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Beitchman JA, Lifshitz J, Harris NG, Thomas TC, Lafrenaye AD, Hånell A, Dixon CE, Povlishock JT, Rowe RK. Spatial Distribution of Neuropathology and Neuroinflammation Elucidate the Biomechanics of Fluid Percussion Injury. Neurotrauma Rep 2021; 2:59-75. [PMID: 34223546 PMCID: PMC8240834 DOI: 10.1089/neur.2020.0046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Diffuse brain injury is better described as multi-focal, where pathology can be found adjacent to seemingly uninjured neural tissue. In experimental diffuse brain injury, pathology and pathophysiology have been reported far more lateral than predicted by the impact site. We hypothesized that local thickening of the rodent skull at the temporal ridges serves to focus the intracranial mechanical forces experienced during brain injury and generate predictable pathology. We demonstrated local thickening of the skull at the temporal ridges using contour analysis on magnetic resonance imaging. After diffuse brain injury induced by midline fluid percussion injury (mFPI), pathological foci along the anterior-posterior length of cortex under the temporal ridges were evident acutely (1, 2, and 7 days) and chronically (28 days) post-injury by deposition of argyophilic reaction product. Area CA3 of the hippocampus and lateral nuclei of the thalamus showed pathological change, suggesting that mechanical forces to or from the temporal ridges shear subcortical regions. A proposed model of mFPI biomechanics suggests that injury force vectors reflect off the skull base and radiate toward the temporal ridge, thereby injuring ventral thalamus, dorsolateral hippocampus, and sensorimotor cortex. Surgically thinning the temporal ridge before injury reduced injury-induced inflammation in the sensorimotor cortex. These data build evidence for temporal ridges of the rodent skull to contribute to the observed pathology, whether by focusing extracranial forces to enter the cranium or intracranial forces to escape the cranium. Pre-clinical investigations can take advantage of the predicted pathology to explore injury mechanisms and treatment efficacy.
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Affiliation(s)
- Joshua A Beitchman
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA.,Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona, USA.,Midwestern University, Glendale, Arizona, USA
| | - Jonathan Lifshitz
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA.,Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona, USA.,Arizona State University, Tempe, Arizona, USA.,Phoenix VA Health Care System, Phoenix, Arizona, USA
| | - Neil G Harris
- UCLA Brain Injury Research Center, Department of Neurosurgery, and Intellectual Development and Disabilities Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, USA
| | - Theresa Currier Thomas
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA.,Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona, USA.,Arizona State University, Tempe, Arizona, USA.,Phoenix VA Health Care System, Phoenix, Arizona, USA
| | | | - Anders Hånell
- Virginia Commonwealth University, Richmond, Virginia, USA.,Uppsala University Hospital, Uppsala, Sweden
| | | | | | - Rachel K Rowe
- BARROW Neurological Institute at Phoenix Children's Hospital, Phoenix, Arizona, USA.,Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona, USA.,Phoenix VA Health Care System, Phoenix, Arizona, USA
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Otani N, Nawashiro H, Nagatani K, Takeuchi S, Kobayashi H, Shima K. Mitogen-Activated Protein Kinase Pathways Following Traumatic Brain Injury. ACTA ACUST UNITED AC 2011. [DOI: 10.4236/nm.2011.23028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Mao H, Jin X, Zhang L, Yang KH, Igarashi T, Noble-Haeusslein LJ, King AI. Finite element analysis of controlled cortical impact-induced cell loss. J Neurotrauma 2010; 27:877-88. [PMID: 20199194 DOI: 10.1089/neu.2008.0616] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The controlled cortical impact (CCI) model has been extensively used to study region-specific patterns of neuronal injury and cell death after a focal traumatic brain injury. Although external parameters such as impact velocity and depth of penetration have been defined in this injury model, little is known about the intracranial mechanical responses within cortical and subcortical brain regions where neuronal loss is prevalent. At present, one of the best methods to determine the internal responses of the brain is finite element (FE) modeling. A previously developed and biomechanically validated detailed three-dimensional FE rat brain model, consisting of 255,700 hexahedral elements and representing all essential anatomical features of a rat brain, was used to study intracranial responses in a series of CCI experiments in which injury severity ranged from mild to severe. A linear relationship was found between the percentage of the neuronal loss observed in vivo and the FE model-predicted maximum principal strain (R(2) = 0.602). Interestingly, the FE model also predicted some risk of injury in the cerebellum, located remote from the point of impact, with a 25% neuronal loss for the "severe" impact condition. More research is needed to examine other regions that do not have histological data for comparison with FE model predictions before this injury mechanism and the associated injury threshold can be fully established.
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Affiliation(s)
- Haojie Mao
- Bioengineering Center, Wayne State University, Detroit, Michigan 48201, USA
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Gasparovic C, Yeo R, Mannell M, Ling J, Elgie R, Phillips J, Doezema D, Mayer AR. Neurometabolite concentrations in gray and white matter in mild traumatic brain injury: an 1H-magnetic resonance spectroscopy study. J Neurotrauma 2010; 26:1635-43. [PMID: 19355814 DOI: 10.1089/neu.2009.0896] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Single-voxel proton magnetic resonance imaging ((1)H-MRS) and proton MR spectroscopic imaging ((1)H-MRSI) were used to compare brain metabolite levels in semi-acute mild traumatic brain injury (mTBI) patients (n = 10) and matched healthy controls (n = 9). The (1)H-MRS voxel was positioned in the splenium, a region known to be susceptible to axonal injury in TBI, and a single (1)H-MRSI slice was positioned above the lateral ventricles. To increase sensitivity to the glutamate (Glu) and the combined glutamate-glutamine (Glx) signal, an inter-pulse echo time shown to emphasize the major Glu signals was used along with an analysis method that reduces partial volume errors by using water as a concentration standard. Our preliminary findings indicate significantly lower levels of gray matter Glx and higher levels of white matter creatine-phosphocreatine (Cr) in mTBI subjects relative to healthy controls. Furthermore, Cr levels were predictive of executive function and emotional distress in the combined groups. These results suggest that perturbations in Cr, a critical component of the brain's energy metabolism, and Glu, the brain's major neurotransmitter, may occur following mTBI. Moreover, the different pattern of results for gray and white matter suggests tissue-specific metabolic responses to mTBI.
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Otani N, Nawashiro H, Fukui S, Ooigawa H, Ohsumi A, Toyooka T, Shima K. Role of the activated extracellular signal-regulated kinase pathway on histological and behavioral outcome after traumatic brain injury in rats. J Clin Neurosci 2007; 14:42-8. [PMID: 17138068 DOI: 10.1016/j.jocn.2005.11.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Accepted: 11/14/2005] [Indexed: 11/19/2022]
Abstract
The extracellular signal-regulated kinase (ERK) pathway, which modulates the activity of many transcriptional factors leading to the proliferation of various cells, is activated in lesions in regions of selective vulnerability after traumatic brain injury (TBI). In the present study, using the ERK inhibitor U0126, we investigated the role of the ERK pathway in histopathological and behavioral outcomes after TBI. Adult male Sprague-Dawley rats, weighing 300-400 g were subjected to lateral fluid percussion brain injury. The ERK inhibitor U0126 was injected intravenously before injury at 100, 200 and 400 microg/kg. The severity of CA3 neuronal damage was evaluated by the number of surviving CA3 neurons 7 days after injury. The contusional lesion volume 72 h after injury was analysed using a computer-assisted analysis system. Three different motor skill tasks were measured on days 1-5, 7, 14 and 21 after injury. Pretreatment with U0126 significantly reduced both CA3 neuronal damage and contusional lesion volume after injury. In addition, administration of U0126 ameliorated motor function recovery on days 3, 4 and 5 after injury. Therefore, inhibition of ERK phosphorylation could be a potentially effective therapeutic target after TBI.
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Affiliation(s)
- Naoki Otani
- Department of Neurosurgery, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Abstract
Interleukin-1 (IL-1) has many roles in the brain in addition to mediating inflammatory processes in the glia, and has also been implicated in neurodegenerative disease. Traumatic brain injury (TBI) is one of the most prevalent causes of morbidity and mortality in young persons. We conducted a study to assess the effect of IL-1 on the TBI-induced death of hippocampal neurons. After TBI was induced in adult male Sprague-Dawley rats under anesthesia, we evaluated neuronal damage score through microscopic examination and Pulsinelli's grading system. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to measure the levels of IL-1alpha and IL- 1beta in brain tissue at different points after the induction of TBI. Over a 4-day period, the specific sites of release of IL-1alpha and IL-1beta in the brain were elucidated by immunocytochemistry with double- labeling. TBI to the hippocampus was followed by disruption of the blood-brain barrier and severe neuronal loss. Levels of IL-1alpha RNA and protein were significantly elevated at 3 h after TBI, peaked at 12 h, and remained elevated for 168 h. IL-1beta RNA and protein expression were also elevated at 3 h after TBI, but remained so only for 48 h. Our findings indicate that the observed TBI-induced increases in IL-1alpha and IL-1beta occur largely through release of these cytokines from neurons and astrocytes, respectively. Intraventricular administration of antibodies to IL-1alpha and IL-1beta before TBI significantly attenuated the TBI-induced loss of hippocampal neurons. These results show that IL-1alpha and IL-1beta play important roles in the TBI-induced loss of hippocampal neurons.
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Affiliation(s)
- Kwok-Tung Lu
- Department of Life Science, National Taiwan Normal University, Taipei, Taiwan
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Thompson HJ, Lifshitz J, Marklund N, Grady MS, Graham DI, Hovda DA, McIntosh TK. Lateral fluid percussion brain injury: a 15-year review and evaluation. J Neurotrauma 2005; 22:42-75. [PMID: 15665602 DOI: 10.1089/neu.2005.22.42] [Citation(s) in RCA: 338] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
This article comprehensively reviews the lateral fluid percussion (LFP) model of traumatic brain injury (TBI) in small animal species with particular emphasis on its validity, clinical relevance and reliability. The LFP model, initially described in 1989, has become the most extensively utilized animal model of TBI (to date, 232 PubMed citations), producing both focal and diffuse (mixed) brain injury. Despite subtle variations in injury parameters between laboratories, universal findings are evident across studies, including histological, physiological, metabolic, and behavioral changes that serve to increase the reliability of the model. Moreover, demonstrable histological damage and severity-dependent behavioral deficits, which partially recover over time, validate LFP as a clinically-relevant model of human TBI. The LFP model, also has been used extensively to evaluate potential therapeutic interventions, including resuscitation, pharmacologic therapies, transplantation, and other neuroprotective and neuroregenerative strategies. Although a number of positive studies have identified promising therapies for moderate TBI, the predictive validity of the model may be compromised when findings are translated to severely injured patients. Recently, the clinical relevance of LFP has been enhanced by combining the injury with secondary insults, as well as broadening studies to incorporate issues of gender and age to better approximate the range of human TBI within study design. We conclude that the LFP brain injury model is an appropriate tool to study the cellular and mechanistic aspects of human TBI that cannot be addressed in the clinical setting, as well as for the development and characterization of novel therapeutic interventions. Continued translation of pre-clinical findings to human TBI will enhance the predictive validity of the LFP model, and allow novel neuroprotective and neuroregenerative treatment strategies developed in the laboratory to reach the appropriate TBI patients.
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Affiliation(s)
- Hilaire J Thompson
- Traumatic Brain Injury Laboratory, Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Ashwal S, Holshouser B, Tong K, Serna T, Osterdock R, Gross M, Kido D. Proton MR spectroscopy detected glutamate/glutamine is increased in children with traumatic brain injury. J Neurotrauma 2005; 21:1539-52. [PMID: 15684647 DOI: 10.1089/neu.2004.21.1539] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Adults with traumatic brain injury (TBI) have been shown by invasive methods to have increased levels of the excitatory neurotransmitter glutamate. It is unclear whether glutamate release contributes to primary or secondary injury and whether its protracted elevation is predictive of a poor outcome. Preliminary studies at our institution in adults found that early increases in magnetic resonance spectroscopy (MRS)-detected glutamate/glutamine (Glx) were associated with poor outcomes. We therefore studied 38 children (mean age, 11 years; range, 1.6-17 years) who had TBI with quantitative short-echo time (STEAM, TE = 20 msec) proton MRS, a mean of 7 +/- 4 (range, 1-17) days after injury in order to determine if their occipital or parietal Glx levels correlated with the severity of injury or outcome. Occipital Glx was significantly increased in children with TBI compared to controls (13.5 +/- 2.4 vs. 10.7 +/- 1.8; p = 0.002), but there was no difference between children with good compared to poor outcomes as determined by the Pediatric Cerebral Performance Category Scale score at 6-12 months after injury. We also did not find a correlation between the amount of Glx and the initial Glasgow Coma Scale score, duration of coma, nor with changes in spectral metabolites, including N-acetyl aspartate, choline, and myoinositol. In part, this may have occurred because, in this study, most patients with poor outcomes were studied later than patients with good outcomes, potentially beyond the time frame for peak elevation of Glx after injury. Additional early and late studies of patients with varying degrees of injury are required to assess the importance to the pathophysiology of TBI of this excitatory neurotransmitter.
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Affiliation(s)
- S Ashwal
- Department of Pediatrics, Loma Linda University School of Medicine, Loma Linda, California 92350, USA.
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10
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Hallam TM, Floyd CL, Folkerts MM, Lee LL, Gong QZ, Lyeth BG, Muizelaar JP, Berman RF. Comparison of behavioral deficits and acute neuronal degeneration in rat lateral fluid percussion and weight-drop brain injury models. J Neurotrauma 2004; 21:521-39. [PMID: 15165361 DOI: 10.1089/089771504774129865] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The behavioral and histological effects of the lateral fluid percussion (LFP) brain injury model were compared with the weight drop impact-acceleration model with 10 min of secondary hypoxia (WDIA + H). LFP injury resulted in significant motor deficits on the beam walk and inclined plane, and memory deficits on the radial arm maze and Morris water maze. Motor deficits following LFP remained throughout 6 weeks of behavioral testing. WDIA + H injury produced significant motor deficits on the beam walk and inclined plane immediately following injury, but these effects were transient and recovered by 14 days post-injury. In contrast to the LFP injury, the WDIA + H injured animals showed no memory deficits on the radial arm maze and Morris water maze. In order to determine if the differences in behavioral outcome between models were due to differences in injury mechanism or injury severity, 10 LFP-injured animals were matched with 10 WDIA-injured animals based on injury severity (i.e., time to regain righting reflex after brain injury). The LFP-matched injury group showed greater impairment than the WDIA + H matched injury group on the radial arm maze and Morris water maze. Histological examination of LFP-injured brains with Fluoro-Jade staining 24 h, 48 h, and 7 days post-injury revealed degenerating neurons in the cortex, thalamus, hippocampus, caudate-putamen, brainstem, and cerebellum, with degenerating fibers tracts in the corpus callosum and other major tracts throughout the brain. Fluoro-Jade staining following WDIA+H injury revealed damage to fibers in the optic tract, lateral olfactory tract, corpus callosum, anterior commissure, caudate-putamen, brain stem, and cerebellum. While both models produce reliable and characteristic behavioral and neuronal pathologies, their differences are important to consider when choosing a brain injury model.
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Affiliation(s)
- Thomas M Hallam
- Department of Neurological Surgery, University of California Davis, Davis, California 95616, USA
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Arundine M, Chopra GK, Wrong A, Lei S, Aarts MM, MacDonald JF, Tymianski M. Enhanced vulnerability to NMDA toxicity in sublethal traumatic neuronal injury in vitro. J Neurotrauma 2004; 20:1377-95. [PMID: 14748985 DOI: 10.1089/089771503322686166] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Traumatic brain injury causes neuronal disruption and triggers secondary events leading to additional neuronal death. To study injuries triggered by secondary events, we exposed cultured cortical neurons to sublethal mechanical stretch, thus eliminating confounding death from primary trauma. Sublethally stretched neurons maintained cell membrane integrity, viability, and electrophysiological function. However, stretching induced in the cells a heightened vulnerability to subsequent challenges with L-glutamate or NMDA. This heightened vulnerability was specifically mediated by NMDA receptors (NMDARs), as stretched neurons did not become more vulnerable to either kainate toxicity or to that induced by the Ca(2+) ionophore A23187. Stretch-enhanced vulnerability to NMDA occurred independently of endogenous glutamate release, but required Ca(2+) and Na(+) influx through NMDARs. Stretch did not affect the electrophysiological properties of NMDARs nor excitatory synaptic activity, indicating that specificity of enhanced vulnerability to NMDA involves postsynaptic mechanisms downstream from NMDARs. To test whether this specificity requires physical interactions between NMDARs and cytoskeletal elements, we perturbed actin filaments and microtubules, both of which are linked to NMDARs. This had no effect on the stretch-induced vulnerability to NMDA, suggesting that sublethal stretch does not affect cell survival through the cytoskeleton. Our data illustrate that sublethal in vitro stretch injury triggers distinct signaling pathways that lead to secondary injury, rather than causing a generalized increase in vulnerability to secondary insults.
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Affiliation(s)
- Mark Arundine
- Toronto Western Hospital Research Institute, Toronto, Ontario, Canada
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Yi JH, Pow DV, Hazell AS. Early loss of the glutamate transporter splice-variant GLT-1v in rat cerebral cortex following lateral fluid-percussion injury. Glia 2004; 49:121-33. [PMID: 15390098 DOI: 10.1002/glia.20099] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Glutamate transporter proteins are essential for the control of interstitial glutamate levels, with an impairment of their function or levels being a major potential contributor to excitotoxicity. We have investigated the effects of lateral fluid percussion on the levels of the glutamate transporter proteins GLT-1alpha, its splice variant GLT-1v, GLAST, and EAAC1 in the rat in order to evaluate their pathogenetic role in this model of traumatic brain injury (TBI). Immunoblot analysis revealed neuronal loss in the cerebral cortex was accompanied by a 54% decrease in GLT-1v 6 h following the insult which progressed to an 83% loss of the transporter after 24 h. No changes in GLT-1alpha, GLAST, or EAAC1 were observed in this brain region at either time point. GLT-1v content was also decreased by 55% and 68% in the hippocampus and thalamus, respectively, at 6 h post-injury, but recovered fully after 24 h in both brain regions. In contrast, levels of GLT-1alpha were increased in the hippocampus at 6 h and 24 h post-TBI. These alterations in transporter protein content were also confirmed using immunohistochemical methods. Our results show for the first time a pattern of early, dynamic changes in the levels of GLT-1 transporter splice variants in different brain regions in this trauma model. In addition, correlation of GLT-1v levels with both neuronal cell loss and alpha-internexin content in the injured cortex suggests that loss of this novel glutamate transporter may be a key factor in determining cerebral vulnerability following this type of brain injury.
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Affiliation(s)
- Jae-Hyuk Yi
- Department of Medicine, Hôpital Saint-Luc, University of Montreal, Montreal, Quebec, Canada
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Zanier ER, Lee SM, Vespa PM, Giza CC, Hovda DA. Increased hippocampal CA3 vulnerability to low-level kainic acid following lateral fluid percussion injury. J Neurotrauma 2003; 20:409-20. [PMID: 12803974 DOI: 10.1089/089771503765355496] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This study was designed to determine whether a secondary increase in neuronal activity induced by a low dose of kainic acid (KA), a glutamate analogue, exacerbates the anatomical damage in hippocampal regions following a mild lateral fluid percussion (LFP) brain injury. KA (9 mg/kg) was injected intraperitoneally in LFP-injured rats (n = 16) 1 h post-trauma. The neuronal loss in the CA3, CA4, and hilar regions at 7 days was quantified by two-dimensional cell counts. Hippocampal activation 15 min following KA injection was assessed by measuring local glucose metabolic rates (lCMR(glc)). Following LFP + KA, the ipsilateral side exhibited a 62.7%, 75.7%, and 52.1% decrease in the number of CA3, CA4 and hilar neurons, respectively, compared to naive rats (n = 3). These CA3 and CA4 neuronal counts were also significantly decreased compared to LFP + saline (n = 5) and sham + KA (n = 9) groups. The median Racine Score, used to rate the severity of behavioral seizures, was 4 in LFP + KA and 2 in sham + KA groups (p < 0.015), suggesting a reduction in seizure threshold following injury. lCMRglc in CA3 following LFP + KA was 121.8 +/- 2.0 (mean +/- SE) ipsilaterally and 71.5 +/- 5.4 contralaterally (p < 0.0012). No changes were found in the BBB permeability as measured by [(14)C]aminoisobutyric acid in CA3, CA4, and hilar regions. We conclude that the presence of low-level KA 1 h after LFP dramatically increases the extent of hippocampal activation and induces a striking loss of ipsilateral CA3 and CA4 pyramidal neurons. Neuronal excitation during a time of cellular vulnerability may trigger or amplify the cycle of secondary damage in functionally impaired, but potentially viable, tissue.
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Affiliation(s)
- Elisa Roncati Zanier
- Brain Injury Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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14
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Otani N, Nawashiro H, Fukui S, Nomura N, Shima K. Temporal and spatial profile of phosphorylated mitogen-activated protein kinase pathways after lateral fluid percussion injury in the cortex of the rat brain. J Neurotrauma 2002; 19:1587-96. [PMID: 12542859 DOI: 10.1089/089771502762300247] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mitogen-activated protein kinases (MAPK) play a crucial role in signal transduction that regulates gene expression through transcriptional factor activity. The purpose of this study was to investigate the temporal expression and topographic distribution of the activated MAPK pathways including extracellular signal-regulated protein kinase (ERK), c-Jun NH(2)-terminal kinase (JNK), and p38 MAPK following traumatic brain injury (TBI) in the cortex of the rat brain. Adult male Sprague-Dawley rats (300-400 g) were subjected to lateral fluid percussion injury of moderate severity (3.5-4.0 atm) using the Dragonfly device model (no. HPD-1700). Phosphorylated-MAPK protein levels were quantified using Western blot analysis. Topographic distribution of immunoreactivity for phosphorylated-MAPK was examined using immunohistochemistry. Our findings showed that TBI significantly increased the phosphorylated-ERK (p-ERK) and -JNK (p-JNK) levels, but not the -p38 (p-p38) protein levels in the cortex surrounding the injury site. The immunoreactivity for p-ERK and p-JNK immediately after TBI were localized in neurons. The immunoreactivity for p-JNK was uniformly but only transiently induced and returned to control levels 1 h after TBI. The immunoreactivity for p-ERK was confirmed up until 30 min after TBI in the superficial neuronal layers. Double immunostaining using a glial-specific marker demonstrated that p-ERK was prominent in astrocytes 6 h after TBI. The current results suggest that the ERK and JNK pathways, but not the p38 MAPK pathways are involved in signal transduction in the cortex following TBI.
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Affiliation(s)
- Naoki Otani
- Department of Neurosurgery, National Defense Medical College, Tokorozawa, Japan.
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15
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Lea PM, Faden AI. Traumatic brain injury: developmental differences in glutamate receptor response and the impact on treatment. Ment Retard Dev Disabil Res Rev 2002; 7:235-48. [PMID: 11754517 DOI: 10.1002/mrdd.1033] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Perinatal brain injury following trauma, hypoxia, and/or ischemia represents a substantial cause of pediatric disabilities including mental retardation. Such injuries lead to neuronal cell death through either necrosis or apoptosis. Numerous in vivo and in vitro studies implicate ionotropic (iGluRs) and metabotropic (mGluRs) glutamate receptors in the modulation of such cell death. Expression of glutamate receptors changes as a function of developmental age, with substantial implications for understanding mechanisms of post-injury cell death and its potential treatment. Recent findings suggest that the developing brain is more susceptible to apoptosis after injury and that such caspase mediated cell death may be exacerbated by treatment with N-methyl-D-aspartate receptor antagonists. Moreover, group I metabotropic glutamate receptors appear to have opposite effects on necrotic and apoptotic cell death. Understanding the relative roles of glutamate receptors in post-traumatic or post-ischemic cell death as a function of developmental age may lead to novel targeted approaches to the treatment of pediatric brain injury.
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Affiliation(s)
- P M Lea
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC, USA
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Runnerstam M, Bao F, Huang Y, Shi J, Gutierrez E, Hamberger A, Hansson HA, Viano D, Haglid K. A new model for diffuse brain injury by rotational acceleration: II. Effects on extracellular glutamate, intracranial pressure, and neuronal apoptosis. J Neurotrauma 2001; 18:259-73. [PMID: 11284547 DOI: 10.1089/08977150151070892] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The aim of this study is to monitor excitatory amino acids (EAAs) in the extracellular fluids of the brain and to characterize regional neuronal damage in a new experimental model for brain injury, in which rabbits were exposed to 180-260 krad/s2 rotational head acceleration. This loading causes extensive subarachnoid hemorrhage, focal tissue bleeding, reactive astrocytosis, and axonal damage. Animals were monitored for intracranial pressure (ICP) and for amino acids in the extracellular fluids. Immunohistochemistry was used to study expression of the gene c-Jun and apoptosis with the terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) technique. Extracellular glutamate, glycine, and taurine increased significantly in the hippocampus within a few hours and remained high after 24 h. Neuronal nuclei in the granule layers of the hippocampus and cerebellum were positive for c-Jun after 24 h. Little immunoreactivity was detected in the cerebral cortex. c-Jun-positive neuronal perikarya and processes were found in granule and pyramidal CA4 layers of the hippocampus and among the Purkinje cells of the cerebellum. Also some microglial cells stained positively for c-Jun. TUNEL reactivity was most intense at 10 days after trauma and was extensive in neurons of the cerebral cortex, hippocampus, and cerebellum. The initial response of the brain after rotational head injury involves brain edema after 24 h and an excitotoxic neuronal microenvironment in the first hour, which leads to extensive delayed neuronal cell death by apoptosis necrosis in the cerebral cortex, hippocampus and cerebellum.
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Affiliation(s)
- M Runnerstam
- Department of Neurosurgery, Sahlgrenska University Hospital, Gothenburg, Sweden
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Rao VLR, Dogan A, Bowen KK, Todd KG, Dempsey RJ. Antisense knockdown of the glial glutamate transporter GLT-1 exacerbates hippocampal neuronal damage following traumatic injury to rat brain. Eur J Neurosci 2001. [DOI: 10.1046/j.1460-9568.2001.01367.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Rao VLR, Dogan A, Bowen KK, Todd KG, Dempsey RJ. Antisense knockdown of the glial glutamate transporter GLT-1 exacerbates hippocampal neuronal damage following traumatic injury to rat brain. Eur J Neurosci 2001. [DOI: 10.1111/j.1460-9568.2001.01367.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Asai S, Kohno T, Katayama Y, Iribe Y, Hosoi I, Kanematsu K, Kunimatsu T, Ishikawa K. Oxygen-independent real-time monitoring of distinct biphasic glutamate release using dialysis electrode in rat striatum during anoxia: in vivo evaluation of glutamate release and reversed uptake. J Neurotrauma 2000; 17:1105-14. [PMID: 11101212 DOI: 10.1089/neu.2000.17.1105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Using a dialysis electrode, previous studies showed a clear biphasic release of glutamate during anoxia and ischemia. In this study, we examined two hypotheses: (1) glutamate is of vesicular origin and its release is thus Ca2+- and ATP-dependent in the first phase, while in the second phase glutamate is derived primarily from the metabolic pool, and (2) reversed glutamate uptake, due to electrogenic stoichiometry, produces the second phase during anoxic insult in the rat brain. A dialysis electrode continuously perfused with glutamate oxidase and ferrocene-conjugated bovine serum albumin (BSA) optimized the time resolution of monitoring, allowing quantitative oxygen-independent, real-time measurement of the extracellular glutamate concentration ([Glu]e) during anoxia. [Glu]e dynamics were analyzed during anoxia by combining the dialysis electrode with focal microinjection of substances inducing glutamate release. Following anoxia in the rat brain, a sharp and rapid [Glu]e elevation took place (first phase). The [Glu]e elevation then shifted, continuing a gently sloping rise throughout the anoxic period (second phase). This first phase disappeared with intracranial administration of either Co2+ or omega-conotoxin. The second phase rise increased with focal microinjection of KCl (300 mM, 1 microL) and decreased with NaCl (300 mM, 1 microL), ultimately reaching a plateau in both cases. Preloading with a novel glutamate transporter inhibitor (tPDC) decreased both the first and second phases of [Glu]e elevation. This dialysis electrode system provides data supporting in vivo evidence that the peak of the first phase of [Glu]e elevation is derived from the "neurotransmitter pool," while the second phase is derived from the neuronal and glial "metabolic pool," which is, at least, partly related to a "reversed uptake" mechanism in the anoxic rat brain.
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Affiliation(s)
- S Asai
- Department of Pharmacology, Nihon University School of Medicine, Itabashi, Tokyo, Japan.
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Abstract
It is now commonly accepted that glaucoma is a neurodegenerative disease of the optic nerve. Thus, at any given time, there are neurons that, though still viable, are vulnerable to the hostile extracellular milieu and are therefore amenable to neuroprotective therapy. Neuroprotection refers to any intervention, either external to the optic nerve or internally, that will lead to an intracellular change in the balance between survival and death signals in favor of survival. Several potential sites and modalities for such intervention may exist. When designing neuroprotective therapy, ways must be sought to recruit the physiologic self-repair mechanisms awakened by the primary or secondary risk factors. These mechanisms appear to be insufficiently effective when in their natural state, but they may be simulated or boosted by appropriate therapeutic compounds or cells.
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Affiliation(s)
- M Schwartz
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
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Abstract
A short review of the most widely used and popular experimental models of traumatic brain injury is presented. This review focuses on current animal models of traumatic brain injury that apply mechanical energy to the skull or, after trephination of the skull, to the intact dura. Recent experimental studies evaluating the pathobiology of traumatic brain injury using these models are also discussed. This article attempts to provide a broad overview of current knowledge and controversies in experimental animal research on brain trauma.
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Affiliation(s)
- H L Laurer
- Department of Neurosurgery, School of Medicine, University of Pennsylvania, Philadelphia 19104-6316, USA.
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