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Solár P, Zamani A, Lakatosová K, Joukal M. The blood-brain barrier and the neurovascular unit in subarachnoid hemorrhage: molecular events and potential treatments. Fluids Barriers CNS 2022; 19:29. [PMID: 35410231 PMCID: PMC8996682 DOI: 10.1186/s12987-022-00312-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/24/2022] [Indexed: 12/12/2022] Open
Abstract
The response of the blood-brain barrier (BBB) following a stroke, including subarachnoid hemorrhage (SAH), has been studied extensively. The main components of this reaction are endothelial cells, pericytes, and astrocytes that affect microglia, neurons, and vascular smooth muscle cells. SAH induces alterations in individual BBB cells, leading to brain homeostasis disruption. Recent experiments have uncovered many pathophysiological cascades affecting the BBB following SAH. Targeting some of these pathways is important for restoring brain function following SAH. BBB injury occurs immediately after SAH and has long-lasting consequences, but most changes in the pathophysiological cascades occur in the first few days following SAH. These changes determine the development of early brain injury as well as delayed cerebral ischemia. SAH-induced neuroprotection also plays an important role and weakens the negative impact of SAH. Supporting some of these beneficial cascades while attenuating the major pathophysiological pathways might be decisive in inhibiting the negative impact of bleeding in the subarachnoid space. In this review, we attempt a comprehensive overview of the current knowledge on the molecular and cellular changes in the BBB following SAH and their possible modulation by various drugs and substances.
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Affiliation(s)
- Peter Solár
- Department of Anatomy, Cellular and Molecular Neurobiology Research Group, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic
- Department of Neurosurgery, Faculty of Medicine, Masaryk University and St. Anne's University Hospital Brno, Pekařská 53, 656 91, Brno, Czech Republic
| | - Alemeh Zamani
- Department of Anatomy, Cellular and Molecular Neurobiology Research Group, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic
| | - Klaudia Lakatosová
- Department of Anatomy, Cellular and Molecular Neurobiology Research Group, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic
| | - Marek Joukal
- Department of Anatomy, Cellular and Molecular Neurobiology Research Group, Faculty of Medicine, Masaryk University, 625 00, Brno, Czech Republic.
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2
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Toffa DH, Sow AD. The enigma of headaches associated with electromagnetic hyperfrequencies: Hypotheses supporting non-psychogenic algogenic processes. Electromagn Biol Med 2020; 39:196-205. [PMID: 32401641 DOI: 10.1080/15368378.2020.1762638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Although an electrohypersensitivity (EHS) is reported in numerous studies, some authors associate hyperfrequencies (HF)-related pains with a nocebo effect while others suggest a biological effect. Therefore, we aimed to suggest hypotheses about the complex mechanisms of headaches related to HF-exposure. We crossed basic features of headaches with relevant studies (from the year 2000 up to 2018) emphasizing on the HF effects that may lead to pain genesis: neuroglial dysmetabolism, neuroinflammation, changes in cerebral blood perfusion, blood-brain barrier dysfunction and electrophysiological evidences of hyperexcitability. We privileged studies implying a sham exposure (for in vivo studies) and a specific absorption rate lower than 4 W/Kg. HF-induced headaches may involve an indirect inflammatory process (neurogenic, magnetogenic or thermogenic) as well as a direct biophysical effect (thermogenic or magnetogenic). We linked inflammatory processes to meningeal dysperfusion or primary neuroglial dysfunction triggered by non-thermal irradiation or HF-induced heating at thermal powers. In the latter case, HF-induced excitoxicity and oxidative stress probably play a crucial role. Such disorders may lead to vascular-trigeminal activation in predisposed people. Interestingly, an abnormal oxidative stress predisposition had been demonstrated in overall 80% of EHS self-reporting patients. In the case of direct effects, pain pathways' activation may be directly triggered by HF-irradiation (heating and/or transcranial HF-induced ectopic action potentials). Further research on HF-related headaches is needed.
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Affiliation(s)
- D H Toffa
- Division of Neurosciences, Centre de Recherche du Centre Hospitalier de l'Université de Montréal , Montreal, Canada
| | - A D Sow
- Division of Neurology, CHUN Fann, Université Cheikh Anta Diop , Dakar, Senegal
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3
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Hansen FB, Secher N, Jensen MS, Østergaard L, Tønnesen E, Granfeldt A. Cortical spreading depolarizations in the postresuscitation period in a cardiac arrest male rat model. J Neurosci Res 2017; 95:2040-2050. [PMID: 28198552 DOI: 10.1002/jnr.24033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 12/28/2016] [Accepted: 01/17/2017] [Indexed: 12/14/2022]
Abstract
Neurological injury develops over days following cardiac arrest (CA); however, the exact mechanisms remain unknown. After stroke or trauma, the progression of neurological injury is associated with cortical-spreading depolarizations (CSDs). The objective was to investigate whether CA and subsequent resuscitation in rats are associated with 1) the development of spontaneous negative direct current (DC) shifts indicative of CSDs, and 2) changes in artificially induced CSDs in the postresuscitation period. Male Sprague-Dawley rats were randomized into four groups: 1) CA 90, 2) Control 90, 3) CA 360, and 4) Control 360. Following 8 min of asphyxial CA, animals were resuscitated using adrenaline, ventilation, and chest compressions. Animals were observed for 90 or 360 min, respectively, before a 210-min data collection period. Cortical potentials were recorded through burr holes over the right hemisphere. Animals were intubated and monitored with invasive blood pressure, ECG, and arterial blood gas samples throughout the study. Spontaneous DC shifts occurred in only 1 of the 14 CA animals. In control animals, DC shifts were easy to induce, and their shape was highly uniform, consistent with that of classical CSDs. In CA animals, significantly fewer DC shifts could be induced, and their shape was profoundly altered compared with controls. We observed frequent epileptiform discharges and temporal clusters of activity. Spontaneous CSDs were not a consistent finding in CA animals. Instead, spontaneous epileptiform discharges and temporal cluster of activity were observed, while the shapes of induced DC shifts were profoundly altered compared with controls. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Frederik Boe Hansen
- Department of Anesthesiology and Intensive Care, Aarhus University Hospital, Aarhus, Denmark.,Department of Accident and Emergency Medicine, Regional Hospital Horsens, Horsens, Denmark
| | - Niels Secher
- Department of Anesthesiology and Intensive Care, Aarhus University Hospital, Aarhus, Denmark
| | | | - Leif Østergaard
- Center of Functionally Integrative Neuroscience, Aarhus University Hospital, Aarhus, Denmark
| | - Else Tønnesen
- Department of Anesthesiology and Intensive Care, Aarhus University Hospital, Aarhus, Denmark
| | - Asger Granfeldt
- Department of Anesthesiology and Intensive Care, Aarhus University Hospital, Aarhus, Denmark
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Fujita S, Mizoguchi N, Aoki R, Cui Y, Koshikawa N, Kobayashi M. Cytoarchitecture-Dependent Decrease in Propagation Velocity of Cortical Spreading Depression in the Rat Insular Cortex Revealed by Optical Imaging. Cereb Cortex 2015; 26:1580-1589. [PMID: 25595184 DOI: 10.1093/cercor/bhu336] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cortical spreading depression (SD) is a self-propagating wave of depolarization accompanied by a substantial disturbance of the ionic distribution between the intra- and extracellular compartments. Glial cells, including astrocytes, play critical roles in maintenance of the extracellular environment, including ionic distribution. Therefore, SD propagation in the cerebral cortex may depend on the density of astrocytes. The present study aimed to examine the profile of SD propagation in the insular cortex (IC), which is located between the neocortex and paleocortex and is where the density of astrocytes gradually changes. The velocity of SD propagation in the neocortex, including the somatosensory, motor, and granular insular cortices (5.7 mm/min), was higher than that (2.8 mm/min) in the paleocortex (agranular insular and piriform cortices). Around thick vessels, including the middle cerebral artery, SD propagation was frequently delayed and sometimes disappeared. Immunohistological analysis of glial fibrillary acidic protein (GFAP) demonstrated the sparse distribution of astrocytes in the somatosensory cortex and the IC dorsal to the rhinal fissure, whereas the ventral IC showed a higher density of astrocytes. These results suggest that cortical cytoarchitectonic features, which possibly involve the distribution of astrocytes, are crucial for regulating the velocity of SD propagation in the cerebral cortex.
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Affiliation(s)
- Satoshi Fujita
- Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.,Division of Oral and Craniomaxillofacial Research, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Naoko Mizoguchi
- Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.,Division of Physiology, Department of Human Development and Fostering
| | - Ryuhei Aoki
- Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.,Division of Oral and Maxillofacial Surgery, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama 350-0283, Japan
| | - Yilong Cui
- Molecular Dynamics Imaging Unit, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Noriaki Koshikawa
- Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.,Division of Oral and Craniomaxillofacial Research, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
| | - Masayuki Kobayashi
- Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.,Division of Oral and Craniomaxillofacial Research, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.,Molecular Dynamics Imaging Unit, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
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Pusic KM, Pusic AD, Kemme J, Kraig RP. Spreading depression requires microglia and is decreased by their M2a polarization from environmental enrichment. Glia 2014; 62:1176-94. [PMID: 24723305 PMCID: PMC4081540 DOI: 10.1002/glia.22672] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 03/25/2014] [Accepted: 03/27/2014] [Indexed: 12/12/2022]
Abstract
Microglia play an important role in fine-tuning neuronal activity. In part, this involves their production of tumor necrosis factor-alpha (TNFα), which increases neuronal excitability. Excessive synaptic activity is necessary to initiate spreading depression (SD). Increased microglial production of proinflammatory cytokines promotes initiation of SD, which, when recurrent, may play a role in conversion of episodic to high frequency and chronic migraine. Previous work shows that this potentiation of SD occurs through increased microglial production of TNFα and reactive oxygen species, both of which are associated with an M1-skewed microglial population. Hence, we explored the role of microglia and their M1 polarization in SD initiation. Selective ablation of microglia from rat hippocampal slice cultures confirmed that microglia are essential for initiation of SD. Application of minocycline to dampen M1 signaling led to increased SD threshold. In addition, we found that SD threshold was increased in rats exposed to environmental enrichment. These rats had increased neocortical levels of interleukin-11 (IL-11), which decreases TNFα signaling and polarized microglia to an M2a-dominant phenotype. M2a microglia reduce proinflammatory signaling and increase production of anti-inflammatory cytokines, and therefore may protect against SD. Nasal administration of IL-11 to mimic effects of environmental enrichment likewise increased M2a polarization and increased SD threshold, an effect also seen in vitro. Similarly, application of conditioned medium from M2a polarized primary microglia to slice cultures also increased SD threshold. Thus, microglia and their polarization state play an essential role in SD initiation, and perhaps by extension migraine with aura and migraine.
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Affiliation(s)
- Kae M. Pusic
- Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
| | - Aya D. Pusic
- Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
- Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, USA
| | - Jordan Kemme
- Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
| | - Richard P. Kraig
- Department of Neurology, The University of Chicago, Chicago, IL 60637, USA
- Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, USA
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6
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Torrente D, Cabezas R, Avila MF, García-Segura LM, Barreto GE, Guedes RCA. Cortical spreading depression in traumatic brain injuries: is there a role for astrocytes? Neurosci Lett 2014; 565:2-6. [PMID: 24394907 DOI: 10.1016/j.neulet.2013.12.058] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/21/2013] [Accepted: 12/23/2013] [Indexed: 10/25/2022]
Abstract
Cortical spreading depression (CSD) is a presumably pathophysiological phenomenon that interrupts local cortical function for periods of minutes to hours. This phenomenon is important due to its association with different neurological disorders such as migraine, malignant stroke and traumatic brain injury (TBI). Glial cells, especially astrocytes, play an important role in the regulation of CSD and in the protection of neurons under brain trauma. The correlation of TBI with CSD and the astrocytic function under these conditions remain unclear. This review discusses the possible link of TBI and CSD and its implication for neuronal survival. Additionally, we highlight the importance of astrocytic function for brain protection, and suggest possible therapeutic strategies targeting astrocytes to improve the outcome following TBI-associated CSD.
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Affiliation(s)
- Daniel Torrente
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
| | - Ricardo Cabezas
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
| | - Marco Fidel Avila
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
| | | | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
| | - Rubem Carlos Araújo Guedes
- Departamento de Nutrição, Centro de Ciências da Saúde, Universidade Federal de Pernambuco, Recife, PE, Brazil.
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7
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Chen C, Yang JM, Hu TT, Xu TJ, Xu WP, Wei W. Elevated dopamine D2 receptor in prefrontal cortex of CUMS rats is associated with downregulated cAMP-independent signaling pathway. Can J Physiol Pharmacol 2013; 91:750-8. [PMID: 23984873 DOI: 10.1139/cjpp-2012-0399] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Because depression is associated with significant morbidity and functional disability, it is important to reveal the mechanism of action. A variety of studies have suggested the involvement of dopaminergic receptors in the pathophysiological mechanism of non-stress-associated depression-like behavior in rodents. Nevertheless, controversy exists about whether chronic stress acts on dopaminergic receptors in the prefrontal cortex. Thus, we investigated the level of dopamine D2 receptors (DRD2) and the possible mechanisms involved in a chronic unpredictable mild stress (CUMS) rat model of depression. The results showed CUMS-induced, depression-like symptoms in the rat, characterized by reduced sucrose consumption and body mass, and increased duration of immobility in a forced swimming test. Moreover, chronic stress upregulated the expression of DRD2 but downregulated protein kinase A (PKA), transcription factor cAMP response element binding protein (CREB), and phospho-CREB (p-CREB) in the prefrontal cortex, as demonstrated by Western blot. Notably, in the rat model of depression, decreased cyclic adenine monophosphate (cAMP) levels and PKA activity were present at the same time, which is consistent with clinical findings in depressed patients. Our findings suggested that dopaminergic system dysfunction could play a central role in stress-related disorders such as depression.
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Affiliation(s)
- Cheng Chen
- Institute of Clinical Pharmacology of Anhui Medical University, Key Laboratory of Anti-inflammatory and Immunopharmacology of Education Ministry, Hefei 230032, Anhui, China
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8
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Diffusing substances during spreading depolarization: analytical expressions for propagation speed, triggering, and concentration time courses. J Neurosci 2013; 33:5915-23. [PMID: 23554473 DOI: 10.1523/jneurosci.5115-12.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Spreading depolarization (SD) is an important phenomenon in stroke and migraine. However, the processes underlying the propagation of SD are still poorly understood, and an elementary model that is both physiological and quantitative is lacking. We show that, during the onset and propagation of SD, the concentration time courses of excitatory substances such as potassium and glutamate can be described with a reaction-diffusion equation. This equation contains four physiological parameters: (1) a concentration threshold for excitation; (2) a release rate; (3) a removal rate; and (4) an effective diffusion constant. Solving this equation yields expressions for the propagation velocity, concentration time courses, and the minimum stimulus that can trigger SD. This framework allows for analyzing experimental results in terms of these four parameters. The derived time courses are validated with measurements of potassium in rat brain tissue.
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Yu Y, Santos LM, Mattiace LA, Costa ML, Ferreira LC, Benabou K, Kim AH, Abrahams J, Bennett MVL, Rozental R. Reentrant spiral waves of spreading depression cause macular degeneration in hypoglycemic chicken retina. Proc Natl Acad Sci U S A 2012; 109:2585-9. [PMID: 22308470 PMCID: PMC3289307 DOI: 10.1073/pnas.1121111109] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spreading depression (SD), a slow diffusion-mediated self-sustained wave of depolarization that severely disrupts neuronal function, has been implicated as a cause of cellular injury in a number of central nervous system pathologies, including blind spots in the retina. Here we show that in the hypoglycemic chicken retina, spontaneous episodes of SD can occur, resulting in irreversible punctate lesions in the macula, the region of highest visual acuity in the central region of the retina. These lesions in turn can act as sites of origin for secondary self-sustained reentrant spiral waves of SD that progressively enlarge the lesions. Furthermore, we show that the degeneration of the macula under hypoglycemic conditions can be prevented by blocking reentrant spiral SDs or by blocking caspases. The observation that spontaneous formation of reentrant spiral SD waves leads to the development of progressive retinal lesions under conditions of hypoglycemia establishes a potential role of SD in initiation and progression of macular degeneration, one of the leading causes of visual disability worldwide.
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Affiliation(s)
- Yufei Yu
- Departments of Cell Biology and Anatomy
| | - Laura M. Santos
- Programa de Ciências Morfológicas, Instituto de Ciências Biomédicas
- Stratego/Thermopraxis, Bio-Rio Polo de Biotecnologia, 21941-904 Rio de Janeiro, Brazil
| | | | - Manoel L. Costa
- Programa de Ciências Morfológicas, Instituto de Ciências Biomédicas
| | | | | | - Ana H. Kim
- Otolaryngology, and
- New York Eye and Ear Infirmary, New York, NY 10003
| | - John Abrahams
- Neurosurgery, New York Medical College, Valhalla, NY 10595
| | - Michael V. L. Bennett
- Domick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461; and
| | - Renato Rozental
- Departments of Cell Biology and Anatomy
- Programa de Ciências Morfológicas, Instituto de Ciências Biomédicas
- Biotechnology Innovation Center-Paulo de Góes, Maternidade Escola, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
- Department of Neurosurgery, Medical College of Georgia, Augusta, GA 30912
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10
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Clauss RP. Neurotransmitters in disorders of consciousness and brain damage. Med Hypotheses 2011; 77:209-13. [PMID: 21549512 DOI: 10.1016/j.mehy.2011.04.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 03/30/2011] [Accepted: 04/08/2011] [Indexed: 01/17/2023]
Abstract
Restorations from disorders of consciousness such as the minimally conscious state and the vegetative state have been achieved spontaneously or by pharmacological agents such as zolpidem, baclofen, dopaminergic agents and tricyclic antidepressants in some patients. Other restoration methods have included electric and magnetic nerve stimulation, oxygen, Kreb's cycle constituent substitution and axonal re-growth. Although apparently unrelated, these methods all influence neurotransmitter availability or production within the brain. This review proposes depleted neurotransmitter function as a cause for long term brain suppression and disorders of consciousness. It unifies fundamentally different treatment approaches and explores the restoration of neurotransmitter function as a common theme to improve brain function after brain damage.
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Affiliation(s)
- R P Clauss
- Nuclear Medicine Department, Royal Surrey County Hospital, Guildford, Surrey GU27XX, UK.
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11
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Neuroinflammation and brain infections: historical context and current perspectives. ACTA ACUST UNITED AC 2010; 66:152-73. [PMID: 20883721 DOI: 10.1016/j.brainresrev.2010.09.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 09/20/2010] [Accepted: 09/22/2010] [Indexed: 12/25/2022]
Abstract
An overview of current concepts on neuroinflammation and on the dialogue between neurons and non-neuronal cells in three important infections of the central nervous systems (rabies, cerebral malaria, and human African trypanosomiasis or sleeping sickness) is here presented. Large numbers of cases affected by these diseases are currently reported. In the context of an issue dedicated to Camillo Golgi, historical notes on seminal discoveries on these diseases are also presented. Neuroinflammation is currently closely associated with pathogenetic mechanisms of chronic neurodegenerative diseases. Neuroinflammatory signaling in brain infections is instead relatively neglected in the neuroscience community, despite the fact that the above infections provide paradigmatic examples of alterations of the intercellular crosstalk between neurons and non-neuronal cells. In rabies, strategies of immune evasion of the host lead to silencing neuroinflammatory signaling. In the intravascular pathology which characterizes cerebral malaria, leukocytes and Plasmodium do not enter the brain parenchyma. In sleeping sickness, leukocytes and African trypanosomes invade the brain parenchyma at an advanced stage of infection. Both the latter pathologies leave open many questions on the targeting of neuronal functions and on the pathogenetic role of non-neuronal cells, and in particular astrocytes and microglia, in these diseases. All three infections are hallmarked by very severe clinical pictures and relative sparing of neuronal structure. Multidisciplinary approaches and a concerted action of the neuroscience community are needed to shed light on intercellular crosstalk in these dreadful brain diseases. Such effort could also lead to new knowledge on non-neuronal mechanisms which determine neuronal death or survival.
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