51
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Alluri H, Grimsley M, Anasooya Shaji C, Varghese KP, Zhang SL, Peddaboina C, Robinson B, Beeram MR, Huang JH, Tharakan B. Attenuation of Blood-Brain Barrier Breakdown and Hyperpermeability by Calpain Inhibition. J Biol Chem 2016; 291:26958-26969. [PMID: 27875293 DOI: 10.1074/jbc.m116.735365] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 10/19/2016] [Indexed: 01/11/2023] Open
Abstract
Blood-brain barrier (BBB) breakdown and the associated microvascular hyperpermeability followed by brain edema are hallmark features of several brain pathologies, including traumatic brain injuries (TBI). Recent studies indicate that pro-inflammatory cytokine interleukin-1β (IL-1β) that is up-regulated following traumatic injuries also promotes BBB dysfunction and hyperpermeability, but the underlying mechanisms are not clearly known. The objective of this study was to determine the role of calpains in mediating BBB dysfunction and hyperpermeability and to test the effect of calpain inhibition on the BBB following traumatic insults to the brain. In these studies, rat brain microvascular endothelial cell monolayers exposed to calpain inhibitors (calpain inhibitor III and calpastatin) or transfected with calpain-1 siRNA demonstrated attenuation of IL-1β-induced monolayer hyperpermeability. Calpain inhibition led to protection against IL-1β-induced loss of zonula occludens-1 (ZO-1) at the tight junctions and alterations in F-actin cytoskeletal assembly. IL-1β treatment had no effect on ZO-1 gene (tjp1) or protein expression. Calpain inhibition via calpain inhibitor III and calpastatin decreased IL-1β-induced calpain activity significantly (p < 0.05). IL-1β had no detectable effect on intracellular calcium mobilization or endothelial cell viability. Furthermore, calpain inhibition preserved BBB integrity/permeability in a mouse controlled cortical impact model of TBI when studied using Evans blue assay and intravital microscopy. These studies demonstrate that calpain-1 acts as a mediator of IL-1β-induced loss of BBB integrity and permeability by altering tight junction integrity, promoting the displacement of ZO-1, and disorganization of cytoskeletal assembly. IL-1β-mediated alterations in permeability are neither due to the changes in ZO-1 expression nor cell viability. Calpain inhibition has beneficial effects against TBI-induced BBB hyperpermeability.
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Affiliation(s)
| | | | | | - Kevin Paul Varghese
- the Department of Biomedical Engineering, University of Texas, Austin, Texas 78712, and
| | - Shenyuan L Zhang
- the Department of Medical Physiology, Texas A&M University Health Science Center College of Medicine, Temple, Texas 76504
| | | | | | - Madhava R Beeram
- Pediatrics, Texas A&M University Health Science Center College of Medicine/Baylor Scott and White Health, Temple, Texas 76504
| | | | - Binu Tharakan
- From the Departments of Surgery, .,Pediatrics, Texas A&M University Health Science Center College of Medicine/Baylor Scott and White Health, Temple, Texas 76504
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52
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Yu W, Parakramaweera R, Teng S, Gowda M, Sharad Y, Thakker-Varia S, Alder J, Sesti F. Oxidation of KCNB1 Potassium Channels Causes Neurotoxicity and Cognitive Impairment in a Mouse Model of Traumatic Brain Injury. J Neurosci 2016; 36:11084-11096. [PMID: 27798188 PMCID: PMC5098843 DOI: 10.1523/jneurosci.2273-16.2016] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/25/2016] [Accepted: 09/07/2016] [Indexed: 01/08/2023] Open
Abstract
The delayed rectifier potassium (K+) channel KCNB1 (Kv2.1), which conducts a major somatodendritic current in cortex and hippocampus, is known to undergo oxidation in the brain, but whether this can cause neurodegeneration and cognitive impairment is not known. Here, we used transgenic mice harboring human KCNB1 wild-type (Tg-WT) or a nonoxidable C73A mutant (Tg-C73A) in cortex and hippocampus to determine whether oxidized KCNB1 channels affect brain function. Animals were subjected to moderate traumatic brain injury (TBI), a condition characterized by extensive oxidative stress. Dasatinib, a Food and Drug Administration-approved inhibitor of Src tyrosine kinases, was used to impinge on the proapoptotic signaling pathway activated by oxidized KCNB1 channels. Thus, typical lesions of brain injury, namely, inflammation (astrocytosis), neurodegeneration, and cell death, were markedly reduced in Tg-C73A and dasatinib-treated non-Tg animals. Accordingly, Tg-C73A mice and non-Tg mice treated with dasatinib exhibited improved behavioral outcomes in motor (rotarod) and cognitive (Morris water maze) assays compared to controls. Moreover, the activity of Src kinases, along with oxidative stress, were significantly diminished in Tg-C73A brains. Together, these data demonstrate that oxidation of KCNB1 channels is a contributing mechanism to cellular and behavioral deficits in vertebrates and suggest a new therapeutic approach to TBI. SIGNIFICANCE STATEMENT This study provides the first experimental evidence that oxidation of a K+ channel constitutes a mechanism of neuronal and cognitive impairment in vertebrates. Specifically, the interaction of KCNB1 channels with reactive oxygen species plays a major role in the etiology of mouse model of traumatic brain injury (TBI), a condition associated with extensive oxidative stress. In addition, a Food and Drug Administration-approved drug ameliorates the outcome of TBI in mouse, by directly impinging on the toxic pathway activated in response to oxidation of the KCNB1 channel. These findings elucidate a basic mechanism of neurotoxicity in vertebrates and might lead to a new therapeutic approach to TBI in humans, which, despite significant efforts, is a condition that remains without effective pharmacological treatments.
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Affiliation(s)
- Wei Yu
- Department of Neuroscience and Cell Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Randika Parakramaweera
- Department of Neuroscience and Cell Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Shavonne Teng
- Department of Neuroscience and Cell Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Manasa Gowda
- Department of Neuroscience and Cell Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Yashsavi Sharad
- Department of Neuroscience and Cell Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Smita Thakker-Varia
- Department of Neuroscience and Cell Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Janet Alder
- Department of Neuroscience and Cell Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
| | - Federico Sesti
- Department of Neuroscience and Cell Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
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53
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Perez EJ, Cepero ML, Perez SU, Coyle JT, Sick TJ, Liebl DJ. EphB3 signaling propagates synaptic dysfunction in the traumatic injured brain. Neurobiol Dis 2016; 94:73-84. [PMID: 27317833 PMCID: PMC5662938 DOI: 10.1016/j.nbd.2016.06.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/25/2016] [Accepted: 06/14/2016] [Indexed: 12/25/2022] Open
Abstract
Traumatic brain injury (TBI), ranging from mild concussion to severe penetrating wounds, can involve brain regions that contain damaged or lost synapses in the absence of neuronal death. These affected regions significantly contribute to sensory, motor and/or cognitive deficits. Thus, studying the mechanisms responsible for synaptic instability and dysfunction is important for protecting the nervous system from the consequences of progressive TBI. Our controlled cortical impact (CCI) injury produces ~20% loss of synapses and mild changes in synaptic protein levels in the CA3-CA1 hippocampus without neuronal losses. These synaptic changes are associated with functional deficits, indicated by >50% loss in synaptic plasticity and impaired learning behavior. We show that the receptor tyrosine kinase EphB3 participates in CCI injury-induced synaptic damage, where EphB3(-/-) mice show preserved long-term potentiation and hippocampal-dependent learning behavior as compared with wild type (WT) injured mice. Improved synaptic function in the absence of EphB3 results from attenuation in CCI injury-induced synaptic losses and reduced d-serine levels compared with WT injured mice. Together, these findings suggest that EphB3 signaling plays a deleterious role in synaptic stability and plasticity after TBI.
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Affiliation(s)
- Enmanuel J Perez
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Maria L Cepero
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Sebastian U Perez
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Joseph T Coyle
- Harvard Medical School, Department of Psychiatry, McLean Hospital, Boston, MA 02115, USA
| | - Thomas J Sick
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Daniel J Liebl
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL, USA.
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54
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Shultz SR, McDonald SJ, Vonder Haar C, Meconi A, Vink R, van Donkelaar P, Taneja C, Iverson GL, Christie BR. The potential for animal models to provide insight into mild traumatic brain injury: Translational challenges and strategies. Neurosci Biobehav Rev 2016; 76:396-414. [PMID: 27659125 DOI: 10.1016/j.neubiorev.2016.09.014] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 09/07/2016] [Accepted: 09/16/2016] [Indexed: 12/14/2022]
Abstract
Mild traumatic brain injury (mTBI) is a common health problem. There is tremendous variability and heterogeneity in human mTBI, including mechanisms of injury, biomechanical forces, injury severity, spatial and temporal pathophysiology, genetic factors, pre-injury vulnerability and resilience factors, and clinical outcomes. Animal models greatly reduce this variability and heterogeneity, and provide a means to study mTBI in a rigorous, controlled, and efficient manner. Rodent models, in particular, are time- and cost-efficient, and they allow researchers to measure morphological, cellular, molecular, and behavioral variables in a single study. However, inter-species differences in anatomy, morphology, metabolism, neurobiology, and lifespan create translational challenges. Although the term "mild" TBI is used often in the pre-clinical literature, clearly defined criteria for mild, moderate, and severe TBI in animal models have not been agreed upon. In this review, we introduce current issues facing the mTBI field, summarize the available research methodologies and previous studies in mTBI animal models, and discuss how a translational research approach may be useful in advancing our understanding and management of mTBI.
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Affiliation(s)
- Sandy R Shultz
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia.
| | - Stuart J McDonald
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, VIC, Australia
| | - Cole Vonder Haar
- Department of Psychology, The University of British Columbia, Vancouver, BC, Canada
| | - Alicia Meconi
- Division of Medical Sciences, The University of Victoria, Victoria, BC, Canada
| | - Robert Vink
- Division of Health Sciences, The University of South Australia, Adelaide, SA, Australia
| | - Paul van Donkelaar
- School of Health and Exercise Sciences, The University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Chand Taneja
- Division of Medical Sciences, The University of Victoria, Victoria, BC, Canada
| | - Grant L Iverson
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Home Base, A Red Sox Foundation and Massachusetts General Hospital Program, and MassGeneral Hospital for Children™ Sports Concussion Program, Boston, MA, USA
| | - Brian R Christie
- Division of Medical Sciences, The University of Victoria, Victoria, BC, Canada
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55
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Ko J, Hemphill MA, Gabrieli D, Wu L, Yelleswarapu V, Lawrence G, Pennycooke W, Singh A, Meaney DF, Issadore D. Smartphone-enabled optofluidic exosome diagnostic for concussion recovery. Sci Rep 2016; 6:31215. [PMID: 27498963 PMCID: PMC4976377 DOI: 10.1038/srep31215] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/15/2016] [Indexed: 01/23/2023] Open
Abstract
A major impediment to improving the treatment of concussion is our current inability to identify patients that will experience persistent problems after the injury. Recently, brain-derived exosomes, which cross the blood-brain barrier and circulate following injury, have shown great potential as a noninvasive biomarker of brain recovery. However, clinical use of exosomes has been constrained by their small size (30–100 nm) and the extensive sample preparation (>24 hr) needed for traditional exosome measurements. To address these challenges, we developed a smartphone-enabled optofluidic platform to measure brain-derived exosomes. Sample-to-answer on our chip is 1 hour, 10x faster than conventional techniques. The key innovation is an optofluidic device that can detect enzyme amplified exosome biomarkers, and is read out using a smartphone camera. Using this approach, we detected and profiled GluR2+ exosomes in the post-injury state using both in vitro and murine models of concussion.
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Affiliation(s)
- Jina Ko
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Matthew A Hemphill
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - David Gabrieli
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Leon Wu
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Venkata Yelleswarapu
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Gladys Lawrence
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Wesley Pennycooke
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Anup Singh
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
| | - Dave F Meaney
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States.,Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - David Issadore
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States.,Department of Electrical and Systems Engineering, School of Engineering and Applied Sciences, University of Pennsylvania. Philadelphia, Pennsylvania, United States
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56
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Witcher KG, Eiferman DS, Godbout JP. Priming the inflammatory pump of the CNS after traumatic brain injury. Trends Neurosci 2016; 38:609-620. [PMID: 26442695 DOI: 10.1016/j.tins.2015.08.002] [Citation(s) in RCA: 160] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/14/2015] [Accepted: 08/18/2015] [Indexed: 12/14/2022]
Abstract
Traumatic brain injury (TBI) can lead to secondary neuropsychiatric problems that develop and persist years after injury. Mounting evidence indicates that neuroinflammatory processes progress after the initial head injury and worsen with time. Microglia contribute to this inflammation by maintaining a primed profile long after the acute effects of the injury have dissipated. This may set the stage for glial dysfunction and hyperactivity to challenges including subsequent head injury, stress, or induction of a peripheral immune response. This review discusses the evidence that microglia become primed following TBI and how this corresponds with vulnerability to a 'second hit' and subsequent neuropsychiatric and neurodegenerative complications.
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Affiliation(s)
- Kristina G Witcher
- Department of Neuroscience, The Ohio State University, 333 West 10th Avenue, Columbus, OH, USA
| | - Daniel S Eiferman
- Department of Surgery, The Ohio State University, 395 West 12th Avenue, Columbus, OH, USA
| | - Jonathan P Godbout
- Department of Neuroscience, The Ohio State University, 333 West 10th Avenue, Columbus, OH, USA; Center for Brain and Spinal Cord Repair, The Ohio State University, 460 West 12th Avenue, Columbus, OH, USA; Institute for Behavioral Medicine Research, The Ohio State University, 460 Medical Center Drive, Columbus, OH, USA.
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57
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Alluri H, Wilson RL, Anasooya Shaji C, Wiggins-Dohlvik K, Patel S, Liu Y, Peng X, Beeram MR, Davis ML, Huang JH, Tharakan B. Melatonin Preserves Blood-Brain Barrier Integrity and Permeability via Matrix Metalloproteinase-9 Inhibition. PLoS One 2016; 11:e0154427. [PMID: 27152411 PMCID: PMC4859489 DOI: 10.1371/journal.pone.0154427] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 04/13/2016] [Indexed: 01/30/2023] Open
Abstract
Microvascular hyperpermeability that occurs at the level of the blood-brain barrier (BBB) often leads to vasogenic brain edema and elevated intracranial pressure following traumatic brain injury (TBI). At a cellular level, tight junction proteins (TJPs) between neighboring endothelial cells maintain the integrity of the BBB via TJ associated proteins particularly, zonula occludens-1 (ZO-1) that binds to the transmembrane TJPs and actin cytoskeleton intracellularly. The pro-inflammatory cytokine, interleukin-1β (IL-1β) as well as the proteolytic enzymes, matrix metalloproteinase-9 (MMP-9) are key mediators of trauma-associated brain edema. Recent studies indicate that melatonin a pineal hormone directly binds to MMP-9 and also might act as its endogenous inhibitor. We hypothesized that melatonin treatment will provide protection against TBI-induced BBB hyperpermeability via MMP-9 inhibition. Rat brain microvascular endothelial cells grown as monolayers were used as an in vitro model of the BBB and a mouse model of TBI using a controlled cortical impactor was used for all in vivo studies. IL-1β (10 ng/mL; 2 hours)-induced endothelial monolayer hyperpermeability was significantly attenuated by melatonin (10 μg/mL; 1 hour), GM6001 (broad spectrum MMP inhibitor; 10 μM; 1 hour), MMP-9 inhibitor-1 (MMP-9 specific inhibitor; 5 nM; 1 hour) or MMP-9 siRNA transfection (48 hours) in vitro. Melatonin and MMP-9 inhibitor-1 pretreatment attenuated IL-1β-induced MMP-9 activity, loss of ZO-1 junctional integrity and f-actin stress fiber formation. IL-1β treatment neither affected ZO-1 protein or mRNA expression or cell viability. Acute melatonin treatment attenuated BBB hyperpermeability in a mouse controlled cortical impact model of TBI in vivo. In conclusion, one of the protective effects of melatonin against BBB hyperpermeability occurs due to enhanced BBB integrity via MMP-9 inhibition. In addition, acute melatonin treatment provides protection against BBB hyperpermeability in a mouse model of TBI indicating its potential as a therapeutic agent for brain edema when established in humans.
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Affiliation(s)
- Himakarnika Alluri
- Department of Surgery, Baylor Scott & White Health/Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Rickesha L. Wilson
- Department of Surgery, Baylor Scott & White Health/Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Chinchusha Anasooya Shaji
- Department of Surgery, Baylor Scott & White Health/Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Katie Wiggins-Dohlvik
- Department of Surgery, Baylor Scott & White Health/Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Savan Patel
- Department of Surgery, Baylor Scott & White Health/Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Yang Liu
- Department of Medical Physiology, Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Xu Peng
- Department of Medical Physiology, Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Madhava R. Beeram
- Department of Pediatrics, Baylor Scott & White Health/Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Matthew L. Davis
- Department of Medical Physiology, Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Jason H. Huang
- Department of Neurosurgery, Baylor Scott & White Health/ Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
| | - Binu Tharakan
- Department of Surgery, Baylor Scott & White Health/Texas A&M University Health Science Center College of Medicine, Temple, Texas, United States of America
- * E-mail:
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58
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Tu TW, Williams RA, Lescher JD, Jikaria N, Turtzo LC, Frank JA. Radiological-pathological correlation of diffusion tensor and magnetization transfer imaging in a closed head traumatic brain injury model. Ann Neurol 2016; 79:907-20. [PMID: 27230970 DOI: 10.1002/ana.24641] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/13/2016] [Accepted: 03/14/2016] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Metrics of diffusion tensor imaging (DTI) and magnetization transfer imaging (MTI) can detect diffuse axonal injury in traumatic brain injury (TBI). The relationship between the changes in these imaging measures and the underlying pathologies is still relatively unknown. This study investigated the radiological-pathological correlation between these imaging techniques and immunohistochemistry using a closed head rat model of TBI. METHODS TBI was performed on female rats followed longitudinally by magnetic resonance imaging (MRI) out to 30 days postinjury, with a subset of animals selected for histopathological analyses. A MRI-based finite element analysis was generated to characterize the pattern of the mechanical insult and estimate the extent of brain injury to direct the pathological correlation with imaging findings. RESULTS DTI axial diffusivity and fractional anisotropy (FA) were sensitive to axonal integrity, whereas radial diffusivity showed significant correlation to the myelin compactness. FA was correlated with astrogliosis in the gray matter, whereas mean diffusivity was correlated with increased cellularity. Secondary inflammatory responses also partly affected the changes of these DTI metrics. The magnetization transfer ratio (MTR) at 3.5ppm demonstrated a strong correlation with both axon and myelin integrity. Decrease in MTR at 20ppm correlated with the extent of astrogliosis in both gray and white matter. INTERPRETATION Although conventional T2-weighted MRI did not detect abnormalities following TBI, DTI and MTI afforded complementary insight into the underlying pathologies reflecting varying injury states over time, and thus may substitute for histology to reveal diffusive axonal injury pathologies in vivo. This correlation of MRI and histology furthers understanding of the microscopic pathology underlying DTI and MTI changes in TBI. Ann Neurol 2016;79:907-920.
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Affiliation(s)
- Tsang-Wei Tu
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Rashida A Williams
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Jacob D Lescher
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD
| | - Neekita Jikaria
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD
| | - L Christine Turtzo
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD.,Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD
| | - Joseph A Frank
- Frank Laboratory, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD.,National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD
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59
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Smith CJ, Xiong G, Elkind JA, Putnam B, Cohen AS. Brain Injury Impairs Working Memory and Prefrontal Circuit Function. Front Neurol 2015; 6:240. [PMID: 26617569 PMCID: PMC4643141 DOI: 10.3389/fneur.2015.00240] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 10/30/2015] [Indexed: 12/13/2022] Open
Abstract
More than 2.5 million Americans suffer a traumatic brain injury (TBI) each year. Even mild to moderate TBI causes long-lasting neurological effects. Despite its prevalence, no therapy currently exists to treat the underlying cause of cognitive impairment suffered by TBI patients. Following lateral fluid percussion injury (LFPI), the most widely used experimental model of TBI, we investigated alterations in working memory and excitatory/inhibitory synaptic balance in the prefrontal cortex. LFPI impaired working memory as assessed with a T-maze behavioral task. Field excitatory postsynaptic potentials recorded in the prefrontal cortex were reduced in slices derived from brain-injured mice. Spontaneous and miniature excitatory postsynaptic currents onto layer 2/3 neurons were more frequent in slices derived from LFPI mice, while inhibitory currents onto layer 2/3 neurons were smaller after LFPI. Additionally, an increase in action potential threshold and concomitant decrease in firing rate was observed in layer 2/3 neurons in slices from injured animals. Conversely, no differences in excitatory or inhibitory synaptic transmission onto layer 5 neurons were observed; however, layer 5 neurons demonstrated a decrease in input resistance and action potential duration after LFPI. These results demonstrate synaptic and intrinsic alterations in prefrontal circuitry that may underlie working memory impairment caused by TBI.
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Affiliation(s)
- Colin J. Smith
- Research Institute of Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Neuroscience Graduate Group, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Guoxiang Xiong
- Research Institute of Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jaclynn A. Elkind
- Research Institute of Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Brendan Putnam
- Research Institute of Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Akiva S. Cohen
- Research Institute of Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Anesthesiology and Critical Care Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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60
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Tschiffely A, Ahlers S, Norris J. Examining the relationship between blast-induced mild traumatic brain injury and posttraumatic stress-related traits. J Neurosci Res 2015; 93:1769-77. [DOI: 10.1002/jnr.23641] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 08/12/2015] [Accepted: 08/12/2015] [Indexed: 01/04/2023]
Affiliation(s)
- A.E. Tschiffely
- Department of Neurotrauma; Operational and Undersea Medicine Directorate, Naval Medical Research Center; Silver Spring Maryland
- Henry M. Jackson Foundation; Bethesda Maryland
| | - S.T. Ahlers
- Department of Neurotrauma; Operational and Undersea Medicine Directorate, Naval Medical Research Center; Silver Spring Maryland
| | - J.N. Norris
- Department of Neurotrauma; Operational and Undersea Medicine Directorate, Naval Medical Research Center; Silver Spring Maryland
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