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Morris G, Avoli M, Bernard C, Connor K, de Curtis M, Dulla CG, Jefferys JGR, Psarropoulou C, Staley KJ, Cunningham MO. Can in vitro studies aid in the development and use of antiseizure therapies? A report of the ILAE/AES Joint Translational Task Force. Epilepsia 2023; 64:2571-2585. [PMID: 37642296 DOI: 10.1111/epi.17744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/11/2023] [Accepted: 08/11/2023] [Indexed: 08/31/2023]
Abstract
In vitro preparations (defined here as cultured cells, brain slices, and isolated whole brains) offer a variety of approaches to modeling various aspects of seizures and epilepsy. Such models are particularly amenable to the application of anti-seizure compounds, and consequently are a valuable tool to screen the mechanisms of epileptiform activity, mode of action of known anti-seizure medications (ASMs), and the potential efficacy of putative new anti-seizure compounds. Despite these applications, all disease models are a simplification of reality and are therefore subject to limitations. In this review, we summarize the main types of in vitro models that can be used in epilepsy research, describing key methodologies as well as notable advantages and disadvantages of each. We argue that a well-designed battery of in vitro models can form an effective and potentially high-throughput screening platform to predict the clinical usefulness of ASMs, and that in vitro models are particularly useful for interrogating mechanisms of ASMs. To conclude, we offer several key recommendations that maximize the potential value of in vitro models in ASM screening. This includes the use of multiple in vitro tests that can complement each other, carefully combined with in vivo studies, the use of tissues from chronically epileptic (rather than naïve wild-type) animals, and the integration of human cell/tissue-derived preparations.
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Affiliation(s)
- Gareth Morris
- Division of Neuroscience, Faculty of Biology, Medicine and Health, School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Massimo Avoli
- Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery, McGill University, Montréal, Quebec, Canada
- Department of Physiology, McGill University, Montréal, Quebec, Canada
| | - Christophe Bernard
- Inserm, INS, Institut de Neurosciences des Systèmes, Aix Marseille Univ, Marseille, France
| | - Kate Connor
- Discipline of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Chris G Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - John G R Jefferys
- Department of Physiology, 2nd Medical School, Motol, Charles University, Prague, Czech Republic
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Caterina Psarropoulou
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Kevin J Staley
- Neurology Department, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Mark O Cunningham
- Discipline of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
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Walter FR, Santa-Maria AR, Mészáros M, Veszelka S, Dér A, Deli MA. Surface charge, glycocalyx, and blood-brain barrier function. Tissue Barriers 2021; 9:1904773. [PMID: 34003072 DOI: 10.1080/21688370.2021.1904773] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The negative surface charge of brain microvessel endothelial cells is derived from the special composition of their membrane lipids and the thick endothelial surface glycocalyx. They are important elements of the unique defense systems of the blood-brain barrier. The tissue-specific properties, components, function and charge of the brain endothelial glycocalyx have only been studied in detail in the past 15 years. This review highlights the importance of the negative surface charge in the permeability of macromolecules and nanoparticles as well as in drug interactions. We discuss surface charge and glycoxalyx changes in pathologies related to the brain microvasculature and protective measures against glycocalyx shedding and damage. We present biophysical techniques, including a microfluidic chip device, to measure surface charge of living brain endothelial cells and imaging methods for visualization of surface charge and glycocalyx.
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Affiliation(s)
- Fruzsina R Walter
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary.,Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Ana R Santa-Maria
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary.,Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Mária Mészáros
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Szilvia Veszelka
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - András Dér
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Mária A Deli
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
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3
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Shi S, Zhang H, Yin X, Wang Z, Tang B, Luo Y, Ding H, Chen Z, Cao Y, Wang T, Xiao B, Zhang M. 3D digital anatomic angioarchitecture of the mouse brain using synchrotron-radiation-based propagation phase-contrast imaging. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:1742-1750. [PMID: 31490166 DOI: 10.1107/s160057751900674x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 05/10/2019] [Indexed: 06/10/2023]
Abstract
Thorough investigation of the three-dimensional (3D) configuration of the vasculature of mouse brain remains technologically difficult because of its complex anatomical structure. In this study, a systematic analysis is developed to visualize the 3D angioarchitecture of mouse brain at ultrahigh resolution using synchrotron-radiation-based propagation phase-contrast imaging. This method provides detailed restoration of the intricate brain microvascular network in a precise 3D manner. In addition to depicting the delicate 3D arrangements of the vascular network, 3D virtual micro-endoscopy is also innovatively performed to visualize randomly a selected vessel within the brain for both external 3D micro-imaging and endoscopic visualization of any targeted microvessels, which improves the understanding of the intrinsic properties of the mouse brain angioarchitecture. Based on these data, hierarchical visualization has been established and a systematic assessment on the 3D configuration of the mouse brain microvascular network has been achieved at high resolution which will aid in advancing the understanding of the role of vasculature in the perspective of structure and function in depth. This holds great promise for wider application in various models of neurovascular diseases.
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Affiliation(s)
- Shupeng Shi
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Haoran Zhang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Xianzhen Yin
- Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, People's Republic of China
| | - Zhuolu Wang
- Department of Breast Surgery, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410008, People's Republic of China
| | - Bin Tang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Yuebei Luo
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Hui Ding
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Zhuohui Chen
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Yong Cao
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha 410008, People's Republic of China
| | - Tiantian Wang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Mengqi Zhang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
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Sanavio B, Librizzi L, Pennacchio P, Beznoussenko GV, Sousa F, Silva PJ, Mironov AA, Frassoni C, Stellacci F, de Curtis M, Krol S. Distribution of superparamagnetic Au/Fe nanoparticles in an isolated guinea pig brain with an intact blood brain barrier. NANOSCALE 2018; 10:22420-22428. [PMID: 30475372 DOI: 10.1039/c8nr07182a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Diagnosis and treatment of brain disorders, such as epilepsy, neurodegenerative diseases and tumors, would benefit from innovative approaches to deliver therapeutic or diagnostic compounds into the brain parenchyma, with either a homogeneous or a targeted localized distribution pattern. To assess the mechanistic aspect of penetration of nanoparticles (NPs) into the brain parenchyma, a complex, yet controlled and facilitated environment was used: the isolated guinea pig brain maintained in vitro by arterial perfusion. In this unique preparation the blood-brain barrier and the interactions between vascular and neuronal compartments are morphologically and functionally preserved. In this study, superparamagnetic Au/Fe nanoparticles (MUS:OT Au/Fe NPs), recently studied as a promising magnetic resonance T2 contrast agent with high cellular penetration, were arterially perfused into the in vitro isolated brain and showed high and homogeneous penetration through transcytosis into the brain parenchyma. Ultramicroscopy investigation of the in vitro isolated brain sections by TEM analysis of the electron-dense core of the MUS:OT Au/Fe NPs was conducted to understand NPs' brain penetration through the BBB after in vitro arterial perfusion and their distribution in the parenchyma. Our data suggest that MUS:OT Au/Fe NPs enter the brain utilizing a physiological route and therefore can be exploited as brain penetrating nanomaterials with potential contrast agent and theranostics capabilities.
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Affiliation(s)
- Barbara Sanavio
- Nanomedicine Laboratory, Fondazione IRCCS Istituto Neurologico Carlo Besta, c/o AMADEOLAB, via G.A. Amadeo 42, 20133 Milan, Italy.
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Haeren RHL, Vink H, Staals J, van Zandvoort MAMJ, Dings J, van Overbeeke JJ, Hoogland G, Rijkers K, Schijns OEMG. Protocol for intraoperative assessment of the human cerebrovascular glycocalyx. BMJ Open 2017; 7:e013954. [PMID: 28057660 PMCID: PMC5223665 DOI: 10.1136/bmjopen-2016-013954] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION Adequate functioning of the blood-brain barrier (BBB) is important for brain homoeostasis and normal neuronal function. Disruption of the BBB has been described in several neurological diseases. Recent reports suggest that an increased permeability of the BBB also contributes to increased seizure susceptibility in patients with epilepsy. The endothelial glycocalyx is coating the luminal side of the endothelium and can be considered as the first barrier of the BBB. We hypothesise that an altered glycocalyx thickness plays a role in the aetiology of temporal lobe epilepsy (TLE), the most common type of epilepsy. Here, we propose a protocol that allows intraoperative assessment of the cerebrovascular glycocalyx thickness in patients with TLE and assess whether its thickness is decreased in patients with TLE when compared with controls. METHODS AND ANALYSIS This protocol is designed as a prospective observational case-control study in patients who undergo resective brain surgery as treatment for TLE. Control subjects are patients without a history of epileptic seizures, who undergo a craniotomy or burr hole surgery for other indications. Intraoperative glycocalyx thickness measurements of sublingual, cortical and hippocampal microcirculation are performed by video microscopy using sidestream dark-field imaging. Demographic details, seizure characteristics, epilepsy risk factors, intraoperative haemodynamic parameters and histopathological evaluation are additionally recorded. ETHICS AND DISSEMINATION This protocol has been ethically approved by the local medical ethical committee (ID: NL51594.068.14) and complies with the Declaration of Helsinki and principles of Good Clinical Practice. Informed consent is obtained before study enrolment and only coded data will be stored in a secured database, enabling an audit trail. Results will be submitted to international peer-reviewed journals and presented at international conferences. TRIAL REGISTRATION NUMBER NTR5568.
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Affiliation(s)
- R H L Haeren
- Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - H Vink
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - J Staals
- Department of Neurology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - M A M J van Zandvoort
- Department of Genetics & Cell Biology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
- Institute for Molecular Cardiovascular Research, IMCAR, Universitätsklinikum, Aachen University, Aachen, Germany
| | - J Dings
- Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
- Academic Center for Epileptology, Maastricht University Medical Center and Kempenhaeghe, Maastricht/Heeze, The Netherlands
| | - J J van Overbeeke
- Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
- Academic Center for Epileptology, Maastricht University Medical Center and Kempenhaeghe, Maastricht/Heeze, The Netherlands
| | - G Hoogland
- Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
- Academic Center for Epileptology, Maastricht University Medical Center and Kempenhaeghe, Maastricht/Heeze, The Netherlands
| | - K Rijkers
- Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Neurosurgery, Zuyderland Medical Center, Heerlen, The Netherlands
| | - O E M G Schijns
- Department of Neurosurgery, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
- Academic Center for Epileptology, Maastricht University Medical Center and Kempenhaeghe, Maastricht/Heeze, The Netherlands
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Carone D, Librizzi L, Cattalini A, Sala G, Conti E, Cuccione E, Versace A, Cai R, Monza L, de Curtis M, Ferrarese C, Beretta S. Pravastatin acute neuroprotective effects depend on blood brain barrier integrity in experimental cerebral ischemia. Brain Res 2015; 1615:31-41. [DOI: 10.1016/j.brainres.2015.04.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 04/11/2015] [Accepted: 04/14/2015] [Indexed: 12/20/2022]
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7
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de Curtis M, Librizzi L, Uva L. The in vitro isolated whole guinea pig brain as a model to study epileptiform activity patterns. J Neurosci Methods 2015; 260:83-90. [PMID: 25843067 DOI: 10.1016/j.jneumeth.2015.03.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 01/02/2023]
Abstract
BACKGROUND Research on ictogenesis is based on the study of activity between seizures and during seizures in animal models of epilepsy (chronic condition) or in in vitro slices obtained from naïve non-epileptic brains after treatment with pro-convulsive drugs, manipulations of the extracellular medium and specific stimulation protocols. NEW METHOD The in vitro isolated guinea pig brain retains the functional connectivity between brain structures and maintains interactions between neuronal, glial and vascular compartments. It is a close-to-in vivo preparation that offers experimental advantages not achieved with the use of other experimental models. Neurophysiological and imaging techniques can be utilized in this preparation to study brain activity during and between seizures induced by pharmacological or functional manipulations. RESULTS Cellular and network determinants of interictal and ictal discharges that reproduce abnormal patterns observed in human focal epilepsies and the associated changes in extracellular ion and blood-brain permeability can be identified and analyzed in the isolated guinea pig brain. COMPARISON WITH EXISTING METHODS Ictal and interictal patterns recorded in in vitro slices may show substantial differences from seizure activity recorded in vivo due to slicing procedure itself. The isolated guinea pig brain maintained in vitro by arterial perfusion combines the typical facilitated access of in vitro preparations, that are difficult to approach during in vivo experiments, with the preservation of larger neuronal networks. CONCLUSIONS The in vitro whole isolated guinea pig brain preparation offers an unique experimental model to study systemic and neurovascular changes during ictogenesis.
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Affiliation(s)
- Marco de Curtis
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy.
| | - Laura Librizzi
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Laura Uva
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
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Bucharles C, Bizet P, Arthaud S, Arabo A, Leprince J, Lefranc B, Cartier D, Anouar Y, Lihrmann I. Concordant localization of functional urotensin II and urotensin II-related peptide binding sites in the rat brain: Atypical occurrence close to the fourth ventricle. J Comp Neurol 2014; 522:2634-49. [DOI: 10.1002/cne.23553] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 01/23/2014] [Accepted: 01/23/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Christine Bucharles
- Inserm, U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedicine; University of Rouen; Mont-Saint-Aignan France
- Normandy University, University of Rouen; Mont-Saint-Aignan France
| | - Patrice Bizet
- Inserm, U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedicine; University of Rouen; Mont-Saint-Aignan France
- Normandy University, University of Rouen; Mont-Saint-Aignan France
| | - Sébastien Arthaud
- Inserm, U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedicine; University of Rouen; Mont-Saint-Aignan France
- Normandy University, University of Rouen; Mont-Saint-Aignan France
| | - Arnaud Arabo
- Normandy University, University of Rouen; Mont-Saint-Aignan France
- Faculty of Sciences; University of Rouen; Mont-Saint-Aignan France
| | - Jérôme Leprince
- Inserm, U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedicine; University of Rouen; Mont-Saint-Aignan France
- Normandy University, University of Rouen; Mont-Saint-Aignan France
| | - Benjamin Lefranc
- Inserm, U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedicine; University of Rouen; Mont-Saint-Aignan France
- Normandy University, University of Rouen; Mont-Saint-Aignan France
| | - Dorthe Cartier
- Inserm, U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedicine; University of Rouen; Mont-Saint-Aignan France
- Normandy University, University of Rouen; Mont-Saint-Aignan France
| | - Youssef Anouar
- Inserm, U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedicine; University of Rouen; Mont-Saint-Aignan France
- Normandy University, University of Rouen; Mont-Saint-Aignan France
| | - Isabelle Lihrmann
- Inserm, U982, Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, Institute for Research and Innovation in Biomedicine; University of Rouen; Mont-Saint-Aignan France
- Normandy University, University of Rouen; Mont-Saint-Aignan France
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Zehendner CM, Librizzi L, Hedrich J, Bauer NM, Angamo EA, de Curtis M, Luhmann HJ. Moderate hypoxia followed by reoxygenation results in blood-brain barrier breakdown via oxidative stress-dependent tight-junction protein disruption. PLoS One 2013; 8:e82823. [PMID: 24324834 PMCID: PMC3855783 DOI: 10.1371/journal.pone.0082823] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 10/28/2013] [Indexed: 11/19/2022] Open
Abstract
Re-canalization of cerebral vessels in ischemic stroke is pivotal to rescue dysfunctional brain areas that are exposed to moderate hypoxia within the penumbra from irreversible cell death. Goal of the present study was to evaluate the effect of moderate hypoxia followed by reoxygenation (MHR) on the evolution of reactive oxygen species (ROS) and blood-brain barrier (BBB) integrity in brain endothelial cells (BEC). BBB integrity was assessed in BEC in vitro and in microvessels of the guinea pig whole brain in situ preparation. Probes were exposed to MHR (2 hours 67-70 mmHg O2, 3 hours reoxygenation, BEC) or towards occlusion of the arteria cerebri media (MCAO) with or without subsequent reperfusion in the whole brain preparation. In vitro BBB integrity was evaluated using trans-endothelial electrical resistance (TEER) and transwell permeability assays. ROS in BEC were evaluated using 2',7'-dichlorodihydrofluorescein diacetate (DCF), MitoSox and immunostaining for nitrotyrosine. Tight-junction protein (TJ) integrity in BEC, stainings for nitrotyrosine and FITC-albumin extravasation in the guinea pig brain preparation were assessed by confocal microscopy. Diphenyleneiodonium (DPI) was used to investigate NADPH oxidase dependent ROS evolution and its effect on BBB parameters in BEC. MHR impaired TJ proteins zonula occludens 1 (ZO-1) and claudin 5 (Cl5), decreased TEER, and significantly increased cytosolic ROS in BEC. These events were blocked by the NADPH oxidase inhibitor DPI. MCAO with or without subsequent reoxygenation resulted in extravasation of FITC-albumin and ROS generation in the penumbra region of the guinea pig brain preparation and confirmed BBB damage. BEC integrity may be impaired through ROS in MHR on the level of TJ and the BBB is also functionally impaired in moderate hypoxic conditions followed by reperfusion in a complex guinea pig brain preparation. These findings suggest that the BBB is susceptible towards MHR and that ROS play a key role in this process.
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Affiliation(s)
- Christoph M. Zehendner
- Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
- * E-mail:
| | - Laura Librizzi
- Unit of Experimental Neurophysiology and Epileptology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Jana Hedrich
- Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Nina M. Bauer
- Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Eskedar A. Angamo
- Centre for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Marco de Curtis
- Unit of Experimental Neurophysiology and Epileptology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Heiko J. Luhmann
- Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
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Breschi GL, Cametti M, Mastropietro A, Librizzi L, Baselli G, Resnati G, Metrangolo P, de Curtis M. Different permeability of potassium salts across the blood-brain barrier follows the Hofmeister series. PLoS One 2013; 8:e78553. [PMID: 24205257 PMCID: PMC3810376 DOI: 10.1371/journal.pone.0078553] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 09/20/2013] [Indexed: 11/18/2022] Open
Abstract
The passage of ions across biological membranes is regulated by passive and active mechanisms. Passive ion diffusion into organs depends on the ion-pairing properties of salts present in the serum. Potassium ions could affect brain activity by crossing the blood-brain barrier (BBB) and its accumulation in the extracellular cerebral space could precipitate seizures. In the present study, we analyze passive diffusion of a series of potassium salts in the in vitro isolated guinea pig brain preparation. Different potassium counter-anions confer ion-pairing and lipophilicity properties that modulate membrane diffusion of the salt. Extracellular recordings in different cortical areas demonstrated the presence of epileptiform activities that strongly relate to anion identity, following the qualitative order of the Hofmeister series. Indeed, highly lipophilic salts that easily cross the BBB enhanced extracellular potassium concentration measured by ion-selective electrodes and were the most effective pro-epileptic species. This study constitutes a novel contribution for the understanding of the potential epileptogenicity of potassium salts and, more generally, of the role of counter-anions in the passive passage of salts through biological membranes.
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Affiliation(s)
- Gian Luca Breschi
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova, Italy
| | - Massimo Cametti
- Department of Chemistry, Materials and Chemical Engineering Giulio Natta, Politecnico di Milano, Milano, Italy
| | - Alfonso Mastropietro
- Scientific Direction Unit, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
- Department of Bioengineering, Politecnico di Milano, Milano, Italy
| | - Laura Librizzi
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Giuseppe Baselli
- Department of Bioengineering, Politecnico di Milano, Milano, Italy
| | - Giuseppe Resnati
- Department of Chemistry, Materials and Chemical Engineering Giulio Natta, Politecnico di Milano, Milano, Italy
| | - Pierangelo Metrangolo
- Department of Chemistry, Materials and Chemical Engineering Giulio Natta, Politecnico di Milano, Milano, Italy
| | - Marco de Curtis
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
- * E-mail:
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Librizzi L, Noè F, Vezzani A, de Curtis M, Ravizza T. Seizure-induced brain-borne inflammation sustains seizure recurrence and blood-brain barrier damage. Ann Neurol 2012; 72:82-90. [DOI: 10.1002/ana.23567] [Citation(s) in RCA: 189] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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12
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Neuronal Networks in the In Vitro Isolated Guinea Pig Brain. ISOLATED CENTRAL NERVOUS SYSTEM CIRCUITS 2012. [DOI: 10.1007/978-1-62703-020-5_12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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13
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Kuhlmann CRW, Librizzi L, Closhen D, Pflanzner T, Lessmann V, Pietrzik CU, de Curtis M, Luhmann HJ. Mechanisms of C-reactive protein-induced blood-brain barrier disruption. Stroke 2009; 40:1458-66. [PMID: 19246692 DOI: 10.1161/strokeaha.108.535930] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Increased mortality after stroke is associated with brain edema formation and high plasma levels of the acute phase reactant C-reactive protein (CRP). The aim of this study was to examine whether CRP directly affects blood-brain barrier stability and to analyze the underlying signaling pathways. METHODS We used a cell coculture model of the blood-brain barrier and the guinea pig isolated whole brain preparation. RESULTS We could show that CRP at clinically relevant concentrations (10 to 20 microg/mL) causes a disruption of the blood-brain barrier in both approaches. The results of our study further demonstrate CRP-induced activation of surface Fcgamma receptors CD16/32 followed by p38-mitogen-activated protein kinase-dependent reactive oxygen species formation by the NAD(P)H-oxidase. The resulting oxidative stress increased myosin light chain kinase activity leading to an activation of the contractile machinery. Blocking myosin light chain phosphorylation prevented the CRP-induced blood-brain barrier breakdown and the disruption of tight junctions. CONCLUSIONS Our data identify a previously unrecognized mechanism linking CRP and brain edema formation and present a signaling pathway that offers new sites of therapeutic intervention.
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Affiliation(s)
- Christoph R W Kuhlmann
- Institute of Physiology and Pathophysiology, Johannes Gutenberg University of Mainz, Mainz, Germany.
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Carriero G, Uva L, Gnatkovsky V, de Curtis M. Distribution of the olfactory fiber input into the olfactory tubercle of the in vitro isolated guinea pig brain. J Neurophysiol 2008; 101:1613-9. [PMID: 18922946 DOI: 10.1152/jn.90792.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The olfactory tubercle (OT) is a cortical component of the olfactory system involved in reward mechanisms of drug abuse. This region covers an extensive part of the rostral ventral cerebrum and is relatively poorly studied. The intrinsic network interactions evoked by olfactory input are analyzed in the OT of the in vitro isolated guinea pig brain by means of field potential analysis and optical imaging of voltage-sensitive signals. Stimulation of the lateral olfactory tract induces a monosynaptic response that progressively decreases in amplitude from lateral to medial. The monosynaptic input induces a disynaptic response that is proportionally larger in the medial portion of the OT. Direct stimulation of the piriform cortex and subsequent lesion of this pathway showed the existence of an associative disynaptic projection from the anterior part of the piriform cortex to the lateral part of the OT that integrates with the component mediated by the local intra-OT collaterals. Optical and electrophysiological recordings of the signals evoked by stimulation of the olfactory tract during arterial perfusion with the voltage-sensitive dye di-2-ANEPEQ confirmed the pattern of distribution of the mono and disynaptic responses in the OT. Finally, current source density analysis of laminar profiles recorded with 16-channel silicon probes confirmed that the monosynaptic and disynaptic potentials localize in the most superficial and the deep portions of the plexiform layer I, as suggested by previous reports. This study sets the standard for further analysis of the modulation of network properties in this largely unexplored brain region.
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Affiliation(s)
- Giovanni Carriero
- Unit of Experimental Epileptology and Neurophisiology, Fondazione Istituto Neurologico Carlo Besta, via Celoria 11, 20133 Milano, Italy
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Arterially perfused neurosphere-derived cells distribute outside the ischemic core in a model of transient focal ischemia and reperfusion in vitro. PLoS One 2008; 3:e2754. [PMID: 18648648 PMCID: PMC2453234 DOI: 10.1371/journal.pone.0002754] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Accepted: 06/25/2008] [Indexed: 01/19/2023] Open
Abstract
Background Treatment with neural stem cells represents a potential strategy to improve functional recovery of post-ischemic cerebral injury. The potential benefit of such treatment in acute phases of human ischemic stroke depends on the therapeutic viability of a systemic vascular delivery route. In spite of the large number of reports on the beneficial effects of intracerebral stem cells injection in experimental stroke, very few studies demonstrated the effectiveness of the systemic intravenous delivery approach. Metodology/Principal Findings We utilized a novel in vitro model of transient focal ischemia to analyze the brain distribution of neurosphere-derived cells (NCs) in the early 3 hours that follow transient occlusion of the medial cerebral artery (MCA). NCs obtained from newborn C57/BL6 mice are immature cells with self-renewal properties that could differentiate into neurons, astrocytes and oligodendrocytes. MCA occlusion for 30 minutes in the in vitro isolated guinea pig brain preparation was followed by arterial perfusion with 1×106 NCs charged with a green fluorescent dye, either immediately or 60 minutes after reperfusion onset. Changes in extracellular pH and K+ concentration during and after MCAO were measured through ion-sensitive electrodes. Conclusion/Significance It is demonstrated that NCs injected through the vascular system do not accumulate in the ischemic core and preferentially distribute in non-ischemic areas, identified by combined electrophysiological and morphological techniques. Direct measurements of extracellular brain ions during and after MCA occlusion suggest that anoxia-induced tissue changes, such as extracellular acidosis, may prevent NCs from entering the ischemic area in our in vitro model of transitory focal ischemia and reperfusion suggesting a role played by the surrounding microenviroment in driving NCs outside the ischemic core. These findings strongly suggest that the potential beneficial effect of NCs in experimental focal brain ischemia is not strictly dependent on their homing into the ischemic region, but rather through a bystander mechanism possibly mediated by the release of neuroprotective factors in the peri-infarct region.
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Librizzi L, Regondi MC, Pastori C, Frigerio S, Frassoni C, de Curtis M. Expression of Adhesion Factors Induced by Epileptiform Activity in the Endothelium of the Isolated Guinea Pig Brain In Vitro. Epilepsia 2007; 48:743-51. [PMID: 17386052 DOI: 10.1111/j.1528-1167.2007.01047.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Brain inflammation has been recently considered in the pathogenesis of focal epilepsies. Synthesis of pro-inflammatory mediators in the brain was described both in experimental models of seizures and in human postsurgical tissue. Inflammatory mediators may up-regulate endothelial adhesion molecules, therefore promoting adhesion and homing of leucocytes into the brain. In the present study, expression of inducible adhesion factors in brain endothelium was verified after pharmacological induction of seizure-like activity in specific brain areas of the in vitro isolated guinea pig brain. METHODS Experiments were performed in isolated guinea-pig brains maintained in vitro by arterial perfusion. In this preparation, brief application of the GABAa receptor-antagonist, bicuculline, consistently induced focal ictal discharges in the limbic region that secondarily diffuse to the neocortex, as verified by simultaneous electrophysiological recording of extracellular activity. At the end of the electrophysiological experiment (after 5 h in vitro), brains were fixed and immunostaining for adhesion molecules P-selectin and ICAM-1 and for Fos protein was evaluated. RESULTS Immunohistochemical analysis of isolated brains in which seizure-like activity was induced revealed expression of inducible adhesion factors P-selectin and ICAM-1 in the endothelium of small-medium size brain vessels. In particular, the expression of these molecules was consistently observed in all areas involved in epileptic seizure-like ictal activity (limbic cortices and neocortex), and was infrequently found in regions that generated interictal spiking (piriform cortex), suggesting a trigger role played by seizures for endothelial activation. An increase in Fos protein expression was evident in all analyzed limbic areas and in the neocortex, indicating a correlation between the areas of neuronal and endothelial activation. In control brains maintained in vitro for comparable times without induction of epileptiform activity, no immunoreactivity for Fos and adhesion molecules was observed. CONCLUSIONS Seizure-like activity in an in vitro isolated brain preparation induces the expression of adhesion molecules in the cerebral endothelium. These observations indicate that local endothelial activation may represent a crucial step for the development of an inflammatory response induced by seizures, and suggest a possible novel pathogenic mechanism during the process of epileptogenesis.
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Affiliation(s)
- Laura Librizzi
- Department of Clinical Epileptology and Experimental Neurophysiology, Istituto Nazionale Neurologico, Milan, Italy
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17
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Ohtsuki S, Yamaguchi H, Asashima T, Terasaki T. Establishing a Method to Isolate Rat Brain Capillary Endothelial Cells by Magnetic Cell Sorting and Dominant mRNA Expression of Multidrug Resistance-associated Protein 1 and 4 in Highly Purified Rat Brain Capillary Endothelial Cells. Pharm Res 2007; 24:688-94. [PMID: 17318419 DOI: 10.1007/s11095-006-9188-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Accepted: 11/06/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE To establish a method for isolating highly purified brain capillary endothelial cells (BCECs) from rat brain by using magnetic cell sorting, and clarify the expression levels of multidrug resistance-associated protein (Mrp) subtypes in these highly purified BCECs. METHODS The cells were prepared from the capillary enriched-fraction by enzyme digestion, and reacted with anti-PECAM-1 antibody. The cell sorting was performed by autoMACS. The mRNA levels were measured by quantitative real-time PCR analysis. RESULTS From five rats, 2.3 x 10(6) cells were isolated in the PECAM-1(+) fraction and the percentage of labeled cells in this was 85.9%. PECAM-1, claudin-5 and Tie-2 mRNA were concentrated in the PECAM-1(+) fraction compared with rat brain. The contamination by neurons and astrocytes was markedly less than in the brain capillary fraction prepared by the glass bead column method. Mrp1 and 4 were predominantly expressed in the PECAM-1(+) fraction at similar levels to Mdr1a. The mRNA levels of Mrp5 and 3 were 10.6 and 7.60% of that of Mrp1, respectively. CONCLUSIONS This new purification method provides BCECs with less contamination by neural cells. In the isolated BCECs, Mrp1 and 4 are predominantly expressed, suggesting that they play an important role at the rat blood-brain barrier.
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Affiliation(s)
- Sumio Ohtsuki
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Sendai, Japan
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18
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Pastori C, Regondi MC, Librizzi L, de Curtis M. Early excitability changes in a novel acute model of transient focal ischemia and reperfusion in the in vitro isolated guinea pig brain. Exp Neurol 2006; 204:95-105. [PMID: 17141221 DOI: 10.1016/j.expneurol.2006.09.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Revised: 09/01/2006] [Accepted: 09/30/2006] [Indexed: 11/19/2022]
Abstract
The study of the early events that characterize cerebral ischemia is limited in available experimental models. The study of neurophysiological network changes that occur in brain tissue during the early minutes that follow focal ischemia induction is restricted in the in vivo condition. Very simplified systems, such as in vitro brain slices and in isolated neurons, have been utilized for this type of studies. We describe here a new model of transient focal ischemia and reperfusion developed in the isolated guinea pig brain, maintained in vitro by arterial perfusion with a complex saline solution without blood cells. In this preparation, that combines the advantage of an in vitro preparation with the functional preservation of both vascular and neuronal compartments, the arteries of the Willis circle are directly accessible by visual control. To induce transitory focal ischemia, one medial cerebral artery (MCA) was transiently tied for 30 min, while brain activity was recorded with multiple electrodes positioned in brain areas within and outside MCA territory. Anoxic depression in ischemic areas propagated to the surrounding tissue and was associated with the abolition of evoked responses due to both functional impairment of afferent olfactory input and tissue depression. Recovery of evoked responses was obtained after MCA reperfusion. The spatial distribution of hypoxic depressions was characterized and was correlated with the extension of brain damage, defined by immunohistochemical analysis with antibodies against microtubule-associated protein (MAP-2). We propose that the present model can be utilized to analyze brain activity changes that occur in early stages of focal brain ischemia and reperfusion.
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Affiliation(s)
- Chiara Pastori
- Neurology Residency School University of Milano-Bicocca, Monza, Italy
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Lafuente JV, Argandoña EG, Mitre B. VEGFR-2 expression in brain injury: its distribution related to brain-blood barrier markers. J Neural Transm (Vienna) 2006; 113:487-96. [PMID: 16550327 DOI: 10.1007/s00702-005-0407-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2005] [Accepted: 09/26/2005] [Indexed: 12/21/2022]
Abstract
VEGF is a major regulator of angiogenesis and vascular permeability in development and injury. The involvement of one of its receptors, Flk-1 in angiogenesis has been widely demonstrated, but few studies elucidate its role as a mediator of the BBB permeability and none displays its distribution following a cortical micronecrosis. A microvascular marker (LEA lectin), two BBB markers (EBA, GluT-1) and the VEGFR2 receptor were studied in adult rats after a minimal brain injury. Immunohistochemistry shows an increase of positive vessels, somata and processes around the micronecrosis from 6 to 72 hours after injury. Flk-1 was overexpressed mainly in endothelial cells, but also in astrocytes, neuronal somata and processes adjacent to the damage. This increase correlates to the lose of positivity for EBA. After injury, VEGFR-2 expression increases and its distribution corresponds to VEGF one. The whole system seems to play a role in the disruption of the BBB.
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Affiliation(s)
- J V Lafuente
- Laboratory of Clinical and Experimental Neuroscience (LaNCE), Department of Neuroscience, University of the Basque Country, Leioa, Spain.
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20
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Librizzi L, Mazzetti S, Pastori C, Frigerio S, Salmaggi A, Buccellati C, Di Gennaro A, Folco G, Vitellaro-Zuccarello L, de Curtis M. Activation of cerebral endothelium is required for mononuclear cell recruitment in a novel in vitro model of brain inflammation. Neuroscience 2006; 137:1211-9. [PMID: 16359809 DOI: 10.1016/j.neuroscience.2005.10.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 10/11/2005] [Accepted: 10/14/2005] [Indexed: 01/30/2023]
Abstract
Brain inflammation is a common event in the pathogenesis of several neurological diseases. It is unknown whether leukocyte/endothelium interactions are sufficient to promote homing of blood-borne cells into the brain compartment. The role of mononuclear cells and endothelium was analyzed in a new experimental model, the isolated guinea-pig brain maintained in vitro by arterial perfusion. This preparation allows one to investigate early steps of brain inflammation that are impracticable in vivo. We demonstrate by confocal microscopy analysis that in vitro co-perfusion of pro-inflammatory agents and pre-activated fluorescent mononuclear cells induced endothelial expression of selectins and intracellular adhesion molecule-1 in correspondence of arrested mononuclear cells, and correlates with a moderate increase in blood-brain barrier permeability. Separate perfusion of pro-inflammatory agents and mononuclear cells induced neither mononuclear cell adhesion nor adhesion molecule expression. We demonstrate that co-activation of mononuclear cells and cerebral endothelium is an essential requirement for cell arrest and adhesion in the early stages of experimental cerebral inflammation.
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Affiliation(s)
- L Librizzi
- Dipartimento di Neurofisiologia Sperimentale, Istituto Nazionale Neurologico, Via Celoria, 11 20133 Milano, Italy
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21
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Argandoña EG, Bengoetxea H, Lafuente JV. Lack of experience-mediated differences in the immunohistochemical expression of blood-brain barrier markers (EBA and GluT-1) during the postnatal development of the rat visual cortex. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2005; 156:158-66. [PMID: 16099302 DOI: 10.1016/j.devbrainres.2005.02.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2004] [Revised: 02/11/2005] [Accepted: 02/15/2005] [Indexed: 10/25/2022]
Abstract
The development of the cortical vascular tree depends on functional development. External inputs are an essential requirement in the modeling of the visual cortex, mainly during the critical period, when congruous blood supply is needed. The blood brain barrier (BBB) function regulates the passage of substances between the blood and the brain parenchyma, which is one of the main differential features of central nervous system (CNS) microvessels. The endothelial barrier antigen (EBA) has been reported as a specific marker for the BBB physiological function in rats. We studied the postnatal development of EBA expression in the visual cortex of rats reared under opposite paradigms of visual experience, e.g., standard laboratory conditions, dark rearing, and enriched environment at 14, 21, 28, 35, 42, 49, 56, and 63 days postnatal (dpn). Parallel sections were immunohistochemically processed for endothelial barrier antigen (EBA) and glucose transporter-1 (GluT-1). Total vasculature was quantified by Lycopersicon esculentum (LEA) lectin histochemistry. No differences in EBA expression were found between groups, although quantitative differences were recorded paralleling differences in vascular density. Paradoxically, there was no expression in certain cortical vessels which were GluT-1 immunopositive and positivity was consistent in non-barrier areas such as the pineal gland. These findings were completely independent of age or experimental conditions. Therefore, the role of the EBA antigen in the BBB remains unclear: it has been undeniably linked to vascular permeability, but its presence in non-barrier vessels suggests another vascular function. Although visual experience modifies vascular density in the visual cortex, it has not been shown to have an influence on the maturation of the BBB function.
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Affiliation(s)
- Enrike G Argandoña
- Laboratory of Clinical and Experimental Neuroscience (LaNCE), Department of Neuroscience, School of Medicine, Euskal Herriko Unibertsitatea/University of the Basque Country, Leioako Campusa, Leioa E-48940, Spain.
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Librizzi L, Pastori C, de Grazia U, Croci D, de Curtis M. Rapid in vitro elimination of anesthetic doses of thiopental in the isolated guinea pig brain. Neurosci Lett 2005; 380:66-9. [PMID: 15854752 DOI: 10.1016/j.neulet.2005.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Revised: 12/16/2004] [Accepted: 01/06/2005] [Indexed: 11/24/2022]
Abstract
Electrophysiological and metabolic activities in brain tissue preparations maintained in vitro may be influenced by the persistent effect of anesthetic drugs utilized during tissue dissection. In order to clarify this issue, we studied elimination kinetics of the barbiturate thiopental from the brain parenchyma in the isolated guinea pig brain maintained in vitro, arterially perfused with a protein-free saline solution [M. de Curtis, G. Biella, C. Buccellati, G. Folco, Simultaneous investigation of the neuronal and vascular compartments in the guinea pig brain isolated in vitro, Brain Res. Protoc. 3 (1998) 21-28]. At the onset of anesthesia induced by a single i.p. injection of 125 mg/kg thiopental, the brain concentration of the drug, measured by high-performance liquid chromatographic assay, was 44.22+/-5.1 mg/L (mean+/-S.E.; n=7). After 30 min of arterial perfusion in vitro with a thiopental-free solution, the cerebral levels of the barbiturate decreased to 2.03+/-0.56 mg/L (n=3), and reached values close to zero within 1 h. No significant changes in thiopental elimination curve were observed when in vitro perfusion rate was either increased or decreased. The study demonstrates that thiopental is rapidly eliminated from the brain tissue with a mono-exponential kinetic. It can be concluded that barbiturate anesthesia utilized during brain dissection is not likely to influence activities recorded from the in vitro isolated brain preparation.
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Affiliation(s)
- Laura Librizzi
- Department of Experimental Neurophysiology, Istituto Nazionale Neurologico Carlo Besta, via Celoria 11, 20133 Milano, Italy
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