.12.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/03/2014] [Accepted: 12/04/2014] [Indexed: 12/13/2022]
Abstract
We investigated whether balance control in young TBI patients can be promoted by an 8-week balance training program and whether this is associated with neuroplastic alterations in brain structure. The cerebellum and cerebellar peduncles were selected as regions of interest because of their importance in postural control as well as their vulnerability to brain injury. Young patients with moderate to severe TBI and typically developing (TD) subjects participated in balance training using PC-based portable balancers with storage of training data and real-time visual feedback. An additional control group of TD subjects did not attend balance training. Mean diffusivity and fractional anisotropy were determined with diffusion MRI scans and were acquired before, during (4 weeks) and at completion of training (8 weeks) together with balance assessments on the EquiTest® System (NeuroCom) which included the Sensory Organization Test, Rhythmic Weight Shift and Limits of Stability protocols. Following training, TBI patients showed significant improvements on all EquiTest protocols, as well as a significant increase in mean diffusivity in the inferior cerebellar peduncle. Moreover, in both training groups, diffusion metrics in the cerebellum and/or cerebellar peduncles at baseline were predictive of the amount of performance increase after training. Finally, amount of training-induced improvement on the Rhythmic Weight Shift test in TBI patients was positively correlated with amount of change in fractional anisotropy in the inferior cerebellar peduncle. This suggests that training-induced plastic changes in balance control are associated with alterations in the cerebellar white matter microstructure in TBI patients. Brain injury patients and healthy subjects attended 8-weeks of balance training. Diffusion MRI and postural tests were acquired before, during and after training. Cerebellum and cerebellar peduncles were selected as regions of interest. Training-induced changes shown in postural control and inferior cerebellar peduncle Correlations between change in balance and change in white matter microstructure
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Key Words
- Balance control training
- Brain injury
- Cerebellum
- Diffusion tensor imaging
- ICP, inferior cerebellar peduncle
- LOS, Limits of Stability
- MCP, middle cerebellar peduncle
- Plasticity
- RWS, Rhythmic Weight Shift
- SCP, superior cerebellar peduncle
- SOT, Sensory Organization Test
- TBI, traumatic brain injury
- TBI-t, TBI group with training
- TD, typically developing
- TD-c, TD group without training
- TD-t, TD group with training
- UF, uncinate fasciculus
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Schober K, Ondruschka B, Dreßler J, Abend M. Detection of hypoxia markers in the cerebellum after a traumatic frontal cortex injury: a human postmortem gene expression analysis. Int J Legal Med 2014; 129:701-7. [PMID: 25432860 PMCID: PMC4475240 DOI: 10.1007/s00414-014-1129-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 11/14/2014] [Indexed: 12/28/2022]
Abstract
PURPOSE The response to traumatic brain injury (TBI) is complex and induces various biological pathways in all brain regions that contribute to bad outcomes. The cerebellar hypoxia after a frontal cortex injury may potentiate the pathophysiological impacts of TBI. Therefore, a gene expression analysis was conducted to determine the influence of hypoxia on TBIs. MATERIAL AND METHODS Total RNA, including microRNAs, was isolated from the cerebellum of individuals who had died from severe frontal cortex injuries or due to natural causes of death (reference group). RESULTS From a total of 19,596 genes, an average of 59.56% messenger RNAs (mRNAs) appeared expressed with 42 of them showing significant >2-fold differences of upregulated (n = 18) and downregulated (n = 24) genes. The validity of 14 candidate genes (with low p values and high fold differences or based on cited literature) was confirmed using qRT-PCR (Spearman correlation r(2) = 0.93). Only four genes appeared to be either upregulated (FOSB and IL6) or downregulated (HSD11B1 and HSPA12B). From a total of 667 microRNAs, altogether, 248 microRNAs appeared expressed with 13 of them showing significant differences in the mean gene expression. The combination of two mRNAs (HSPA12B/FOSB or IL6/HSD11B1) or two microRNAs (either miR-138/miR-744 or miR-195/miR-324-5p) completely discriminated both groups, a finding unaltered by potential confounders such as age at biosampling, survival time, and the postmortem interval. CONCLUSIONS Cerebellar hypoxia markers are important to understand the pathophysiology of TBIs and could be used for therapeutic strategies or forensic purposes, e.g., to assess the severity of a brain injury.
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Affiliation(s)
- K Schober
- German Air Force Center for Aerospace Medicine, Postfach 1264/KFL, 82242, Fürstenfeldbruck, Germany,
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Williams WM, Castellani RJ, Weinberg A, Perry G, Smith MA. Do β-defensins and other antimicrobial peptides play a role in neuroimmune function and neurodegeneration? ScientificWorldJournal 2012; 2012:905785. [PMID: 22606066 PMCID: PMC3346844 DOI: 10.1100/2012/905785] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 10/26/2011] [Indexed: 12/25/2022] Open
Abstract
It is widely accepted that the brain responds to mechanical trauma and development of most neurodegenerative diseases with an inflammatory sequelae that was once thought exclusive to systemic immunity. Mostly cationic peptides, such as the β-defensins, originally assigned an antimicrobial function are now recognized as mediators of both innate and adaptive immunity. Herein supporting evidence is presented for the hypothesis that neuropathological changes associated with chronic disease conditions of the CNS involve abnormal expression and regulatory function of specific antimicrobial peptides. It is also proposed that these alterations exacerbate proinflammatory conditions within the brain that ultimately potentiate the neurodegenerative process.
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Affiliation(s)
- Wesley M Williams
- Department of Biological Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.
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Irimia A, Chambers MC, Torgerson CM, Filippou M, Hovda DA, Alger JR, Gerig G, Toga AW, Vespa PM, Kikinis R, Van Horn JD. Patient-tailored connectomics visualization for the assessment of white matter atrophy in traumatic brain injury. Front Neurol 2012; 3:10. [PMID: 22363313 PMCID: PMC3275792 DOI: 10.3389/fneur.2012.00010] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 01/16/2012] [Indexed: 01/21/2023] Open
Abstract
Available approaches to the investigation of traumatic brain injury (TBI) are frequently hampered, to some extent, by the unsatisfactory abilities of existing methodologies to efficiently define and represent affected structural connectivity and functional mechanisms underlying TBI-related pathology. In this paper, we describe a patient-tailored framework which allows mapping and characterization of TBI-related structural damage to the brain via multimodal neuroimaging and personalized connectomics. Specifically, we introduce a graphically driven approach for the assessment of trauma-related atrophy of white matter connections between cortical structures, with relevance to the quantification of TBI chronic case evolution. This approach allows one to inform the formulation of graphical neurophysiological and neuropsychological TBI profiles based on the particular structural deficits of the affected patient. In addition, it allows one to relate the findings supplied by our workflow to the existing body of research that focuses on the functional roles of the cortical structures being targeted. A graphical means for representing patient TBI status is relevant to the emerging field of personalized medicine and to the investigation of neural atrophy.
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Affiliation(s)
- Andrei Irimia
- Laboratory of Neuro Imaging, Department of Neurology, University of California Los Angeles Los Angeles, CA, USA
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19
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Kan EM, Ling EA, Lu J. Microenvironment changes in mild traumatic brain injury. Brain Res Bull 2012; 87:359-72. [PMID: 22289840 DOI: 10.1016/j.brainresbull.2012.01.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 01/10/2012] [Accepted: 01/12/2012] [Indexed: 02/08/2023]
Abstract
Traumatic brain injury (TBI) is a major public-health problem for which mild TBI (MTBI) makes up majority of the cases. MTBI is a poorly-understood health problem and can persist for years manifesting into neurological and non-neurological problems that can affect functional outcome. Presently, diagnosis of MTBI is based on symptoms reporting with poor understanding of ongoing pathophysiology, hence precluding prognosis and intervention. Other than rehabilitation, there is still no pharmacological treatment for the treatment of secondary injury and prevention of the development of cognitive and behavioural problems. The lack of external injuries and absence of detectable brain abnormalities lend support to MTBI developing at the cellular and biochemical level. However, the paucity of suitable and validated non-invasive methods for accurate diagnosis of MTBI poses as a substantial challenge. Hence, it is crucial that a clinically useful evaluation and management procedure be instituted for MTBI that encompasses both molecular pathophysiology and functional outcome. The acute microenvironment changes post-MTBI presents an attractive target for modulation of MTBI symptoms and the development of cognitive changes later in life.
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Affiliation(s)
- Enci Mary Kan
- Combat Care Laboratory, Defence Medical and Environmental Research Institute, DSO National Laboratories, 27 Medical Drive, Singapore 117510, Singapore
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20
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Caeyenberghs K, Leemans A, Geurts M, Linden CV, Smits-Engelsman BCM, Sunaert S, Swinnen SP. Correlations between white matter integrity and motor function in traumatic brain injury patients. Neurorehabil Neural Repair 2011; 25:492-502. [PMID: 21427274 DOI: 10.1177/1545968310394870] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Deterioration of motor function is one of several clinical manifestations following traumatic brain injury (TBI) in children and adolescents. OBJECTIVE To investigate the relationship between white matter (WM) integrity using diffusion tensor imaging (DTI) and motor functioning in young TBI patients. METHODS A group with moderate to severe TBI (n = 24) and a control group (n = 17) were scanned using DTI along with standard anatomical scans. Using ExploreDTI software, WM regions/tracts that carry efferent output (motor) from the brain were evaluated, as well as the corpus callosum, brainstem, internal capsule, and subcortical WM structures. Motor function was assessed using the Movement Assessment Battery for Children (M-ABC), consisting of manual dexterity, ball skills, and static and dynamic balance items. RESULTS TBI patients were less successful on the M-ABC than the controls and showed lower WM fractional anisotropy (FA) in the corpus callosum, anterior corona radiata, corticospinal tract, and cerebellum. Decreased FA was associated with lower motor performance in the TBI group but not in the control group. CONCLUSION This study provides evidence for a structural alteration of motor pathways and regions in children and adolescents with TBI that are correlated with motor functioning. Further studies may be able to identify therapeutic targets and monitor the effects of new interventions.
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McAllister TW, Stein MB. Effects of psychological and biomechanical trauma on brain and behavior. Ann N Y Acad Sci 2010; 1208:46-57. [PMID: 20955325 DOI: 10.1111/j.1749-6632.2010.05720.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The current conflicts in Iraq and Afghanistan have resulted in a large cohort of military personnel exposed to combat-related psychological trauma as well as biomechanical trauma, including proximity to blast events. Historically, the long-term effects of both types of trauma have been viewed as having different neural substrates, with some controversy over the proper attribution of such symptoms evident after each of the major conflicts of the last century. Recently, great effort has been directed toward distinguishing which neuropsychiatric sequelae are due to which type of trauma. Of interest, however, is that the chronic effects of exposure to either process are associated with a significant overlap in clinical symptoms. Furthermore, similar brain regions are vulnerable to the effects of either psychological or biomechanical trauma, raising the possibility that shared mechanisms may underlie the clinically observed overlap in symptom profile. This paper reviews the literature on the neural substrate of biomechanical and psychological injury and discusses the implications for evaluation and treatment of the neuropsychiatric sequelae of these processes.
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Affiliation(s)
- Thomas W McAllister
- Department of Psychiatry, Section of Neuropsychiatry, Dartmouth Medical School, Lebanon, New Hampshire 03756, USA.
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Caeyenberghs K, Leemans A, Geurts M, Taymans T, Linden CV, Smits-Engelsman BCM, Sunaert S, Swinnen SP. Brain-behavior relationships in young traumatic brain injury patients: DTI metrics are highly correlated with postural control. Hum Brain Mapp 2010; 31:992-1002. [PMID: 19998364 DOI: 10.1002/hbm.20911] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Traumatic brain injury (TBI) is a major cause of impairment and functional disability in children and adolescents, including deterioration in fine as well as gross motor skills. The aim of this study was to assess deficits in sensory organization and postural ability in a young group of TBI patients versus controls by using quantitative force-platform recordings, and to test whether balance deficits are related to variation in structural properties of the motor and sensory white matter pathways. Twelve patients with TBI and 14 controls (aged 8-20 years) performed the Sensory Organisation Test (SOT) protocol of the EquiTest (Neurocom). All participants were scanned using Diffusion Tensor Imaging (DTI) along with standard anatomical scans. Quantitative comparisons of DTI parameters (fractional anisotropy, axial and radial diffusivity) between TBI patients and controls were performed. Correlations between DTI parameters and SOT balance scores were determined. Findings revealed that the TBI group scored generally lower than the control group on the SOT, indicative of deficits in postural control. In the TBI group, reductions in fractional anisotropy were noted in the cerebellum, posterior thalamic radiation, and corticospinal tract. Degree of white matter deterioration was highly correlated with balance deficits. This study supports the view that DTI is a valuable tool for assessing the integrity of white matter structures and for selectively predicting functional motor deficits in TBI patients.
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Affiliation(s)
- Karen Caeyenberghs
- Motor Control Laboratory, Katholieke Universiteit Leuven, Leuven, Belgium
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Seo TB, Kim BK, Ko IG, Kim DH, Shin MS, Kim CJ, Yoon JH, Kim H. Effect of treadmill exercise on Purkinje cell loss and astrocytic reaction in the cerebellum after traumatic brain injury. Neurosci Lett 2010; 481:178-82. [PMID: 20603186 DOI: 10.1016/j.neulet.2010.06.087] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 06/22/2010] [Accepted: 06/29/2010] [Indexed: 02/02/2023]
Abstract
The cerebellum is one of the brain areas, which is selectively vulnerable to forebrain traumatic brain injuries (TBI). Physical exercise in animals is known to promote cell survival and functional recovery after brain injuries. However, the detailed pathologic and functional alterations by exercise following an indirect cerebellar injury induced by a TBI are largely unknown. We determined the effects of treadmill exercise on survival of Purkinje neurons and on a population of reactive astrocytes in the gyrus of lobules VIII and IX of the cerebellum after TBI. The rats were divided into four groups: the sham-operation group, the sham-operation with exercise group, the TBI-induction group, and the TBI-induction with exercise group. Cell biological changes of Purkinje neurons following indirect cerebellar injury were analyzed by immunohistochemistry. TBI-induced loss of calbindin-stained Purkinje neurons in the posterior region of the cerebellum and TBI also increased formation of reactive astroyctes in both the granular and molecular layers of the cerebellar posterior region. Treadmill exercise for 10 days after TBI increased the number of calbindin-stained Purkinje neurons and suppressed formation of reactive astroyctes. The present study provides the possibility that treadmill exercise may be an important mediator to enhance survival of Purkinje neurons in TBI-induced indirect cerebellar injury.
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Affiliation(s)
- Tae-Beom Seo
- Department of Physiology, College of Medicine, Kyung Hee University, Hoigi-dong, Dongdaemoon-gu, Seoul 130-701, Republic of Korea
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Gugger OS, Kapfhammer JP. Reduced size of the dendritic tree does not protect Purkinje cells from excitotoxic death. J Neurosci Res 2010; 88:774-83. [PMID: 19798747 DOI: 10.1002/jnr.22247] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Purkinje cell loss by excitotoxic damage is a typical finding in many cerebellar diseases. One important aspect of this high sensitivity of Purkinje cells to excitotoxic death might be the enormous size of their dendritic tree, with a high load of excitatory glutamate receptors. We have studied whether reduction in the size of the dendritic tree might confer resistance against excitotoxic death to Purkinje cells. We have grown Purkinje cells in organotypic cerebellar slice cultures under chronic activation of metabotropic glutamate receptors or of protein kinase C. Both treatments strongly reduced dendritic tree size. After this treatment, cells were exposed to the glutamate receptor agonist AMPA, which has a strong excitotoxic effect on Purkinje cells. We found that Purkinje cells with small dendritic trees were as sensitive to AMPA exposure as untreated control cells with large dendritic trees. Immunostaining against vesicular glutamate transporter 1 revealed that the small dendritic trees were densely covered by glutamatergic terminals. Our results indicate that the expansion of the dendritic tree and the total number of AMPA receptors per neuron do not play a major role in determining the susceptibility of Purkinje cells to excitotoxic death.
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Affiliation(s)
- Olivia S Gugger
- Anatomical Institute, Department of Biomedicine, University of Basel, Basel, Switzerland
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Neuroprotection of locomotor networks after experimental injury to the neonatal rat spinal cord in vitro. Neuroscience 2010; 165:996-1010. [DOI: 10.1016/j.neuroscience.2009.10.066] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 10/07/2009] [Accepted: 10/29/2009] [Indexed: 02/08/2023]
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Verdes JM, Moraña JA, Battes D, Gutiérrez F, Guerrero F, Goicoa A, Fidalgo LE, Barbeito CG, Zanuzzi CN, Portiansky EL, Gimeno EJ. Calbindin D28k expression and the absence of apoptosis in the cerebellum of Solanum bonariense L-intoxicated bovines. Vet Pathol 2009; 47:569-72. [PMID: 20234028 DOI: 10.1177/0300985809358040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Solanum bonariense intoxication is characterized by cerebellar neuronal vacuolation, degeneration, and necrosis. Cerebellar Purkinje cells seem especially susceptible, but more research is needed to determine the pathogenesis of neuronal necrosis and the mechanism of Purkinje cell susceptibility. Calbindin D28k (CbD28k) is highly expressed in Purkinje cells and has been used as a marker for normal and degenerative Purkinje cells. The goal of this study was to describe S bonariense-induced disease by ascertaining Purkinje cell-specific degenerative changes using CbD28k expression and to correlate this with apoptosis in Purkinje cells, as determined using TUNEL (transferase-mediated dUTP-biotin nick end-labeling) and ultrastructural changes. In all cases, an increase in both dose and duration of S bonariense intoxication resulted in a decrease in the number of Purkinje cells. CbD28k immunohistochemistry was an excellent marker for Purkinje cells because immunoreactivity did not change in normal or degenerative tissues. This finding suggests that excessive calcium excitatory stimulation does not induce rapid neuronal degeneration and death. As found in previous studies, TUNEL tests and electron microscopy suggest that Purkinje cell degeneration and death are not occurring via an apoptotic process. These findings suggest that S bonariense poisoning induces progressive Purkinje cell death that is not mediated by excitotoxicity or apoptotic activation.
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Affiliation(s)
- J M Verdes
- Department of Molecular and Cellular Biology (Biophysics), School of Veterinary, Universidad de la República, Av. A. Lasplaces 1550, CP 11600, Montevideo, Uruguay.
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Potts MB, Adwanikar H, Noble-Haeusslein LJ. Models of traumatic cerebellar injury. THE CEREBELLUM 2009; 8:211-21. [PMID: 19495901 PMCID: PMC2734258 DOI: 10.1007/s12311-009-0114-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 05/07/2009] [Indexed: 01/16/2023]
Abstract
Traumatic brain injury (TBI) is a major cause of morbidity and mortality worldwide. Studies of human TBI demonstrate that the cerebellum is sometimes affected even when the initial mechanical insult is directed to the cerebral cortex. Some of the components of TBI, including ataxia, postural instability, tremor, impairments in balance and fine motor skills, and even cognitive deficits, may be attributed in part to cerebellar damage. Animal models of TBI have begun to explore the vulnerability of the cerebellum. In this paper, we review the clinical presentation, pathogenesis, and putative mechanisms underlying cerebellar damage with an emphasis on experimental models that have been used to further elucidate this poorly understood but important aspect of TBI. Animal models of indirect (supratentorial) trauma to the cerebellum, including fluid percussion, controlled cortical impact, weight drop impact acceleration, and rotational acceleration injuries, are considered. In addition, we describe models that produce direct trauma to the cerebellum as well as those that reproduce specific components of TBI including axotomy, stab injury, in vitro stretch injury, and excitotoxicity. Overall, these models reveal robust characteristics of cerebellar damage including regionally specific Purkinje cell injury or loss, activation of glia in a distinct spatial pattern, and traumatic axonal injury. Further research is needed to better understand the mechanisms underlying the pathogenesis of cerebellar trauma, and the experimental models discussed here offer an important first step toward achieving that objective.
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Affiliation(s)
- Matthew B Potts
- Department of Neurological Surgery, University of California, Brain and Spinal Injury Center, San Francisco, CA 94143, USA
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An analysis of regional microvascular loss and recovery following two grades of fluid percussion trauma: a role for hypoxia-inducible factors in traumatic brain injury. J Cereb Blood Flow Metab 2009; 29:575-84. [PMID: 19088740 DOI: 10.1038/jcbfm.2008.151] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Secondary hypoxic/ischemic injuries, stemming from reductions in cerebral blood flow are important contributing factors in progressive neuronal dysfunction after brain trauma. A greater preclinical understanding of how brain trauma leads to secondary hypoxia/ischemia is necessary in the development of posttraumatic brain injury (TBI) therapeutics. To this end, we examined the density of microvascular coverage in the injured and contralateral cortical hemispheres using two intensities of fluid percussion trauma in rats. A silicone microangiography technique showed a significant loss in microvascular density in 2 atmosphere (atm) (16.9+/-3.8%) and 3 atm (15.7+/-1.3%) injured animals relative to sham animals (29.9+/-2.5%; P<0.01). RECA-1 immunohistochemistry indicated that capillary changes involved a reduction in capillary number and diameter. Reduction in microvascular density was shown to be a diffuse phenomenon occurring up to 4 mm rostral and caudal to the injury epicenter. Recovery of microvasculature occurred by 2 weeks after injury only in the 2 atm injury group. Expression of HIF1alpha and increased vascular endothelial growth factor expression were observed in the ipsilateral hippocampus suggesting sufficiently impaired microcirculation resulting in the expression of hypoxic-response proteins. Collectively, the results indicate diffuse and heterogeneous microvascular alterations as well as endogenous expression of neuroprotective and neovascularization pathways after TBI.
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Caeyenberghs K, van Roon D, Swinnen S, Smits-Engelsman B. Deficits in executed and imagined aiming performance in brain-injured children. Brain Cogn 2009; 69:154-61. [DOI: 10.1016/j.bandc.2008.07.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 07/01/2008] [Accepted: 07/01/2008] [Indexed: 11/25/2022]
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Caeyenberghs K, Wenderoth N, Smits-Engelsman BCM, Sunaert S, Swinnen SP. Neural correlates of motor dysfunction in children with traumatic brain injury: exploration of compensatory recruitment patterns. Brain 2009; 132:684-94. [PMID: 19153150 DOI: 10.1093/brain/awn344] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Traumatic brain injury (TBI) is a common form of disability in children. Persistent deficits in motor control have been documented following TBI but there has been less emphasis on changes in functional cerebral activity. In the present study, children with moderate to severe TBI (n = 9) and controls (n = 17) were scanned while performing cyclical movements with their dominant and non-dominant hand and foot according to the easy isodirectional (same direction) and more difficult non-isodirectional (opposite direction) mode. Even though the children with TBI were shown to be less successful on various items of a clinical motor test battery than the control group, performance on the coordination task during scanning was similar between groups, allowing a meaningful interpretation of their brain activation differences. fMRI analysis revealed that the TBI children showed enhanced activity in medial and anterior parietal areas as well as posterior cerebellum as compared with the control group. Brain activation generally increased during the non-isodirectional as compared with the isodirectional mode and additional regions were involved, consistent with their differential degree of difficulty. However, this effect did not interact with group. Overall, the findings indicate that motor impairment in TBI children is associated with changes in functional cerebral activity, i.e. they exhibit compensatory activation reflecting increased recruitment of neural resources for attentional deployment and somatosensory processing.
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Affiliation(s)
- K Caeyenberghs
- Department of Biomedical Kinesiology, Motor Control Laboratory, Research Center for Motor Control and Neuroplasticity, Group Biomedical Sciences, K.U. Leuven, Belgium
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Neuropsychology and clinical neuroscience of persistent post-concussive syndrome. J Int Neuropsychol Soc 2008; 14:1-22. [PMID: 18078527 DOI: 10.1017/s135561770808017x] [Citation(s) in RCA: 261] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Revised: 08/16/2007] [Accepted: 08/16/2007] [Indexed: 01/17/2023]
Abstract
On the mild end of the acquired brain injury spectrum, the terms concussion and mild traumatic brain injury (mTBI) have been used interchangeably, where persistent post-concussive syndrome (PPCS) has been a label given when symptoms persist for more than three months post-concussion. Whereas a brief history of concussion research is overviewed, the focus of this review is on the current status of PPCS as a clinical entity from the perspective of recent advances in the biomechanical modeling of concussion in human and animal studies, particularly directed at a better understanding of the neuropathology associated with concussion. These studies implicate common regions of injury, including the upper brainstem, base of the frontal lobe, hypothalamic-pituitary axis, medial temporal lobe, fornix, and corpus callosum. Limitations of current neuropsychological techniques for the clinical assessment of memory and executive function are explored and recommendations for improved research designs offered, that may enhance the study of long-term neuropsychological sequelae of concussion.
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Slemmer JE, Haasdijk ED, Engel DC, Plesnila N, Weber JT. Aldolase C-positive cerebellar Purkinje cells are resistant to delayed death after cerebral trauma and AMPA-mediated excitotoxicity. Eur J Neurosci 2007; 26:649-56. [PMID: 17686042 DOI: 10.1111/j.1460-9568.2007.05708.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The cerebellum has been shown to be vulnerable to global ischemic damage in tightly controlled zones of Purkinje cells (PCs) that lack aldolase C, an enzyme critical for glycolysis. Here, we investigated whether aldolase C-negative PCs were more likely to die after cerebral trauma in vivo, and whether this death was mediated by excitotoxic [alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-mediated] means in vitro. Mice were subjected to controlled cortical impact, or remained uninjured, and were killed at 6 h, 24 h or 7 days after injury. Cerebellar sections (both ipsilateral and contralateral to the site of cerebral injury) were stained against aldolase C and calbindin (a marker of PCs). The number of viable, calbindin-positive PCs decreased significantly at 24 h and 7 days after injury, and the percentage of surviving, aldolase C-positive PCs significantly increased at those time-points. In addition, we subjected murine cerebellar cultures to AMPA (30 microm, 20 min), which killed a significant number of PCs at 24 h post-treatment. A similar number of PCs was lost after transfection with aldolase C siRNA, and this effect was exacerbated in transfected cultures treated with AMPA. The results from the present study indicate that aldolase C provides marked neuroprotection to PCs after trauma and excitotoxicity.
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Affiliation(s)
- Jennifer E Slemmer
- Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
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Bell JD, Ai J, Chen Y, Baker AJ. Mild in vitro trauma induces rapid Glur2 endocytosis, robustly augments calcium permeability and enhances susceptibility to secondary excitotoxic insult in cultured Purkinje cells. ACTA ACUST UNITED AC 2007; 130:2528-42. [PMID: 17664176 DOI: 10.1093/brain/awm164] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mild brain trauma results in a wide range of neurological symptoms that are not easily explained by the primary pathology. Purkinje neurons of the cerebellum are selectively vulnerable to brain trauma, including indirect remote trauma to the forebrain. This vulnerability manifests itself as a selective and delayed cell loss, for which the underlying mechanisms are poorly understood. Alterations to the surface expression of calcium impermeable AMPA receptors (GluR2-containing) may mediate post-traumatic calcium overload, and initiate biochemical cascades that ultimately cause progressive cell death. Our current study examined this hypothesis using an in vitro model of mild Purkinje trauma, delivered by an elastic stretch at 2.5-2.9 pounds per square inch (psi). This mild trauma alone did not increase cell loss as measured by propidium iodide (PI) uptake (at 20 h) compared to uninjured controls. However, there was a marked increase in cell loss, when cells following mild trauma, were exposed to 10 microM AMPA for 1 h compared to either mild trauma or AMPA exposure alone. Mild injury rendered Purkinje neurons significantly more permeable to AMPA-stimulated (4 microM) calcium influx at 15 min post-injury, including a sustained calcium plateau. This effect was eliminated by inhibiting protein kinase C-dependent GluR2 endocytosis with 2 microM Go6976 or blocking the calcium pore of GluR1/3 containing AMPARs with 500 nM 1-naphthylacetyl spermine (Naspm). Nifedipine (2 microM) eliminated the calcium plateau following mild injury but not the initial spike of Ca2+ increase. These results suggest that mild injuries resulted in a rapid AMPA receptor subtype switch (GluR2 was replaced by GluR1/3), which in turn resulted in an enhanced Ca2+ permeability. We further confirmed this by immunocytochemistry. Dendritic GluR2 co-localization with the pre-synaptic marker synaptophysin was markedly down-regulated at 15 min following mild stretch (P < 0.01), indicative of a rapid decrease in the synaptic expression of receptors containing this subunit. Carboxyfluorescence (CBF) assays revealed that mild stretch did not alter membrane integrity. Finally, we demonstrated that the combination of 500 nM Naspm and 5 nM Go6976 conferred a powerful neuroprotective effect on Purkinje cells by effectively eliminating the effects of mild stretch combined with AMPA in 95% of cells. These results represent a newly described mechanism rendering neurons susceptible to secondary injuries following trauma. Prevention of GluR2 endocytosis may be critical in the development of pharmacotherapies aimed at mild, seemingly inconsequential trauma, to avoid ensuing secondary damage.
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Affiliation(s)
- Joshua D Bell
- Cara Phelan Center for Trauma Research, St Michaels Hospital, Toronto, Ontario, Canada
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35
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Hare GMT, Mazer CD, Hutchison JS, McLaren AT, Liu E, Rassouli A, Ai J, Shaye RE, Lockwood JA, Hawkins CE, Sikich N, To K, Baker AJ. Severe hemodilutional anemia increases cerebral tissue injury following acute neurotrauma. J Appl Physiol (1985) 2007; 103:1021-9. [PMID: 17556499 DOI: 10.1152/japplphysiol.01315.2006] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Anemia may worsen neurological outcomes following traumatic brain injury (TBI) by undefined mechanisms. We hypothesized that hemodilutional anemia accentuates hypoxic cerebral injury following TBI. Anesthetized rats underwent unilateral TBI or sham injury (n > or = 7). Target hemoglobin concentrations between 50 and 70 g/l were achieved by exchanging 40-50% of the blood volume (1:1) with pentastarch. The effect of TBI, anemia, and TBI-anemia was assessed by measuring brain tissue oxygen tension (Pbr(O(2))), regional cerebral blood flow (rCBF), jugular venous oxygen saturation (Sjv(O(2))), cerebral contusion area, and nuclear staining for programmed cell death. Baseline postinjury Pbr(O(2)) values in the TBI and TBI-anemia groups (9.3 +/- 1.3 and 11.3 +/- 4.1 Torr, respectively) were lower than the uninjured controls (18.2 +/- 5.2 Torr, P < 0.05 for both). Hemodilution caused a further reduction in Pbr(O(2)) in the TBI-anemia group relative to the TBI group without anemia (7.8 +/- 2.7 vs. 14.8 +/- 3.9 Torr, P < 0.05). The rCBF remained stable after TBI and increased comparably after hemodilution in both anemia and TBI-anemia groups. The Sjv(O(2)) was elevated after TBI (87.4 +/- 8.9%, P < 0.05) and increased further following hemodilution (95.0 +/- 1.6%, P < 0.05). Cerebral contusion area and nuclear counts for programmed cell death were increased following TBI-anemia (4.1 +/- 3.0 mm(2) and 686 +/- 192, respectively) relative to TBI alone (1.3 +/- 0.3 mm(2) and 404 +/- 133, respectively, P < 0.05 for both). Hemodilutional anemia reduced cerebral Pbr(O(2)) and oxygen extraction and increased cell death following TBI. These results support our hypothesis that acute anemia accentuated hypoxic cerebral injury after neurotrauma.
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Affiliation(s)
- Gregory M T Hare
- Department of Anesthesia, University of Toronto, St. Michael's Hospital, 30 Bond St., Toronto, Ontario M5B 1W8, Canada.
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Tweedie D, Milman A, Holloway HW, Li Y, Harvey BK, Shen H, Pistell PJ, Lahiri DK, Hoffer BJ, Wang Y, Pick CG, Greig NH. Apoptotic and behavioral sequelae of mild brain trauma in mice. J Neurosci Res 2007; 85:805-15. [PMID: 17243171 DOI: 10.1002/jnr.21160] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mild traumatic brain injury (mTBI) is a not uncommon event in adolescents and young adults. Although it does not result in clear morphological brain defects, it is associated with long-term cognitive, emotional, and behavioral problems. Herein, we characterized the biochemical and behavioral changes associated with experimental mTBI in mice that may act as either targets or surrogate markers for interventional therapy. Specifically, mTBI was induced by 30-g and 50-g weight drop, and at 8 and 72 hr thereafter markers of cellular apoptosis-caspase-3, Bax, apoptosis-inducing factor (AIF), and cytochrome-c (Cyt-c)-were quantified by Western blot analysis in hippocampus ipsilateral to the impact. Levels of amyloid-beta precursor protein (APP) were also measured, and specific behavioral tests-passive avoidance, open field, and forced swimming (Porsolt) paradigms-were undertaken to assess learning, emotionality, and emotional memory. In the absence of hemorrhage or infarcts, as assessed by triphenyltetrazolium chloride staining, procaspase-3 and Bax levels were markedly altered following mTBI at both times. No cleaved caspase-3 was detected, and levels of AIF and Cyt-c, but not APP, were significantly changed at 72 hr. Mice subjected to mTBI were indistinguishable from controls by neurological examination at 1 and 24 hr, and by passive avoidance/open field at 72 hr, but could be differentiated in the forced swimming paradigm. In general, this model mimics the diffuse effects of mTBI on brain function associated with the human condition and highlights specific apoptotic proteins and a behavioral paradigm as potential markers for prospective interventional strategies.
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Affiliation(s)
- David Tweedie
- Drug Design and Development Section, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, Baltimore, Maryland 21224, USA.
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Yi JH, Herrero R, Chen G, Hazell AS. Glutamate transporter EAAT4 is increased in hippocampal astrocytes following lateral fluid-percussion injury in the rat. Brain Res 2007; 1154:200-5. [PMID: 17490622 DOI: 10.1016/j.brainres.2007.04.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 04/01/2007] [Accepted: 04/02/2007] [Indexed: 11/22/2022]
Abstract
Functional impairment of glutamate transporters contributes to excitotoxic damage and exacerbation of injury in certain neurodegenerative disorders. Several high-affinity sodium-dependent glutamate transporters have been cloned thus far. Of these, EAAT4 is abundantly expressed in Purkinje cells of the cerebellum in rats. However, little is currently known regarding levels of EAAT4 following traumatic brain injury (TBI). In this study, EAAT4 changes were examined for up to 7 days after moderate fluid-percussion by immunoblotting and immunohistochemistry. TBI caused a 20% and 25% increase in EAAT4 levels in the injured hippocampus at day 3 and day 7 following the insult. Immunohistochemical analysis revealed this increase to be localized in cells exhibiting morphological characteristics of astrocytes. In addition, increased EAAT4 immunoreactivity was observed in astrocytes in the ipsilateral cortex and cerebellum at day 3 post-injury that persisted up to 7 days after the insult. Given the reported novel characteristics of chloride conductance displayed by this transporter, our findings of increased EAAT4 levels suggest this protein may play an important role in the pathophysiology of TBI.
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Affiliation(s)
- Jae-Hyuk Yi
- Department of Medicine, University of Montreal, Montreal, Quebec, Canada
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38
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Fehlings MG, Baker A. Is there a role for hyperoxia in the management of severe traumatic brain injury? J Neurosurg 2007; 106:525; discussion 525. [PMID: 17432699 DOI: 10.3171/jns.2007.106.4.525] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Alcock J, Scotting P, Sottile V. Bergmann glia as putative stem cells of the mature cerebellum. Med Hypotheses 2007; 69:341-5. [PMID: 17337128 DOI: 10.1016/j.mehy.2007.01.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Accepted: 01/02/2007] [Indexed: 10/23/2022]
Abstract
The adult brain is known to retain a population of stem cells with self-renewing and differentiation ability, which have been identified in two main regions. Recent reports now suggest the presence of such cells in the cerebellum, a part of the CNS which was not formerly thought to harbour stem cells. The precise nature and localisation of these potential new stem cells within the tissue remains unclear, as they have primarily been described at early postnatal stages, before completion of the extensive cell migration accompanying cerebellum maturation. We have shown that a discrete cell population of the cerebellar cortex, the Bergmann glia, shares the expression of key molecular markers with neural stem cells. We examine the hypothesis that the Bergmann glia may represent a novel and abundant stem cell population in the mature cerebellum.
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Affiliation(s)
- Joëlle Alcock
- Institute of Genetics, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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40
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Park E, Ai J, Baker AJ. Cerebellar injury: clinical relevance and potential in traumatic brain injury research. PROGRESS IN BRAIN RESEARCH 2007; 161:327-38. [PMID: 17618988 DOI: 10.1016/s0079-6123(06)61023-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A treatment for traumatic brain injury (TBI) remains elusive despite compelling evidence from animal models for a variety of therapeutic targets. Numerous animal models have been developed to address the wide spectrum of mechanisms involved in the progression of secondary injury after TBI. Evidence from well-established models such as the fluid percussion injury (FPI) device, cortical impact model, and the impact acceleration model has demonstrated diffuse pathophysiological mechanisms throughout various brain structures. More specifically, we have recently extended characterization of the FPI model to include pathophysiological changes in the cerebellum following unilateral fluid percussion. Data suggest that the cerebellum is susceptible to selective Purkinje cell loss as well as white matter dysfunction. Despite the cerebellum's low profile in TBI research, there is evidence to warrant further study of the cerebellum to examine mechanisms of neuronal death and traumatic axonal injury. Furthermore, evidence from clinical literature and basic science suggests that some components of TBI pathophysiology have a basis in cerebellar dysfunction. This review highlights some of the recent findings in cerebellar trauma and builds an argument for including the cerebellum as a model to assess mechanisms of secondary injury and its potential contribution to the pathology of TBI.
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Affiliation(s)
- Eugene Park
- St. Michael's Hospital, Trauma Research, and University of Toronto, Institute of Medical Sciences, Toronto, ON, M5S 1A, Canada
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41
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Park E, Liu E, Shek M, Park A, Baker AJ. Heavy neurofilament accumulation and alpha-spectrin degradation accompany cerebellar white matter functional deficits following forebrain fluid percussion injury. Exp Neurol 2006; 204:49-57. [PMID: 17070521 DOI: 10.1016/j.expneurol.2006.09.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 08/10/2006] [Accepted: 09/22/2006] [Indexed: 11/21/2022]
Abstract
Evidence for diffuse traumatic axonal injury (TAI) in clinical cases and animal models of traumatic brain injury (TBI) indicate that pathophysiological mechanisms extend to regions remote from the injury epicenter. The potential for indirect cerebellar trauma contributing to TBI pathophysiology is of significance since impairment of motor function and coordination is a common consequence of TBI but is also a domain associated with cerebellar function. The relationship between cerebellar white matter structure and function following traumatic head injury has not been examined. Using the fluid percussion injury (FPI) device applied unilaterally in the forebrain, evoked compound action potential (CAP) recordings from cerebellar white matter of Sprague-Dawley rats indicated a spatial and temporal pattern of electrophysiological deficits throughout the cerebellar vermis. The posterior and middle lobules of the cerebellum exhibited significant declines in evoked CAP amplitude compared to sham controls (p=0.004, p=0.005, respectively). Duration of the CAP decay also increased, suggesting that functional white matter deficits were a combination of axonal loss and compromised axonal integrity. Functional white matter deficits persisted at 14 days post-injury in the posterior and middle regions of the cerebellum. Evidence of heavy chain neurofilament (NF200) degradation was observed at 1 day post-injury by Western blot. Immunohistochemistry labeling for NF200 indicated the presence of highly immunoreactive NF200 axonal swellings consistent with morphological features of TAI. alpha-Spectrin degradation was also observed between 1 and 14 days post-injury. This study demonstrates the electrophysiological consequences of cerebellar white matter injury and a temporal profile of NF200 and spectrin degradation following forebrain FPI.
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Affiliation(s)
- Eugene Park
- Cara Phelan Center for Trauma Research, St. Michael's Hospital, 7082 Bond Wing, 30 Bond Street, Toronto, Ontario, Canada, M5B 1W8
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Igarashi T, Potts MB, Noble-Haeusslein LJ. Injury severity determines Purkinje cell loss and microglial activation in the cerebellum after cortical contusion injury. Exp Neurol 2006; 203:258-68. [PMID: 17045589 DOI: 10.1016/j.expneurol.2006.08.030] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Revised: 08/05/2006] [Accepted: 08/10/2006] [Indexed: 10/24/2022]
Abstract
Clinical evidence suggests that the cerebellum is damaged after traumatic brain injury (TBI) and experimental studies have validated these observations. We have previously shown cerebellar vulnerability, as demonstrated by Purkinje cell loss and microglial activation, after fluid percussion brain injury. In this study, we examine the effect of graded controlled cortical impact (CCI) injury on the cerebellum in the context of physiologic and anatomical parameters that have been shown by others to be sensitive to injury severity. Adult male rats received mild, moderate, or severe CCI and were euthanized 7 days later. We first validated the severity of the initial injury using physiologic criteria, including apnea and blood pressure, during the immediate postinjury period. Increasing injury severity was associated with an increased incidence of apnea and higher mortality. Severe injury also induced transient hypertension followed by hypotension, while lower grade injuries produced an immediate and sustained hypotension. We next evaluated the pattern of subcortical neuronal loss in response to graded injuries. There was significant neuronal loss in the ipsilateral cortex, hippocampal CA2/CA3, and laterodorsal thalamus that was injury severity-dependent and that paralleled microglial activation. Similarly, there was a distinctive pattern of Purkinje cell loss and microglial activation in the cerebellar vermis that varied with injury severity. Together, these findings emphasize the vulnerability of the cerebellum to TBI. That a selective pattern of Purkinje cell loss occurs regardless of the type of injury suggests a generalized response that is a likely determinant of recovery and a target for therapeutic intervention.
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Affiliation(s)
- Takuji Igarashi
- Department of Neurological Surgery, University of California, San Francisco, 521 Parnassus Avenue, Room C-224, San Francisco, CA 94143-0520, USA
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