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Mitchell R, Mikolajczak M, Kersten C, Fleetwood-Walker S. ErbB1-dependent signalling and vesicular trafficking in primary afferent nociceptors associated with hypersensitivity in neuropathic pain. Neurobiol Dis 2020; 142:104961. [DOI: 10.1016/j.nbd.2020.104961] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/26/2020] [Accepted: 06/08/2020] [Indexed: 02/06/2023] Open
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Licht-Mayer S, Campbell GR, Canizares M, Mehta AR, Gane AB, McGill K, Ghosh A, Fullerton A, Menezes N, Dean J, Dunham J, Al-Azki S, Pryce G, Zandee S, Zhao C, Kipp M, Smith KJ, Baker D, Altmann D, Anderton SM, Kap YS, Laman JD, Hart BA', Rodriguez M, Watzlawick R, Schwab JM, Carter R, Morton N, Zagnoni M, Franklin RJM, Mitchell R, Fleetwood-Walker S, Lyons DA, Chandran S, Lassmann H, Trapp BD, Mahad DJ. Enhanced axonal response of mitochondria to demyelination offers neuroprotection: implications for multiple sclerosis. Acta Neuropathol 2020; 140:143-167. [PMID: 32572598 PMCID: PMC7360646 DOI: 10.1007/s00401-020-02179-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/25/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022]
Abstract
Axonal loss is the key pathological substrate of neurological disability in demyelinating disorders, including multiple sclerosis (MS). However, the consequences of demyelination on neuronal and axonal biology are poorly understood. The abundance of mitochondria in demyelinated axons in MS raises the possibility that increased mitochondrial content serves as a compensatory response to demyelination. Here, we show that upon demyelination mitochondria move from the neuronal cell body to the demyelinated axon, increasing axonal mitochondrial content, which we term the axonal response of mitochondria to demyelination (ARMD). However, following demyelination axons degenerate before the homeostatic ARMD reaches its peak. Enhancement of ARMD, by targeting mitochondrial biogenesis and mitochondrial transport from the cell body to axon, protects acutely demyelinated axons from degeneration. To determine the relevance of ARMD to disease state, we examined MS autopsy tissue and found a positive correlation between mitochondrial content in demyelinated dorsal column axons and cytochrome c oxidase (complex IV) deficiency in dorsal root ganglia (DRG) neuronal cell bodies. We experimentally demyelinated DRG neuron-specific complex IV deficient mice, as established disease models do not recapitulate complex IV deficiency in neurons, and found that these mice are able to demonstrate ARMD, despite the mitochondrial perturbation. Enhancement of mitochondrial dynamics in complex IV deficient neurons protects the axon upon demyelination. Consequently, increased mobilisation of mitochondria from the neuronal cell body to the axon is a novel neuroprotective strategy for the vulnerable, acutely demyelinated axon. We propose that promoting ARMD is likely to be a crucial preceding step for implementing potential regenerative strategies for demyelinating disorders.
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Affiliation(s)
- Simon Licht-Mayer
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Graham R Campbell
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Marco Canizares
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Arpan R Mehta
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Angus B Gane
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Katie McGill
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Aniket Ghosh
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Alexander Fullerton
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Niels Menezes
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Jasmine Dean
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Jordon Dunham
- Department of Neuroscience, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, OH44195, USA
| | - Sarah Al-Azki
- Barts and The London School of Medicine and Dentistry, Blizard Institute, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Gareth Pryce
- Barts and The London School of Medicine and Dentistry, Blizard Institute, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Stephanie Zandee
- Centre for Inflammation Research, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Chao Zhao
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK
| | - Markus Kipp
- Institute of Anatomy, Rostock University Medical Center, Gertrudenstrasse 9, 18057, Rostock, Germany
| | - Kenneth J Smith
- Department of Neuroinflammation, The UCL Queen Square Institute of Neurology, University College London, 1 Wakefield Street, London, WC1N 1PJ, UK
| | - David Baker
- Barts and The London School of Medicine and Dentistry, Blizard Institute, Queen Mary University of London, 4 Newark Street, London, E1 2AT, UK
| | - Daniel Altmann
- Faculty of Medicine, Department of Medicine, Hammersmith Campus, London, UK
| | - Stephen M Anderton
- Centre for Inflammation Research, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4SB, UK
| | - Yolanda S Kap
- Department of Immunobiology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Jon D Laman
- Department of Immunobiology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
- Dept. Biomedical Sciences of Cells and Systems and MS Center Noord Nederland (MSCNN), University Medical Center Groningen, University Groningen, Groningen, The Netherlands
| | - Bert A 't Hart
- Department of Immunobiology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
- Dept. Biomedical Sciences of Cells and Systems and MS Center Noord Nederland (MSCNN), University Medical Center Groningen, University Groningen, Groningen, The Netherlands
- Department Anatomy and Neuroscience, Amsterdam University Medical Center (V|UMC|), Amsterdam, Netherlands
| | - Moses Rodriguez
- Department of Neurology and Immunology, Mayo College of Medicine and Science, Rochester, MN, MN55905, USA
| | - Ralf Watzlawick
- Department of Neurosurgery, Freiburg University Medical Center, Freiburg, Germany
| | - Jan M Schwab
- Spinal Cord Injury Medicine, Department of Neurology, The Ohio State University, Wexner Medical Center, Columbus, USA
| | - Roderick Carter
- Centre for Cardiovascular Science, Queens Medical Research Institute, 47 Little France Crescent, Edinburgh, UK
| | - Nicholas Morton
- Centre for Cardiovascular Science, Queens Medical Research Institute, 47 Little France Crescent, Edinburgh, UK
| | - Michele Zagnoni
- Centre for Microsystems and Photonics, Electronic and Electrical Engineering, University of Strathclyde, Glasgow, UK
| | - Robin J M Franklin
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK
| | - Rory Mitchell
- Centre for Discovery Brain Science, Edinburgh Medical School, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Sue Fleetwood-Walker
- Centre for Discovery Brain Science, Edinburgh Medical School, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - David A Lyons
- Centre for Discovery Brain Science, Edinburgh Medical School, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Siddharthan Chandran
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Hans Lassmann
- Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Spitalgasse 4, 1090, Vienna, Austria
| | - Bruce D Trapp
- Department of Neuroscience, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, OH44195, USA
| | - Don J Mahad
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
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Sun L, Fleetwood-Walker S, Mitchell R, Joosten EA, Cheung CW. Prolonged Analgesia by Spinal Cord Stimulation Following a Spinal Injury Associated With Activation of Adult Neural Progenitors. Pain Pract 2020; 20:859-877. [PMID: 32474998 DOI: 10.1111/papr.12921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 01/29/2020] [Accepted: 05/20/2020] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Responses of spinal progenitors to spinal cord stimulation (SCS) following spinal cord injury (SCI) in rats were assessed to reveal their potential contribution to SCS-induced analgesia. METHODS Spinal epidural electrodes were implanted in rats at T12 rostral to a quadrant dorsal horn injury at T13. Further groups additionally received either a microlesion to the dorsolateral funiculus (DLF) or gabapentin (10 mg/kg). SCS was performed at 25 Hz for 10 minutes on day 4 (early SCS) and at 10 Hz for 10 minutes on day 8 (late SCS) after injury. Paw withdrawal threshold (PWT) was measured before injury, 30 minutes before or after SCS, and before cull on day 14, followed by immunostaining assessment. RESULTS Paw withdrawal thresholds in uninjured animals (51.0 ± 4.0 g) were markedly reduced after SCI (17.3 ± 2.2 g). This was significantly increased by early SCS (38.5 ± 5.2 g, P < 0.01) and further enhanced by late SCS (50.9 ± 1.9 g, P < 0.01) over 6 days. Numbers of neural progenitors expressing nestin, Sox2, and doublecortin (DCX) in the spinal dorsal horn were increased 6 days after SCS by 6-fold, 2-fold, and 2.5-fold, respectively (P < 0.05 to 0.01). The elevated PWT evoked by SCS was abolished by DLF microlesions (48.9 ± 2.6 g vs. 19.0 ± 3.9 g, P < 0.01) and the number of nestin-positive cells was reduced to the level without SCS (P < 0.05). Gabapentin enhanced late SCS-induced analgesia from 37.0 ± 3.9 g to 54.0 ± 0.8 g (P < 0.01) and increased gamma-aminobutyric acid (GABA)-ergic neuronal marker vesicular GABA transporter-positive newborn cells 2-fold (P < 0.01). CONCLUSIONS Spinal progenitor cells appear to be activated by SCS via descending pathways, which may be enhanced by gabapentin and potentially contributes to relief of SCI-induced neuropathic pain.
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Affiliation(s)
- Liting Sun
- Brain and Spinal Cord Innovation Research Center, The First Rehabilitation Hospital of Shanghai, Tongji University School of Medicine, Shanghai, China
| | - Sue Fleetwood-Walker
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh, UK
| | - Rory Mitchell
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh, UK
| | - Elbert A Joosten
- Department of Anesthesiology/Pain Management, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Chi Wai Cheung
- Laboratory and Clinical Research Institute for Pain, Department of Anaesthesiology, University of Hong Kong, HKSAR, China
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Sun L, Tai L, Qiu Q, Mitchell R, Fleetwood-Walker S, Joosten EA, Cheung CW. Endocannabinoid activation of CB 1 receptors contributes to long-lasting reversal of neuropathic pain by repetitive spinal cord stimulation. Eur J Pain 2017; 21:804-814. [PMID: 28107590 DOI: 10.1002/ejp.983] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2016] [Indexed: 12/16/2022]
Abstract
BACKGROUND Spinal cord stimulation (SCS) has been shown to be effective in the management of certain neuropathic pain conditions, however, the underlying mechanisms are incompletely understood. In this study, we investigated repetitive SCS in a rodent neuropathic pain model, revealing long-lasting and incremental attenuation of hyperalgesia and a mechanism of action involving endocannabinoids. METHOD Animals were implanted with monopolar electrodes at the time of partial sciatic nerve injury. Dorsal columns at spinal segments T12/13 were stimulated 3 days later (early SCS), and again at day 7 (late SCS) using low-frequency parameters. Hypersensitivity to cutaneous mechanical stimuli was assessed using von Frey filaments. Pharmacological agents, selected to identify endocannabinoid and opioid involvement, were administered intraperitoneally, 10 min before SCS. RESULTS Early SCS caused partial reversal of mechanical hypersensitivity with corresponding changes in the biomarker of central sensitization, [phospho-Tyr1472 ]-GluN2B. The partial reversal of hyperalgesia by early SCS was amplified by co-administration of LY 2183240, an inhibitor of endocannabinoid reuptake/breakdown. This amplification was inhibited by a CB1 R antagonist, AM251, but not by a CB2 R antagonist, AM630. Early SCS-induced reversal of hyperalgesia was attenuated by naloxone, indicating a role for opioids. Late SCS resulted in an incremental level of reversal of hyperalgesia, which was inhibited by AM251, but not by CB2 or opioid receptor antagonists. CONCLUSION The endocannabinoid system, and in particular the CB1 R, plays a pivotal role in the long-lasting and incremental reversal of hyperalgesia induced by repetitive SCS in a neuropathic pain model. SIGNIFICANCE Alternative parameters for repetitive spinal cord stimulation (SCS) at 25/10 Hz elicit particularly long-lasting and incremental reversal of hyperalgesia in a neuropathic pain model through a mechanism involving endocannabinoids.
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Affiliation(s)
- L Sun
- Laboratory and Clinical Research Institute for Pain, Department of Anaesthesiology, The University of Hong Kong, HKSAR, China
| | - L Tai
- Laboratory and Clinical Research Institute for Pain, Department of Anaesthesiology, The University of Hong Kong, HKSAR, China
| | - Q Qiu
- Laboratory and Clinical Research Institute for Pain, Department of Anaesthesiology, The University of Hong Kong, HKSAR, China
| | - R Mitchell
- Centre for Integrative Physiology, Edinburgh Medical School: Biomedical Sciences, The University of Edinburgh, UK
| | - S Fleetwood-Walker
- Centre for Integrative Physiology, Edinburgh Medical School: Biomedical Sciences, The University of Edinburgh, UK
| | - E A Joosten
- Department of Anesthesiology/Pain Management, The University Pain Center Maastricht, Maastricht University Medical Center, The Netherlands
| | - C W Cheung
- Laboratory and Clinical Research Institute for Pain, Department of Anaesthesiology, The University of Hong Kong, HKSAR, China
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Vinuela-Fernandez I, Sun L, Jerina H, Curtis J, Allchorne A, Gooding H, Rosie R, Holland P, Tas B, Mitchell R, Fleetwood-Walker S. The TRPM8 channel forms a complex with the 5-HT(1B) receptor and phospholipase D that amplifies its reversal of pain hypersensitivity. Neuropharmacology 2013; 79:136-51. [PMID: 24269608 DOI: 10.1016/j.neuropharm.2013.11.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 10/07/2013] [Accepted: 11/11/2013] [Indexed: 12/25/2022]
Abstract
Effective relief from chronic hypersensitive pain states remains an unmet need. Here we report the discovery that the TRPM8 ion channel, co-operating with the 5-HT(1B) receptor (5-HT(1B)R) in a subset of sensory afferents, exerts an influence at the spinal cord level to suppress central hypersensitivity in pain processing throughout the central nervous system. Using cell line models, ex vivo rat neural tissue and in vivo pain models, we assessed functional Ca(2+) fluorometric responses, protein:protein interactions, immuno-localisation and reflex pain behaviours, with pharmacological and molecular interventions. We report 5-HT(1B)R expression in many TRPM8-containing afferents and direct interaction of these proteins in a novel multi-protein signalling complex, which includes phospholipase D1 (PLD1). We provide evidence that the 5-HT(1B)R activates PLD1 to subsequently activate PIP 5-kinase and generate PIP2, an allosteric enhancer of TRPM8, achieving a several-fold increase in potency of TRPM8 activation. The enhanced activation responses of synaptoneurosomes prepared from spinal cord and cortical regions of animals with a chronic inflammatory pain state are inhibited by TRPM8 activators that were applied in vivo topically to the skin, an effect potentiated by co-administered 5-HT(1B)R agonists and attenuated by 5-HT(1B)R antagonists, while 5-HT(1B)R agents alone had no detectable effect. Corresponding results are seen when assessing reflex behaviours in inflammatory and neuropathic pain models. Control experiments with alternative receptor/TRP channel combinations reveal no such synergy. Identification of this novel receptor/effector/channel complex and its impact on nociceptive processing give new insights into possible strategies for enhanced analgesia in chronic pain.
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Affiliation(s)
- Ignacio Vinuela-Fernandez
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Liting Sun
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Helen Jerina
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - John Curtis
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Andrew Allchorne
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Hayley Gooding
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Roberta Rosie
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Pamela Holland
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Basak Tas
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom
| | - Rory Mitchell
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom.
| | - Sue Fleetwood-Walker
- Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, United Kingdom.
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Gauff F, Jerina H, Jones E, Mitchell R, Fleetwood-Walker S, Licka T. Pain-associated changes in the dorsal root ganglia of laminitic horses. J Equine Vet Sci 2013. [DOI: 10.1016/j.jevs.2013.08.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Barclay Z, Dickson L, Robertson D, Johnson M, Holland P, Rosie R, Sun L, Jerina H, Lutz E, Fleetwood-Walker S, Mitchell R. Attenuated PLD1 association and signalling at the H452Y polymorphic form of the 5-HT2A receptor. Cell Signal 2013; 25:814-21. [DOI: 10.1016/j.cellsig.2013.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 12/18/2012] [Accepted: 01/06/2013] [Indexed: 11/24/2022]
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Brydges NM, Whalley HC, Jansen MA, Merrifield GD, Wood ER, Lawrie SM, Wynne SM, Day M, Fleetwood-Walker S, Steele D, Marshall I, Hall J, Holmes MC. Imaging conditioned fear circuitry using awake rodent fMRI. PLoS One 2013; 8:e54197. [PMID: 23349824 PMCID: PMC3551953 DOI: 10.1371/journal.pone.0054197] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 12/11/2012] [Indexed: 01/16/2023] Open
Abstract
Functional magnetic resonance imaging (fMRI) is a powerful method for exploring emotional and cognitive brain responses in humans. However rodent fMRI has not previously been applied to the analysis of learned behaviour in awake animals, limiting its use as a translational tool. Here we have developed a novel paradigm for studying brain activation in awake rats responding to conditioned stimuli using fMRI. Using this method we show activation of the amygdala and related fear circuitry in response to a fear-conditioned stimulus and demonstrate that the magnitude of fear circuitry activation is increased following early life stress, a rodent model of affective disorders. This technique provides a new translatable method for testing environmental, genetic and pharmacological manipulations on emotional and cognitive processes in awake rodent models.
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Affiliation(s)
- Nichola M. Brydges
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Heather C. Whalley
- Edinburgh Neuroscience, University of Edinburgh, Edinburgh, United Kingdom
| | - Maurits A. Jansen
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Preclinical Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Gavin D. Merrifield
- Edinburgh Preclinical Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Emma R. Wood
- Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephen M. Lawrie
- Edinburgh Neuroscience, University of Edinburgh, Edinburgh, United Kingdom
| | - Sara-Madge Wynne
- Edinburgh Preclinical Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Mark Day
- Strategic Transactions Group, Bristol-Myers Squibb Company, Wallingford, Connecticut, United States of America
| | | | - Douglas Steele
- Medical Research Institute, University of Dundee, Dundee, United Kingdom
| | - Ian Marshall
- Edinburgh Neuroscience, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Preclinical Imaging, University of Edinburgh, Edinburgh, United Kingdom
| | - Jeremy Hall
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Neuroscience, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
| | - Megan C. Holmes
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Neuroscience, University of Edinburgh, Edinburgh, United Kingdom
- Edinburgh Preclinical Imaging, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Fleetwood-Walker S, Sun L, Jerina H, Mitchell R. Assessment of animal pain and mechanism-based strategies for its reversal. Vet J 2012; 193:305-6. [PMID: 22884986 DOI: 10.1016/j.tvjl.2012.07.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 07/16/2012] [Indexed: 11/16/2022]
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Molony V, Fleetwood-Walker S. Recognition of pain. Vet Rec 1986; 118:595. [PMID: 3739151 DOI: 10.1136/vr.118.21.595-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Iggo A, Steedman WM, Fleetwood-Walker S. Spinal processing: anatomy and physiology of spinal nociceptive mechanisms. Philos Trans R Soc Lond B Biol Sci 1985; 308:235-52. [PMID: 2858881 DOI: 10.1098/rstb.1985.0024] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The processing of nociceptive input that occurs at the spinal level represents the first stage of effective control over its access to higher regions of the central nervous system. Recent developments in both the anatomy and physiology of nociceptive processing pathways at this level are beginning to yield an integrated understanding of structure and function. Most small afferent axons terminate in the more superficial laminae of dorsal horn, but technical difficulties have, until recently, prevented analysis of the functional properties of identified small fibres. A direct input of nociceptive afferents on to particular dorsal horn neurons is difficult to establish in view of the slow impulse conduction in these fibres and the small size of target neurons in the substantia gelatinosa. The small cells themselves are being analysed for relations between structure and function, using physiological, intracellular staining and immunocytochemical techniques to characterize their properties. They appear to be a highly heterogeneous population with many sub-classes, whether typed according to the transmitter they contain, e.g. enkephalin, to their physiological responses: whether excitatory or inhibitory to nociceptive and other inputs, or to both. The multireceptive neurons that project out of the dorsal horn toward supraspinal regions are, in general, located in deeper laminae and are likely to receive nociceptive information through polysynaptic pathways. The nocireceptive neurons in lamina I, which receive exclusively nociceptive inputs from myelinated and non-myelinated afferents project, at least in part, to thalamic and brain stem regions. Polysynaptic nociceptive pathways in dorsal horn may be subject to different controls from neurons in laminae I and II. Tonic descending inhibition is operative on the former and it is becoming clearly established that descending systems such as those containing noradrenaline, can regulate the access of nociceptive information to higher levels. The mechanisms of such descending controls and the importance of their interaction with segmental control systems, such as those involving the dynorphin opioids, are just beginning to be understood. Many somatosensory neurons in dorsal horn, both the large cells, some of which project supraspinally, and the small cells of superficial laminae, receive convergent nociceptive and non-nociceptive inputs. Although solely nociresponsive neurons are clearly likely to fill a role in the processing and signalling of pain in the conscious central nervous system, the way in which such useful specificity could be conveyed by multireceptive neurons is difficult to appreciate.(ABSTRACT TRUNCATED AT 400 WORDS)
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Gilbey MP, Coote JH, Fleetwood-Walker S, Peterson DF. The influence of the paraventriculo-spinal pathway, and oxytocin and vasopressin on sympathetic preganglionic neurones. Brain Res 1982; 251:283-90. [PMID: 7139327 DOI: 10.1016/0006-8993(82)90745-4] [Citation(s) in RCA: 141] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In anaesthetized rats the effect of two procedures was studied on antidromically identified sympathetic preganglionic neurones (SPN) in the second thoracic (T) segment of the spinal cord: the application of iontophoresed oxytocin and vasopressin, and bipolar electrical stimulation of the paraventricular nucleus of the hypothalamus (PVN). In the majority of cases (16/23) oxytocin inhibited SPN firing, 1/23 being excited. Vasopressin inhibited 8/14 neurones and excited 4/14. PVN stimulation inhibited SPN apparently by an action on the membrane of SPN. The possibility that oxytocin and vasopressin act as transmitters in the paraventriculo-spinal pathway, and their possible involvement in the mediation of PVN evoked inhibition of SPN activity has been discussed.
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14
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Coote JH, Macleod VH, Fleetwood-Walker S, Gilbey MP. The response of individual sympathetic preganglionic neurones to microelectrophoretically applied endogenous monoamines. Brain Res 1981; 215:135-45. [PMID: 7260583 DOI: 10.1016/0006-8993(81)90497-2] [Citation(s) in RCA: 135] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In anaesthetized cats the effect on antidromically identified single sympathetic preganglionic neurones (SPN) in the third thoracic segment of microelectrophoretically applied monoamines, amino acids and acetyl choline was examined. 5-Hydroxytryptamine (5-HT) creatinine sulphate and bimaleate excited a majority of SPN. A few cells were inhibited by 5-HT creatinine sulphate. These effects were observed on spontaneously active SPN (cardiac and non-cardiac type) and on silent SPN. Noradrenaline, adrenaline and dopamine inhibited all 'types' of SPN, including spontaneously active neurons, silent neurones activated by glutamate or DL-homocysteic acid and neurones synaptically activated by electrically stimulating a brain stem excitatory region. Acetyl choline had no effect on different types of SPN.
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