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Mosneag IE, Flaherty SM, Wykes RC, Allan SM. Stroke and Translational Research - Review of Experimental Models with a Focus on Awake Ischaemic Induction and Anaesthesia. Neuroscience 2024; 550:89-101. [PMID: 38065289 DOI: 10.1016/j.neuroscience.2023.11.034] [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: 09/13/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 12/17/2023]
Abstract
Animal models are an indispensable tool in the study of ischaemic stroke with hundreds of drugs emerging from the preclinical pipeline. However, all of these drugs have failed to translate into successful treatments in the clinic. This has brought into focus the need to enhance preclinical studies to improve translation. The confounding effects of anaesthesia on preclinical stroke modelling has been raised as an important consideration. Various volatile and injectable anaesthetics are used in preclinical models during stroke induction and for outcome measurements such as imaging or electrophysiology. However, anaesthetics modulate several pathways essential in the pathophysiology of stroke in a dose and drug dependent manner. Most notably, anaesthesia has significant modulatory effects on cerebral blood flow, metabolism, spreading depolarizations, and neurovascular coupling. To minimise anaesthetic complications and improve translational relevance, awake stroke induction has been attempted in limited models. This review outlines anaesthetic strategies employed in preclinical ischaemic rodent models and their reported cerebral effects. Stroke related complications are also addressed with a focus on infarct volume, neurological deficits, and thrombolysis efficacy. We also summarise routinely used focal ischaemic stroke rodent models and discuss the attempts to induce some of these models in awake rodents.
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Affiliation(s)
- Ioana-Emilia Mosneag
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom; Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance NHS Foundation Trust, University of Manchester, Manchester, United Kingdom.
| | - Samuel M Flaherty
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom; Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance NHS Foundation Trust, University of Manchester, Manchester, United Kingdom
| | - Robert C Wykes
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom; Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance NHS Foundation Trust, University of Manchester, Manchester, United Kingdom; Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Stuart M Allan
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom; Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance NHS Foundation Trust, University of Manchester, Manchester, United Kingdom
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2
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Foss KD, Billhymer AC. Magnetic resonance imaging in canine idiopathic epilepsy: a mini-review. Front Vet Sci 2024; 11:1427403. [PMID: 39021411 PMCID: PMC11251927 DOI: 10.3389/fvets.2024.1427403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Accepted: 06/19/2024] [Indexed: 07/20/2024] Open
Abstract
Magnetic resonance imaging (MRI) in an integral part of the diagnostic workup in canines with idiopathic epilepsy (IE). While highly sensitive and specific in identifying structural lesions, conventional MRI is unable to detect changes at the microscopic level. Utilizing more advanced neuroimaging techniques may provide further information on changes at the neuronal level in the brain of canines with IE, thus providing crucial information on the pathogenesis of canine epilepsy. Additionally, earlier detection of these changes may aid clinicians in the development of improved and targeted therapies. Advances in MRI techniques are being developed which can assess metabolic, cellular, architectural, and functional alterations; as well alterations in neuronal tissue mechanical properties, some of which are currently being applied in research on canine IE. This mini-review focuses on novel MRI techniques being utilized to better understand canine epilepsy, which include magnetic resonance spectroscopy, diffusion-weighted imaging, diffusion tensor imaging, perfusion-weighted imaging, voxel based morphometry, and functional MRI; as well as techniques applied in human medicine and their potential use in veterinary species.
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Affiliation(s)
- Kari D. Foss
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL, United States
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3
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Montagni E, Resta F, Tort-Colet N, Scaglione A, Mazzamuto G, Destexhe A, Pavone FS, Allegra Mascaro AL. Mapping brain state-dependent sensory responses across the mouse cortex. iScience 2024; 27:109692. [PMID: 38689637 PMCID: PMC11059133 DOI: 10.1016/j.isci.2024.109692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/20/2024] [Accepted: 04/05/2024] [Indexed: 05/02/2024] Open
Abstract
Sensory information must be integrated across a distributed brain network for stimulus processing and perception. Recent studies have revealed specific spatiotemporal patterns of cortical activation for the early and late components of sensory-evoked responses, which are associated with stimulus features and perception, respectively. Here, we investigated how the brain state influences the sensory-evoked activation across the mouse cortex. We utilized isoflurane to modulate the brain state and conducted wide-field calcium imaging of Thy1-GCaMP6f mice to monitor distributed activation evoked by multi-whisker stimulation. Our findings reveal that the level of anesthesia strongly shapes the spatiotemporal features and the functional connectivity of the sensory-activated network. As anesthesia levels decrease, we observe increasingly complex responses, accompanied by the emergence of the late component within the sensory-evoked response. The persistence of the late component under anesthesia raises new questions regarding the potential existence of perception during unconscious states.
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Affiliation(s)
- Elena Montagni
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- Neuroscience Institute, National Research Council, Pisa, Italy
| | - Francesco Resta
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- National Institute of Optics, National Research Council, Sesto Fiorentino, Italy
| | - Núria Tort-Colet
- Paris-Saclay University, CNRS, Institut des Neurosciences (NeuroPSI), Saclay, France
- Barcelonaβ Brain Research Center, Barcelona, Spain
- Hospital del Mar Medical Research Institute, Barcelona, Spain
| | - Alessandro Scaglione
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, Italy
| | - Giacomo Mazzamuto
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- National Institute of Optics, National Research Council, Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, Italy
| | - Alain Destexhe
- Paris-Saclay University, CNRS, Institut des Neurosciences (NeuroPSI), Saclay, France
| | - Francesco Saverio Pavone
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- National Institute of Optics, National Research Council, Sesto Fiorentino, Italy
- Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, Italy
| | - Anna Letizia Allegra Mascaro
- European Laboratory for Non-Linear Spectroscopy (LENS), Sesto Fiorentino, Italy
- Neuroscience Institute, National Research Council, Pisa, Italy
- Department of Physics and Astronomy, University of Florence, Sesto Fiorentino, Italy
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4
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An S, Hwang G, Noh SA, Lee HC, Hwang TS. Quantitative Analysis of Brain CT Perfusion in Healthy Beagle Dogs: A Pilot Study. Vet Sci 2023; 10:469. [PMID: 37505873 PMCID: PMC10385523 DOI: 10.3390/vetsci10070469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/11/2023] [Accepted: 07/16/2023] [Indexed: 07/29/2023] Open
Abstract
Brain computed tomography (CT) perfusion is a technique that allows for the fast evaluation of cerebral hemodynamics. However, quantitative studies of brain CT perfusion in veterinary medicine are lacking. The purpose of this study was to investigate the normal range of perfusion determined via CT in brains of healthy dogs and to compare values between white matter and gray matter, differences in aging, and each hemisphere. Nine intact male beagle dogs were prospectively examined using dynamic CT scanning and post-processing for brain perfusion. Regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), mean transit time, and time to peak were calculated. Tissue ROIs were drawn in the gray matter and white matter of the frontal, temporal, parietal, and occipital lobes; caudate nucleus; thalamus; piriform lobe; hippocampus; and cerebellum. Significant differences were observed between the white matter regions and gray matter regions for rCBV and rCBF (p < 0.05). However, no significant differences were identified between hemispheres and between young and old groups in brain regions. The findings obtained in this study involving healthy beagle dogs might serve as a reference for regional CT perfusion values in specific brain regions. These results may aid in the characterization of various brain diseases in dogs.
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Affiliation(s)
- Soyon An
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Gunha Hwang
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Seul Ah Noh
- AniCom Medical Center, Animal Hospital, Seoul 04599, Republic of Korea
| | - Hee Chun Lee
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Republic of Korea
| | - Tae Sung Hwang
- Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju 52828, Republic of Korea
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5
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Lee S, Meyer BP, Hernandez-Garcia L, Kurpad SN, Schmit BD, Budde MD. Comparison and optimization of pCASL and VSASL for rat thoracolumbar spinal cord MRI at 9.4 T. Magn Reson Med 2023; 89:2305-2317. [PMID: 36744728 PMCID: PMC10050093 DOI: 10.1002/mrm.29603] [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: 08/16/2022] [Revised: 01/06/2023] [Accepted: 01/12/2023] [Indexed: 02/07/2023]
Abstract
PURPOSE To evaluate pseudo-continuous arterial spin labeling (pCASL) and velocity-selective arterial spin labeling (VSASL) for quantification of spinal cord blood flow (SCBF) in the rat thoracolumbar spinal cord. METHODS Labeling efficiency (LE) was compared between pCASL and three VSASL variants in simulations and both phantom and in vivo experiments at 9.4 T. For pCASL, the effects of label plane position and shimming were systematically evaluated. For VSASL, the effects of composite pulses and phase cycling were evaluated to reduce artifacts. Additionally, vessel suppression, respiratory, and cardiac gating were evaluated to reduce motion artifacts. pCASL and VSASL maps of spinal cord blood flow were acquired with the optimized protocols. RESULTS LE of the descending aorta was larger in pCASL compared to VSASL variants. In pCASL, LE off-isocenter was improved by local shimming positioned at the label plane and the anatomical level of labeling for the thoracic cord was only viable at the level of the T10 vertebra. Cardiac gating was essential to reduce motion artifacts. Both pCASL and VSASL successfully demonstrated comparable SCBF values in the thoracolumbar cord. CONCLUSION pCASL demonstrated high and consistent LE in the thoracic aorta, and VSASL was also feasible, but with reduced efficiency. A combination of cardiac gating and recording of actual post-label delays was important for accurate SCBF quantification. These results highlight the challenges and solutions to achieve sufficient ASL labeling and contrast at high field in organs prone to motion.
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Affiliation(s)
- Seongtaek Lee
- Joint Department of Biomedical Engineering, Marquette University & Medical College of Wisconsin, Milwaukee, WI
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI
| | - Briana P Meyer
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI
| | - Luis Hernandez-Garcia
- FMRI Laboratory, Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI
| | - Shekar N Kurpad
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
| | - Brian D Schmit
- Joint Department of Biomedical Engineering, Marquette University & Medical College of Wisconsin, Milwaukee, WI
| | - Matthew D Budde
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI
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Pavlova I, Drazanova E, Kratka L, Amchova P, Macicek O, Starcukova J, Starcuk Z, Ruda-Kucerova J. Laterality in functional and metabolic state of the bulbectomised rat brain detected by ASL and 1H MRS: A pilot study. World J Biol Psychiatry 2022; 24:414-428. [PMID: 36102141 DOI: 10.1080/15622975.2022.2124450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
OBJECTIVES Pilot study validating the animal model of depression - the bilateral olfactory bulbectomy in rats - by two nuclear magnetic resonance methods, indirectly detecting the metabolic state of the brain. Furthermore, the study focussed on potential differences in brain laterality. METHODS Arterial spin labelling assessed cerebral brain flow in prefrontal, sensorimotor, and piriform cortices, nucleus accumbens, hippocampus, thalamus, circle of Willis, and whole brain. Proton magnetic resonance spectroscopy provided information about relative metabolite concentrations in the cortex and hippocampus. RESULTS Arterial spin labelling found no differences in cerebral perfusion in the group comparison but revealed lateralisation in the thalamus of the control group and the sensorimotor cortex of the bulbectomized rats. Lower Cho/tCr and Cho/NAA levels were found in the right hippocampus in bulbectomized rats. The differences in lateralisation were shown in the hippocampus: mI/tCr in the control group, Cho/NAA, NAA/tCr, Tau/tCr in the model group, and in the cortex: NAA/tCr, mI/tCr in the control group. CONCLUSION Olfactory bulbectomy affects the neuronal and biochemical profile of the rat brain laterally and, as a model of depression, was validated by two nuclear magnetic resonance methods.
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Affiliation(s)
- Iveta Pavlova
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic.,Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Eva Drazanova
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic.,Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Lucie Kratka
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Petra Amchova
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Ondrej Macicek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Jana Starcukova
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Zenon Starcuk
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Jana Ruda-Kucerova
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
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van Vliet EA, Immonen R, Prager O, Friedman A, Bankstahl JP, Wright DK, O'Brien TJ, Potschka H, Gröhn O, Harris NG. A companion to the preclinical common data elements and case report forms for in vivo rodent neuroimaging: A report of the TASK3-WG3 Neuroimaging Working Group of the ILAE/AES Joint Translational Task Force. Epilepsia Open 2022. [PMID: 35962745 DOI: 10.1002/epi4.12643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 02/01/2022] [Indexed: 11/10/2022] Open
Abstract
The International League Against Epilepsy/American Epilepsy Society (ILAE/AES) Joint Translational Task Force established the TASK3 working groups to create common data elements (CDEs) for various aspects of preclinical epilepsy research studies, which could help improve the standardization of experimental designs. In this article, we discuss CDEs for neuroimaging data that are collected in rodent models of epilepsy, with a focus on adult rats and mice. We provide detailed CDE tables and case report forms (CRFs), and with this companion manuscript, we discuss the methodologies for several imaging modalities and the parameters that can be collected.
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Affiliation(s)
- Erwin A van Vliet
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam UMC Location University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Riikka Immonen
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Ofer Prager
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Alon Friedman
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Department of Medical Neuroscience and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - David K Wright
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Terence J O'Brien
- The Royal Melbourne Hospital, The University of Melbourne, The Alfred Hospital, Monash University, Melbourne, Victoria, Australia
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Olli Gröhn
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Neil G Harris
- Department of Neurosurgery UCLA, UCLA Brain Injury Research Center, Los Angeles, California, USA
- Intellectual and Developmental Disabilities Research Center, UCLA, Los Angeles, California, USA
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8
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Dhaya I, Griton M, Konsman JP. Magnetic resonance imaging under isoflurane anesthesia alters cortical cyclooxygenase-2 expression and glial cell morphology during sepsis-associated neurological dysfunction in rats. Animal Model Exp Med 2021; 4:249-260. [PMID: 34557651 PMCID: PMC8446714 DOI: 10.1002/ame2.12167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/19/2021] [Indexed: 01/31/2023] Open
Abstract
Background Magnetic resonance imaging (MRI) of rodents combined with histology allows to determine what mechanisms underlie functional and structural brain changes during sepsis-associated encephalopathy. However, the effects of MRI performed in isoflurane-anesthetized rodents on modifications of the blood-brain barrier and the production of vasoactive prostaglandins and glia cells, which have been proposed to mediate sepsis-associated brain dysfunction, are unknown. Methods This study addressed the effect of MRI under isoflurane anesthesia on blood-brain barrier integrity, cyclooxygenase-2 expression, and glial cell activation during cecal ligature and puncture-induced sepsis-associated brain dysfunction in rats. Results Cecal ligature and puncture reduced food intake and the righting reflex. MRI under isoflurane anesthesia reduced blood-brain barrier breakdown, decreased circularity of white matter astrocytes, and increased neuronal cyclooxygenase-2 immunoreactivity in the cortex 24 hours after laparotomy. In addition, it annihilated cecal ligature and puncture-induced increased circularity of white matter microglia. MRI under isoflurane anesthesia, however, did not alter sepsis-associated perivascular cyclooxygenase-2 induction. Conclusion These findings indicate that MRI under isoflurane anesthesia of rodents can modify neurovascular and glial responses and should, therefore, be interpreted with caution.
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Affiliation(s)
- Ibtihel Dhaya
- INCIAInstitut de Neurosciences Cognitives et Intégratives d'AquitaineCNRS UMR 5287BordeauxFrance
- Univ. BordeauxINCIAUMR 5287BordeauxFrance
- Laboratoire de Neurophysiologie Fonctionnelle et PathologiesUR/11ES09Faculté des Sciences MathématiquesPhysiques et NaturellesUniversité de Tunis El ManarTunisTunisie
| | - Marion Griton
- INCIAInstitut de Neurosciences Cognitives et Intégratives d'AquitaineCNRS UMR 5287BordeauxFrance
- Univ. BordeauxINCIAUMR 5287BordeauxFrance
- Service de Réanimation Anesthésie NeurochirurgicaleCentre Hospitalier Universitaire (CHU) de BordeauxBordeauxFrance
| | - Jan Pieter Konsman
- INCIAInstitut de Neurosciences Cognitives et Intégratives d'AquitaineCNRS UMR 5287BordeauxFrance
- Univ. BordeauxINCIAUMR 5287BordeauxFrance
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Meyer BP, Hirschler L, Lee S, Kurpad SN, Warnking JM, Barbier EL, Budde MD. Optimized cervical spinal cord perfusion MRI after traumatic injury in the rat. J Cereb Blood Flow Metab 2021; 41:2010-2025. [PMID: 33509036 PMCID: PMC8327111 DOI: 10.1177/0271678x20982396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 10/11/2020] [Accepted: 11/22/2020] [Indexed: 11/17/2022]
Abstract
Despite the potential to guide clinical management of spinal cord injury and disease, noninvasive methods of monitoring perfusion status of the spinal cord clinically remain an unmet need. In this study, we optimized pseudo-continuous arterial spin labeling (pCASL) for the rodent cervical spinal cord and demonstrate its utility in identifying perfusion deficits in an acute contusion injury model. High-resolution perfusion sagittal images with reduced imaging artifacts were obtained with optimized background suppression and imaging readout. Following moderate contusion injury, perfusion was clearly and reliably decreased at the site of injury. Implementation of time-encoded pCASL confirmed injury site perfusion deficits with blood flow measurements corrected for variability in arterial transit times. The noninvasive protocol of pCASL in the spinal cord can be utilized in future applications to examine perfusion changes after therapeutic interventions in the rat and translation to patients may offer critical implications for patient management.
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Affiliation(s)
- Briana P Meyer
- Department of Neurosurgery, Medical College of Wisconsin,
Milwaukee, WI, USA
- Biophysics Graduate Program, Medical College of Wisconsin,
Milwaukee, WI, USA
- Neuroscience Doctoral Program, Medical College of Wisconsin,
Milwaukee, WI, USA
| | - Lydiane Hirschler
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut des
Neurosciences, Grenoble, France
- Department of Radiology, C.J. Gorter Center for High Field MRI,
Leiden University Medical Center, Leiden, the Netherlands
| | - Seongtaek Lee
- Department of Neurosurgery, Medical College of Wisconsin,
Milwaukee, WI, USA
- Biomedical Engineering Graduate Program, Marquette University
& Medical College of Wisconsin, Milwaukee, WI, USA
| | - Shekar N Kurpad
- Department of Neurosurgery, Medical College of Wisconsin,
Milwaukee, WI, USA
| | - Jan M Warnking
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut des
Neurosciences, Grenoble, France
| | - Emmanuel L Barbier
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut des
Neurosciences, Grenoble, France
| | - Matthew D Budde
- Department of Neurosurgery, Medical College of Wisconsin,
Milwaukee, WI, USA
- Clement J Zablocki Veteran's Affairs Medical Center, Milwaukee,
WI, USA
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Hoffmann AC, Ruel Y, Gnirs K, Papageorgiou S, Zilberstein L, Nahmani S, Boddaert N, Gaillot H. Brain perfusion magnetic resonance imaging using pseudocontinuous arterial spin labeling in 314 dogs and cats. J Vet Intern Med 2021; 35:2327-2341. [PMID: 34291497 PMCID: PMC8478041 DOI: 10.1111/jvim.16215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 06/17/2021] [Accepted: 06/22/2021] [Indexed: 11/30/2022] Open
Abstract
Background Arterial spin labeling (ASL) is a noninvasive brain perfusion magnetic resonance imaging (MRI) technique that has not been assessed in clinical veterinary medicine. Hypothesis/Objectives To test the feasibility of ASL using a 1.5 Tesla scanner and provide recommendations for optimal quantification of cerebral blood flow (CBF) in dogs and cats. Animals Three hundred fourteen prospectively selected client‐owned dogs and cats. Methods Each animal underwent brain MRI including morphological sequences and ≥1 ASL sequences using different sites of blood labeling and postlabeling delays (PLD). Calculated ASL success rates were compared. The CBF was quantified in animals that had morphologically normal brain MRI results and parameters of ASL optimization were investigated. Results Arterial spin labeling was easily implemented with an overall success rate of 95% in animals with normal brain MRI. Technical recommendations included (a) positioning of the imaging slab at the foramen magnum and (b) selected PLD of 1025 ms in cats and dogs <7 kg, 1525 ms in dogs 7 to 38 kg, and 2025 ms in dogs >38 kg. In 37 dogs, median optimal CBF in the cortex and thalamic nuclei were 114 and 95 mL/100 g/min, respectively. In 28 cats, median CBF in the cortex and thalamic nuclei were 113 and 114 mL/100 g/min, respectively. Conclusions and Clinical Importance Our survey of brain perfusion ASL‐MRI demonstrated the feasibility of ASL at 1.5 Tesla, suggested technical recommendations and provided CBF values that should be helpful in the characterization of various brain diseases in dogs and cats.
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Affiliation(s)
- Anne-Cécile Hoffmann
- Unit of Diagnostic Imaging, ADVETIA Veterinary Referral Hospital, Vélizy-Villacoublay, France
| | - Yannick Ruel
- Unit of Diagnostic Imaging, ADVETIA Veterinary Referral Hospital, Vélizy-Villacoublay, France
| | - Kirsten Gnirs
- Unit of Neurology, ADVETIA Veterinary Referral Hospital, Vélizy-Villacoublay, France
| | - Stella Papageorgiou
- Unit of Neurology, ADVETIA Veterinary Referral Hospital, Vélizy-Villacoublay, France
| | - Luca Zilberstein
- Unit of Anesthesiology-Analgesia, ADVETIA Veterinary Referral Hospital, Vélizy-Villacoublay, France
| | - Sarah Nahmani
- Paediatric Radiology Department, AP-HP, Hôpital Necker Enfants Malades, Université de Paris, Paris, France
| | - Nathalie Boddaert
- Paediatric Radiology Department, AP-HP, Hôpital Necker Enfants Malades, Université de Paris, Paris, France.,Universié de Paris, Institut Imagine INSERM U1163, Paris, France
| | - Hugues Gaillot
- Unit of Diagnostic Imaging, ADVETIA Veterinary Referral Hospital, Vélizy-Villacoublay, France
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11
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Lee S, Wilkins N, Schmit BD, Kurpad SN, Budde MD. Relationships between spinal cord blood flow measured with flow-sensitive alternating inversion recovery (FAIR) and neurobehavioral outcomes in rat spinal cord injury. Magn Reson Imaging 2021; 78:42-51. [PMID: 33556483 DOI: 10.1016/j.mri.2021.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 01/15/2021] [Accepted: 02/03/2021] [Indexed: 12/24/2022]
Abstract
In the traumatically injured spinal cord, decreased perfusion is believed to contribute to secondary tissue damage beyond the primary mechanical impact, and restoration of perfusion is believed to be a promising therapeutic target. However, methods to monitor spinal cord perfusion non-invasively are limited. Perfusion magnetic resonance imaging (MRI) techniques established for the brain have not been routinely adopted to the spinal cord. The purpose of this study was to examine the relationship between spinal cord blood flow (SCBF) and injury severity in a rat thoracic spinal cord contusion injury (SCI) model using flow-sensitive alternating inversion recovery (FAIR) with two variants of the label position. SCBF as a marker of severity was compared to T1 mapping and to spinal cord-optimized diffusion weighted imaging (DWI) with filtered parallel apparent diffusion coefficient. Thirty-eight rats underwent a T10 contusion injury with varying severities (8 sham; 10 mild; 10 moderate; 10 severe) with MRI performed at 1 day post injury at the lesion site and follow-up neurological assessments using the Basso, Beattie, Bresnahan (BBB) locomotor scoring up to 28 days post injury. Using whole-cord regions of interest at the lesion epicenter, SCBF was decreased with injury severity and had a significant correlation with BBB scores at 28 days post injury. Importantly, estimates of arterial transit times (ATT) in the injured spinal cord were not altered after injury, which suggests that FAIR protocols optimized to measure SCBF provide more value in the context of acute traumatic injury to the cord. T1-relaxation time constants were strongly related to injury severity and had a larger extent of changes than either SCBF or DWI measures. These findings suggest that perfusion decreases in the spinal cord can be monitored non-invasively after injury, and multi-parametric MRI assessments of perfusion, diffusion, and relaxation capture unique features of the pathophysiology of preclinical injury.
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Affiliation(s)
- Seongtaek Lee
- Department of Biomedical Engineering, Marquette University & Medical College of Wisconsin, Milwaukee, WI, United States of America; Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States of America.
| | - Natasha Wilkins
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States of America
| | - Brian D Schmit
- Department of Biomedical Engineering, Marquette University & Medical College of Wisconsin, Milwaukee, WI, United States of America
| | - Shekar N Kurpad
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States of America; Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI, United States of America
| | - Matthew D Budde
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States of America; Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI, United States of America
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12
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Becq GJPC, Habet T, Collomb N, Faucher M, Delon-Martin C, Coizet V, Achard S, Barbier EL. Functional connectivity is preserved but reorganized across several anesthetic regimes. Neuroimage 2020; 219:116945. [DOI: 10.1016/j.neuroimage.2020.116945] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 04/21/2020] [Accepted: 05/11/2020] [Indexed: 12/12/2022] Open
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13
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Matin N, Fisher C, Lansdell TA, Hammock BD, Yang J, Jackson WF, Dorrance AM. Soluble epoxide hydrolase inhibition improves cognitive function and parenchymal artery dilation in a hypertensive model of chronic cerebral hypoperfusion. Microcirculation 2020; 28:e12653. [PMID: 32767848 DOI: 10.1111/micc.12653] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/30/2020] [Accepted: 07/30/2020] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Parenchymal arterioles (PAs) regulate perfusion of the cerebral microcirculation, and impaired PA endothelium-dependent dilation occurs in dementia models mimicking chronic cerebral hypoperfusion (CCH). Epoxyeicosatrienoic acids (EETs) are vasodilators; their actions are potentiated by soluble epoxide hydrolase (sEH) inhibition. We hypothesized that chronic sEH inhibition with trifluoromethoxyphenyl-3 (1-propionylpiperidin-4-yl) urea (TPPU) would prevent cognitive dysfunction and improve PA dilation in a hypertensive CCH model. METHODS Bilateral carotid artery stenosis (BCAS) was used to induce CCH in twenty-week-old male stroke-prone spontaneously hypertensive rats (SHSRP) that were treated with vehicle or TPPU for 8 weeks. Cognitive function was assessed by novel object recognition. PA dilation and structure were assessed by pressure myography, and mRNA expression in brain tissue was assessed by qRT-PCR. RESULTS TPPU did not enhance resting cerebral perfusion, but prevented CCH-induced memory deficits. TPPU improved PA endothelium-dependent dilation but reduced the sensitivity of PAs to a nitric oxide donor. TPPU treatment had no effect on PA structure or biomechanical properties. TPPU treatment increased brain mRNA expression of brain derived neurotrophic factor, doublecortin, tumor necrosis factor-alpha, sEH, and superoxide dismutase 3, CONCLUSIONS: These data suggest that sEH inhibitors may be viable treatments for cognitive impairments associated with hypertension and CCH.
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Affiliation(s)
- Nusrat Matin
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Courtney Fisher
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Theresa A Lansdell
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Bruce D Hammock
- Department of Entomology &, University of California Comprehensive Cancer Center, Davis, CA, USA
| | - Jun Yang
- Department of Entomology &, University of California Comprehensive Cancer Center, Davis, CA, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
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Weerasekera A, Crabbé M, Tomé SO, Gsell W, Sima D, Casteels C, Dresselaers T, Deroose C, Van Huffel S, Rudolf Thal D, Van Damme P, Himmelreich U. Non-invasive characterization of amyotrophic lateral sclerosis in a hTDP-43 A315T mouse model: A PET-MR study. NEUROIMAGE-CLINICAL 2020; 27:102327. [PMID: 32653817 PMCID: PMC7352080 DOI: 10.1016/j.nicl.2020.102327] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 05/02/2020] [Accepted: 06/21/2020] [Indexed: 12/13/2022]
Abstract
Currently TAR DNA binding protein 43 (TDP-43) pathology, underlying Amyotrophic Lateral Sclerosis (ALS), remains poorly understood which hinders both clinical diagnosis and drug discovery efforts. To better comprehend the disease pathophysiology, positron emission tomography (PET) and multi-parametric magnetic resonance imaging (mp-MRI) provide a non-invasive mode to investigate molecular, structural, and neurochemical abnormalities in vivo. For the first time, we report the findings of a longitudinal PET-MR study in the TDP-43A315T ALS mouse model, investigating disease-related changes in the mouse brain. 2-deoxy-2-[18F]fluoro-D-glucose [18F]FDG PET showed significantly lowered glucose metabolism in the motor and somatosensory cortices of TDP-43A315T mice whereas metabolism was elevated in the region covering the bilateral substantia nigra, reticular and amygdaloid nucleus between 3 and 7 months of age, as compared to non-transgenic controls. MR spectroscopy data showed significant changes in glutamate + glutamine (Glx) and choline levels in the motor cortex and hindbrain of TDP-43A315T mice compared to controls. Cerebral blood flow (CBF) measurements, using an arterial spin labelling approach, showed no significant age- or group-dependent changes in brain perfusion. Diffusion MRI indices demonstrated transient changes in different motor areas of the brain in TDP-43A315T mice around 14 months of age. Cytoplasmic TDP-43 proteinaceous inclusions were observed in the brains of symptomatic, 18-month-old mice, but not in non-symptomatic transgenic or wild-type mice. Our results reveal that disease- and age-related functional and neurochemical alterations, together with limited structural changes, occur in specific brain regions of transgenic TDP-43A315T mice, as compared to their healthy counterparts. Altogether these findings shed new light on TDP-43A315T disease pathogenesis and may prove useful for clinical management of ALS.
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Affiliation(s)
- Akila Weerasekera
- Biomedical MRI Unit/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium; A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School (MGH/HMS), Boston, MA, USA
| | - Melissa Crabbé
- Division of Nuclear Medicine, Department of Imaging and Pathology, KU Leuven, Belgium; MoSAIC - Molecular Small Animal Imaging Centre, KU Leuven, Leuven, Belgium.
| | - Sandra O Tomé
- Laboratory for Neuropathology, Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Willy Gsell
- Biomedical MRI Unit/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Diana Sima
- Icometrix, R&D department, Leuven, Belgium; Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, KU Leuven, Leuven, Belgium
| | - Cindy Casteels
- Division of Nuclear Medicine, Department of Imaging and Pathology, KU Leuven, Belgium; MoSAIC - Molecular Small Animal Imaging Centre, KU Leuven, Leuven, Belgium
| | - Tom Dresselaers
- Division of Radiology, Department of Imaging and Pathology, University Hospitals Leuven, Leuven, Belgium
| | - Christophe Deroose
- Division of Nuclear Medicine, Department of Imaging and Pathology, KU Leuven, Belgium; MoSAIC - Molecular Small Animal Imaging Centre, KU Leuven, Leuven, Belgium
| | - Sabine Van Huffel
- Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, KU Leuven, Leuven, Belgium
| | - Dietmar Rudolf Thal
- Laboratory for Neuropathology, Department of Neurosciences, KU Leuven, Leuven, Belgium; Department of Pathology, University Hospitals Leuven, Leuven, Belgium
| | - Philip Van Damme
- Laboratory of Neurobiology, Department of Neurosciences, KU Leuven, Leuven, Belgium; Center for Brain & Disease Research, VIB, Leuven, Belgium; Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI Unit/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
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15
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Drazanova E, Kratka L, Vaskovicova N, Skoupy R, Horska K, Babinska Z, Kotolova H, Vrlikova L, Buchtova M, Starcuk Z, Ruda-Kucerova J. Olanzapine exposure diminishes perfusion and decreases volume of sensorimotor cortex in rats. Pharmacol Rep 2019; 71:839-847. [PMID: 31394417 DOI: 10.1016/j.pharep.2019.04.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/24/2019] [Accepted: 04/29/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Olanzapine is a frequently used atypical antipsychotic drug known to exert structural brain alterations in animals. This study investigated whether chronic olanzapine exposure alters regional blood brain perfusion assessed by Arterial Spin Labelling (ASL) magnetic resonance imaging (MRI) in a validated model of olanzapine-induced metabolic disturbances. An effect of acute olanzapine exposure on brain perfusion was also assessed for comparison. METHODS Adult Sprague-Dawley female rats were treated by intramuscular depot olanzapine injections (100 mg/kg every 14 days) or vehicle for 8 weeks. ASL scanning was performed on a 9.4 T Bruker BioSpec 94/30USR scanner under isoflurane anesthesia. Serum samples were used to assay leptin and TNF-α level while brains were sliced for histology. Another group received only one non-depot intraperitoneal dose of olanzapine (7 mg/kg) during MRI scanning, thus exposing its acute effect on brain perfusion. RESULTS Both acute and chronic dosing of olanzapine resulted in decreased perfusion in the sensorimotor cortex, while no effect was observed in the piriform cortex or hippocampus. Furthermore, in the chronically treated group decreased cortex volume was observed. Chronic olanzapine dosing led to increased body weight, adipose tissue mass and leptin level, confirming its expected metabolic effects. CONCLUSION This study demonstrates region-specific decreases in blood perfusion associated with olanzapine exposure present already after the first dose. These findings extend our understanding of olanzapine-induced functional and structural brain changes.
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Affiliation(s)
- Eva Drazanova
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic; Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic.
| | - Lucie Kratka
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Nadezda Vaskovicova
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Radim Skoupy
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Katerina Horska
- Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
| | - Zuzana Babinska
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Hana Kotolova
- Department of Human Pharmacology and Toxicology, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic
| | - Lucie Vrlikova
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Marcela Buchtova
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Zenon Starcuk
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Jana Ruda-Kucerova
- Department of Pharmacology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
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Lei H, Preitner F, Labouèbe G, Gruetter R, Thorens B. Glucose transporter 2 mediates the hypoglycemia-induced increase in cerebral blood flow. J Cereb Blood Flow Metab 2019; 39:1725-1736. [PMID: 29561214 PMCID: PMC6727137 DOI: 10.1177/0271678x18766743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glucose transporter 2 (Glut2)-positive cells are sparsely distributed in brain and play an important role in the stimulation of glucagon secretion in response to hypoglycemia. We aimed to determine if Glut2-positive cells can influence another response to hypoglycemia, i.e. increased cerebral blood flow (CBF). CBF of adult male mice devoid of Glut2, either globally (ripglut1:glut2-/-) or in the nervous system only (NG2KO), and their respective controls were studied under basal glycemia and insulin-induced hypoglycemia using quantitative perfusion magnetic resonance imaging at 9.4 T. The effect on CBF of optogenetic activation of hypoglycemia responsive Glut2-positive neurons of the paraventricular thalamic area was measured in mice expressing channelrhodopsin2 under the control of the Glut2 promoter. We found that in both ripglut1:glut2-/- mice and NG2KO mice, CBF in basal conditions was higher than in their respective controls and not further activated by hypoglycemia, as measured in the hippocampus, hypothalamus and whole brain. Conversely, optogenetic activation of Glut2-positive cells in the paraventricular thalamic nucleus induced a local increase in CBF similar to that induced by hypoglycemia. Thus, Glut2 expression in the nervous system is required for the control of CBF in response to changes in blood glucose concentrations.
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Affiliation(s)
- Hongxia Lei
- 1 AIT, Center for Biomedical Imaging (CIBM-AIT), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,2 Department of Radiology, University of Geneva, Geneva, Switzerland
| | - Frédéric Preitner
- 3 Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.,4 Mouse Metabolic Evaluation Facility, Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Gwenaël Labouèbe
- 3 Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Rolf Gruetter
- 1 AIT, Center for Biomedical Imaging (CIBM-AIT), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,2 Department of Radiology, University of Geneva, Geneva, Switzerland.,5 Department of Radiology, University of Lausanne, Lausanne, Switzerland
| | - Bernard Thorens
- 3 Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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17
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Larkin JR, Simard MA, Khrapitchev AA, Meakin JA, Okell TW, Craig M, Ray KJ, Jezzard P, Chappell MA, Sibson NR. Quantitative blood flow measurement in rat brain with multiphase arterial spin labelling magnetic resonance imaging. J Cereb Blood Flow Metab 2019; 39:1557-1569. [PMID: 29498562 PMCID: PMC6681434 DOI: 10.1177/0271678x18756218] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 12/01/2017] [Accepted: 12/22/2017] [Indexed: 11/29/2022]
Abstract
Cerebral blood flow is an important parameter in many diseases and functional studies that can be accurately measured in humans using arterial spin labelling (ASL) MRI. However, although rat models are frequently used for preclinical studies of both human disease and brain function, rat CBF measurements show poor consistency between studies. This lack of reproducibility is due, partly, to the smaller size and differing head geometry of rats compared to humans, as well as the differing analysis methodologies employed and higher field strengths used for preclinical MRI. To address these issues, we have implemented, optimised and validated a multiphase pseudo-continuous ASL technique, which overcomes many of the limitations of rat CBF measurement. Three rat strains (Wistar, Sprague Dawley and Berlin Druckrey IX) were used, and CBF values validated against gold-standard autoradiography measurements. Label positioning was found to be optimal at 45°, while post-label delay was optimised to 0.55 s. Whole brain CBF measures were 109 ± 22, 111 ± 18 and 100 ± 15 mL/100 g/min by multiphase pCASL, and 108 ± 12, 116 ± 14 and 122 ± 16 mL/100 g/min by autoradiography in Wistar, SD and BDIX cohorts, respectively. Tumour model analysis shows that the developed methods also apply in disease states. Thus, optimised multiphase pCASL provides robust, reproducible and non-invasive measurement of CBF in rats.
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Affiliation(s)
- James R Larkin
- Department of Oncology, Cancer Research
UK & Medical Research Council Oxford Institute for Radiation Oncology,
University of Oxford, Oxford, UK
| | - Manon A Simard
- Department of Oncology, Cancer Research
UK & Medical Research Council Oxford Institute for Radiation Oncology,
University of Oxford, Oxford, UK
| | - Alexandre A Khrapitchev
- Department of Oncology, Cancer Research
UK & Medical Research Council Oxford Institute for Radiation Oncology,
University of Oxford, Oxford, UK
| | - James A Meakin
- Wellcome Centre for Integrative
Neuroimaging, FMRIB Division, University of Oxford, John Radcliffe Hospital,
Headington, Oxford, UK
| | - Thomas W Okell
- Wellcome Centre for Integrative
Neuroimaging, FMRIB Division, University of Oxford, John Radcliffe Hospital,
Headington, Oxford, UK
| | - Martin Craig
- Institute of Biomedical Engineering,
University of Oxford, Oxford, UK
| | - Kevin J Ray
- Department of Oncology, Cancer Research
UK & Medical Research Council Oxford Institute for Radiation Oncology,
University of Oxford, Oxford, UK
| | - Peter Jezzard
- Wellcome Centre for Integrative
Neuroimaging, FMRIB Division, University of Oxford, John Radcliffe Hospital,
Headington, Oxford, UK
| | | | - Nicola R Sibson
- Department of Oncology, Cancer Research
UK & Medical Research Council Oxford Institute for Radiation Oncology,
University of Oxford, Oxford, UK
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18
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Pham L, Shultz SR, Kim HA, Brady RD, Wortman RC, Genders SG, Hale MW, O'Shea RD, Djouma E, van den Buuse M, Church JE, Christie BR, Drummond GR, Sobey CG, McDonald SJ. Mild Closed-Head Injury in Conscious Rats Causes Transient Neurobehavioral and Glial Disturbances: A Novel Experimental Model of Concussion. J Neurotrauma 2019; 36:2260-2271. [DOI: 10.1089/neu.2018.6169] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Louise Pham
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, Australia
| | - Sandy R. Shultz
- Department Neuroscience, Monash University, Melbourne, Australia
- Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Hyun Ah Kim
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, Australia
| | - Rhys D. Brady
- Department Neuroscience, Monash University, Melbourne, Australia
- Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Ryan C. Wortman
- Department Neuroscience, Monash University, Melbourne, Australia
| | - Shannyn G. Genders
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, Australia
| | - Matthew W. Hale
- Department of Psychology and Counseling, La Trobe University, Bundoora, Australia
| | - Ross D. O'Shea
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, Australia
| | - Elvan Djouma
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, Australia
| | - Maarten van den Buuse
- Department of Psychology and Counseling, La Trobe University, Bundoora, Australia
- Department of Pharmacology, University of Melbourne, Melbourne, Australia
- The College of Public Health, Medical, and Veterinary Sciences, James Cook University, Queensland, Australia
| | - Jarrod E. Church
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, Australia
| | - Brian R. Christie
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Grant R. Drummond
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, Australia
| | - Christopher G. Sobey
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, Australia
| | - Stuart J. McDonald
- Department of Physiology, Anatomy, and Microbiology, La Trobe University, Bundoora, Australia
- Department Neuroscience, Monash University, Melbourne, Australia
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Physiological Considerations of Functional Magnetic Resonance Imaging in Animal Models. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2019; 4:522-532. [DOI: 10.1016/j.bpsc.2018.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 02/06/2023]
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20
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Peng SL, Chiu H, Wu CY, Huang CW, Chung YH, Shih CT, Shen WC. The effect of caffeine on cerebral metabolism during alpha-chloralose anesthesia differs from isoflurane anesthesia in the rat brain. Psychopharmacology (Berl) 2019; 236:1749-1757. [PMID: 30604185 DOI: 10.1007/s00213-018-5157-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 12/19/2018] [Indexed: 10/27/2022]
Abstract
RATIONALE Caffeine is a widely studied psychostimulant, even though its exact effect on brain activity remains to be elucidated. Positron emission tomography (PET) allows studying mechanisms underlying cerebral metabolic responses to caffeine in caffeine-naïve rats. Rodent studies are typically performed under anesthesia. However, the anesthesia may affect neurotransmitter systems targeted by tested drugs. OBJECTIVES The scope of the present study was to address the impairing or enhancing effect of two common anesthetics, alpha-chloralose and isoflurane, on the kinetics of caffeine. METHODS The first group of rats (n = 15) were anesthetized under 1.5% isoflurane anesthesia. The second group of rats (n = 15) were anesthetized under alpha-chloralose (80 mg/kg). These rats received an intravenous injection of saline (n = 5) or of 2.5 mg/kg (n = 5) or 40 mg/kg (n = 5) caffeine for both groups. RESULTS With 2.5 mg/kg or 40 mg/kg caffeine, whole-brain cerebral metabolism was significantly reduced by 17.2% and 17% (both P < 0.01), respectively, under alpha-chloralose anesthesia. However, the lower dose of caffeine (2.5 mg/kg) had a limited effect on brain metabolism, whereas its higher dose (40 mg/kg) produced enhancements in brain metabolism in the striatum, hippocampus, and thalamus (all P < 0.05) under isoflurane anesthesia. CONCLUSION These findings demonstrate significant differences in brain responses to caffeine on the basic of the anesthesia regimen used, which highlights the importance of attention to the anesthetic used when interpreting findings from animal pharmacological studies because of possible interactions between the anesthetic and the drug under study.
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Affiliation(s)
- Shin-Lei Peng
- Department of Biomedical Imaging and Radiological Science, China Medical University, 91 Hsueh-Shih Road, Taichung, 40402, Taiwan.
| | - Han Chiu
- Center for Advanced Molecular Imaging and Translation, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chun-Yi Wu
- Department of Biomedical Imaging and Radiological Science, China Medical University, 91 Hsueh-Shih Road, Taichung, 40402, Taiwan
| | - Chiun-Wei Huang
- Center for Advanced Molecular Imaging and Translation, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yi-Hsiu Chung
- Center for Advanced Molecular Imaging and Translation, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Cheng-Ting Shih
- Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan
| | - Wu-Chung Shen
- Department of Biomedical Imaging and Radiological Science, China Medical University, 91 Hsueh-Shih Road, Taichung, 40402, Taiwan.,Department of Radiology, China Medical University Hospital, Taichung, Taiwan
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21
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Govaerts K, Lechat B, Struys T, Kremer A, Borghgraef P, Van Leuven F, Himmelreich U, Dresselaers T. Longitudinal assessment of cerebral perfusion and vascular response to hypoventilation in a bigenic mouse model of Alzheimer's disease with amyloid and tau pathology. NMR IN BIOMEDICINE 2019; 32:e4037. [PMID: 30489666 DOI: 10.1002/nbm.4037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 06/09/2023]
Abstract
Alzheimer's disease is the most common neurodegenerative disease, and many patients also present with vascular dysfunction. In this study, we aimed to assess cerebral blood flow (CBF) and cerebrovascular response (CVR) as early, pre-symptomatic (3 months of age), imaging markers in a bigenic model of Alzheimer's disease (APP.V717IxTau.P301L, biAT) and in the monogenic parental strains. We further developed our previously published combination of pulsed arterial spin labeling perfusion MRI and hypo-ventilation paradigm, which allows weaning of the mice from the ventilator. Furthermore, the commonly used isoflurane anesthesia induces vasodilation and is thereby inherently a vascular challenge. We therefore assessed perfusion differences in the mouse models under free-breathing isoflurane conditions. We report (i) that we can determine CBF and hypoventilation-based CVR under ketamine/midazolam anesthesia and wean mice from the ventilator, making it a valuable tool for assessment of CBF and CVR in mice, (ii) that biAT mice exhibit lower cortical CBF than wild-type mice at age 3 months, (iii) that CVR was increased in both biAT and APP.V717I mice but not in Tau.P301L mice, identifying the APP genotype as a strong influencer of brain CVR and (iv) that perfusion differences at baseline are masked by the widely used isoflurane anesthesia.
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Affiliation(s)
- Kristof Govaerts
- Biomedical MRI/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Benoit Lechat
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Tom Struys
- Morphology Research Group, Biomedical Research Institute, Universiteit Hasselt, Hasselt, Belgium
| | - Anna Kremer
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Peter Borghgraef
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Fred Van Leuven
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Tom Dresselaers
- Biomedical MRI/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
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22
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Marjańska M, Shestov AA, Deelchand DK, Kittelson E, Henry PG. Brain metabolism under different anesthetic conditions using hyperpolarized [1- 13 C]pyruvate and [2- 13 C]pyruvate. NMR IN BIOMEDICINE 2018; 31:e4012. [PMID: 30276897 PMCID: PMC6449100 DOI: 10.1002/nbm.4012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 07/25/2018] [Accepted: 08/13/2018] [Indexed: 05/12/2023]
Abstract
Carbon-13 NMR spectroscopy (13 C MRS) offers the unique capability to measure brain metabolic rates in vivo. Hyperpolarized 13 C reduces the time required to assess brain metabolism from hours to minutes when compared with conventional 13 C MRS. This study investigates metabolism of hyperpolarized [1-13 C]pyruvate and [2-13 C]pyruvate in the rat brain in vivo under various anesthetics: pentobarbital, isoflurane, α-chloralose, and morphine. The apparent metabolic rate from pyruvate to lactate modeled using time courses obtained after injection of hyperpolarized [1-13 C]pyruvate was significantly greater for isoflurane than for all other anesthetic conditions, and significantly greater for morphine than for α-chloralose. The apparent metabolic rate from pyruvate to bicarbonate was significantly greater for morphine than for all other anesthetic conditions, and significantly lower for pentobarbital than for α-chloralose. Results show that relative TCA cycle rates determined from hyperpolarized 13 C data are consistent with rates previously measured using conventional 13 C MRS under similar anesthetic conditions, and that using morphine for sedation greatly improves detection of downstream metabolic products compared with other anesthetics.
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Affiliation(s)
- Małgorzata Marjańska
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, 2021 6 ST SE, Minneapolis, Minnesota 55455, United States
| | - Alexander A. Shestov
- Department of Radiology, University of Pennsylvania, 423 Guardian Drive, Philadelphia, PA 19104, United States
| | - Dinesh K. Deelchand
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, 2021 6 ST SE, Minneapolis, Minnesota 55455, United States
| | - Emily Kittelson
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, 2021 6 ST SE, Minneapolis, Minnesota 55455, United States
| | - Pierre-Gilles Henry
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, 2021 6 ST SE, Minneapolis, Minnesota 55455, United States
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23
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Bazzigaluppi P, Adams C, Koletar MM, Dorr A, Pikula A, Carlen PL, Stefanovic B. Oophorectomy Reduces Estradiol Levels and Long-Term Spontaneous Neurovascular Recovery in a Female Rat Model of Focal Ischemic Stroke. Front Mol Neurosci 2018; 11:338. [PMID: 30271324 PMCID: PMC6146137 DOI: 10.3389/fnmol.2018.00338] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 08/28/2018] [Indexed: 12/31/2022] Open
Abstract
Although epidemiological evidence suggests significant sex and gender-based differences in stroke risk and recovery, females have been widely under-represented in preclinical stroke research. The neurovascular sequelae of brain ischemia in females, in particular, are largely uncertain. We set out to address this gap by a multimodal in vivo study of neurovascular recovery from endothelin-1 model of cortical focal-stroke in sham vs. ovariectomized female rats. Three weeks post ischemic insult, sham operated females recapitulated the phenotype previously reported in male rats in this model, of normalized resting perfusion but sustained peri-lesional cerebrovascular hyperreactivity. In contrast, ovariectomized (Ovx) females showed reduced peri-lesional resting blood flow, and elevated cerebrovascular responsivity to hypercapnia in the peri-lesional and contra-lateral cortices. Electrophysiological recordings showed an attenuation of theta to low-gamma phase-amplitude coupling in the peri-lesional tissue of Ovx animals, despite relative preservation of neuronal power. Further, this chronic stage neuronal network dysfunction was inversely correlated with serum estradiol concentration. Our pioneering data demonstrate dramatic differences in spontaneous recovery in the neurovascular unit between Ovx and Sham females in the chronic stage of stroke, underscoring the importance of considering hormonal-dependent aspects of the ischemic sequelae in the development of novel therapeutic approaches and patient recruitment in clinical trials.
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Affiliation(s)
- Paolo Bazzigaluppi
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Conner Adams
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Margaret M Koletar
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Adrienne Dorr
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Aleksandra Pikula
- Adult Vascular Neurology, Toronto Western Hospital, Toronto, ON, Canada
| | - Peter L Carlen
- Fundamental Neurobiology, Krembil Research Institute, Toronto, ON, Canada
| | - Bojana Stefanovic
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
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24
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Coquery N, Meurice P, Janvier R, Bobillier E, Quellec S, Fu M, Roura E, Saint-Jalmes H, Val-Laillet D. fMRI-Based Brain Responses to Quinine and Sucrose Gustatory Stimulation for Nutrition Research in the Minipig Model: A Proof-of-Concept Study. Front Behav Neurosci 2018; 12:151. [PMID: 30140206 PMCID: PMC6094987 DOI: 10.3389/fnbeh.2018.00151] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/03/2018] [Indexed: 01/08/2023] Open
Abstract
The minipig model is of high interest for brain research in nutrition and associated pathologies considering the similarities to human nutritional physiology, brain structures, and functions. In the context of a gustatory stimulation paradigm, fMRI can provide crucial information about the sensory, cognitive, and hedonic integration of exteroceptive stimuli in healthy and pathological nutritional conditions. Our aims were (i) to validate the experimental setup, i.e., fMRI acquisition and SPM-based statistical analysis, with a visual stimulation; (ii) to implement the fMRI procedure in order to map the brain responses to different gustatory stimulations, i.e., sucrose (5%) and quinine (10 mM), and (ii) to investigate the differential effects of potentially aversive (quinine) and appetitive/pleasant (sucrose) oral stimulation on brain responses, especially in the limbic and reward circuits. Six Yucatan minipigs were imaged on an Avanto 1.5-T MRI under isoflurane anesthesia and mechanical ventilation. BOLD signal was recorded during visual or gustatory (artificial saliva, sucrose, or quinine) stimulation with a block paradigm. With the visual stimulation, brain responses were detected in the visual cortex, thus validating our experimental and statistical setup. Quinine and sucrose stimulation promoted different cerebral activation patterns that were concordant, to some extent, to results from human studies. The insular cortex (i.e., gustatory cortex) was activated with both sucrose and quinine, but other regions were specifically activated by one or the other stimulation. Gustatory stimulation combined with fMRI analysis in large animals such as minipigs is a promising approach to investigate the integration of gustatory stimulation in healthy or pathological conditions such as obesity, eating disorders, or dysgeusia. To date, this is the first intent to describe gustatory stimulation in minipigs using fMRI.
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Affiliation(s)
- Nicolas Coquery
- INRA, INSERM, Univ Rennes, Nutrition Metabolisms and Cancer, NuMeCan, Rennes, France
| | - Paul Meurice
- INRA, INSERM, Univ Rennes, Nutrition Metabolisms and Cancer, NuMeCan, Rennes, France
| | - Régis Janvier
- INRA, INSERM, Univ Rennes, Nutrition Metabolisms and Cancer, NuMeCan, Rennes, France
| | - Eric Bobillier
- INRA, INSERM, Univ Rennes, Nutrition Metabolisms and Cancer, NuMeCan, Rennes, France
| | | | - Minghai Fu
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, QLD, Australia
| | - Eugeni Roura
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, QLD, Australia
| | - Hervé Saint-Jalmes
- CLCC Eugène Marquis, Inserm, LTSI-UMR 1099, Université de Rennes, Rennes, France
| | - David Val-Laillet
- INRA, INSERM, Univ Rennes, Nutrition Metabolisms and Cancer, NuMeCan, Rennes, France
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25
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Meconi A, Wortman RC, Wright DK, Neale KJ, Clarkson M, Shultz SR, Christie BR. Repeated mild traumatic brain injury can cause acute neurologic impairment without overt structural damage in juvenile rats. PLoS One 2018; 13:e0197187. [PMID: 29738554 PMCID: PMC5940222 DOI: 10.1371/journal.pone.0197187] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 04/27/2018] [Indexed: 11/19/2022] Open
Abstract
Repeated concussion is becoming increasingly recognized as a serious public health concern around the world. Moreover, there is a greater awareness amongst health professionals of the potential for repeated pediatric concussions to detrimentally alter the structure and function of the developing brain. To better study this issue, we developed an awake closed head injury (ACHI) model that enabled repeated concussions to be performed reliably and reproducibly in juvenile rats. A neurological assessment protocol (NAP) score was generated immediately after each ACHI to help quantify the cumulative effects of repeated injury on level of consciousness, and basic motor and reflexive capacity. Here we show that we can produce a repeated ACHI (4 impacts in two days) in both male and female juvenile rats without significant mortality or pain. We show that both single and repeated injuries produce acute neurological deficits resembling clinical concussion symptoms that can be quantified using the NAP score. Behavioural analyses indicate repeated ACHI acutely impaired spatial memory in the Barnes maze, and an interesting sex effect was revealed as memory impairment correlated moderately with poorer NAP score performance in a subset of females. These cognitive impairments occurred in the absence of motor impairments on the Rotarod, or emotional changes in the open field and elevated plus mazes. Cresyl violet histology and structural magnetic resonance imaging (MRI) indicated that repeated ACHI did not produce significant structural damage. MRI also confirmed there was no volumetric loss in the cortex, hippocampus, or corpus callosum of animals at 1 or 7 days post-ACHI. Together these data indicate that the ACHI model can provide a reliable, high throughput means to study the effects of concussions in juvenile rats.
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Affiliation(s)
- Alicia Meconi
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Ryan C. Wortman
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - David K. Wright
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Katie J. Neale
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Melissa Clarkson
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Sandy R. Shultz
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Brian R. Christie
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
- Centre for Brain Health and Program in Neuroscience, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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26
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Gomez-Smith M, Janik R, Adams C, Lake EM, Thomason LA, Jeffers MS, Stefanovic B, Corbett D. Reduced Cerebrovascular Reactivity and Increased Resting Cerebral Perfusion in Rats Exposed to a Cafeteria Diet. Neuroscience 2018; 371:166-177. [DOI: 10.1016/j.neuroscience.2017.11.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 11/28/2017] [Accepted: 11/30/2017] [Indexed: 01/15/2023]
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27
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Pérez-Cervera L, Caramés JM, Fernández-Mollá LM, Moreno A, Fernández B, Pérez-Montoyo E, Moratal D, Canals S, Pacheco-Torres J. Mapping Functional Connectivity in the Rodent Brain Using Electric-Stimulation fMRI. Methods Mol Biol 2018; 1718:117-134. [PMID: 29341006 DOI: 10.1007/978-1-4939-7531-0_8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Since its discovery in the early 90s, BOLD signal-based functional Magnetic Resonance Imaging (fMRI) has become a fundamental technique for the study of brain activity in basic and clinical research. Functional MRI signals provide an indirect but robust and quantitative readout of brain activity through the tight coupling between cerebral blood flow and neuronal activation, the so-called neurovascular coupling. Combined with experimental techniques only available in animal models, such as intracerebral micro-stimulation, optogenetics or pharmacogenetics, provides a powerful framework to investigate the impact of specific circuit manipulations on overall brain dynamics. The purpose of this chapter is to provide a comprehensive protocol to measure brain activity using fMRI with intracerebral electric micro-stimulation in murine models. Preclinical research (especially in rodents) opens the door to very sophisticated and informative experiments, but at the same time imposes important constrains (i.e., anesthetics, translatability), some of which will be addressed here.
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Affiliation(s)
- Laura Pérez-Cervera
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Spain
| | - José María Caramés
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Spain
| | | | - Andrea Moreno
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Spain
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Valencia, 46022, Spain
| | - Begoña Fernández
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Spain
| | - Elena Pérez-Montoyo
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Spain
| | - David Moratal
- Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Valencia, 46022, Spain
| | - Santiago Canals
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Spain
| | - Jesús Pacheco-Torres
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, Sant Joan d'Alacant, 03550, Spain.
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28
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Zhou H, Arias-Ramos N, López-Larrubia P, Mason RP, Cerdán S, Pacheco-Torres J. Oxygenation Imaging by Nuclear Magnetic Resonance Methods. Methods Mol Biol 2018; 1718:297-313. [PMID: 29341016 DOI: 10.1007/978-1-4939-7531-0_18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Oxygen monitoring is a topic of exhaustive research due to its central role in many biological processes, from energy metabolism to gene regulation. The ability to monitor in vivo the physiological distribution and the dynamics of oxygen from subcellular to macroscopic levels is a prerequisite to better understand the mechanisms associated with both normal and disease states (cancer, neurodegeneration, stroke, etc.). This chapter focuses on magnetic resonance imaging (MRI) based techniques to assess oxygenation in vivo. The first methodology uses injected fluorinated agents to provide quantitative pO2 measurements with high precision and suitable spatial and temporal resolution for many applications. The second method exploits changes in endogenous contrasts, i.e., deoxyhemoglobin and oxygen molecules through measurements of T 2* and T 1, in response to an intervention to qualitatively evaluate hypoxia and its potential modulation.
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Affiliation(s)
- Heling Zhou
- Prognostic Imaging Research Laboratory, Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Nuria Arias-Ramos
- Departament de Bioquímica i Biologia Molecular, Unitat de Bioquímica de Biociències, Edifici Cs, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Pilar López-Larrubia
- Instituto de Investigaciones Biomédicas 'Alberto Sols' C.S.I.C./U.A.M., Madrid, Spain
| | - Ralph P Mason
- Prognostic Imaging Research Laboratory, Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sebastián Cerdán
- Instituto de Investigaciones Biomédicas 'Alberto Sols' C.S.I.C./U.A.M., Madrid, Spain
| | - Jesús Pacheco-Torres
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas, Universidad Miguel Hernández, San Juan de Alicante, Alicante, Spain.
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29
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Vognsen M, Fabian-Jessing BK, Secher N, Løfgren B, Dezfulian C, Andersen LW, Granfeldt A. Contemporary animal models of cardiac arrest: A systematic review. Resuscitation 2017; 113:115-123. [PMID: 28214538 DOI: 10.1016/j.resuscitation.2017.01.024] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/21/2017] [Accepted: 01/25/2017] [Indexed: 01/01/2023]
Abstract
AIM OF THE STUDY Animal models are widely used in cardiac arrest research. This systematic review aimed to provide an overview of contemporary animal models of cardiac arrest. METHODS Using a comprehensive research strategy, we searched PubMed and EMBASE from March 8, 2011 to March 8, 2016 for cardiac arrest animal models. Two investigators reviewed titles and abstracts for full text inclusion from which data were extracted according to pre-defined definitions. RESULTS Search criteria yielded 1741 unique titles and abstracts of which 490 full articles were included. The most common animals used were pigs (52%) followed by rats (35%) and mice (6%). Studies favored males (52%) over females (16%); 17% of studies included both sexes, while 14% omitted to report on sex. The most common methods for induction of cardiac arrest were either electrically-induced ventricular fibrillation (54%), asphyxia (25%), or potassium (8%). The median no-flow time was 8min (quartiles: 5, 8, range: 0-37min). The majority of studies used adrenaline during resuscitation (64%), while bicarbonate (17%), vasopressin (8%) and other drugs were used less prevalently. In 53% of the studies, the post-cardiac arrest observation time was ≥24h. Neurological function was an outcome in 48% of studies while 43% included assessment of a cardiac outcome. CONCLUSIONS Multiple animal models of cardiac arrest exist. The great heterogeneity of these models along with great variability in definitions and reporting make comparisons between studies difficult. There is a need for standardization of animal cardiac arrest research and reporting.
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Affiliation(s)
- Mikael Vognsen
- Research Center for Emergency Medicine, Aarhus University Hospital, Aarhus, Denmark
| | | | - Niels Secher
- Department of Anaesthesiology and Intensive Care Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Bo Løfgren
- Research Center for Emergency Medicine, Aarhus University Hospital, Aarhus, Denmark; Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Internal Medicine, Regional Hospital of Randers, Randers, Denmark
| | - Cameron Dezfulian
- Safar Center for Resuscitation Research, Vascular Medicine Institute and Critical Care Medicine Department, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Lars W Andersen
- Research Center for Emergency Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Asger Granfeldt
- Department of Anaesthesiology and Intensive Care Medicine, Aarhus University Hospital, Aarhus, Denmark; Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.
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30
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Struys T, Govaerts K, Oosterlinck W, Casteels C, Bronckaers A, Koole M, Van Laere K, Herijgers P, Lambrichts I, Himmelreich U, Dresselaers T. In vivo evidence for long-term vascular remodeling resulting from chronic cerebral hypoperfusion in mice. J Cereb Blood Flow Metab 2017; 37:726-739. [PMID: 26994041 PMCID: PMC5381461 DOI: 10.1177/0271678x16638349] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We have characterized both acute and long-term vascular and metabolic effects of unilateral common carotid artery occlusion in mice by in vivo magnetic resonance imaging and positron emission tomography. This common carotid artery occlusion model induces chronic cerebral hypoperfusion and is therefore relevant to both preclinical stroke studies, where it serves as a control condition for a commonly used mouse model of ischemic stroke, and neurodegeneration, as chronic hypoperfusion is causative to cognitive decline. By using perfusion magnetic resonance imaging, we demonstrate that under isoflurane anesthesia, cerebral perfusion levels recover gradually over one month. This recovery is paralleled by an increase in lumen diameter and altered tortuosity of the contralateral internal carotid artery at one year post-ligation as derived from magnetic resonance angiography data. Under urethane/α-chloralose anesthesia, no acute perfusion differences are observed, but the vascular response capacity to hypercapnia is found to be compromised. These hemispheric perfusion alterations are confirmed by water [15O]-H2O positron emission tomography. Glucose metabolism ([18F]-FDG positron emission tomography) or white matter organization (diffusion-weighted magnetic resonance imaging) did not show any significant alterations. In conclusion, permanent unilateral common carotid artery occlusion results in acute and long-term vascular remodeling, which may have immediate consequences for animal models of stroke but also vascular dementia.
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Affiliation(s)
- Tom Struys
- 1 Biomedical Research Institute - Morphology Research Group, Hasselt University, Hasselt, Belgium
| | - Kristof Govaerts
- 2 Biomedical MRI Unit - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Wouter Oosterlinck
- 3 Research Unit of Experimental Cardiac Surgery, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Cindy Casteels
- 4 Nuclear Medicine - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Annelies Bronckaers
- 1 Biomedical Research Institute - Morphology Research Group, Hasselt University, Hasselt, Belgium
| | - Michel Koole
- 4 Nuclear Medicine - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Koen Van Laere
- 4 Nuclear Medicine - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Paul Herijgers
- 3 Research Unit of Experimental Cardiac Surgery, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Ivo Lambrichts
- 1 Biomedical Research Institute - Morphology Research Group, Hasselt University, Hasselt, Belgium
| | - Uwe Himmelreich
- 2 Biomedical MRI Unit - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
| | - Tom Dresselaers
- 2 Biomedical MRI Unit - MoSAIC, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium.,5 Radiology, University Hospitals, Leuven, Belgium
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31
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Lu H, Li Y, Bo B, Yuan L, Lu X, Li H, Tong S. Hemodynamic effects of intraoperative anesthetics administration in photothrombotic stroke model: a study using laser speckle imaging. BMC Neurosci 2017; 18:10. [PMID: 28056813 PMCID: PMC5217600 DOI: 10.1186/s12868-016-0327-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 12/24/2016] [Indexed: 12/19/2022] Open
Abstract
Background
Previous neuroimaging studies have shown the hemodynamic effect of either preconditioning or postconditioning anesthesia in ischemic stroke model. However, the anesthetic effect in hemodynamics during and immediately after the stroke modeling surgery remains unknown due to the lack of appropriate anesthesia-free stroke model and intraoperative imaging technology. In the present study, we utilized our recently developed photothrombotic model of focal cerebral ischemia in conscious and freely moving rats, and investigated transient hemodynamic changes with or without isoflurane administration. Laser speckle imaging was applied to acquire real-time two-dimensional full-field cerebral blood flow (CBF) information throughout the surgical operations and early after. Results Significantly larger CBF reduction area was observed in conscious rats from 8 min immediately after the onset of stroke modeling, compared with anesthetized rats. Stroke rats without isoflurane administration also showed larger lesion volume identified by magnetic resonance imaging 3 h post occlusion (58.9%), higher neurological severity score 24 h post occlusion (28.3%), and larger infarct volume from 2,3,5-triphenyltetrazolium chloride staining 24 h post occlusion (46.9%). Conclusions Our results demonstrated that the hemodynamic features were affected by anesthetics at as early as during the stroke induction. Also, our findings about the neuroprotection of intraoperative anesthetics administration bring additional insights into understanding the translational difficulty in stroke research.
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Affiliation(s)
- Hongyang Lu
- School of Biomedical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.,Med-X Research Institute, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China
| | - Yao Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China. .,Med-X Research Institute, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China.
| | - Bin Bo
- School of Biomedical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Lu Yuan
- Med-X Research Institute, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China
| | - Xiaodan Lu
- Med-X Research Institute, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China
| | - Hangdao Li
- Med-X Research Institute, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China
| | - Shanbao Tong
- School of Biomedical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China. .,Med-X Research Institute, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China.
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32
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Foley LM, Clark RS, Vazquez AL, Hitchens TK, Alexander H, Ho C, Kochanek PM, Manole MD. Enduring disturbances in regional cerebral blood flow and brain oxygenation at 24 h after asphyxial cardiac arrest in developing rats. Pediatr Res 2017; 81:94-98. [PMID: 27636898 PMCID: PMC5287715 DOI: 10.1038/pr.2016.175] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Accepted: 07/25/2016] [Indexed: 11/24/2022]
Abstract
BACKGROUND Disturbances in cerebral blood flow (CBF) and brain oxygenation (PbO2) are present early after pediatric cardiac arrest (CA). CBF-targeted therapies improved neurological outcome in our CA model. To assess the therapeutic window for CBF- and PbO2-targeted therapies, we propose to determine if CBF and PbO2 disturbances persist at 24 h after experimental pediatric CA. METHODS Regional CBF and PbO2 were measured at 24 h after asphyxial CA in immature rats (n = 26, 6-8/group) using arterial spin label MRI and tissue electrodes, respectively. RESULTS In all regions but the thalamus, CBF recovered to sham values by 24 h; thalamic CBF was >32% higher after CA vs. sham. PbO2 values at 24 h after CA in the cortex and thalamus were similar to shams in rats who received supplemental oxygen, however, on room air, cortical PbO2 was lower after CA vs. shams. CONCLUSION CBF remains increased in the thalamus at 24 h after CA and PbO2 is decreased to hypoxic levels in cortex at 24 h after CA in rats who do not receive supplemental oxygen. Given the enduring disturbances in this model and the lack of routine CBF or PbO2 monitoring in patients, our data suggest the need for clinical correlation.
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Affiliation(s)
- Lesley M. Foley
- Animal Imaging Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robert S.B. Clark
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Safar Center for Resuscitation Research, Pittsburgh, PA, USA
| | - Alberto L. Vazquez
- Animal Imaging Center, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - T. Kevin Hitchens
- Animal Imaging Center, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Henry Alexander
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Safar Center for Resuscitation Research, Pittsburgh, PA, USA
| | - Chien Ho
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Patrick M. Kochanek
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Safar Center for Resuscitation Research, Pittsburgh, PA, USA
- Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Department of Clinical and Translational Science, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Mioara D. Manole
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Safar Center for Resuscitation Research, Pittsburgh, PA, USA
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33
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Hartmann A, Driesen A, Lautenschläger IE, Scholz VB, Schmidt MJ. Quantitative analysis of brain perfusion in healthy dogs by means of magnetic resonance imaging. Am J Vet Res 2016; 77:1227-1235. [DOI: 10.2460/ajvr.77.11.1227] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Shultz SR, McDonald SJ, Vonder Haar C, Meconi A, Vink R, van Donkelaar P, Taneja C, Iverson GL, Christie BR. The potential for animal models to provide insight into mild traumatic brain injury: Translational challenges and strategies. Neurosci Biobehav Rev 2016; 76:396-414. [PMID: 27659125 DOI: 10.1016/j.neubiorev.2016.09.014] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 09/07/2016] [Accepted: 09/16/2016] [Indexed: 12/14/2022]
Abstract
Mild traumatic brain injury (mTBI) is a common health problem. There is tremendous variability and heterogeneity in human mTBI, including mechanisms of injury, biomechanical forces, injury severity, spatial and temporal pathophysiology, genetic factors, pre-injury vulnerability and resilience factors, and clinical outcomes. Animal models greatly reduce this variability and heterogeneity, and provide a means to study mTBI in a rigorous, controlled, and efficient manner. Rodent models, in particular, are time- and cost-efficient, and they allow researchers to measure morphological, cellular, molecular, and behavioral variables in a single study. However, inter-species differences in anatomy, morphology, metabolism, neurobiology, and lifespan create translational challenges. Although the term "mild" TBI is used often in the pre-clinical literature, clearly defined criteria for mild, moderate, and severe TBI in animal models have not been agreed upon. In this review, we introduce current issues facing the mTBI field, summarize the available research methodologies and previous studies in mTBI animal models, and discuss how a translational research approach may be useful in advancing our understanding and management of mTBI.
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Affiliation(s)
- Sandy R Shultz
- Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia.
| | - Stuart J McDonald
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, VIC, Australia
| | - Cole Vonder Haar
- Department of Psychology, The University of British Columbia, Vancouver, BC, Canada
| | - Alicia Meconi
- Division of Medical Sciences, The University of Victoria, Victoria, BC, Canada
| | - Robert Vink
- Division of Health Sciences, The University of South Australia, Adelaide, SA, Australia
| | - Paul van Donkelaar
- School of Health and Exercise Sciences, The University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Chand Taneja
- Division of Medical Sciences, The University of Victoria, Victoria, BC, Canada
| | - Grant L Iverson
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Home Base, A Red Sox Foundation and Massachusetts General Hospital Program, and MassGeneral Hospital for Children™ Sports Concussion Program, Boston, MA, USA
| | - Brian R Christie
- Division of Medical Sciences, The University of Victoria, Victoria, BC, Canada
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Constantinides C, Murphy K. Molecular and Integrative Physiological Effects of Isoflurane Anesthesia: The Paradigm of Cardiovascular Studies in Rodents using Magnetic Resonance Imaging. Front Cardiovasc Med 2016; 3:23. [PMID: 27525256 PMCID: PMC4965459 DOI: 10.3389/fcvm.2016.00023] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/04/2016] [Indexed: 12/19/2022] Open
Abstract
To-this-date, the exact molecular, cellular, and integrative physiological mechanisms of anesthesia remain largely unknown. Published evidence indicates that anesthetic effects are multifocal and occur in a time-dependent and coordinated manner, mediated via central, local, and peripheral pathways. Their effects can be modulated by a range of variables, and their elicited end-effect on the integrative physiological response is highly variable. This review summarizes the major cellular and molecular sites of anesthetic action with a focus on the paradigm of isoflurane (ISO) - the most commonly used anesthetic nowadays - and its use in prolonged in vivo rodent studies using imaging modalities, such as magnetic resonance imaging (MRI). It also presents established evidence for normal ranges of global and regional physiological cardiac function under ISO, proposes optimal, practical methodologies relevant to the use of anesthetic protocols for MRI and outlines the beneficial effects of nitrous oxide supplementation.
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Affiliation(s)
- Christakis Constantinides
- Chi Biomedical Ltd., Nicosia, Cyprus; Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Kathy Murphy
- Division of Biomedical Sciences, University of Oxford , Oxford , UK
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36
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Chatelin S, Humbert-Claude M, Garteiser P, Ricobaraza A, Vilgrain V, Van Beers BE, Sinkus R, Lenkei Z. Cannabinoid receptor activation in the juvenile rat brain results in rapid biomechanical alterations: Neurovascular mechanism as a putative confounding factor. J Cereb Blood Flow Metab 2016; 36:954-64. [PMID: 26661178 PMCID: PMC4853836 DOI: 10.1177/0271678x15606923] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 08/03/2015] [Indexed: 12/21/2022]
Abstract
We have recently reported cannabinoid-induced rapid changes in the structure of individual neurons. In order to investigate the presence of similar effects at the regional level, measures of brain tissue biomechanics are required. However, cannabinoids are known to alter cerebral blood flow (CBF), putatively resulting in presently unexplored changes in cerebral tissue biomechanics. Here we used magnetic resonance elastography (MRE) and flow-sensitive alternating inversion recovery (FAIR) imaging to measure in vivo alterations of mechanical properties and CBF, respectively, in the rat hippocampus, a brain region with a high density of type-1 cannabinoid receptors (CB1R). Systemic injection of the cannabinoid agonist CP55,940 (0.7 mg/kg) induced a significant stiffness decrease of 10.5 ± 1.2% at 15 minutes. FAIR imaging indicated a comparable decrease (11.3 ± 1.9%) in CBF. Both effects were specific to CB1R activation, as shown by pretreatment with the CB1R-specific antagonist AM251. Strikingly, similar rapid parallel changes of brain elasticity and CBF were also observed after systemic treatment with the hypotensive drug nicardipine. Our results reveal important drug-induced parallel changes in CBF and brain mechanical characteristics, and show that blood flow-dependent tissue softening has to be considered as an important putative confounding factor when cerebral viscoelastic changes are investigated.
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Affiliation(s)
- Simon Chatelin
- Laboratory of Imaging Biomarkers, UMR1149 INSERM-University Paris Diderot, Sorbonne Paris Cité, Paris, France These authors contributed equally to this work
| | - Marie Humbert-Claude
- Brain Plasticity Unit, CNRS UMR8249, ESPCI-ParisTech, PSL Research University, Paris, France These authors contributed equally to this work
| | - Philippe Garteiser
- Laboratory of Imaging Biomarkers, UMR1149 INSERM-University Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Ana Ricobaraza
- Brain Plasticity Unit, CNRS UMR8249, ESPCI-ParisTech, PSL Research University, Paris, France
| | - Valérie Vilgrain
- Laboratory of Imaging Biomarkers, UMR1149 INSERM-University Paris Diderot, Sorbonne Paris Cité, Paris, France Department of Radiology, Assistance-Publique Hôpitaux de Paris, Clichy, France
| | - Bernard E Van Beers
- Laboratory of Imaging Biomarkers, UMR1149 INSERM-University Paris Diderot, Sorbonne Paris Cité, Paris, France Department of Radiology, Assistance-Publique Hôpitaux de Paris, Clichy, France
| | - Ralph Sinkus
- Laboratory of Imaging Biomarkers, UMR1149 INSERM-University Paris Diderot, Sorbonne Paris Cité, Paris, France These authors contributed equally to this work
| | - Zsolt Lenkei
- Brain Plasticity Unit, CNRS UMR8249, ESPCI-ParisTech, PSL Research University, Paris, France These authors contributed equally to this work
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A novel anesthesia regime enables neurofunctional studies and imaging genetics across mouse strains. Sci Rep 2016; 6:24523. [PMID: 27080031 PMCID: PMC4832200 DOI: 10.1038/srep24523] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 03/30/2016] [Indexed: 12/18/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) has revolutionized neuroscience by opening a unique window that allows neurocircuitry function and pathological alterations to be probed non-invasively across brain disorders. Here we report a novel sustainable anesthesia procedure for small animal neuroimaging that overcomes shortcomings of anesthetics commonly used in rodent fMRI. The significantly improved preservation of cerebrovascular dynamics enhances sensitivity to neural activity changes for which it serves as a proxy in fMRI readouts. Excellent cross-species/strain applicability provides coherence among preclinical findings and is expected to improve translation to clinical fMRI investigations. The novel anesthesia procedure based on the GABAergic anesthetic etomidate was extensively validated in fMRI studies conducted in a range of genetically engineered rodent models of autism and strains commonly used for transgenic manipulations. Etomidate proved effective, yielded long-term stable physiology with basal cerebral blood flow of ~0.5 ml/g/min and full recovery. Cerebrovascular responsiveness of up to 180% was maintained as demonstrated with perfusion- and BOLD-based fMRI upon hypercapnic, pharmacological and sensory stimulation. Hence, etomidate lends itself as an anesthetic-of-choice for translational neuroimaging studies across rodent models of brain disorders.
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Dumas N, Moulin-Sallanon M, Fender P, Tournier BB, Ginovart N, Charnay Y, Millet P. In Vivo Quantification of 5-HT2A Brain Receptors in Mdr1a KO Rats with 123I-R91150 Single-Photon Emission Computed Tomography. Mol Imaging 2016; 14. [PMID: 26105563 DOI: 10.2310/7290.2015.00006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Our goal was to identify suitable image quantification methods to image 5-hydroxytryptamine2A (5-HT2A) receptors in vivo in Mdr1a knockout (KO) rats (i.e., P-glycoprotein KO) using 123I-R91150 single-photon emission computed tomography (SPECT). The 123I-R91150 binding parameters estimated with different reference tissue models (simplified reference tissue model [SRTM], Logan reference tissue model, and tissue ratio [TR] method) were compared to the estimates obtained with a comprehensive three-tissue/seven-parameter (3T/7k)-based model. The SRTM and Logan reference tissue model estimates of 5-HT2A receptor (5-HT2AR) nondisplaceable binding potential (BPND) correlated well with the absolute receptor density measured with the 3T/7k gold standard (r > .89). Quantification of 5-HT2AR using the Logan reference tissue model required at least 90 minutes of scanning, whereas the SRTM required at least 110 minutes. The TR method estimates were also highly correlated to the 5-HT2AR density (r > .91) and only required a single 20-minute scan between 100 and 120 minutes postinjection. However, a systematic overestimation of the BPND values was observed. The Logan reference tissue method is more convenient than the SRTM for the quantification of 5-HT2AR in Mdr1a KO rats using 123I-R91150 SPECT. The TR method is an interesting and simple alternative, despite its bias, as it still provides a valid index of 5-HT2AR density.
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Floriano BP, Wagatsuma JT, Ferreira JZ, Abimussi CJX, Menegheti TM, Santos PSP, Oliva VNLS. Effects on indicators of tissue perfusion in dogs anesthetized with isoflurane at two multiples of the minimum alveolar concentration. Am J Vet Res 2016; 77:24-31. [DOI: 10.2460/ajvr.77.1.24] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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40
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Wanek T, Römermann K, Mairinger S, Stanek J, Sauberer M, Filip T, Traxl A, Kuntner C, Pahnke J, Bauer F, Erker T, Löscher W, Müller M, Langer O. Factors Governing P-Glycoprotein-Mediated Drug-Drug Interactions at the Blood-Brain Barrier Measured with Positron Emission Tomography. Mol Pharm 2015. [PMID: 26202880 PMCID: PMC4566129 DOI: 10.1021/acs.molpharmaceut.5b00168] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
![]()
The
adenosine triphosphate-binding cassette transporter P-glycoprotein
(ABCB1/Abcb1a) restricts at the blood–brain barrier (BBB) brain
distribution of many drugs. ABCB1 may be involved in drug–drug
interactions (DDIs) at the BBB, which may lead to changes in brain
distribution and central nervous system side effects of drugs. Positron
emission tomography (PET) with the ABCB1 substrates (R)-[11C]verapamil and [11C]-N-desmethyl-loperamide and the ABCB1 inhibitor tariquidar has allowed
direct comparison of ABCB1-mediated DDIs at the rodent and human BBB.
In this work we evaluated different factors which could influence
the magnitude of the interaction between tariquidar and (R)-[11C]verapamil or [11C]-N-desmethyl-loperamide at the BBB and thereby contribute to previously
observed species differences between rodents and humans. We performed in vitro transport experiments with [3H]verapamil
and [3H]-N-desmethyl-loperamide in ABCB1
and Abcb1a overexpressing cell lines. Moreover we conducted in vivo PET experiments and biodistribution studies with
(R)-[11C]verapamil and [11C]-N-desmethyl-loperamide in wild-type mice without and with
tariquidar pretreatment and in homozygous Abcb1a/1b(−/−) and heterozygous Abcb1a/1b(+/−) mice. We found no differences for in vitro transport of [3H]verapamil and [3H]-N-desmethyl-loperamide by ABCB1 and Abcb1a and its inhibition
by tariquidar. [3H]-N-Desmethyl-loperamide
was transported with a 5 to 9 times higher transport ratio than [3H]verapamil in ABCB1- and Abcb1a-transfected cells. In vivo, brain radioactivity concentrations were lower for
[11C]-N-desmethyl-loperamide than for
(R)-[11C]verapamil. Both radiotracers
showed tariquidar dose dependent increases in brain distribution with
tariquidar half-maximum inhibitory concentrations (IC50) of 1052 nM (95% confidence interval CI: 930–1189) for (R)-[11C]verapamil and 1329 nM (95% CI: 980–1801)
for [11C]-N-desmethyl-loperamide. In homozygous Abcb1a/1b(−/−) mice brain radioactivity
distribution was increased by 3.9- and 2.8-fold and in heterozygous Abcb1a/1b(+/−) mice by 1.5- and 1.1-fold,
for (R)-[11C]verapamil and [11C]-N-desmethyl-loperamide, respectively, as compared
with wild-type mice. For both radiotracers radiolabeled metabolites
were detected in plasma and brain. When brain and plasma radioactivity
concentrations were corrected for radiolabeled metabolites, brain
distribution of (R)-[11C]verapamil and
[11C]-N-desmethyl-loperamide was increased
in tariquidar (15 mg/kg) treated animals by 14.1- and 18.3-fold, respectively,
as compared with vehicle group. Isoflurane anesthesia altered [11C]-N-desmethyl-loperamide but not (R)-[11C]verapamil metabolism, and this had a
direct effect on the magnitude of the increase in brain distribution
following ABCB1 inhibition. Our data furthermore suggest that in the
absence of ABCB1 function brain distribution of [11C]-N-desmethyl-loperamide but not (R)-[11C]verapamil may depend on cerebral blood flow. In conclusion,
we have identified a number of important factors, i.e., substrate
affinity to ABCB1, brain uptake of radiolabeled metabolites, anesthesia,
and cerebral blood flow, which can directly influence the magnitude
of ABCB1-mediated DDIs at the BBB and should therefore be taken into
consideration when interpreting PET results.
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Affiliation(s)
- Thomas Wanek
- Health & Environment Department, AIT Austrian Institute of Technology GmbH , Seibersdorf, Austria
| | - Kerstin Römermann
- Department of Pharmacology, Toxicology & Pharmacy, University of Veterinary Medicine Hannover , Hannover, Germany.,Department of Clinical Pharmacology, Medical University of Vienna , Vienna, Austria
| | - Severin Mairinger
- Health & Environment Department, AIT Austrian Institute of Technology GmbH , Seibersdorf, Austria
| | - Johann Stanek
- Health & Environment Department, AIT Austrian Institute of Technology GmbH , Seibersdorf, Austria.,Department of Clinical Pharmacology, Medical University of Vienna , Vienna, Austria
| | - Michael Sauberer
- Health & Environment Department, AIT Austrian Institute of Technology GmbH , Seibersdorf, Austria
| | - Thomas Filip
- Health & Environment Department, AIT Austrian Institute of Technology GmbH , Seibersdorf, Austria
| | - Alexander Traxl
- Health & Environment Department, AIT Austrian Institute of Technology GmbH , Seibersdorf, Austria
| | - Claudia Kuntner
- Health & Environment Department, AIT Austrian Institute of Technology GmbH , Seibersdorf, Austria
| | - Jens Pahnke
- Department of Neuro-/Pathology, University of Oslo (UiO) and Oslo University Hospital (OUS) , Oslo, Norway.,Lübeck Institute of Experimental Dermatology, University of Lübeck , Lübeck, Germany
| | - Florian Bauer
- Department of Medicinal Chemistry, University of Vienna , Vienna, Austria
| | - Thomas Erker
- Department of Medicinal Chemistry, University of Vienna , Vienna, Austria
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology & Pharmacy, University of Veterinary Medicine Hannover , Hannover, Germany
| | - Markus Müller
- Department of Clinical Pharmacology, Medical University of Vienna , Vienna, Austria
| | - Oliver Langer
- Health & Environment Department, AIT Austrian Institute of Technology GmbH , Seibersdorf, Austria.,Department of Clinical Pharmacology, Medical University of Vienna , Vienna, Austria
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41
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Haensel JX, Spain A, Martin C. A systematic review of physiological methods in rodent pharmacological MRI studies. Psychopharmacology (Berl) 2015; 232:489-99. [PMID: 25585682 PMCID: PMC4302233 DOI: 10.1007/s00213-014-3855-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 12/19/2014] [Indexed: 10/28/2022]
Abstract
RATIONALE Pharmacological magnetic resonance imaging (phMRI) provides an approach to study effects of drug challenges on brain processes. Elucidating mechanisms of drug action helps us to better understand the workings of neurotransmitter systems, map brain function or facilitate drug development. phMRI is increasingly used in preclinical research employing rodent models; however, data interpretation and integration are complicated by the use of different experimental approaches between laboratories. In particular, the effects of different anaesthetic regimes upon neuronal and haemodynamic processes and baseline physiology could be problematic. OBJECTIVES This paper investigates how differences in phMRI research methodologies are manifested and considers associated implications, placing particular emphasis on choice of anaesthetic regimes. METHODS A systematic review of rodent phMRI studies was conducted. Factors such as those describing anaesthetic regimes (e.g. agent, dosage) and parameters relating to physiological maintenance (e.g. ventilatory gases) and MRI method were recorded. RESULTS We identified 126 eligible studies and found that the volatile agents isoflurane (43.7 %) and halothane (33.3 %) were most commonly used for anaesthesia, but dosage and mixture of ventilatory gases varied substantially between laboratories. Relevant physiological parameters were usually recorded, although 32 % of studies did not provide cardiovascular measures. CONCLUSIONS Anaesthesia and animal preparation can influence phMRI data profoundly. The variation of anaesthetic type, dosage regime and ventilatory gases makes consolidation of research findings (e.g. within a specific neurotransmitter system) difficult. Standardisation of a small(er) number of preclinical phMRI research methodologies and/or increased consideration of approaches that do not require anaesthesia is necessary to address these challenges.
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Affiliation(s)
- Jennifer X. Haensel
- Department of Psychology, University of Sheffield, Western Bank, Sheffield, S10 2TP UK
| | - Aisling Spain
- Department of Psychology, University of Sheffield, Western Bank, Sheffield, S10 2TP UK
| | - Chris Martin
- Department of Psychology, University of Sheffield, Western Bank, Sheffield, S10 2TP UK
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42
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Huang C, Ackerman JL, Petibon Y, Brady TJ, El Fakhri G, Ouyang J. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: phantom study. Med Phys 2014; 41:041910. [PMID: 24694141 DOI: 10.1118/1.4868457] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. METHODS Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic(18)F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. RESULTS Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from -0.6% to 3.4% as compared to a bias ranging from -25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%-156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R(2) = 0.978 ± 0.007 (0.588 ± 0.010, respectively). CONCLUSIONS Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast.
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Affiliation(s)
- Chuan Huang
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Jerome L Ackerman
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Yoann Petibon
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Thomas J Brady
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Georges El Fakhri
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Jinsong Ouyang
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115
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Petraglia AL, Dashnaw ML, Turner RC, Bailes JE. Models of Mild Traumatic Brain Injury. Neurosurgery 2014; 75 Suppl 4:S34-49. [DOI: 10.1227/neu.0000000000000472] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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44
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Pohlmann A, Karczewski P, Ku MC, Dieringer B, Waiczies H, Wisbrun N, Kox S, Palatnik I, Reimann HM, Eichhorn C, Waiczies S, Hempel P, Lemke B, Niendorf T, Bimmler M. Cerebral blood volume estimation by ferumoxytol-enhanced steady-state MRI at 9.4 T reveals microvascular impact of α1 -adrenergic receptor antibodies. NMR IN BIOMEDICINE 2014; 27:1085-1093. [PMID: 25060359 DOI: 10.1002/nbm.3160] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/11/2014] [Accepted: 06/05/2014] [Indexed: 06/03/2023]
Abstract
Cerebrovascular abnormality is frequently accompanied by cognitive dysfunctions, such as dementia. Antibodies against the α1 -adrenoceptor (α1 -AR) can be found in patients with Alzheimer's disease with cerebrovascular disease, and have been shown to affect the larger vessels of the brain in rodents. However, the impact of α1 -AR antibodies on the cerebral vasculature remains unclear. In the present study, we established a neuroimaging method to measure the relative cerebral blood volume (rCBV) in small rodents with the ultimate goal to detect changes in blood vessel density and/or vessel size induced by α1 -AR antibodies. For this purpose, mapping of R2 * and R2 was performed using MRI at 9.4 T, before and after the injection of intravascular iron oxide particles (ferumoxytol). The change in the transverse relaxation rates (ΔR2 *, ΔR2 ) showed a significant rCBV decrease in the cerebrum, cortex and hippocampus of rats (except hippocampal ΔR2 ), which was more pronounced for ΔR2 * than for ΔR2 . Immunohistological analyses confirmed that the α1 -AR antibody induced blood vessel deficiencies. Our findings support the hypothesis that α1 -AR antibodies lead to cerebral vessel damage throughout the brain, which can be monitored by MRI-derived rCBV, a non-invasive neuroimaging method. This demonstrates the value of rCBV estimation by ferumoxytol-enhanced MRI at 9.4 T, and further underlines the significance of this antibody in brain diseases involving vasculature impairments, such as dementia.
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Affiliation(s)
- Andreas Pohlmann
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine, Berlin, Germany
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Global and regional differences in cerebral blood flow after asphyxial versus ventricular fibrillation cardiac arrest in rats using ASL-MRI. Resuscitation 2014; 85:964-71. [PMID: 24727136 DOI: 10.1016/j.resuscitation.2014.03.314] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 02/11/2014] [Accepted: 03/31/2014] [Indexed: 12/20/2022]
Abstract
Both ventricular fibrillation cardiac arrest (VFCA) and asphyxial cardiac arrest (ACA) are frequent causes of CA. However, only isolated reports compared cerebral blood flow (CBF) reperfusion patterns after different types of CA, and even fewer reports used methods that allow serial and regional assessment of CBF. We hypothesized that the reperfusion patterns of CBF will differ between individual types of experimental CA. In a prospective block-randomized study, fentanyl-anesthetized adult rats were subjected to 8min VFCA or ACA. Rats were then resuscitated with epinephrine, bicarbonate, manual chest compressions and mechanical ventilation. After the return of spontaneous circulation, CBF was then serially assessed via arterial spin-labeling magnetic resonance imaging (ASL-MRI) in cortex, thalamus, hippocampus and amygdala/piriform complex over 1h resuscitation time (RT). Both ACA and VFCA produced significant temporal and regional differences in CBF. All regions in both models showed significant changes over time (p<0.01), with early hyperperfusion and delayed hypoperfusion. ACA resulted in early hyperperfusion in cortex and thalamus (both p<0.05 vs. amygdala/piriform complex). In contrast, VFCA induced early hyperperfusion only in cortex (p<0.05 vs. other regions). Hyperperfusion was prolonged after ACA, peaking at 7min RT (RT7; 199% vs. BL, Baseline, in cortex and 201% in thalamus, p<0.05), then returning close to BL at ∼RT15. In contrast, VFCA model induced mild hyperemia, peaking at RT7 (141% vs. BL in cortex). Both ACA and VFCA showed delayed hypoperfusion (ACA, ∼30% below BL in hippocampus and amygdala/piriform complex, p<0.05; VFCA, 34-41% below BL in hippocampus and amygdala/piriform complex, p<0.05). In conclusion, both ACA and VFCA in adult rats produced significant regional and temporal differences in CBF. In ACA, hyperperfusion was most pronounced in cortex and thalamus. In VFCA, the changes were more modest, with hyperperfusion seen only in cortex. Both insults resulted in delayed hypoperfusion in all regions. Both early hyperperfusion and delayed hypoperfusion may be important therapeutic targets. This study was approved by the University of Pittsburgh IACUC 1008816-1.
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Deng J, Lei C, Chen Y, Fang Z, Yang Q, Zhang H, Cai M, Shi L, Dong H, Xiong L. Neuroprotective gases – Fantasy or reality for clinical use? Prog Neurobiol 2014; 115:210-45. [DOI: 10.1016/j.pneurobio.2014.01.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 01/03/2014] [Accepted: 01/03/2014] [Indexed: 12/17/2022]
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Specificity of stimulus-evoked fMRI responses in the mouse: the influence of systemic physiological changes associated with innocuous stimulation under four different anesthetics. Neuroimage 2014; 94:372-384. [PMID: 24495809 DOI: 10.1016/j.neuroimage.2014.01.046] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 01/09/2014] [Accepted: 01/24/2014] [Indexed: 02/07/2023] Open
Abstract
Functional magnetic resonance (fMRI) in mice has become an attractive tool for mechanistic studies, for characterizing models of human disease, and for evaluation of novel therapies. Yet, controlling the physiological state of mice is challenging, but nevertheless important as changes in cardiovascular parameters might affect the hemodynamic readout which constitutes the basics of the fMRI signal. In contrast to rats, fMRI studies in mice report less robust brain activation of rather widespread character to innocuous sensory stimulation. Anesthesia is known to influence the characteristics of the fMRI signal. To evaluate modulatory effects imposed by the anesthesia on stimulus-evoked fMRI responses, we compared blood oxygenation level dependent (BOLD) and cerebral blood volume (CBV) signal changes to electrical hindpaw stimulation using the four commonly used anesthetics isoflurane, medetomidine, propofol and urethane. fMRI measurements were complemented by assessing systemic physiological parameters throughout the experiment. Unilateral stimulation of the hindpaw elicited widespread fMRI responses in the mouse brain displaying a bilateral pattern irrespective of the anesthetic used. Analysis of magnitude and temporal profile of BOLD and CBV signals indicated anesthesia-specific modulation of cerebral hemodynamic responses and differences observed for the four anesthetics could be largely explained by their known effects on animal physiology. Strikingly, independent of the anesthetic used our results reveal that fMRI responses are influenced by stimulus-induced cardiovascular changes, which indicate an arousal response, even to innocuous stimulation. This may mask specific fMRI signal associated to the stimulus. Hence, studying the processing of peripheral input in mice using fMRI techniques constitutes a major challenge and adapted paradigms and/or alternative fMRI readouts should also be considered when studying sensory processing in mice.
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Manole MD, Kochanek PM, Bayır H, Alexander H, Dezfulian C, Fink EL, Bell MJ, Clark RS. Brain tissue oxygen monitoring identifies cortical hypoxia and thalamic hyperoxia after experimental cardiac arrest in rats. Pediatr Res 2014; 75:295-301. [PMID: 24226633 PMCID: PMC3970819 DOI: 10.1038/pr.2013.220] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 07/04/2013] [Indexed: 11/13/2022]
Abstract
BACKGROUND Optimization of cerebral oxygenation after pediatric cardiac arrest (CA) may reduce neurological damage associated with the post-CA syndrome. We hypothesized that important alterations in regional partial pressure of brain tissue oxygen (PbO2) occur after resuscitation from CA and that clinically relevant interventions such as hyperoxia and blood pressure augmentation would influence PbO2. METHODS Cortical and thalamic PbO2 were monitored in immature rats subjected to asphyxial CA (9 or 12 min asphyxia) and sham-operated rats using oxygen sensors. RESULTS Thalamus and cortex showed similar baseline PbO2. Postresuscitation, there was early and sustained cortical hypoxia in an insult-duration dependent fashion. In contrast, thalamic PbO2 initially increased fourfold and afterwards returned to baseline values. PbO2 level was dependent on the fraction of inspired O2, and the response to oxygen was more pronounced after a 9 vs. 12 min CA. After a 12 min CA, PbO2 was modestly affected by blood pressure augmentation using epinephrine in the thalamus but not in the cortex. CONCLUSION After asphyxial pediatric CA, there is marked regional variability of cerebral oxygenation. Cortical hypoxia is pronounced and appears early, whereas thalamic hyperoxia is followed by normoxia. Compromised PbO2 in the cortex may represent a relevant and clinically measurable therapeutic target aimed at improving neurological outcome after pediatric CA.
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Affiliation(s)
- Mioara D. Manole
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA,Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA
| | - Patrick M. Kochanek
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA,Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA,Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Hulya Bayır
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA,Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Henry Alexander
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA,Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Cameron Dezfulian
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA,Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA,Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Ericka L. Fink
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA,Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Michael J. Bell
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA,Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Robert S.B. Clark
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA,Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA,Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA
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Huang C, Ackerman JL, Petibon Y, Normandin MD, Brady TJ, El Fakhri G, Ouyang J. Motion compensation for brain PET imaging using wireless MR active markers in simultaneous PET-MR: phantom and non-human primate studies. Neuroimage 2014; 91:129-37. [PMID: 24418501 DOI: 10.1016/j.neuroimage.2013.12.061] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 12/16/2013] [Accepted: 12/30/2013] [Indexed: 11/19/2022] Open
Abstract
Brain PET scanning plays an important role in the diagnosis, prognostication and monitoring of many brain diseases. Motion artifacts from head motion are one of the major hurdles in brain PET. In this work, we propose to use wireless MR active markers to track head motion in real time during a simultaneous PET-MR brain scan and incorporate the motion measured by the markers in the listmode PET reconstruction. Several wireless MR active markers and a dedicated fast MR tracking pulse sequence module were built. Data were acquired on an ACR Flangeless PET phantom with multiple spheres and a non-human primate with and without motion. Motions of the phantom and monkey's head were measured with the wireless markers using a dedicated MR tracking sequence module. The motion PET data were reconstructed using list-mode reconstruction with and without motion correction. Static reference was used as gold standard for quantitative analysis. The motion artifacts, which were prominent on the images without motion correction, were eliminated by the wireless marker based motion correction in both the phantom and monkey experiments. Quantitative analysis was performed on the phantom motion data from 24 independent noise realizations. The reduction of bias of sphere-to-background PET contrast by active marker based motion correction ranges from 26% to 64% and 17% to 25% for hot (i.e., radioactive) and cold (i.e., non-radioactive) spheres, respectively. The motion correction improved the channelized Hotelling observer signal-to-noise ratio of the spheres by 1.2 to 6.9 depending on their locations and sizes. The proposed wireless MR active marker based motion correction technique removes the motion artifacts in the reconstructed PET images and yields accurate quantitative values.
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Affiliation(s)
- Chuan Huang
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Jerome L Ackerman
- Department of Radiology, Harvard Medical School, Boston, MA 02115, USA; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA.
| | - Yoann Petibon
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Laboratoire d'imagerie fonctionnelle (LIF), UMRS-678, INSERM, Université Pierre et Marie Curie, CHU Pitié-Salpêtrière, Paris, France.
| | - Marc D Normandin
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Thomas J Brady
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Georges El Fakhri
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA.
| | - Jinsong Ouyang
- Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA.
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Foley LM, Hitchens TK, Barbe B, Zhang F, Ho C, Rao GR, Nemoto EM. Quantitative temporal profiles of penumbra and infarction during permanent middle cerebral artery occlusion in rats. Transl Stroke Res 2013; 1:220-9. [PMID: 21666857 DOI: 10.1007/s12975-010-0032-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The basic premise of neuroprotection in acute stroke is the presence of salvageable tissue, but the spatiotemporal volume profiles of the penumbra and infarction remain poorly defined in preclinical animal models of acute stroke used to evaluate therapies for clinical application. Our aim was to define these profiles using magnetic resonance imaging (MRI) quantitative cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) for dual-parameter voxel analysis in the rat suture permanent middle cerebral artery occlusion (pMCAO) model. Eleven male Sprague Dawley rats were subjected to pMCAO with MRI measurements of quantitative CBF and ADC at baseline, over the first 4 h (n=9) and at 7, 14, and 21 days (n=4). Voxel analysis of CBF and ADC was used to characterize brain tissue ischemic transitions. Penumbra, core, and hyperemic infarction volumes were significantly elevated (P<0.05) and unchanged over the first 4 h of pMCAO while the total lesion volume progressively rose. At 7, 14, and 21 days, tissue compartment transitions reflected infarction, tissue cavitation, and selective ischemic neuronal necrosis. Anatomical distribution of penumbra and core revealed marked heterogeneity with penumbra scattered within core and penumbra persisting even after 4 h of permanent MCAO.
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Affiliation(s)
- Lesley M Foley
- Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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