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Adam CD, Mirzakhalili E, Gagnon KG, Cottone C, Arena JD, Ulyanova AV, Johnson VE, Wolf JA. Disrupted Hippocampal Theta-Gamma Coupling and Spike-Field Coherence Following Experimental Traumatic Brain Injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596704. [PMID: 39314320 PMCID: PMC11418945 DOI: 10.1101/2024.05.30.596704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Traumatic brain injury (TBI) often results in persistent learning and memory deficits, likely due to disrupted hippocampal circuitry underlying these processes. Precise temporal control of hippocampal neuronal activity is important for memory encoding and retrieval and is supported by oscillations that dynamically organize single unit firing. Using high-density laminar electrophysiology, we discovered a loss of oscillatory power across CA1 lamina, with a profound, layer-specific reduction in theta-gamma phase amplitude coupling in injured rats. Interneurons from injured animals were less strongly entrained to theta and gamma oscillations, suggesting a mechanism for the loss of coupling, while pyramidal cells were entrained to a later phase of theta. During quiet immobility, we report decreased ripple amplitudes from injured animals during sharp-wave ripple events. These results reveal deficits in information encoding and retrieval schemes essential to cognition that likely underlie TBI-associated learning and memory impairments, and elucidate potential targets for future neuromodulation therapies.
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Affiliation(s)
- Christopher D Adam
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Ehsan Mirzakhalili
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Kimberly G Gagnon
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Carlo Cottone
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - John D Arena
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - Alexandra V Ulyanova
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, USA
| | - Victoria E Johnson
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
| | - John A Wolf
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania, Philadelphia, USA
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, USA
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2
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Zhao F, Behnisch T. The Enigmatic CA2: Exploring the Understudied Region of the Hippocampus and Its Involvement in Parkinson's Disease. Biomedicines 2023; 11:1996. [PMID: 37509636 PMCID: PMC10377725 DOI: 10.3390/biomedicines11071996] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disease that affects both motor and non-motor functions. Although motor impairment is a prominent clinical sign of PD, additional neurological symptoms may also occur, particularly in the preclinical and prodromal stages. Among these symptoms, social cognitive impairment is common and detrimental. This article aims to review non-motor symptoms in PD patients, focusing on social cognitive deficits. It also examines the specific characteristics of the CA2 region and its involvement in social behavior, highlighting recent advances and perspectives. Additionally, this review provides critical insights into and analysis of research conducted in rodents and humans, which may help improve the understanding of the current status of putative therapeutic strategies for social cognitive dysfunction in PD and potential avenues related to the function of the hippocampal CA2 region.
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Affiliation(s)
- Fang Zhao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Thomas Behnisch
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
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3
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To XV, Vegh V, Owusu-Amoah N, Cumming P, Nasrallah FA. Hippocampal demyelination is associated with increased magnetic susceptibility in a mouse model of concussion. Exp Neurol 2023; 365:114406. [PMID: 37062352 DOI: 10.1016/j.expneurol.2023.114406] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 04/18/2023]
Abstract
Structural and functional deficits in the hippocampus are a prominent feature of moderate-severe traumatic brain injury (TBI). In this work, we investigated the potential of Quantitative Susceptibility Imaging (QSM) to reveal the temporal changes in myelin integrity in a mouse model of concussion (mild TBI). We employed a cross-sectional design wherein we assigned 43 mice to cohorts undergoing either a concussive impact or a sham procedure, with QSM imaging at day 2, 7, or 14 post-injury, followed by Luxol Fast Blue (LFB) myelin staining to assess the structural integrity of hippocampal white matter (WM). We assessed spatial learning in the mice using the Active Place Avoidance Test (APA), recording their ability to use visual cues to locate and avoid zone-dependent mild electrical shocks. QSM and LFB staining indicated changes in the stratum lacunosum-molecular layer of the hippocampus in the concussion groups, suggesting impairment of this key relay between the entorhinal cortex and the CA1 regions. These imaging and histology findings were consistent with demyelination, namely increased magnetic susceptibility to MR imaging and decreased LFB staining. In the APA test, sham animals showed fewer entries into the shock zone compared to the concussed cohort. Thus, we present radiological, histological, and behavioral findings that concussion can induce significant and alterations in hippocampal integrity and function that evolve over time after the injury.
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Affiliation(s)
- Xuan Vinh To
- The Queensland Brain Institute, The University of Queensland, Australia
| | - Viktor Vegh
- The Centre for Advanced Imaging, The University of Queensland, Australia; The ARC Centre for Innovation in Biomedical Imaging Technology, Brisbane, Australia
| | - Naana Owusu-Amoah
- The Queensland Brain Institute, The University of Queensland, Australia
| | - Paul Cumming
- Department of Nuclear Medicine, Bern University Hospital, Bern, Switzerland; School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia
| | - Fatima A Nasrallah
- The Queensland Brain Institute, The University of Queensland, Australia; The Centre for Advanced Imaging, The University of Queensland, Australia.
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4
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Fiber orientation downsampling compromises the computation of white matter tract-related deformation. J Mech Behav Biomed Mater 2022; 132:105294. [DOI: 10.1016/j.jmbbm.2022.105294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 04/13/2022] [Accepted: 05/21/2022] [Indexed: 11/18/2022]
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5
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Zhou Z, Li X, Domel AG, Dennis EL, Georgiadis M, Liu Y, Raymond SJ, Grant G, Kleiven S, Camarillo D, Zeineh M. The Presence of the Temporal Horn Exacerbates the Vulnerability of Hippocampus During Head Impacts. Front Bioeng Biotechnol 2022; 10:754344. [PMID: 35392406 PMCID: PMC8980591 DOI: 10.3389/fbioe.2022.754344] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Hippocampal injury is common in traumatic brain injury (TBI) patients, but the underlying pathogenesis remains elusive. In this study, we hypothesize that the presence of the adjacent fluid-containing temporal horn exacerbates the biomechanical vulnerability of the hippocampus. Two finite element models of the human head were used to investigate this hypothesis, one with and one without the temporal horn, and both including a detailed hippocampal subfield delineation. A fluid-structure interaction coupling approach was used to simulate the brain-ventricle interface, in which the intraventricular cerebrospinal fluid was represented by an arbitrary Lagrangian-Eulerian multi-material formation to account for its fluid behavior. By comparing the response of these two models under identical loadings, the model that included the temporal horn predicted increased magnitudes of strain and strain rate in the hippocampus with respect to its counterpart without the temporal horn. This specifically affected cornu ammonis (CA) 1 (CA1), CA2/3, hippocampal tail, subiculum, and the adjacent amygdala and ventral diencephalon. These computational results suggest that the presence of the temporal horn exacerbate the vulnerability of the hippocampus, highlighting the mechanobiological dependency of the hippocampus on the temporal horn.
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Affiliation(s)
- Zhou Zhou
- Department of Bioengineering, Stanford University, Stanford, CA, United States
- Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Xiaogai Li
- Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden
| | - August G. Domel
- Department of Bioengineering, Stanford University, Stanford, CA, United States
| | - Emily L. Dennis
- TBI and Concussion Center, Department of Neurology, University of Utah, Salt Lake City, UT, United States
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Marios Georgiadis
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Yuzhe Liu
- Department of Bioengineering, Stanford University, Stanford, CA, United States
| | - Samuel J. Raymond
- Department of Bioengineering, Stanford University, Stanford, CA, United States
| | - Gerald Grant
- Department of Neurosurgery, Stanford University, Stanford, CA, United States
- Department of Neurology, Stanford University, Stanford, CA, United States
| | - Svein Kleiven
- Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden
| | - David Camarillo
- Department of Bioengineering, Stanford University, Stanford, CA, United States
- Department of Neurosurgery, Stanford University, Stanford, CA, United States
- Department of Mechanical Engineering, Stanford University, Stanford, CA, United States
| | - Michael Zeineh
- Department of Radiology, Stanford University, Stanford, CA, United States
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6
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Williams HC, Carlson SW, Saatman KE. A role for insulin-like growth factor-1 in hippocampal plasticity following traumatic brain injury. VITAMINS AND HORMONES 2022; 118:423-455. [PMID: 35180936 DOI: 10.1016/bs.vh.2021.11.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Traumatic brain injury (TBI) initiates a constellation of secondary injury cascades, leading to neuronal damage and dysfunction that is often beyond the scope of endogenous repair mechanisms. Cognitive deficits are among the most persistent morbidities resulting from TBI, necessitating a greater understanding of mechanisms of posttraumatic hippocampal damage and neuroplasticity and identification of therapies that improve recovery by enhancing repair pathways. Focusing here on hippocampal neuropathology associated with contusion-type TBIs, the impact of brain trauma on synaptic structure and function and the process of adult neurogenesis is discussed, reviewing initial patterns of damage as well as evidence for spontaneous recovery. A case is made that insulin-like growth factor-1 (IGF-1), a growth-promoting peptide synthesized in both the brain and the periphery, is well suited to augment neuroplasticity in the injured brain. Essential during brain development, multiple lines of evidence delineate roles in the adult brain for IGF-1 in the maintenance of synapses, regulation of neurotransmission, and modulation of forms of synaptic plasticity such as long-term potentiation. Further, IGF-1 enhances adult hippocampal neurogenesis though effects on proliferation and neuronal differentiation of neural progenitor cells and on dendritic growth of newly born neurons. Post-injury administration of IGF-1 has been effective in rodent models of TBI in improving learning and memory, attenuating death of mature hippocampal neurons and promoting neurogenesis, providing critical proof-of-concept data. More studies are needed to explore the effects of IGF-1-based therapies on synaptogenesis and synaptic plasticity following TBI and to optimize strategies in order to stimulate only appropriate, functional neuroplasticity.
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Affiliation(s)
- Hannah C Williams
- Spinal Cord and Brain Injury Research Center, Department of Physiology, University of Kentucky, Lexington, KY, United States
| | - Shaun W Carlson
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kathryn E Saatman
- Spinal Cord and Brain Injury Research Center, Department of Physiology, University of Kentucky, Lexington, KY, United States.
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7
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Segovia-Oropeza M, Santiago-Castañeda C, Orozco-Suárez SA, Concha L, Rocha L. Sodium Cromoglycate Decreases Sensorimotor Impairment and Hippocampal Alterations Induced by Severe Traumatic Brain Injury in Rats. J Neurotrauma 2020; 37:2595-2603. [PMID: 32484040 DOI: 10.1089/neu.2019.6975] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Severe traumatic brain injury (TBI) results in significant functional disturbances in the hippocampus. Studies support that sodium cromoglycate (CG) induces neuroprotective effects. This study focused on investigating the effects of post-TBI subchronic administration of CG on hippocampal hyperexcitability and damage as well as on sensorimotor impairment in rats. In contrast to the control group (Sham+SS group), animals undergoing severe TBI (TBI+SS group) showed sensorimotor dysfunction over the experimental post-TBI period (day 2, 55%, p < 0.001; day 23, 39.5%, p < 0.001; day 30, 38.6%, p < 0.01). On day 30 post-TBI, TBI+SS group showed neuronal hyperexcitability (63.3%, p < 0.01). The hippocampus ipsilateral to the injury showed volume reduction (14.4%, p < 0.001) with a volume of damage of 0.15 ± 0.09 mm3. These changes were associated with neuronal loss in the dentate gyrus (ipsilateral, 33%, p < 0.05); hilus (ipsilateral, 77%, p < 0.001; contralateral, 51%, p < 0.001); Cornu Ammonis (CA)1 (ipsilateral, 40%, p < 0.01), and CA3 (ipsilateral, 52%, p < 0.001; contralateral, 34%, p < 0.01). Animals receiving subchronic treatment with CG (50 mg/kg, s.c. daily for 10 days) after TBI (TBI+CG group) displayed a sensorimotor dysfunction less evident than that of the TBI+SS group (p < 0.001). Their hippocampal excitability was similar to that of the Sham+SS group (p = 0.21). The TBI+CG group presented hippocampal volume reduction (12.7%, p = 0.94) and damage (0.10 ± 0.03 mm3, p > 0.99) similar to the TBI+SS group. However, their hippocampal neuronal preservation was similar to that of the Sham+SS group. These results indicate that CG represents an appropriate and novel pharmacological strategy to reduce the long-term sensorimotor impairment and hippocampal damage and hyperexcitability that result as consequences of severe TBI.
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Affiliation(s)
| | | | | | - Luis Concha
- Institute of Neurobiology, National Autonomous University of Mexico, Campus Juriquilla, Queretaro, Mexico
| | - Luisa Rocha
- Department of Pharmacobiology, Center of Research and Advanced Studies, Mexico City, Mexico
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8
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Yang Q, Zhou Y, Sun Y, Luo Y, Shen Y, Shao A. Will Sirtuins Be Promising Therapeutic Targets for TBI and Associated Neurodegenerative Diseases? Front Neurosci 2020; 14:791. [PMID: 32848564 PMCID: PMC7411228 DOI: 10.3389/fnins.2020.00791] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/06/2020] [Indexed: 12/17/2022] Open
Abstract
Traumatic brain injury (TBI), a leading cause of morbidity worldwide, induces mechanical, persistent structural, and metabolic abnormalities in neurons and other brain-resident cells. The key pathological features of TBI include neuroinflammation, oxidative stress, excitotoxicity, and mitochondrial dysfunction. These pathological processes persist for a period of time after TBIs. Sirtuins are evolutionarily conserved nicotinamide-adenine dinucleotide (NAD+)-dependent deacetylases and mono-ADP-ribosyl transferases. The mammalian sirtuin family has seven members, referred to as Sirtuin (SIRT) 1-7. Accumulating evidence suggests that SIRT1 and SIRT3 play a neuroprotective role in TBI. Although the evidence is scant, considering the involvement of SIRT2, 4-7 in other brain injury models, they may also intervene in similar pathophysiology in TBI. Neurodegenerative diseases are generally accepted sequelae of TBI. It was found that TBI and neurodegenerative diseases have many similarities and overlaps in pathological features. Besides, sirtuins play some unique roles in some neurodegenerative diseases. Therefore, we propose that sirtuins might be a promising therapeutic target for both TBI and associated neurodegenerative diseases. In this paper, we review the neuroprotective effects of sirtuins on TBI as well as related neurodegeneration and discuss the therapeutic potential of sirtuin modulators.
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Affiliation(s)
- Qianjie Yang
- Department of Ophthalmology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yunxiang Zhou
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yuting Sun
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yi Luo
- The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ye Shen
- Department of Ophthalmology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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9
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The Recovery of GABAergic Function in the Hippocampus CA1 Region After mTBI. Mol Neurobiol 2019; 57:23-31. [DOI: 10.1007/s12035-019-01753-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 08/29/2019] [Indexed: 10/26/2022]
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10
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Kremneva EI, Legostaeva LA, Morozova SN, Sergeev DV, Sinitsyn DO, Iazeva EG, Suslin AS, Suponeva NA, Krotenkova MV, Piradov MA, Maximov II. Feasibility of Non-Gaussian Diffusion Metrics in Chronic Disorders of Consciousness. Brain Sci 2019; 9:brainsci9050123. [PMID: 31137909 PMCID: PMC6562474 DOI: 10.3390/brainsci9050123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/23/2019] [Accepted: 05/23/2019] [Indexed: 01/06/2023] Open
Abstract
Diagnostic accuracy of different chronic disorders of consciousness (DOC) can be affected by the false negative errors in up to 40% cases. In the present study, we aimed to investigate the feasibility of a non-Gaussian diffusion approach in chronic DOC and to estimate a sensitivity of diffusion kurtosis imaging (DKI) metrics for the differentiation of vegetative state/unresponsive wakefulness syndrome (VS/UWS) and minimally conscious state (MCS) from a healthy brain state. We acquired diffusion MRI data from 18 patients in chronic DOC (11 VS/UWS, 7 MCS) and 14 healthy controls. A quantitative comparison of the diffusion metrics for grey (GM) and white (WM) matter between the controls and patient group showed a significant (p < 0.05) difference in supratentorial WM and GM for all evaluated diffusion metrics, as well as for brainstem, corpus callosum, and thalamus. An intra-subject VS/UWS and MCS group comparison showed only kurtosis metrics and fractional anisotropy differences using tract-based spatial statistics, owing mainly to macrostructural differences on most severely lesioned hemispheres. As a result, we demonstrated an ability of DKI metrics to localise and detect changes in both WM and GM and showed their capability in order to distinguish patients with a different level of consciousness.
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Affiliation(s)
- Elena I Kremneva
- Research Center of Neurology, 80 Volokolamskoe shosse, 125367 Moscow, Russia.
| | | | - Sofya N Morozova
- Research Center of Neurology, 80 Volokolamskoe shosse, 125367 Moscow, Russia.
| | - Dmitry V Sergeev
- Research Center of Neurology, 80 Volokolamskoe shosse, 125367 Moscow, Russia.
| | - Dmitry O Sinitsyn
- Research Center of Neurology, 80 Volokolamskoe shosse, 125367 Moscow, Russia.
| | - Elizaveta G Iazeva
- Research Center of Neurology, 80 Volokolamskoe shosse, 125367 Moscow, Russia.
| | - Aleksandr S Suslin
- Research Center of Neurology, 80 Volokolamskoe shosse, 125367 Moscow, Russia.
| | - Natalia A Suponeva
- Research Center of Neurology, 80 Volokolamskoe shosse, 125367 Moscow, Russia.
| | - Marina V Krotenkova
- Research Center of Neurology, 80 Volokolamskoe shosse, 125367 Moscow, Russia.
| | - Michael A Piradov
- Research Center of Neurology, 80 Volokolamskoe shosse, 125367 Moscow, Russia.
| | - Ivan I Maximov
- Department of Psychology, University of Oslo, Forskningsveien 3A, 0373 Oslo, Norway.
- Norwegian Centre for Mental Disorders Research (NORMENT), Norway and Institute of Clinical Medicine, University of Oslo, Oslo Universitetssykehus Bygg 48 Ullevål, 0317 Oslo, Norway.
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11
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Sudhakar SK, Choi TJ, Ahmed OJ. Biophysical Modeling Suggests Optimal Drug Combinations for Improving the Efficacy of GABA Agonists after Traumatic Brain Injuries. J Neurotrauma 2019; 36:1632-1645. [PMID: 30484362 PMCID: PMC6531909 DOI: 10.1089/neu.2018.6065] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Traumatic brain injuries (TBI) lead to dramatic changes in the surviving brain tissue. Altered ion concentrations, coupled with changes in the expression of membrane-spanning proteins, create a post-TBI brain state that can lead to further neuronal loss caused by secondary excitotoxicity. Several GABA receptor agonists have been tested in the search for neuroprotection immediately after an injury, with paradoxical results. These drugs not only fail to offer neuroprotection, but can also slow down functional recovery after TBI. Here, using computational modeling, we provide a biophysical hypothesis to explain these observations. We show that the accumulation of intracellular chloride ions caused by a transient upregulation of Na+-K+-2Cl- (NKCC1) co-transporters as observed following TBI, causes GABA receptor agonists to lead to excitation and depolarization block, rather than the expected hyperpolarization. The likelihood of prolonged, excitotoxic depolarization block is further exacerbated by the extremely high levels of extracellular potassium seen after TBI. Our modeling results predict that the neuroprotective efficacy of GABA receptor agonists can be substantially enhanced when they are combined with NKCC1 co-transporter inhibitors. This suggests a rational, biophysically principled method for identifying drug combinations for neuroprotection after TBI.
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Affiliation(s)
| | - Thomas J. Choi
- Department of Psychology, University of Michigan, Ann Arbor, Michigan
| | - Omar J. Ahmed
- Department of Psychology, University of Michigan, Ann Arbor, Michigan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
- Department of Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan
- Department of Kresge Hearing Research Institute, University of Michigan, Ann Arbor, Michigan
- Department of Michigan Center for Integrative Research in Critical Care, University of Michigan, Ann Arbor, Michigan
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12
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Gerber KJ, Dammer EB, Duong DM, Deng Q, Dudek SM, Seyfried NT, Hepler JR. Specific Proteomes of Hippocampal Regions CA2 and CA1 Reveal Proteins Linked to the Unique Physiology of Area CA2. J Proteome Res 2019; 18:2571-2584. [PMID: 31059263 DOI: 10.1021/acs.jproteome.9b00103] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The hippocampus is well established as an essential brain center for learning and memory. Within the hippocampus, recent studies show that area CA2 is important for social memory and is an anomaly compared to its better-understood neighboring region, CA1. Unlike CA1, CA2 displays a lack of typical synaptic plasticity, enhanced calcium buffering and extrusion, and resilience to cell death following injury. Although recent studies have identified multiple molecular markers of area CA2, the proteins that mediate the unique physiology, signaling, and resilience of this region are unknown. Using a transgenic GFP-reporter mouse line that expresses eGFP in CA2, we were able to perform targeted dissections of area CA2 and CA1 for proteomic analysis. We identified over 100 proteins with robustly enriched expression in area CA2 compared to CA1. Many of these proteins, including RGS14 and NECAB2, have already been shown to be enriched in CA2 and important for its function, while many more merit further study in the context of enhanced expression in this enigmatic brain region. Furthermore, we performed a comprehensive analysis of the entire data set (>2300 proteins) using a weighted protein co-expression network analysis. This identified eight distinct co-expressed patterns of protein co-enrichment associated with increased expression in area CA2 tissue (compared to CA1). The novel data set we present here reveals a specific CA2 hippocampal proteome, laying the groundwork for future studies and a deeper understanding of area CA2 and the proteins mediating its unique physiology and signaling.
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Affiliation(s)
- Kyle J Gerber
- Department of Pharmacology and Chemical Biology, Rollins Research Center , Emory University School of Medicine , Atlanta , Georgia 30322 , United States
| | - Eric B Dammer
- Department of Biochemistry , Emory University School of Medicine , Atlanta , Georgia 30322 , United States.,Center for Neurodegenerative Disease , Emory University , Atlanta , Georgia 30322 , United States
| | - Duc M Duong
- Department of Biochemistry , Emory University School of Medicine , Atlanta , Georgia 30322 , United States.,Center for Neurodegenerative Disease , Emory University , Atlanta , Georgia 30322 , United States
| | - Qiudong Deng
- Department of Biochemistry , Emory University School of Medicine , Atlanta , Georgia 30322 , United States.,Center for Neurodegenerative Disease , Emory University , Atlanta , Georgia 30322 , United States
| | - Serena M Dudek
- Neurobiology Laboratory, National Institute of Environmental Health Sciences , National Institutes of Health , Research Triangle Park , North Carolina 27709 , United States
| | - Nicholas T Seyfried
- Department of Biochemistry , Emory University School of Medicine , Atlanta , Georgia 30322 , United States.,Center for Neurodegenerative Disease , Emory University , Atlanta , Georgia 30322 , United States.,Department of Neurology , Emory University School of Medicine , Atlanta , Georgia 30322 , United States
| | - John R Hepler
- Department of Pharmacology and Chemical Biology, Rollins Research Center , Emory University School of Medicine , Atlanta , Georgia 30322 , United States
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13
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Zamani A, Mychasiuk R, Semple BD. Determinants of social behavior deficits and recovery after pediatric traumatic brain injury. Exp Neurol 2019; 314:34-45. [PMID: 30653969 DOI: 10.1016/j.expneurol.2019.01.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/29/2018] [Accepted: 01/12/2019] [Indexed: 12/15/2022]
Abstract
Traumatic brain injury (TBI) during early childhood is associated with a particularly high risk of developing social behavior impairments, including deficits in social cognition that manifest as reduced social interactions, with profound consequences for the individuals' quality of life. A number of pre-injury, post-injury, and injury-related factors have been identified or hypothesized to determine the extent of social behavior problems after childhood TBI. These include variables associated with the individual themselves (e.g. age, genetics, the injury severity, and extent of white matter damage), proximal environmental factors (e.g. family functioning, parental mental health), and more distal environmental factors (e.g. socioeconomic status, access to resources). In this review, we synthesize the available evidence demonstrating which of these determinants influence risk versus resilience to social behavior deficits after pediatric TBI, drawing upon the available clinical and preclinical literature. Injury-related pathology in neuroanatomical regions associated with social cognition and behaviors will also be described, with a focus on findings from magnetic resonance imaging and diffusion tensor imaging. Finally, study limitations and suggested future directions are highlighted. In summary, while no single variable can alone accurately predict the manifestation of social behavior problems after TBI during early childhood, an increased understanding of how both injury and environmental factors can influence social outcomes provides a useful framework for the development of more effective rehabilitation strategies aiming to optimize recovery for young brain-injured patients.
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Affiliation(s)
- Akram Zamani
- Department of Neuroscience, Monash University, Prahran, VIC, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Monash University, Prahran, VIC, Australia; Department of Psychology, University of Calgary, Calgary, AB, Canada
| | - Bridgette D Semple
- Department of Neuroscience, Monash University, Prahran, VIC, Australia; Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, VIC, Australia.
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Pang CCC, Kiecker C, O'Brien JT, Noble W, Chang RCC. Ammon's Horn 2 (CA2) of the Hippocampus: A Long-Known Region with a New Potential Role in Neurodegeneration. Neuroscientist 2018; 25:167-180. [PMID: 29865938 DOI: 10.1177/1073858418778747] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The hippocampus has a critical role in cognition and human memory and is one of the most studied structures in the brain. Despite more than 400 years of research, little is known about the Ammon's horn region cornu ammonis 2 (CA2) subfield in comparison to other subfield regions (CA1, CA3, and CA4). Recent findings have shown that CA2 plays a bigger role than previously thought. Here, we review understanding of hippocampus and CA2 ontogenesis, together with basic and clinical findings about the potential role of this region in neurodegenerative disease. The CA2 has widespread anatomical connectivity, unique signaling molecules, and intrinsic electrophysiological properties. Experimental studies using in vivo models found that the CA2 region has a role in cognition, especially in social memory and object recognition. In models of epilepsy and hypoxia, the CA2 exhibits higher resilience to cell death and hypoxia in comparison with neighboring regions, and while hippocampal atrophy remains poorly understood in Parkinson's disease (PD) and dementia with Lewy bodies (DLB), findings from postmortem PD brain demonstrates clear accumulation of α-synuclein pathology in CA2, and the CA2-CA3 region shows relatively more atrophy compared with other hippocampal subfields. Taken together, there is a growing body of evidence suggesting that the CA2 can be an ideal hallmark with which to differentiate different neurodegenerative stages of PD. Here, we summarize these recent data and provide new perspectives/ideas for future investigations to unravel the contribution of the CA2 to neurodegenerative diseases.
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Affiliation(s)
- Cindy Chi-Ching Pang
- 1 Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.,2 Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Clemens Kiecker
- 3 Department of Developmental Neurobiology, King's College London, London, UK
| | - John T O'Brien
- 4 Department of Psychiatry, University of Cambridge School of Clinical Medicine, Cambridge, UK
| | - Wendy Noble
- 2 Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Raymond Chuen-Chung Chang
- 1 Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.,5 State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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15
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Misquitta K, Dadar M, Tarazi A, Hussain MW, Alatwi MK, Ebraheem A, Multani N, Khodadadi M, Goswami R, Wennberg R, Tator C, Green R, Colella B, Davis KD, Mikulis D, Grinberg M, Sato C, Rogaeva E, Louis Collins D, Tartaglia MC. The relationship between brain atrophy and cognitive-behavioural symptoms in retired Canadian football players with multiple concussions. Neuroimage Clin 2018; 19:551-558. [PMID: 29984163 PMCID: PMC6029563 DOI: 10.1016/j.nicl.2018.05.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/08/2018] [Accepted: 05/12/2018] [Indexed: 10/31/2022]
Abstract
Multiple concussions, particularly in contact sports, have been associated with cognitive deficits, psychiatric impairment and neurodegenerative diseases like chronic traumatic encephalopathy. We used volumetric and deformation-based morphometric analyses to test the hypothesis that repeated concussions may be associated with smaller regional brain volumes, poorer cognitive performance and behavioural symptoms among former professional football players compared to healthy controls. This study included fifty-three retired Canadian Football League players, 25 age- and education-matched healthy controls, and controls from the Cambridge Centre for Aging and Neuroscience database for validation. Volumetric analyses revealed greater hippocampal atrophy than expected for age in former athletes with multiple concussions than controls and smaller left hippocampal volume was associated with poorer verbal memory performance in the former athletes. Deformation-based morphometry confirmed smaller bilateral hippocampal volume that was associated with poorer verbal memory performance in athletes. Repeated concussions may lead to greater regional atrophy than expected for age.
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Affiliation(s)
- Karen Misquitta
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, 60 Leonard Ave, Toronto, ON M5T 0S8, Canada; Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Mahsa Dadar
- McConnell Brain Imaging Centre, Montreal Neurological Institute, 3801 Rue Universite, Montreal, QC H3A 2B4, Canada
| | - Apameh Tarazi
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Neurology, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada
| | - Mohammed W Hussain
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Neurology, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada
| | - Mohammed K Alatwi
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Neurology, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada
| | - Ahmed Ebraheem
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Neurology, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada
| | - Namita Multani
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, 60 Leonard Ave, Toronto, ON M5T 0S8, Canada; Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada
| | - Mozhgan Khodadadi
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Neurology, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada
| | - Ruma Goswami
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Brain, Imaging and Behaviour-Systems Neuroscience, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada
| | - Richard Wennberg
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Neurology, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada
| | - Charles Tator
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Neurology, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Department of Surgery, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Division of Neurosurgery, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Robin Green
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Toronto Rehabilitation Institute, University Health Network, 550 University Ave., Toronto, ON M5G 2A2, Canada; Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Brenda Colella
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Toronto Rehabilitation Institute, University Health Network, 550 University Ave., Toronto, ON M5G 2A2, Canada
| | - Karen Deborah Davis
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Brain, Imaging and Behaviour-Systems Neuroscience, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - David Mikulis
- Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Department of Medical Imaging, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Mark Grinberg
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, 60 Leonard Ave, Toronto, ON M5T 0S8, Canada
| | - Christine Sato
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, 60 Leonard Ave, Toronto, ON M5T 0S8, Canada
| | - Ekaterina Rogaeva
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, 60 Leonard Ave, Toronto, ON M5T 0S8, Canada
| | - D Louis Collins
- McConnell Brain Imaging Centre, Montreal Neurological Institute, 3801 Rue Universite, Montreal, QC H3A 2B4, Canada
| | - Maria Carmela Tartaglia
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Tower, 60 Leonard Ave, Toronto, ON M5T 0S8, Canada; Canadian Concussion Center, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Division of Neurology, Krembil Neuroscience Centre, Toronto Western Hospital, 399 Bathurst St., Toronto, ON M5T 2S8, Canada; Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
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16
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Igonina TN, Ragaeva DS, Tikhonova MA, Petrova OM, Herbeck YE, Rozhkova IN, Amstislavskaya TG, Amstislavsky SY. Neurodevelopment and behavior in neonatal OXYS rats with genetically determined accelerated senescence. Brain Res 2018; 1681:75-84. [DOI: 10.1016/j.brainres.2017.12.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 11/14/2017] [Accepted: 12/18/2017] [Indexed: 12/29/2022]
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Zhao J, Hylin MJ, Kobori N, Hood KN, Moore AN, Dash PK. Post-Injury Administration of Galantamine Reduces Traumatic Brain Injury Pathology and Improves Outcome. J Neurotrauma 2017; 35:362-374. [PMID: 29088998 DOI: 10.1089/neu.2017.5102] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Acetylcholine is an excitatory neurotransmitter in the central nervous system that plays a key role in cognitive function, including learning and memory. Previous studies have shown that experimental traumatic brain injury (TBI) reduces cholinergic neurotransmission, decreases evoked release of acetylcholine, and alters cholinergic receptor levels. Galantamine (U.S. Food and Drug Administration approved for the treatment of vascular dementia and Alzheimer's disease) has been shown to inhibit acetylcholinesterase activity and allosterically potentiate nicotinic receptor signaling. We investigated whether acute administration of galantamine can reduce TBI pathology and improve cognitive function tested days after the termination of the drug treatment. Post-injury administration of galantamine was found to decrease TBI-triggered blood-brain barrier (BBB) permeability (tested 24 h post-injury), attenuate the loss of both GABAergic and newborn neurons in the ipsilateral hippocampus, and improve hippocampal function (tested 10 days after termination of the drug treatment). Specifically, significant improvements in the Morris water maze, novel object recognition, and context-specific fear memory tasks were observed in injured animals treated with galantamine. Although messenger RNAs for both M1 (Nos2, TLR4, and IL-12ß) and M2 (Arg1, CCL17, and Mcr1) microglial phenotypes were elevated post-TBI, galantamine treatment did not alter microglial polarization tested 24 h and 6 days post-injury. Taken together, these findings support the further investigation of galantamine as a treatment for TBI.
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Affiliation(s)
- Jing Zhao
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School , Houston, Texas
| | - Michael J Hylin
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School , Houston, Texas
| | - Nobuhide Kobori
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School , Houston, Texas
| | - Kimberly N Hood
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School , Houston, Texas
| | - Anthony N Moore
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School , Houston, Texas
| | - Pramod K Dash
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School , Houston, Texas
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18
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DeMaster D, Johnson C, Juranek J, Ewing‐Cobbs L. Memory and the hippocampal formation following pediatric traumatic brain injury. Brain Behav 2017; 7:e00832. [PMID: 29299377 PMCID: PMC5745237 DOI: 10.1002/brb3.832] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 08/15/2017] [Indexed: 12/20/2022] Open
Abstract
Introduction Previous research indicates disruption of learning and memory in children who have experienced traumatic brain injury (TBI). Objective This research evaluates the impact of pediatric TBI on volumetric differences along the long axis of the hippocampus, a region of the brain that is critical for explicit memory. Methods Structural brain data and behavioral measures were collected 6 weeks following TBI or extracranial injury (EI), in children aged 8-15 years and from a group of age matched typically developing controls (TDC). Total hippocampal volume and hippocampal subregion volumes corresponding to hippocampal head, body, and tail were compared across groups and were examined in relation to verbal and visual memory. Results Group differences were evident such that hippocampal body volume was found to be smaller for TBI and EI groups compared to the TDC group. Analysis restricted to the TBI group indicated that hippocampal head volume was associated with severity of injury. The relation between severity of injury and hippocampal head volume is particularly important considering results from our investigation of hippocampal volume-to-memory performance relations indicating positive correlations between hippocampal head volume and performance on memory measures for both the TBI group and the TDC group. Significant negative correlations between hippocampal body volume and memory were evident for the TBI group but not EI or TDC groups. Correlations between memory performance and hippocampal tail volume were not significant for the TBI or TDC groups, although for the EI group, a positive correlation was found between hippocampal tail volume and memory. Conclusion Together these results underscore an important relation between hippocampal structure and memory function during the subacute stage of recovery from pediatric TBI.
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Affiliation(s)
- Dana DeMaster
- Department of PediatricsChildren's Leaning InstituteUniversity of Texas McGovern Medical SchoolHoustonTXUSA
| | - Chad Johnson
- Department of PediatricsChildren's Leaning InstituteUniversity of Texas McGovern Medical SchoolHoustonTXUSA
| | - Jenifer Juranek
- Department of PediatricsChildren's Leaning InstituteUniversity of Texas McGovern Medical SchoolHoustonTXUSA
| | - Linda Ewing‐Cobbs
- Department of PediatricsChildren's Leaning InstituteUniversity of Texas McGovern Medical SchoolHoustonTXUSA
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19
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Pelkey KA, Chittajallu R, Craig MT, Tricoire L, Wester JC, McBain CJ. Hippocampal GABAergic Inhibitory Interneurons. Physiol Rev 2017; 97:1619-1747. [PMID: 28954853 DOI: 10.1152/physrev.00007.2017] [Citation(s) in RCA: 495] [Impact Index Per Article: 70.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/16/2017] [Accepted: 05/26/2017] [Indexed: 12/11/2022] Open
Abstract
In the hippocampus GABAergic local circuit inhibitory interneurons represent only ~10-15% of the total neuronal population; however, their remarkable anatomical and physiological diversity allows them to regulate virtually all aspects of cellular and circuit function. Here we provide an overview of the current state of the field of interneuron research, focusing largely on the hippocampus. We discuss recent advances related to the various cell types, including their development and maturation, expression of subtype-specific voltage- and ligand-gated channels, and their roles in network oscillations. We also discuss recent technological advances and approaches that have permitted high-resolution, subtype-specific examination of their roles in numerous neural circuit disorders and the emerging therapeutic strategies to ameliorate such pathophysiological conditions. The ultimate goal of this review is not only to provide a touchstone for the current state of the field, but to help pave the way for future research by highlighting where gaps in our knowledge exist and how a complete appreciation of their roles will aid in future therapeutic strategies.
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Affiliation(s)
- Kenneth A Pelkey
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ramesh Chittajallu
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Michael T Craig
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ludovic Tricoire
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Jason C Wester
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Chris J McBain
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
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20
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Wolf JA, Johnson BN, Johnson VE, Putt ME, Browne KD, Mietus CJ, Brown DP, Wofford KL, Smith DH, Grady MS, Cohen AS, Cullen DK. Concussion Induces Hippocampal Circuitry Disruption in Swine. J Neurotrauma 2017; 34:2303-2314. [PMID: 28298170 PMCID: PMC5510797 DOI: 10.1089/neu.2016.4848] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Hippocampal-dependent deficits in learning and memory formation are a prominent feature of traumatic brain injury (TBI); however, the role of the hippocampus in cognitive dysfunction after concussion (mild TBI) is unknown. We therefore investigated functional and structural changes in the swine hippocampus following TBI using a model of head rotational acceleration that closely replicates the biomechanics and neuropathology of closed-head TBI in humans. We examined neurophysiological changes using a novel ex vivo hippocampal slice paradigm with extracellular stimulation and recording in the dentate gyrus and CA1 occurring at 7 days following non-impact inertial TBI in swine. Hippocampal neurophysiology post-injury revealed reduced axonal function, synaptic dysfunction, and regional hyperexcitability at one week following even "mild" injury levels. Moreover, these neurophysiological changes occurred in the apparent absence of intra-hippocampal neuronal or axonal degeneration. Input-output curves demonstrated an elevated excitatory post-synaptic potential (EPSP) output for a given fiber volley input in injured versus sham animals, suggesting a form of homeostatic plasticity that manifested as a compensatory response to decreased axonal function in post-synaptic regions. These data indicate that closed-head rotational acceleration-induced TBI, the common cause of concussion in humans, may induce significant alterations in hippocampal circuitry function that have not resolved at 7 days post-injury. This circuitry dysfunction may underlie some of the post-concussion symptomatology associated with the hippocampus, such as post-traumatic amnesia and ongoing cognitive deficits.
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Affiliation(s)
- John A. Wolf
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania
| | - Brian N. Johnson
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Victoria E. Johnson
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Mary E. Putt
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kevin D. Browne
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania
| | - Constance J. Mietus
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Daniel P. Brown
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania
| | - Kathryn L. Wofford
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania
| | - Douglas H. Smith
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - M. Sean Grady
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Akiva S. Cohen
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - D. Kacy Cullen
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, Pennsylvania
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21
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Hylin MJ, Kerr AL, Holden R. Understanding the Mechanisms of Recovery and/or Compensation following Injury. Neural Plast 2017; 2017:7125057. [PMID: 28512585 PMCID: PMC5415868 DOI: 10.1155/2017/7125057] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/24/2017] [Accepted: 03/26/2017] [Indexed: 11/30/2022] Open
Abstract
Injury due to stroke and traumatic brain injury result in significant long-term effects upon behavioral functioning. One central question to rehabilitation research is whether the nature of behavioral improvement observed is due to recovery or the development of compensatory mechanisms. The nature of functional improvement can be viewed from the perspective of behavioral changes or changes in neuroanatomical plasticity that follows. Research suggests that these changes correspond to each other in a bidirectional manner. Mechanisms surrounding phenomena like neural plasticity may offer an opportunity to explain how variables such as experience can impact improvement and influence the definition of recovery. What is more, the intensity of the rehabilitative experiences may influence the ability to recover function and support functional improvement of behavior. All of this impacts how researchers, clinicians, and medical professionals utilize rehabilitation.
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Affiliation(s)
- Michael J. Hylin
- Neurotrauma and Rehabilitation Laboratory, Department of Psychology, Southern Illinois University, Carbondale, IL, USA
| | - Abigail L. Kerr
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Ryan Holden
- Neurotrauma and Rehabilitation Laboratory, Department of Psychology, Southern Illinois University, Carbondale, IL, USA
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22
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Johnson VE, Stewart W, Arena JD, Smith DH. Traumatic Brain Injury as a Trigger of Neurodegeneration. ADVANCES IN NEUROBIOLOGY 2017; 15:383-400. [PMID: 28674990 DOI: 10.1007/978-3-319-57193-5_15] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Although millions of individuals suffer a traumatic brain injury (TBI) worldwide each year, it is only recently that TBI has been recognized as a major public health problem. Beyond the acute clinical manifestations, there is growing recognition that a single severe TBI (sTBI) or repeated mild TBIs (rTBI) can also induce insidious neurodegenerative processes, which may be associated with early dementia, in particular chronic traumatic encephalopathy (CTE). Identified at autopsy examination in individuals with histories of exposure to sTBI or rTBI, CTE is recognized as a complex pathology featuring both macroscopic and microscopic abnormalities. These include cavum septum pellucidum, brain atrophy and ventricular dilation, together with pathologies in tau, TDP-43, and amyloid-β. However, the establishment and characterization of CTE as a distinct disease entity is in its infancy. Moreover, the relative "dose" of TBI, such as the frequency and severity of injury, associated with risk of CTE remains unknown. As such, there is a clear and pressing need to improve the recognition and diagnosis of CTE and to identify mechanistic links between TBI and chronic neurodegeneration.
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Affiliation(s)
- Victoria E Johnson
- Department of Neurosurgery, Penn Center for Brain Injury and Repair, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - William Stewart
- Department of Neurosurgery, Penn Center for Brain Injury and Repair, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Department of Neuropathology, Queen Elizabeth University Hospital, Glasgow, G51 4TF, UK.,University of Glasgow, Glasgow, G12 8QQ, UK
| | - John D Arena
- Department of Neurosurgery, Penn Center for Brain Injury and Repair, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Douglas H Smith
- Department of Neurosurgery, Penn Center for Brain Injury and Repair, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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23
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Wang ZF, Pan ZY, Xu CS, Li ZQ. Activation of G-protein coupled estrogen receptor 1 improves early-onset cognitive impairment via PI3K/Akt pathway in rats with traumatic brain injury. Biochem Biophys Res Commun 2017; 482:948-953. [DOI: 10.1016/j.bbrc.2016.11.138] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 11/25/2016] [Indexed: 01/02/2023]
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24
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Yan H, Feng Y, Wang Q. Altered Effective Connectivity of Hippocampus-Dependent Episodic Memory Network in mTBI Survivors. Neural Plast 2016; 2016:6353845. [PMID: 28074162 PMCID: PMC5198188 DOI: 10.1155/2016/6353845] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 11/14/2016] [Indexed: 11/29/2022] Open
Abstract
Traumatic brain injuries (TBIs) are generally recognized to affect episodic memory. However, less is known regarding how external force altered the way functionally connected brain structures of the episodic memory system interact. To address this issue, we adopted an effective connectivity based analysis, namely, multivariate Granger causality approach, to explore causal interactions within the brain network of interest. Results presented that TBI induced increased bilateral and decreased ipsilateral effective connectivity in the episodic memory network in comparison with that of normal controls. Moreover, the left anterior superior temporal gyrus (aSTG, the concept forming hub), left hippocampus (the personal experience binding hub), and left parahippocampal gyrus (the contextual association hub) were no longer network hubs in TBI survivors, who compensated for hippocampal deficits by relying more on the right hippocampus (underlying perceptual memory) and the right medial frontal gyrus (MeFG) in the anterior prefrontal cortex (PFC). We postulated that the overrecruitment of the right anterior PFC caused dysfunction of the strategic component of episodic memory, which caused deteriorating episodic memory in mTBI survivors. Our findings also suggested that the pattern of brain network changes in TBI survivors presented similar functional consequences to normal aging.
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Affiliation(s)
- Hao Yan
- Neuroimaging Laboratory, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen 518060, China
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
- Departments of Linguistics and Psychology, Xidian University, Xi'an 710071, China
| | - Yanqin Feng
- Departments of Linguistics and Psychology, Xidian University, Xi'an 710071, China
| | - Qian Wang
- School of Foreign Languages, Northwestern Polytechnical University, Xi'an 710029, China
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25
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Abstract
Hippocampal area CA2 has several features that distinguish it from CA1 and CA3, including a unique gene expression profile, failure to display long-term potentiation and relative resistance to cell death. A recent increase in interest in the CA2 region, combined with the development of new methods to define and manipulate its neurons, has led to some exciting new discoveries on the properties of CA2 neurons and their role in behaviour. Here, we review these findings and call attention to the idea that the definition of area CA2 ought to be revised in light of gene expression data.
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Wilson NM, Titus DJ, Oliva AA, Furones C, Atkins CM. Traumatic Brain Injury Upregulates Phosphodiesterase Expression in the Hippocampus. Front Syst Neurosci 2016; 10:5. [PMID: 26903822 PMCID: PMC4742790 DOI: 10.3389/fnsys.2016.00005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/18/2016] [Indexed: 11/13/2022] Open
Abstract
Traumatic brain injury (TBI) results in significant impairments in hippocampal synaptic plasticity. A molecule critically involved in hippocampal synaptic plasticity, 3′,5′-cyclic adenosine monophosphate, is downregulated in the hippocampus after TBI, but the mechanism that underlies this decrease is unknown. To address this question, we determined whether phosphodiesterase (PDE) expression in the hippocampus is altered by TBI. Young adult male Sprague Dawley rats received sham surgery or moderate parasagittal fluid-percussion brain injury. Animals were analyzed by western blotting for changes in PDE expression levels in the hippocampus. We found that PDE1A levels were significantly increased at 30 min, 1 h and 6 h after TBI. PDE4B2 and 4D2 were also significantly increased at 1, 6, and 24 h after TBI. Additionally, phosphorylation of PDE4A was significantly increased at 6 and 24 h after TBI. No significant changes were observed in levels of PDE1B, 1C, 3A, 8A, or 8B between 30 min to 7 days after TBI. To determine the spatial profile of these increases, we used immunohistochemistry and flow cytometry at 24 h after TBI. PDE1A and phospho-PDE4A localized to neuronal cell bodies. PDE4B2 was expressed in neuronal dendrites, microglia and infiltrating CD11b+ immune cells. PDE4D was predominantly found in microglia and infiltrating CD11b+ immune cells. To determine if inhibition of PDE4 would improve hippocampal synaptic plasticity deficits after TBI, we treated hippocampal slices with rolipram, a pan-PDE4 inhibitor. Rolipram partially rescued the depression in basal synaptic transmission and converted a decaying form of long-term potentiation (LTP) into long-lasting LTP. Overall, these results identify several possible PDE targets for reducing hippocampal synaptic plasticity deficits and improving cognitive function acutely after TBI.
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Affiliation(s)
- Nicole M Wilson
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine Miami, FL, USA
| | - David J Titus
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine Miami, FL, USA
| | - Anthony A Oliva
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine Miami, FL, USA
| | - Concepcion Furones
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine Miami, FL, USA
| | - Coleen M Atkins
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine Miami, FL, USA
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27
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Hay J, Johnson VE, Smith DH, Stewart W. Chronic Traumatic Encephalopathy: The Neuropathological Legacy of Traumatic Brain Injury. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2016; 11:21-45. [PMID: 26772317 DOI: 10.1146/annurev-pathol-012615-044116] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Almost a century ago, the first clinical account of the punch-drunk syndrome emerged, describing chronic neurological and neuropsychiatric sequelae occurring in former boxers. Thereafter, throughout the twentieth century, further reports added to our understanding of the neuropathological consequences of a career in boxing, leading to descriptions of a distinct neurodegenerative pathology, termed dementia pugilistica. During the past decade, growing recognition of this pathology in autopsy studies of nonboxers who were exposed to repetitive, mild traumatic brain injury, or to a single, moderate or severe traumatic brain injury, has led to an awareness that it is exposure to traumatic brain injury that carries with it a risk of this neurodegenerative disease, not the sport or the circumstance in which the injury is sustained. Furthermore, the neuropathology of the neurodegeneration that occurs after traumatic brain injury, now termed chronic traumatic encephalopathy, is acknowledged as being a complex, mixed, but distinctive pathology, the detail of which is reviewed in this article.
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Affiliation(s)
- Jennifer Hay
- School of Medicine and.,Department of Neuropathology, Queen Elizabeth University Hospital, Glasgow G51 4TF, United Kingdom
| | - Victoria E Johnson
- Penn Center for Brain Injury and Repair, and Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Douglas H Smith
- Penn Center for Brain Injury and Repair, and Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - William Stewart
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QQ, United Kingdom; .,Department of Neuropathology, Queen Elizabeth University Hospital, Glasgow G51 4TF, United Kingdom
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28
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Butler CR, Boychuk JA, Smith BN. Effects of Rapamycin Treatment on Neurogenesis and Synaptic Reorganization in the Dentate Gyrus after Controlled Cortical Impact Injury in Mice. Front Syst Neurosci 2015; 9:163. [PMID: 26640431 PMCID: PMC4661228 DOI: 10.3389/fnsys.2015.00163] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 11/10/2015] [Indexed: 11/13/2022] Open
Abstract
Post-traumatic epilepsy (PTE) is one consequence of traumatic brain injury (TBI). A prominent cell signaling pathway activated in animal models of both TBI and epilepsy is the mammalian target of rapamycin (mTOR). Inhibition of mTOR with rapamycin has shown promise as a potential modulator of epileptogenesis in several animal models of epilepsy, but cellular mechanisms linking mTOR expression and epileptogenesis are unclear. In this study, the role of mTOR in modifying functional hippocampal circuit reorganization after focal TBI induced by controlled cortical impact (CCI) was investigated. Rapamycin (3 or 10 mg/kg), an inhibitor of mTOR signaling, was administered by intraperitoneal injection beginning on the day of injury and continued daily until tissue collection. Relative to controls, rapamycin treatment reduced dentate granule cell area in the hemisphere ipsilateral to the injury two weeks post-injury. Brain injury resulted in a significant increase in doublecortin immunolabeling in the dentate gyrus ipsilateral to the injury, indicating increased neurogenesis shortly after TBI. Rapamycin treatment prevented the increase in doublecortin labeling, with no overall effect on Fluoro-Jade B staining in the ipsilateral hemisphere, suggesting that rapamycin treatment reduced posttraumatic neurogenesis but did not prevent cell loss after injury. At later times post-injury (8–13 weeks), evidence of mossy fiber sprouting and increased recurrent excitation of dentate granule cells was detected, which were attenuated by rapamycin treatment. Rapamycin treatment also diminished seizure prevalence relative to vehicle-treated controls after TBI. Collectively, these results support a role for adult neurogenesis in PTE development and suggest that suppression of epileptogenesis by mTOR inhibition includes effects on post-injury neurogenesis.
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Affiliation(s)
- Corwin R Butler
- Department of Physiology, College of Medicine, University of Kentucky Lexington, KY, USA
| | - Jeffery A Boychuk
- Department of Physiology, College of Medicine, University of Kentucky Lexington, KY, USA ; Epilepsy Center, University of Kentucky Lexington, KY, USA ; Center for Advanced Translational Stroke Science, University of Kentucky Lexington, KY, USA
| | - Bret N Smith
- Department of Physiology, College of Medicine, University of Kentucky Lexington, KY, USA ; Epilepsy Center, University of Kentucky Lexington, KY, USA ; Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky Lexington, KY, USA
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29
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Kim YJ, Kang TC. The role of TRPC6 in seizure susceptibility and seizure-related neuronal damage in the rat dentate gyrus. Neuroscience 2015; 307:215-30. [PMID: 26327362 DOI: 10.1016/j.neuroscience.2015.08.054] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/18/2015] [Accepted: 08/22/2015] [Indexed: 11/29/2022]
Abstract
Transient receptor potential canonical channel-6 (TRPC6) forms Ca(2+)-permeable non-selective cation channels in neurons. Although TRPC6 plays an important role in neurite outgrowth and neuronal survival during development, TRPC6 expression profiles available to identify distinctive hippocampal neuronal damage and hippocampal excitability in epilepsy are less defined. As compared to normal animals, TRPC6 expression was down-regulated in chronic epileptic rats showing spontaneous recurrent seizures. TRPC6 knockdown increased seizure susceptibility, excitability ratio and paired-pulse inhibition in the dentate gyrus (DG) of normal animals. Furthermore, TRPC6 knockdown promoted programmed neuronal necrosis in dentate granule cells, but prevented it in CA1 and CA3 neurons following status epilepticus. The present data suggest for the first time that TRPC6 may inhibit seizure susceptibility and neuronal vulnerability in the rat DG.
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Affiliation(s)
- Y-J Kim
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon 200-702, South Korea
| | - T-C Kang
- Department of Anatomy and Neurobiology, Institute of Epilepsy Research, College of Medicine, Hallym University, Chunchon 200-702, South Korea.
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30
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Zhu Y, Liu F, Zou X, Torbey M. Comparison of unbiased estimation of neuronal number in the rat hippocampus with different staining methods. J Neurosci Methods 2015; 254:73-9. [PMID: 26238727 DOI: 10.1016/j.jneumeth.2015.07.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 07/20/2015] [Accepted: 07/23/2015] [Indexed: 01/28/2023]
Abstract
BACKGROUND NeuN and Nissl staining (toluidine blue, cresyl violet staining) are routinely used methods in unbiased stereological estimation of the total number of hippocampal neurons. NEW METHOD In the present study, we stained serial frozen coronal sections from 5 normal adult male Sprague-Dawley rat brains with different methods, measured the deformation of hippocampal area in brain sections and estimated the total number of hippocampal neurons using the optical fractionator. RESULTS The deformation in x, y-axis was not obviously different with different staining protocols, but shrinkage in z-axis was significant after staining (p < 0.001). NeuN staining produced significant higher estimate number than cresyl violet staining by 24% (p = 0.002), however, NeuN and Cresyl Violet staining showed a high degree of correlation in quantification of total neuronal numbers and both methods are suitable for unbiased stereological estimation. COMPARISON WITH EXISTING METHOD (S) NeuN is more reliable but if time is limited or the number of animals used in experiments is high, cresyl violet staining may be a feasible method. CONCLUSIONS Compared with previous estimates of the neurons number in rat hippocampus, our present data is reliable and the stereological analysis based on our system is a cost-effective unbiased method for estimation of neuron number.
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Affiliation(s)
- Yongjin Zhu
- Department of Neurology, Wexner Medical Center, The Ohio State University, Columbus, OH, United States
| | - Fuxin Liu
- Department of Neurology, Wexner Medical Center, The Ohio State University, Columbus, OH, United States
| | - Xunchang Zou
- Department of Neurology, Wexner Medical Center, The Ohio State University, Columbus, OH, United States
| | - Michel Torbey
- Department of Neurology, Wexner Medical Center, The Ohio State University, Columbus, OH, United States; Neurosurgery, Wexner Medical Center, The Ohio State University, Columbus, OH, United States.
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31
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Evans PR, Dudek SM, Hepler JR. Regulator of G Protein Signaling 14: A Molecular Brake on Synaptic Plasticity Linked to Learning and Memory. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 133:169-206. [PMID: 26123307 DOI: 10.1016/bs.pmbts.2015.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The regulators of G protein signaling (RGS) proteins are a diverse family of proteins that function as central components of G protein and other signaling pathways. In the brain, regulator of G protein signaling 14 (RGS14) is enriched in neurons in the hippocampus where the mRNA and protein are highly expressed. This brain region plays a major role in processing learning and forming new memories. RGS14 is an unusual RGS protein that acts as a multifunctional scaffolding protein to integrate signaling events and pathways essential for synaptic plasticity, including conventional and unconventional G protein signaling, mitogen-activated protein kinase, and, possibly, calcium signaling pathways. Within the hippocampus of primates and rodents, RGS14 is predominantly found in the enigmatic CA2 subfield. Principal neurons within the CA2 subfield differ from neighboring hippocampal regions in that they lack a capacity for long-term potentiation (LTP) of synaptic transmission, which is widely viewed as the cellular substrate of learning and memory formation. RGS14 was recently identified as a natural suppressor of LTP in hippocampal CA2 neurons as well as forms of learning and memory that depend on the hippocampus. Although CA2 has only recently been studied, compelling recent evidence implicates area CA2 as a critical component of hippocampus circuitry with functional roles in mediating certain types of learning and memory. This review will highlight the known functions of RGS14 in cell signaling and hippocampus physiology, and discuss potential roles for RGS14 in human cognition and disease.
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Affiliation(s)
- Paul R Evans
- Department of Pharmacology, Emory University School of Medicine, Rollins Research Center, Atlanta, Georgia, USA
| | - Serena M Dudek
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - John R Hepler
- Department of Pharmacology, Emory University School of Medicine, Rollins Research Center, Atlanta, Georgia, USA.
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32
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Mayer AR, Hanlon FM, Ling JM. Gray matter abnormalities in pediatric mild traumatic brain injury. J Neurotrauma 2015; 32:723-30. [PMID: 25313896 DOI: 10.1089/neu.2014.3534] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pediatric mild traumatic brain injury (pmTBI) is the most prevalent neurological insult in children and is associated with both acute and chronic neuropsychiatric sequelae. However, little is known about underlying pathophysiology changes in gray matter diffusion and atrophy from a prospective stand-point. Fifteen semi-acute pmTBI patients and 15 well-matched healthy controls were evaluated with a clinical and neuroimaging battery, with a subset of participants returning for a second visit. Clinical measures included tests of attention, processing speed, executive function, working memory, memory, and self-reported post-concussive symptoms. Measures of diffusion (fractional anisotropy [FA]) and atrophy were also obtained for cortical and subcortical gray matter structures to characterize effects of injury as a function of time. Patients exhibited decreased scores in the domains of attention and processing speed relative to controls during the semi-acute injury stage, in conjunction with increased anisotropic diffusion in the left superior temporal gyrus and right thalamus. Evidence of increased diffusion in these regions was also present at four months post-injury, with performance on cognitive tests partially normalizing. In contrast, signs of cortical atrophy in bilateral frontal areas and other left-hemisphere cortical areas only emerged at four months post-injury for patients. Current results suggest potentially differential time-courses of recovery for neurobehavioral markers, anisotropic diffusion and atrophy following pmTBI. Importantly, these data suggest that relying on patient self-report or standard clinical assessments may underestimate the time for true injury recovery.
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Affiliation(s)
- Andrew R Mayer
- 1 The Mind Research Network/Lovelace Biomedical and Environmental Research Institute , Albuquerque, New Mexico
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33
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Miller AP, Shah AS, Aperi BV, Budde MD, Pintar FA, Tarima S, Kurpad SN, Stemper BD, Glavaski-Joksimovic A. Effects of blast overpressure on neurons and glial cells in rat organotypic hippocampal slice cultures. Front Neurol 2015; 6:20. [PMID: 25729377 PMCID: PMC4325926 DOI: 10.3389/fneur.2015.00020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 01/25/2015] [Indexed: 11/13/2022] Open
Abstract
Due to recent involvement in military conflicts, and an increase in the use of explosives, there has been an escalation in the incidence of blast-induced traumatic brain injury (bTBI) among US military personnel. Having a better understanding of the cellular and molecular cascade of events in bTBI is prerequisite for the development of an effective therapy that currently is unavailable. The present study utilized organotypic hippocampal slice cultures (OHCs) exposed to blast overpressures of 150 kPa (low) and 280 kPa (high) as an in vitro bTBI model. Using this model, we further characterized the cellular effects of the blast injury. Blast-evoked cell death was visualized by a propidium iodide (PI) uptake assay as early as 2 h post-injury. Quantification of PI staining in the cornu Ammonis 1 and 3 (CA1 and CA3) and the dentate gyrus regions of the hippocampus at 2, 24, 48, and 72 h following blast exposure revealed significant time dependent effects. OHCs exposed to 150 kPa demonstrated a slow increase in cell death plateauing between 24 and 48 h, while OHCs from the high-blast group exhibited a rapid increase in cell death already at 2 h, peaking at ~24 h post-injury. Measurements of lactate dehydrogenase release into the culture medium also revealed a significant increase in cell lysis in both low- and high-blast groups compared to sham controls. OHCs were fixed at 72 h post-injury and immunostained for markers against neurons, astrocytes, and microglia. Labeling OHCs with PI, neuronal, and glial markers revealed that the blast-evoked extensive neuronal death and to a lesser extent loss of glial cells. Furthermore, our data demonstrated activation of astrocytes and microglial cells in low- and high-blasted OHCs, which reached a statistically significant difference in the high-blast group. These data confirmed that our in vitro bTBI model is a useful tool for studying cellular and molecular changes after blast exposure.
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Affiliation(s)
- Anna P Miller
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Alok S Shah
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Brandy V Aperi
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Matthew D Budde
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Frank A Pintar
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Sergey Tarima
- Division of Biostatistics, Institute for Health and Society, Medical College of Wisconsin , Milwaukee, WI , USA
| | - Shekar N Kurpad
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Brian D Stemper
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Aleksandra Glavaski-Joksimovic
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
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34
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PARP1 activation/expression modulates regional-specific neuronal and glial responses to seizure in a hemodynamic-independent manner. Cell Death Dis 2014; 5:e1362. [PMID: 25101675 PMCID: PMC4454306 DOI: 10.1038/cddis.2014.331] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 06/10/2014] [Accepted: 07/03/2014] [Indexed: 11/08/2022]
Abstract
Poly(ADP-ribose) polymerase-1 (PARP1) plays a regulatory role in apoptosis, necrosis and other cellular processes after injury. Status epilepticus (SE) induces neuronal and astroglial death that show regional-specific patterns in the rat hippocampus and piriform cortex (PC). Thus, we investigated whether PARP1 regulates the differential neuronal/glial responses to pilocarpine (PILO)-induced SE in the distinct brain regions. In the present study, both CA1 and CA3 neurons showed PARP1 hyperactivation-dependent neuronal death pathway, whereas PC neurons exhibited PARP1 degradation-mediated neurodegeneration following SE. PARP1 degradation was also observed in astrocytes within the molecular layer of the dentate gyrus. PARP1 induction was detected in CA1-3-reactive astrocytes, as well as in reactive microglia within the PC. Although PARP1 inhibitors attenuated CA1-3 neuronal death and reactive gliosis in the CA1 region, they deteriorated the astroglial death in the molecular layer of the dentate gyrus and in the stratum lucidum of the CA3 region. Ex vivo study showed the similar regional and cellular patterns of PARP1 activation/degradation. Taken together, our findings suggest that the cellular-specific PARP1 activation/degradation may distinctly involve regional-specific neuronal damage, astroglial death and reactive gliosis in response to SE independently of hemodynamics.
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35
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Kovacs SK, Leonessa F, Ling GSF. Blast TBI Models, Neuropathology, and Implications for Seizure Risk. Front Neurol 2014; 5:47. [PMID: 24782820 PMCID: PMC3988378 DOI: 10.3389/fneur.2014.00047] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/26/2014] [Indexed: 12/31/2022] Open
Abstract
Traumatic brain injury (TBI) due to explosive blast exposure is a leading combat casualty. It is also implicated as a key contributor to war related mental health diseases. A clinically important consequence of all types of TBI is a high risk for development of seizures and epilepsy. Seizures have been reported in patients who have suffered blast injuries in the Global War on Terror but the exact prevalence is unknown. The occurrence of seizures supports the contention that explosive blast leads to both cellular and structural brain pathology. Unfortunately, the exact mechanism by which explosions cause brain injury is unclear, which complicates development of meaningful therapies and mitigation strategies. To help improve understanding, detailed neuropathological analysis is needed. For this, histopathological techniques are extremely valuable and indispensable. In the following we will review the pathological results, including those from immunohistochemical and special staining approaches, from recent preclinical explosive blast studies.
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Affiliation(s)
- S Krisztian Kovacs
- Laboratory of Neurotrauma, Department of Neurology, Uniformed Services University of the Health Sciences , Bethesda, MD , USA
| | - Fabio Leonessa
- Laboratory of Neurotrauma, Department of Neurology, Uniformed Services University of the Health Sciences , Bethesda, MD , USA
| | - Geoffrey S F Ling
- Laboratory of Neurotrauma, Department of Neurology, Uniformed Services University of the Health Sciences , Bethesda, MD , USA
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36
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Brezova V, Moen KG, Skandsen T, Vik A, Brewer JB, Salvesen O, Håberg AK. Prospective longitudinal MRI study of brain volumes and diffusion changes during the first year after moderate to severe traumatic brain injury. NEUROIMAGE-CLINICAL 2014; 5:128-40. [PMID: 25068105 PMCID: PMC4110353 DOI: 10.1016/j.nicl.2014.03.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/14/2014] [Accepted: 03/22/2014] [Indexed: 01/10/2023]
Abstract
The objectives of this prospective study in 62 moderate–severe TBI patients were to investigate volume change in cortical gray matter (GM), hippocampus, lenticular nucleus, lobar white matter (WM), brainstem and ventricles using a within subject design and repeated MRI in the early phase (1–26 days) and 3 and 12 months postinjury and to assess changes in GM apparent diffusion coefficient (ADC) in normal appearing tissue in the cortex, hippocampus and brainstem. The impact of Glasgow Coma Scale (GCS) score at admission, duration of post-traumatic amnesia (PTA), and diffusion axonal injury (DAI) grade on brain volumes and ADC values over time was assessed. Lastly, we determined if MRI-derived brain volumes from the 3-month scans provided additional, significant predictive value to 12-month outcome classified with the Glasgow Outcome Scale—Extended after adjusting for GCS, PTA and age. Cortical GM loss was rapid, largely finished by 3 months, but the volume reduction was unrelated to GCS score, PTA, or presence of DAI. However, cortical GM volume at 3 months was a significant independent predictor of 12-month outcome. Volume loss in the hippocampus and lenticular nucleus was protracted and statistically significant first at 12 months. Slopes of volume reduction over time for the cortical and subcortical GGM were significantly different. Hippocampal volume loss was most pronounced and rapid in individuals with PTA > 2 weeks. The 3-month volumes of the hippocampus and lentiform nucleus were the best independent predictors of 12-month outcome after adjusting for GCS, PTA and age. In the brainstem, volume loss was significant at both 3 and 12 months. Brainstem volume reduction was associated with lower GCS score and the presence of DAI. Lobar WM volume was significantly decreased first after 12 months. Surprisingly DAI grade had no impact on lobar WM volume. Ventricular dilation developed predominantly during the first 3 months, and was strongly associated with volume changes in the brainstem and cortical GM, but not lobar WM volume. Higher ADC values were detected in the cortex in individuals with severe TBI, DAI and PTA > 2 weeks, from 3 months. There were no associations between ADC values and brain volumes, and ADC values did not predict outcome. Longitudinal study of brain volume changes following TBI 3 month MRI derived volumes are independent predictors of outcome at 12 months. PTA, GCS and DAI have different impacts on different brain volumes. Subcortical and cortical GM volume losses follow significantly different trajectories. Significant changes in cortical ADC values develop slowly while volume changes are rapid.
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Affiliation(s)
- Veronika Brezova
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway ; Department of Medical Imaging, St. Olav's Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Kent Gøran Moen
- Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway ; Department of Neurosurgery, St. Olav's Hospital, Trondheim, Norway
| | - Toril Skandsen
- Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway ; Department of Physical Medicine and Rehabilitation, St. Olav's Hospital, Trondheim, Norway
| | - Anne Vik
- Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway ; Department of Neurosurgery, St. Olav's Hospital, Trondheim, Norway
| | - James B Brewer
- Department of Radiology, University of California San Diego, San Diego, USA ; Department of Neurosciences, University of California San Diego, San Diego, USA
| | - Oyvind Salvesen
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Asta K Håberg
- Department of Medical Imaging, St. Olav's Hospital, Trondheim University Hospital, Trondheim, Norway ; Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
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37
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Abstract
There are more than 3.17 million people coping with long-term disabilities due to traumatic brain injury (TBI) in the United States. The majority of TBI research is focused on developing acute neuroprotective treatments to prevent or minimize these long-term disabilities. Therefore, chronic TBI survivors represent a large, underserved population that could significantly benefit from a therapy that capitalizes on the endogenous recovery mechanisms occurring during the weeks to months following brain trauma. Previous studies have found that the hippocampus is highly vulnerable to brain injury, in both experimental models of TBI and during human TBI. Although often not directly mechanically injured by the head injury, in the weeks to months following TBI, the hippocampus undergoes atrophy and exhibits deficits in long-term potentiation (LTP), a persistent increase in synaptic strength that is considered to be a model of learning and memory. Decoding the chronic hippocampal LTP and cell signaling deficits after brain trauma will provide new insights into the molecular mechanisms of hippocampal-dependent learning impairments caused by TBI and facilitate the development of effective therapeutic strategies to improve hippocampal-dependent learning for chronic survivors of TBI.
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Affiliation(s)
- Coleen M Atkins
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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38
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Ling JM, Klimaj S, Toulouse T, Mayer AR. A prospective study of gray matter abnormalities in mild traumatic brain injury. Neurology 2013; 81:2121-7. [PMID: 24259552 DOI: 10.1212/01.wnl.0000437302.36064.b1] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE To examine the underlying pathophysiology of mild traumatic brain injury through changes in gray matter diffusion and atrophy during the semiacute stage. METHODS Fifty patients and 50 sex-, age-, and education-matched controls were evaluated with a clinical and neuroimaging battery approximately 14 days postinjury, with 26 patients returning for follow-up 4 months postinjury. Clinical measures included tests of attention, processing speed, executive function, working memory, memory, and self-reported postconcussive symptoms. Measures of diffusion (fractional anisotropy [FA], mean diffusivity) and atrophy were obtained for cortical and subcortical structures to characterize effects of injury as a function of time. RESULTS Patients reported more cognitive, somatic, and emotional complaints during the semiacute injury phase, which were significantly reduced 4 months postinjury. Patients showed evidence of increased FA in the bilateral superior frontal cortex during the semiacute phase, with the left superior frontal cortex remaining elevated 4 months postinjury. There were no significant differences between patients and matched controls on neuropsychological testing or measures of gray matter atrophy/mean diffusivity at either time point. CONCLUSIONS Increased cortical FA is largely consistent with an emerging animal literature of gray matter abnormalities after neuronal injury. Potential mechanistic explanations for increased FA include cytotoxic edema or reactive gliosis. In contrast, there was no evidence of cortical or subcortical atrophy in the current study, suggesting that frank neuronal or neuropil loss does not occur early in the chronic disease course for patients with typical mild traumatic brain injury.
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Affiliation(s)
- Josef M Ling
- From The Mind Research Network Lovelace Biomedical and Environmental Research Institute (J.M.L., S.K., T.T., A.R.M.), Albuquerque; Department of Psychology (A.R.M.), University of New Mexico, Albuquerque; and Neurology Department (A.R.M.), University of New Mexico School of Medicine, Albuquerque, NM
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Laeremans A, Nys J, Luyten W, D'Hooge R, Paulussen M, Arckens L. AMIGO2 mRNA expression in hippocampal CA2 and CA3a. Brain Struct Funct 2013; 218:123-30. [PMID: 22314660 DOI: 10.1007/s00429-012-0387-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Accepted: 01/17/2012] [Indexed: 10/14/2022]
Abstract
AMIGO2, or amphoterin-induced gene and ORF (open reading frame) 2, belongs to the leucine-rich repeats and immunoglobulin superfamilies. The protein is a downstream target of calcium-dependent survival signals and, therefore, promotes neuronal survival. Here, we describe the mRNA distribution pattern of AMIGO2 throughout the mouse brain with special emphasis on the hippocampus. In the Ammon's horn, a detailed comparison between the subregional mRNA expression patterns of AMIGO2 and Pcp4 (Purkinje cell protein 4)--a known molecular marker of hippocampal CA2 (Cornu Ammonis 2)--revealed a prominent AMIGO2 mRNA expression level in both the CA2 and the CA3a (Cornu Ammonis 3a) subregion of the dorsal and ventral hippocampus. Since this CA2/CA3a region is particularly resistant to neuronal injury and neurotoxicity [Stanfield and Cowan (Brain Res 309(2):299–307 1984); Sloviter (J Comp Neurol 280(2):183–196 1989); Leranth and Ribak (Exp Brain Res 85(1):129–136 1991); Young and Dragunow (Exp Neurol 133(2):125–137 1995); Ochiishi et al. (Neurosci 93(3):955–967 1999)], we suggest that the expression pattern of AMIGO2 indeed fits with its involvement in neuroprotection.
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Affiliation(s)
- Annelies Laeremans
- Laboratory of Neuroplasticity and Neuroproteomics, University of Leuven, Naamsestraat 59, Box 2467, 3000 Leuven, Belgium
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Phosphodiesterase inhibition rescues chronic cognitive deficits induced by traumatic brain injury. J Neurosci 2013; 33:5216-26. [PMID: 23516287 DOI: 10.1523/jneurosci.5133-12.2013] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Traumatic brain injury (TBI) modulates several cell signaling pathways in the hippocampus critical for memory formation. Previous studies have found that the cAMP-protein kinase A signaling pathway is downregulated after TBI and that treatment with a phosphodiesterase (PDE) 4 inhibitor rolipram rescues the decrease in cAMP. In the present study, we examined the effect of rolipram on TBI-induced cognitive impairments. At 2 weeks after moderate fluid-percussion brain injury or sham surgery, adult male Sprague Dawley rats received vehicle or rolipram (0.03 mg/kg) 30 min before water maze acquisition or cue and contextual fear conditioning. TBI animals treated with rolipram showed a significant improvement in water maze acquisition and retention of both cue and contextual fear conditioning compared with vehicle-treated TBI animals. Cue and contextual fear conditioning significantly increased phosphorylated CREB levels in the hippocampus of sham animals, but not in TBI animals. This deficit in CREB activation during learning was rescued in TBI animals treated with rolipram. Hippocampal long-term potentiation was reduced in TBI animals, and this was also rescued with rolipram treatment. These results indicate that the PDE4 inhibitor rolipram rescues cognitive impairments after TBI, and this may be mediated through increased CREB activation during learning.
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Smith DH, Johnson VE, Stewart W. Chronic neuropathologies of single and repetitive TBI: substrates of dementia? Nat Rev Neurol 2013; 9:211-21. [PMID: 23458973 DOI: 10.1038/nrneurol.2013.29] [Citation(s) in RCA: 517] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Traumatic brain injury (TBI) has long been recognized to be a risk factor for dementia. This association has, however, only recently gained widespread attention through the increased awareness of 'chronic traumatic encephalopathy' (CTE) in athletes exposed to repetitive head injury. Originally termed 'dementia pugilistica' and linked to a career in boxing, descriptions of the neuropathological features of CTE include brain atrophy, cavum septum pellucidum, and amyloid-β, tau and TDP-43 pathologies, many of which might contribute to clinical syndromes of cognitive impairment. Similar chronic pathologies are also commonly found years after just a single moderate to severe TBI. However, little consensus currently exists on specific features of these post-TBI syndromes that might permit their confident clinical and/or pathological diagnosis. Moreover, the mechanisms contributing to neurodegeneration following TBI largely remain unknown. Here, we review the current literature and controversies in the study of chronic neuropathological changes after TBI.
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Affiliation(s)
- Douglas H Smith
- Penn Center for Brain Injury and Repair and Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, 105 Hayden Hall, 3320 Smith Walk, Philadelphia, PA 19104, USA
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Pontifex MB, Broglio SP, Drollette ES, Scudder MR, Johnson CR, O'Connor PM, Hillman CH. The relation of mild traumatic brain injury to chronic lapses of attention. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2012; 83:553-559. [PMID: 23367818 DOI: 10.1080/02701367.2012.10599252] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We assessed the extent to which failures in sustained attention were associated with chronic mild traumatic brain injury (mTBI) deficits in cognitive control among college-age young adults with and without a history of sport-related concussion. Participants completed the ImPACT computer-based assessment and a modified flanker task. Results indicated that a history of mTBI, relative to healthy controls, was associated with inferior overall flanker task performance with a greater number of omission errors and more frequent sequentially occurring omission errors. Accordingly, these findings suggest that failures in the ability to maintain attentional vigilance may, in part, underlie mTBI-related cognition deficits.
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Affiliation(s)
- Matthew B Pontifex
- Department of Kinesiology at Michigan State University, East Lansing 48824-1049, USA.
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Abstract
Concussion has been viewed historically as a transient injury with no evidence supporting the existence of persistent effects. However, our recent work demonstrates electroencephalographic and motor control changes in otherwise healthy individuals with a history of concussion. We therefore hypothesize that concussive and subconcussive head impacts set about a cascade of pathological events that accelerates declines in cognitive function typically associated with the aging process.
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Sohn EJ, Kim DW, Kim MJ, Jeong HJ, Shin MJ, Ahn EH, Kwon SW, Kim YN, Kim DS, Han KH, Park J, Hwang HS, Eum WS, Choi SY. PEP-1–metallothionein-III protein ameliorates the oxidative stress-induced neuronal cell death and brain ischemic insults. Biochim Biophys Acta Gen Subj 2012; 1820:1647-55. [DOI: 10.1016/j.bbagen.2012.06.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 06/06/2012] [Accepted: 06/19/2012] [Indexed: 01/13/2023]
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Oliva AA, Kang Y, Sanchez-Molano J, Furones C, Atkins CM. STAT3 signaling after traumatic brain injury. J Neurochem 2012; 120:710-20. [PMID: 22145815 DOI: 10.1111/j.1471-4159.2011.07610.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Astrocytes respond to trauma by stimulating inflammatory signaling. In studies of cerebral ischemia and spinal cord injury, astrocytic signaling is mediated by the cytokine receptor glycoprotein 130 (gp130) and Janus kinase (Jak) which phosphorylates the transcription factor signal transducer and activator of transcription-3 (STAT3). To determine if STAT3 is activated after traumatic brain injury (TBI), adult male Sprague-Dawley rats received moderate parasagittal fluid-percussion brain injury or sham surgery, and then the ipsilateral cortex and hippocampus were analyzed at various post-traumatic time periods for up to 7 days. Western blot analyses indicated that STAT3 phosphorylation significantly increased at 30 min and lasted for 24 h post-TBI. A significant increase in gp130 and Jak2 phosphorylation was also observed. Confocal microscopy revealed that STAT3 was localized primarily within astrocytic nuclei. At 6 and 24 h post-TBI, there was also an increased expression of STAT3 pathway-related genes: suppressor of cytokine signaling 3, nitric oxide synthase 2, colony stimulating factor 2 receptor β, oncostatin M, matrix metalloproteinase 3, cyclin-dependent kinase inhibitor 1A, CCAAT/enhancer-binding protein β, interleukin-2 receptor γ, interleukin-4 receptor α, and α-2-macroglobulin. These results clarify some of the signaling pathways operative in astrocytes after TBI and demonstrate that the gp130-Jak2-STAT3 signaling pathway is activated after TBI in astrocytes.
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Affiliation(s)
- Anthony A Oliva
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
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Tomaiuolo F, Bivona U, Lerch JP, Di Paola M, Carlesimo GA, Ciurli P, Matteis M, Cecchetti L, Forcina A, Silvestro D, Azicnuda E, Sabatini U, Di Giacomo D, Caltagirone C, Petrides M, Formisano R. Memory and anatomical change in severe non missile traumatic brain injury: ∼1 vs. ∼8 years follow-up. Brain Res Bull 2012; 87:373-82. [PMID: 22289841 DOI: 10.1016/j.brainresbull.2012.01.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 01/12/2012] [Accepted: 01/13/2012] [Indexed: 10/14/2022]
Abstract
In previous studies, we investigated a group of subjects who had suffered from a severe non missile traumatic brain injury (nmTBI) without macroscopic focal lesions and we found brain atrophy involving the hippocampus, fornix, corpus callosum, optic chiasm, and optic radiations. Memory test scores correlated mainly with fornix volumes [37,38]. In the present study, we re-examined 11 of these nmTBI subjects approximately 8 yr later. High-spatial resolution T1 weighted magnetic resonance images of the brain (1mm(3)) and standardised memory tests were performed once more in order to compare brain morphology and memory performance originally assessed 3-13 months after head injury (first study) and after 8-10 yr (present study). An overall improvement of memory test performance was demonstrated in the latest assessment, indicating that cognitive recovery in severe nmTBI subjects had not been completed within 3-13 months post-injury. It is notable that the volumes of the fornix and the hippocampus were reduced significantly from normal controls, but these volumes do not differ appreciatively between nmTBI subjects at first (after ∼1 yr) and at second (after ∼8 yr) scans. On the contrary, a clear reduction in the volume of the corpus callosus can be observed after ∼1 yr and a further significant reduction is evident after ∼8 yr, indicating that the neural degeneration in severe nmTBI continues long after the head trauma and relates to specific structures and not to the overall brain.
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Maxwell WL. Traumatic brain injury in the neonate, child and adolescent human: An overview of pathology. Int J Dev Neurosci 2011; 30:167-83. [DOI: 10.1016/j.ijdevneu.2011.12.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 10/27/2011] [Accepted: 12/16/2011] [Indexed: 01/14/2023] Open
Affiliation(s)
- William L. Maxwell
- Anatomy, Thomson BuildingSchool of Medicine Veterinary Medicine and Life SciencesUniversity of GlasgowGlasgowG12 8QQScotlandUnited Kingdom
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A history of sport-related concussion on event-related brain potential correlates of cognition. Int J Psychophysiol 2011; 82:16-23. [DOI: 10.1016/j.ijpsycho.2011.02.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 02/07/2011] [Accepted: 02/11/2011] [Indexed: 11/21/2022]
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Christidi F, Bigler ED, McCauley SR, Schnelle KP, Merkley TL, Mors MB, Li X, Macleod M, Chu Z, Hunter JV, Levin HS, Clifton GL, Wilde EA. Diffusion tensor imaging of the perforant pathway zone and its relation to memory function in patients with severe traumatic brain injury. J Neurotrauma 2011; 28:711-25. [PMID: 21381986 DOI: 10.1089/neu.2010.1644] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Based on the importance of the perforant pathway (PP) for normal hippocampal function, the vulnerability of temporal structures, and significant memory impairment in patients with traumatic brain injury (TBI), we investigated in vivo changes in the PP zone, hippocampus, and temporal lobe white and gray matter using diffusion tensor imaging (DTI) and volumetric analysis, and any specific relations with memory performance (Verbal Selective Reminding Test, Rey-Osterrieth Complex Figure Test), in 14 patients with severe TBI. Compared to a demographically-similar control group, our patients had significantly decreased fractional anisotropy (FA) and higher apparent diffusion coefficient (ADC) for the PP zone bilaterally, and higher ADC bilaterally in the hippocampus. Volumetric analysis revealed significantly decreased volumes in both hippocampi and temporal gray matter bilaterally. Consistent long-term retrieval (CLTR) and delayed recall were significantly related to (1) right and left PP zone ADC, (2) left hippocampus ADC, and (3) left hippocampal volume. Nonverbal memory (immediate and delayed recall) was significantly associated with (1) right and left PP zone ADC, (2) left hippocampal volume, and (3) gray (immediate recall) and white (immediate recall, bilaterally; delayed recall, left) matter temporal volumes. Advanced neuroimaging analysis can detect in vivo changes in the PP zone and temporal structures in patients with severe TBI, with these changes being highly associated with memory impairment.
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Affiliation(s)
- Foteini Christidi
- Postgraduate Program of Clinical Neuropsychology, Medical School of National and Kapodistrian University, Athens, Greece
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Malik SZ, Motamedi S, Royo NC, LeBold D, Watson DJ. Identification of potentially neuroprotective genes upregulated by neurotrophin treatment of CA3 neurons in the injured brain. J Neurotrauma 2011; 28:415-30. [PMID: 21083427 DOI: 10.1089/neu.2010.1487] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Specific neurotrophic factors mediate histological and/or functional improvement in animal models of traumatic brain injury (TBI). In previous work, several lines of evidence indicated that the mammalian neurotrophin NT-4/5 is neuroprotective for hippocampal CA3 pyramidal neurons after experimental TBI. We hypothesized that NT-4/5 neuroprotection is mediated by changes in the expression of specific sets of genes, and that NT-4/5-regulated genes are potential therapeutic targets for blocking delayed neuronal death after TBI. In this study, we performed transcription profiling analysis of CA3 neurons to identify genes regulated by lateral fluid percussion injury, or by treatment with the trkB ligands NT-4/5 or brain-derived neurotrophic factor (BDNF). The results indicate extensive overlap between genes upregulated by neurotrophins and genes upregulated by injury, suggesting that the mechanism behind neurotrophin neuroprotection may mimic the brain's endogenous protective response. A subset of genes selected for further study in vitro exhibited neuroprotection against glutamate excitotoxicity. The neuroprotective genes identified in this study were upregulated at 30 h post-injury, and are thus expected to act during a clinically useful time frame of hours to days after injury. Modulation of these factors and pathways by genetic manipulation or small molecules may confer hippocampal neuroprotection in vivo in preclinical models of TBI.
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Affiliation(s)
- Saafan Z Malik
- Department of Neurosurgery and Center for Brain Injury and Repair, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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