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Rabeh N, Hajjar B, Maraka JO, Sammanasunathan AF, Khan M, Alkhaaldi SMI, Mansour S, Almheiri RT, Hamdan H, Abd-Elrahman KS. Targeting mGluR group III for the treatment of neurodegenerative diseases. Biomed Pharmacother 2023; 168:115733. [PMID: 37862967 DOI: 10.1016/j.biopha.2023.115733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/11/2023] [Accepted: 10/13/2023] [Indexed: 10/22/2023] Open
Abstract
Glutamate, an excitatory neurotransmitter, is essential for neuronal function, and it acts on ionotropic or metabotropic glutamate receptors (mGluRs). A disturbance in glutamatergic signaling is a hallmark of many neurodegenerative diseases. Developing disease-modifying treatments for neurodegenerative diseases targeting glutamate receptors is a promising avenue. The understudied group III mGluR 4, 6-8 are commonly found in the presynaptic membrane, and their activation inhibits glutamate release. Thus, targeted mGluRs therapies could aid in treating neurodegenerative diseases. This review describes group III mGluRs and their pharmacological ligands in the context of amyotrophic lateral sclerosis, Parkinson's, Alzheimer's, and Huntington's diseases. Attempts to evaluate the efficacy of these drugs in clinical trials are also discussed. Despite a growing list of group III mGluR-specific pharmacological ligands, research on the use of these drugs in neurodegenerative diseases is limited, except for Parkinson's disease. Future efforts should focus on delineating the contribution of group III mGluR to neurodegeneration and developing novel ligands with superior efficacy and a favorable side effect profile for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Nadia Rabeh
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates; Department of Anesthesiology, Pharmacology and Therapeutics, and Djavad Mowafaghian Center for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Baraa Hajjar
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Jude O Maraka
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Ashwin F Sammanasunathan
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Mohammed Khan
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Saif M I Alkhaaldi
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Samy Mansour
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Rashed T Almheiri
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Hamdan Hamdan
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates; Healthcare Engineering Innovation Center (HEIC), Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates
| | - Khaled S Abd-Elrahman
- Department of Anesthesiology, Pharmacology and Therapeutics, and Djavad Mowafaghian Center for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada; Department of Pharmacology and Therapeutics, College of Medicine and Health Science, Khalifa University, Abu Dhabi 127788, United Arab Emirates; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria 21521, Egypt.
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Mazzone GL, Coronel MF, Mladinic M, Sámano C. An update to pain management after spinal cord injury: from pharmacology to circRNAs. Rev Neurosci 2023; 34:599-611. [PMID: 36351309 DOI: 10.1515/revneuro-2022-0089] [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: 07/22/2022] [Accepted: 10/19/2022] [Indexed: 08/04/2023]
Abstract
Neuropathic pain (NP) following a spinal cord injury (SCI) is often hard to control and therapies should be focused on the physical, psychological, behavioral, social, and environmental factors that may contribute to chronic sensory symptoms. Novel therapeutic treatments for NP management should be based on the combination of pharmacological and nonpharmacological options. Some of them are addressed in this review with a focus on mechanisms and novel treatments. Several reports demonstrated an aberrant expression of non-coding RNAs (ncRNAs) that may represent key regulatory factors with a crucial role in the pathophysiology of NP and as potential diagnostic biomarkers. This review analyses the latest evidence for cellular and molecular mechanisms associated with the role of circular RNAs (circRNAs) in the management of pain after SCI. Advantages in the use of circRNA are their stability (up to 48 h), and specificity as sponges of different miRNAs related to SCI and nerve injury. The present review discusses novel data about deregulated circRNAs (up or downregulated) that sponge miRNAs, and promote cellular and molecular interactions with mRNAs and proteins. This data support the concept that circRNAs could be considered as novel potential therapeutic targets for NP management especially after spinal cord injuries.
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Affiliation(s)
- Graciela L Mazzone
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Pte. Perón 1500, B1629AHJ, Pilar, Buenos Aires, Argentina
| | - María F Coronel
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Av. Pte. Perón 1500, B1629AHJ, Pilar, Buenos Aires, Argentina
| | - Miranda Mladinic
- Laboratory for Molecular Neurobiology, Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia
| | - Cynthia Sámano
- Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana, Unidad Cuajimalpa. Avenida Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa. Alcaldía Cuajimalpa de Morelos, C.P. 05348, Ciudad de México, México
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3
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Amygdala Metabotropic Glutamate Receptor 1 Influences Synaptic Transmission to Participate in Fentanyl-Induced Hyperalgesia in Rats. Cell Mol Neurobiol 2023; 43:1401-1412. [PMID: 35798932 DOI: 10.1007/s10571-022-01248-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 06/22/2022] [Indexed: 11/03/2022]
Abstract
The underlying mechanisms of opioid-induced hyperalgesia (OIH) remain unclear. Herein, we found that the protein expression of metabotropic glutamate receptor 1 (mGluR1) was significantly increased in the right but not in the left laterocapsular division of central nucleus of the amygdala (CeLC) in OIH rats. In CeLC neurons, the frequency and the amplitude of mini-excitatory postsynaptic currents (mEPSCs) were significantly increased in fentanyl group which were decreased by acute application of a mGluR1 antagonist, A841720. Finally, the behavioral hypersensitivity could be reversed by A841720 microinjection into the right CeLC. These results show that the right CeLC mGluR1 is an important factor associated with OIH that enhances synaptic transmission and could be a potential drug target to alleviate fentanyl-induced hyperalgesia.
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Kinetic fingerprinting of metabotropic glutamate receptors. Commun Biol 2023; 6:104. [PMID: 36707695 PMCID: PMC9883448 DOI: 10.1038/s42003-023-04468-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 01/12/2023] [Indexed: 01/28/2023] Open
Abstract
Dimeric metabotropic glutamate receptors (mGluRs) are abundantly expressed in neurons. In mammals, eight subunit isoforms, mGluR1-8, have been identified, forming the groups I, II, and III. We investigated receptor dimerization and kinetics of these mGluR isoforms in excised membrane patches by FRET and confocal patch-clamp fluorometry. We show that 5 out of 8 homodimeric receptors develop characteristic glutamate-induced on- and off-kinetics, as do 11 out of 28 heterodimers. Glutamate-responsive heterodimers were identified within each group, between groups I and II as well as between groups II and III, but not between groups I and III. The glutamate-responsive heterodimers showed heterogeneous activation and deactivation kinetics. Interestingly, mGluR7, not generating a kinetic response in homodimers, showed fast on-kinetics in mGluR2/7 and mGluR3/7 while off-kinetics retained the speed of mGluR2 or mGluR3 respectively. In conclusion, glutamate-induced conformational changes in heterodimers appear within each group and between groups if one group II subunit is present.
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Mao LM, Mathur N, Shah K, Wang JQ. Roles of metabotropic glutamate receptor 8 in neuropsychiatric and neurological disorders. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2023; 168:349-366. [PMID: 36868634 PMCID: PMC10162486 DOI: 10.1016/bs.irn.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are G protein-coupled receptors. Among eight mGlu subtypes (mGlu1-8), mGlu8 has drawn increasing attention. This subtype is localized to the presynaptic active zone of neurotransmitter release and is among the mGlu subtypes with high affinity for glutamate. As a Gi/o-coupled autoreceptor, mGlu8 inhibits glutamate release to maintain homeostasis of glutamatergic transmission. mGlu8 receptors are expressed in limbic brain regions and play a pivotal role in modulating motivation, emotion, cognition, and motor functions. Emerging evidence emphasizes the increasing clinical relevance of abnormal mGlu8 activity. Studies using mGlu8 selective agents and knockout mice have revealed the linkage of mGlu8 receptors to multiple neuropsychiatric and neurological disorders, including anxiety, epilepsy, Parkinson's disease, drug addiction, and chronic pain. Expression and function of mGlu8 receptors in some limbic structures undergo long-lasting adaptive changes in animal models of these disorders, which may contribute to the remodeling of glutamatergic transmission critical for the pathogenesis and symptomatology of brain illnesses. This review summarizes the current understanding of mGlu8 biology and the possible involvement of the receptor in several common psychiatric and neurological disorders.
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Affiliation(s)
- Li-Min Mao
- Department of Biomedical Sciences, University of Missouri-Kansas City, School of Medicine, Kansas City, MO, United States
| | - Nirav Mathur
- Department of Anesthesiology, University of Missouri-Kansas City, School of Medicine, Kansas City, MO, United States
| | - Karina Shah
- Department of Biomedical Sciences, University of Missouri-Kansas City, School of Medicine, Kansas City, MO, United States
| | - John Q Wang
- Department of Biomedical Sciences, University of Missouri-Kansas City, School of Medicine, Kansas City, MO, United States; Department of Anesthesiology, University of Missouri-Kansas City, School of Medicine, Kansas City, MO, United States.
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Abstract
Modulation of nociception allows animals to optimize chances of survival by adapting their behaviour in different contexts. In mammals, this is executed by neurons from the brain and is referred to as the descending control of nociception. Whether insects have such control, or the neural circuits allowing it, has rarely been explored. Based on behavioural, neuroscientific and molecular evidence, we argue that insects probably have descending controls for nociception. Behavioural work shows that insects can modulate nocifensive behaviour. Such modulation is at least in part controlled by the central nervous system since the information mediating such prioritization is processed by the brain. Central nervous system control of nociception is further supported by neuroanatomical and neurobiological evidence showing that the insect brain can facilitate or suppress nocifensive behaviour, and by molecular studies revealing pathways involved in the inhibition of nocifensive behaviour both peripherally and centrally. Insects lack the endogenous opioid peptides and their receptors that contribute to mammalian descending nociception controls, so we discuss likely alternative molecular mechanisms for the insect descending nociception controls. We discuss what the existence of descending control of nociception in insects may reveal about pain perception in insects and finally consider the ethical implications of these novel findings.
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Affiliation(s)
- Matilda Gibbons
- School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, UK
| | - Sajedeh Sarlak
- Department of Plant Protection, College of Agriculture and Natural Resources, University of Tehran, 31587-77871, Karaj, Iran
| | - Lars Chittka
- School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, UK
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Wen X, Song DX, Li KX, Wang LN, Xiong X, Li HD, Cui CP, Lu XL, Li BY, Liu Y. Ah-type baroreceptor neurons expressing estrogen dependent mGluR7 mediate descending inhibition of cardiac nociception. Neuroscience 2022; 492:18-31. [DOI: 10.1016/j.neuroscience.2022.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 04/03/2022] [Accepted: 04/08/2022] [Indexed: 11/28/2022]
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8
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Formaggio F, Rimondini R, Delprete C, Scalia L, Merlo Pich E, Liguori R, Nicoletti F, Caprini M. L-Acetylcarnitine causes analgesia in mice modeling Fabry disease by up-regulating type-2 metabotropic glutamate receptors. Mol Pain 2022; 18:17448069221087033. [PMID: 35255745 PMCID: PMC9008852 DOI: 10.1177/17448069221087033] [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] [Indexed: 11/15/2022] Open
Abstract
Fabry disease (FD) is a X-linked lysosomal storage disorder caused by deficient
function of the alpha-galactosidase A (α-GalA) enzyme. α-GalA deficiency leads
to multisystemic clinical manifestations caused by the preferential accumulation
of globotriaosylceramide (Gb3). A hallmark symptom of FD patients is neuropathic
pain that appears in the early stage of the disease as a result of peripheral
small fiber damage. Previous studies have shown that Acetyl-L-carnitine (ALC)
has neuroprotective, neurotrophic, and analgesic activity in animal models of
neuropathic pain. To study the action of ALC on neuropathic pain associated with
FD, we treated α-GalA gene null mice (α-GalA(-/0)) with ALC for 30 days. In
α-Gal KO mice, ALC treatment induced acute and long-lasting analgesia, which
persisted 1 month after drug withdrawal. This effect was antagonized by single
administration of LY341495, an orthosteric antagonist of mGlu2/3 metabotropic
glutamate receptors. We also found an up-regulation of mGlu2 receptors in
cultured DRG neurons isolated from 30-day ALC-treated α-GalA KO mice. However,
the up-regulation of mGlu2 receptors was no longer present in DRG neurons
isolated 30 days after the end of treatment. Taken together, these findings
suggest that ALC induces analgesia in an animal model of FD by up-regulating
mGlu2 receptors, and that analgesia is maintained by additional mechanisms after
ALC withdrawal. ALC might represent a valuable pharmacological strategy to
reduce pain in FD patients.
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Affiliation(s)
| | - Roberto Rimondini
- Dipartimento di Scienze Mediche e Chirurgiche 9296University of Bologna
| | - Cecilia Delprete
- Department of Pharmacy and Biotechnology9296University of Bologna
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Palazzo E, Boccella S, Marabese I, Pierretti G, Guida F, Maione S. The Cold Case of Metabotropic Glutamate Receptor 6: Unjust Detention in the Retina? Curr Neuropharmacol 2020; 18:120-125. [PMID: 31573889 PMCID: PMC7324884 DOI: 10.2174/1570159x17666191001141849] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/20/2019] [Accepted: 09/29/2019] [Indexed: 02/03/2023] Open
Abstract
It is a common opinion that metabotropic glutamate receptor subtype 6 (mGluR6) is expressed exclusively in the retina, and in particular in the dendrites of ON-bipolar cells. Glutamate released in darkness from photoreceptors activates mGluR6, which is negatively associated with a membrane non-selective cation channel, the transient receptor potential melanoma-related 1, TRPM1, resulting in cell hyperpolarization. The evidence that mGluR6 is expressed not only in the retina but also in other tissues and cell populations has accumulated over time. The expression of mGluR6 has been identified in microglia, bone marrow stromal and prostate cancer cells, B lymphocytes, melanocytes and keratinocytes and non-neural tissues such as testis, kidney, cornea, conjunctiva, and eyelid. The receptor also appears to be expressed in brain areas, such as the hypothalamus, cortex, hippocampus, nucleus of tractus solitarius, superior colliculus, axons of the corpus callosum and accessory olfactory bulb. The pharmacological activation of mGluR6 in the hippocampus produced an anxiolytic-like effect and in the periaqueductal gray analgesic potential. This review aims to collect all the evidence on the expression and functioning of mGluR6 outside the retina that has been accumulated over the years for a broader view of the potential of the receptor whose retinal confinement appears understimated.
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Affiliation(s)
- E Palazzo
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Naples, Italy
| | - S Boccella
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Naples, Italy
| | - I Marabese
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Naples, Italy
| | - G Pierretti
- Department of Plastic Surgery, University of Campania "L. Vanvitelli", Naples, Italy
| | - F Guida
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Naples, Italy
| | - S Maione
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Naples, Italy
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Kim JH, Marton J, Ametamey SM, Cumming P. A Review of Molecular Imaging of Glutamate Receptors. Molecules 2020; 25:molecules25204749. [PMID: 33081223 PMCID: PMC7587586 DOI: 10.3390/molecules25204749] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 12/22/2022] Open
Abstract
Molecular imaging with positron emission tomography (PET) and single photon emission computed tomography (SPECT) is a well-established and important in vivo technique to evaluate fundamental biological processes and unravel the role of neurotransmitter receptors in various neuropsychiatric disorders. Specific ligands are available for PET/SPECT studies of dopamine, serotonin, and opiate receptors, but corresponding development of radiotracers for receptors of glutamate, the main excitatory neurotransmitter in mammalian brain, has lagged behind. This state of affairs has persisted despite the central importance of glutamate neurotransmission in brain physiology and in disorders such as stroke, epilepsy, schizophrenia, and neurodegenerative diseases. Recent years have seen extensive efforts to develop useful ligands for molecular imaging of subtypes of the ionotropic (N-methyl-D-aspartate (NMDA), kainate, and AMPA/quisqualate receptors) and metabotropic glutamate receptors (types I, II, and III mGluRs). We now review the state of development of radioligands for glutamate receptor imaging, placing main emphasis on the suitability of available ligands for reliable in vivo applications. We give a brief account of the radiosynthetic approach for selected molecules. In general, with the exception of ligands for the GluN2B subunit of NMDA receptors, there has been little success in developing radiotracers for imaging ionotropic glutamate receptors; failure of ligands for the PCP/MK801 binding site in vivo doubtless relates their dependence on the open, unblocked state of the ion channel. Many AMPA and kainite receptor ligands with good binding properties in vitro have failed to give measurable specific binding in the living brain. This may reflect the challenge of developing brain-penetrating ligands for amino acid receptors, compounded by conformational differences in vivo. The situation is better with respect to mGluR imaging, particularly for the mGluR5 subtype. Several successful PET ligands serve for investigations of mGluRs in conditions such as schizophrenia, depression, substance abuse and aging. Considering the centrality and diversity of glutamatergic signaling in brain function, we have relatively few selective and sensitive tools for molecular imaging of ionotropic and metabotropic glutamate receptors. Further radiopharmaceutical research targeting specific subtypes and subunits of the glutamate receptors may yet open up new investigational vistas with broad applications in basic and clinical research.
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Affiliation(s)
- Jong-Hoon Kim
- Neuroscience Research Institute, Gachon University, Incheon 21565, Korea
- Gachon Advanced Institute for Health Science and Technology, Graduate School, Incheon 21565, Korea
- Department of Psychiatry, Gil Medical Center, Gachon University College of Medicine, Gachon University, Incheon 21565, Korea
- Correspondence: (J.-H.K.); (P.C.); Tel.: +41-31-664-0498 (P.C.); Fax: +41-31-632-7663 (P.C.)
| | - János Marton
- ABX Advanced Biochemical Compounds, Biomedizinische Forschungsreagenzien GmbH, Heinrich-Glaeser-Strasse 10-14, D-1454 Radeberg, Germany;
| | - Simon Mensah Ametamey
- Centre for Radiopharmaceutical Sciences ETH-PSI-USZ, Institute of Pharmaceutical Sciences ETH, Vladimir-Prelog-Weg 4, CH-8093 Zürich, Switzerland;
| | - Paul Cumming
- Department of Nuclear Medicine, University of Bern, Inselspital, Freiburgstrasse 18, CH-3010 Bern, Switzerland
- School of Psychology and Counselling, Queensland University of Technology, Brisbane QLD 4059, Australia
- Correspondence: (J.-H.K.); (P.C.); Tel.: +41-31-664-0498 (P.C.); Fax: +41-31-632-7663 (P.C.)
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Boccella S, Marabese I, Guida F, Luongo L, Maione S, Palazzo E. The Modulation of Pain by Metabotropic Glutamate Receptors 7 and 8 in the Dorsal Striatum. Curr Neuropharmacol 2020; 18:34-50. [PMID: 31210112 PMCID: PMC7327935 DOI: 10.2174/1570159x17666190618121859] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/01/2019] [Accepted: 05/31/2019] [Indexed: 12/28/2022] Open
Abstract
The dorsal striatum, apart from controlling voluntary movement, displays a recently demonstrated pain inhibition. It is connected to the descending pain modulatory system and in particular to the rostral ventromedial medulla through the medullary dorsal reticular nucleus. Diseases of the basal ganglia, such as Parkinson's disease, in addition to being characterized by motor disorders, are associated with pain and hyperactivation of the excitatory transmission. A way to counteract glutamatergic hyperactivation is through the activation of group III metabotropic glutamate receptors (mGluRs), which are located on presynaptic terminals inhibiting neurotransmitter release. So far the mGluRs of group III have been the least investigated, owing to a lack of selective tools. More recently, selective ligands for each mGluR of group III, in particular positive and negative allosteric modulators, have been developed and the role of each subtype is starting to emerge. The neuroprotective potential of group III mGluRs in pathological conditions, such as those characterized by elevate glutamate, has been recently shown. In the dorsal striatum, mGluR7 and mGluR8 are located at glutamatergic corticostriatal terminals and their stimulation inhibits pain in pathological conditions such as neuropathic pain. The two receptors in the dorsal striatum have instead a different role in pain control in normal conditions. This review will discuss recent results focusing on the contribution of mGluR7 and mGluR8 in the dorsal striatal control of pain. The role of mGluR4, whose antiparkinsonian activity is widely reported, will also be addressed.
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Affiliation(s)
- Serena Boccella
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Via Costantinopoli 16, 80138 Naples, Italy
| | - Ida Marabese
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Via Costantinopoli 16, 80138 Naples, Italy
| | - Francesca Guida
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Via Costantinopoli 16, 80138 Naples, Italy
| | - Livio Luongo
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Via Costantinopoli 16, 80138 Naples, Italy
| | - Sabatino Maione
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Via Costantinopoli 16, 80138 Naples, Italy
| | - Enza Palazzo
- Department of Experimental Medicine, Pharmacology Division, University of Campania "L. Vanvitelli", Via Costantinopoli 16, 80138 Naples, Italy
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12
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Okubo M, Yamanaka H, Kobayashi K, Noguchi K. Differential expression of mGluRs in rat spinal dorsal horns and their modulatory effects on nocifensive behaviors. Mol Pain 2019; 15:1744806919875026. [PMID: 31432760 PMCID: PMC6751533 DOI: 10.1177/1744806919875026] [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] [Indexed: 11/16/2022] Open
Abstract
Glutamate is a neurotransmitter present in most excitatory synapses in the nervous system. It also plays a key role in the spinal cord’s physiological excitatory circuit and is involved in pathological neurotransmissions such as those observed in inflammatory and neuropathic pain conditions. The actions of glutamate are mediated by different types of ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mGluRs). Although expressions of iGluRs are well studied, those of mGluRs are not fully elucidated in the spinal cord. In this study, we examined the expressions of mGluRs (mGluR1-8) and investigated which mGluR subtypes can modulate pain transmission in the dorsal horn of the spinal cord using an inflammatory pain model. Reverse transcription-polymerase chain reaction revealed that mGluR mRNAs, except for mGluR2 and 6, were detected in the spinal cord. Double labeling analysis, in situ hybridization histochemistry with immunohistochemistry, was used to examine the distribution of each mGluR in neurons or glial cells in the lamina I–II of the spinal dorsal horn. mGluR1, 5, and 7 were generally, and 4 and 8 were frequently, expressed in neurons. mGluR3 was expressed not only in neurons but also in oligodendrocytes. We next examined the distribution of mGluR4 and 8 were expressed in excitatory or inhibitory neurons. Both mGluR4 and 8 were preferentially expressed in inhibitory neurons rather than in excitatory neurons. Furthermore, intrathecal delivery of CPPG((RS)-α-cyclopropyl-4-phosphonophenylglycine), an antagonist for mGluR 4 and 8, attenuated nocifensive behaviors and the increase in fos-positive-excitatory neurons of the dorsal horn induced by intraplantar injection of formalin. These findings suggest that mGluR4 and 8, which are preferentially expressed in inhibitory neurons, may play roles in the modulation of pain transmission in the spinal dorsal horn.
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Affiliation(s)
- Masamichi Okubo
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Hyogo, Japan
| | - Hiroki Yamanaka
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Hyogo, Japan
| | - Kimiko Kobayashi
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Hyogo, Japan
| | - Koichi Noguchi
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Hyogo, Japan
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13
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Rigo FK, Bochi GV, Pereira AL, Adamante G, Ferro PR, Dal-Toé De Prá S, Milioli AM, Damiani AP, da Silveira Prestes G, Dalenogare DP, Chávez-Olórtegui C, Moraes de Andrade V, Machado-de-Ávila RA, Trevisan G. TsNTxP, a non-toxic protein from Tityus serrulatus scorpion venom, induces antinociceptive effects by suppressing glutamate release in mice. Eur J Pharmacol 2019; 855:65-74. [PMID: 31059709 DOI: 10.1016/j.ejphar.2019.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 04/29/2019] [Accepted: 05/02/2019] [Indexed: 01/22/2023]
Abstract
Neuropathic pain is a common type of chronic pain caused by trauma or chemotherapy. However, this type of pain is undertreated. TsNTxP is a non-toxic protein isolated from the venom of the scorpion Tityus serrulatus, and it is structurally similar to neurotoxins that interact with voltage-gated sodium channels. However, the antinociceptive properties of this protein have not been characterized. The purpose of this study was to investigate the antinociceptive effects of TsNTxP in acute and neuropathic pain models. Male and female Swiss mice (25-30 g) were exposed to different models of acute pain (tail-flick test and nociception caused by capsaicin intraplantar injection) or neuropathic pain (chronic pain syndrome induced by paclitaxel or chronic constriction injury of the sciatic nerve). Hypersensitivity to mechanical or cold stimuli were evaluated in the models of neuropathic pain. The ability of TsNTxP to alter the release of glutamate in mouse spinal cord synaptosomes was also evaluated. The results showed that TsNTxP exerted antinociceptive effects in the tail-flick test to a thermal stimulus and in the intraplantar capsaicin administration model. Furthermore, TsNTxP was non-toxic and exerted antiallodynic effects in neuropathic pain models induced by chronic constriction injury of the sciatic nerve and administration of paclitaxel. TsNTxP reduced glutamate release from mouse spinal cord synaptosomes following stimulation with potassium chloride (KCl) or capsaicin. Thus, this T. serrulatus protein may be a promising non-toxic drug for the treatment of neuropathic pain.
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Affiliation(s)
- Flávia Karine Rigo
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil
| | - Guilherme Vargas Bochi
- Graduated Program in Pharmacology, Federal University of Santa Maria (UFSM), 97105-900, Santa Maria, RS, Brazil
| | - Adriano Lana Pereira
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil
| | - Gabriela Adamante
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil
| | - Paula Ronsani Ferro
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil
| | - Samira Dal-Toé De Prá
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil
| | - Alessandra Marcone Milioli
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil
| | - Adriani Paganini Damiani
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil
| | - Gabriele da Silveira Prestes
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil
| | - Diéssica Padilha Dalenogare
- Graduated Program in Pharmacology, Federal University of Santa Maria (UFSM), 97105-900, Santa Maria, RS, Brazil
| | - Carlos Chávez-Olórtegui
- Department of Biochemistry and Immunology, Federal University of Minas Gerais State (UFMG), 31270-901, Belo Horizonte, MG, Brazil
| | - Vanessa Moraes de Andrade
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil
| | | | - Gabriela Trevisan
- Graduated Program in Health Sciences, University of Southern Santa Catarina (UNESC), 88006-000, Criciúma, SC, Brazil; Graduated Program in Pharmacology, Federal University of Santa Maria (UFSM), 97105-900, Santa Maria, RS, Brazil.
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14
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Metabotropic Glutamate Receptor 5 and 8 Modulate the Ameliorative Effect of Ultramicronized Palmitoylethanolamide on Cognitive Decline Associated with Neuropathic Pain. Int J Mol Sci 2019; 20:ijms20071757. [PMID: 30970677 PMCID: PMC6480075 DOI: 10.3390/ijms20071757] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/03/2019] [Accepted: 04/04/2019] [Indexed: 12/23/2022] Open
Abstract
This study investigated whether metabotropic glutamate receptor (mGluR) 5 and 8 are involved in the effect of ultramicronizedpalmitoylethanolamide (um-PEA) on the cognitive behavior and long term potentiation (LTP) at entorhinal cortex (LEC)-dentate gyrus (DG) pathway in mice rendered neuropathic by the spare nerve injury (SNI). SNI reduced discriminative memory and LTP. Um-PEA treatment started after the development of neuropathic pain had no effects in sham mice, whereas it restored cognitive behavior and LTP in SNI mice. 2-Methyl-6-(phenylethynyl) pyridine (MPEP), a selective mGluR5 antagonist, improved cognition in SNI mice and produced a chemical long term depression of the field excitatory postsynaptic potentials (fEPSPs) in sham and SNI mice. After theta burst stimulation (TBS) MPEP restored LTP in SNI mice. In combination with PEA, MPEP antagonized the PEA effect on discriminative memory and decreased LTP in SNI mice. The (RS)-4-(1-amino-1-carboxyethyl)phthalic acid (MDCPG), a selective mGluR8 antagonist, did not affect discriminative memory, but it induced a chemical LTP and prevented the enhancement of fEPSPs after TBS in SNI mice which were treated or not treated with PEA. The effect of PEA on LTP and cognitive behavior was modulated by mGluR5 and mGluR8. In particular in the SNI conditions, the mGluR5 blockade facilitated memory and LTP, but prevented the beneficial effects of PEA on discriminative memory while the mGluR8 blockade, which was ineffective in itself, prevented the favorable action of the PEA on LTP. Thus, although their opposite roles (excitatory/inhibitory of the two receptor subtypes on the glutamatergic system), they appeared to be required for the neuroprotective effect of PEA in conditions of neuropathic pain.
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15
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Activation of peripheral group III metabotropic glutamate receptors inhibits pain transmission by decreasing neuronal excitability in the CFA-inflamed knee joint. Neurosci Lett 2019; 694:111-115. [DOI: 10.1016/j.neulet.2018.11.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 11/20/2022]
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16
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Spampinato SF, Copani A, Nicoletti F, Sortino MA, Caraci F. Metabotropic Glutamate Receptors in Glial Cells: A New Potential Target for Neuroprotection? Front Mol Neurosci 2018; 11:414. [PMID: 30483053 PMCID: PMC6243036 DOI: 10.3389/fnmol.2018.00414] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 10/25/2018] [Indexed: 12/14/2022] Open
Abstract
Neurodegenerative disorders are characterized by excitotoxicity and neuroinflammation that finally lead to slow neuronal degeneration and death. Although neurons are the principal target, glial cells are important players as they contribute by either exacerbating or dampening the events that lead to neuroinflammation and neuronal damage. A dysfunction of the glutamatergic system is a common event in the pathophysiology of these diseases. Metabotropic glutamate (mGlu) receptors belong to a large family of G protein-coupled receptors largely expressed in neurons as well as in glial cells. They often appear overexpressed in areas involved in neurodegeneration, where they can modulate glutamatergic transmission. Of note, mGlu receptor upregulation may involve microglia or, even more frequently, astrocytes, where their activation causes release of factors potentially able to influence neuronal death. The expression of mGlu receptors has been also reported on oligodendrocytes, a glial cell type specifically involved in the development of multiple sclerosis. Here we will provide a general overview on the possible involvement of mGlu receptors expressed on glial cells in the pathogenesis of different neurodegenerative disorders and the potential use of subtype-selective mGlu receptor ligands as candidate drugs for the treatment of neurodegenerative disorders. Negative allosteric modulators (NAM) of mGlu5 receptors might represent a relevant pharmacological tool to develop new neuroprotective strategies in these diseases. Recent evidence suggests that targeting astrocytes and microglia with positive allosteric modulators (PAM) of mGlu3 receptor or oligodendrocytes with mGlu4 PAMS might represent novel pharmacological approaches for the treatment of neurodegenerative disorders.
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Affiliation(s)
| | - Agata Copani
- Department of Drug Sciences, University of Catania, Catania, Italy.,Institute of Biostructure and Bioimaging, National Research Council, Catania, Italy
| | - Ferdinando Nicoletti
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy.,Neuromed, Istituto di Ricovero e Cura a Carattere Scientifico, Pozzilli, Italy
| | - Maria Angela Sortino
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Filippo Caraci
- Department of Drug Sciences, University of Catania, Catania, Italy.,Oasi Research Institute, Istituto di Ricovero e Cura a Carattere Scientifico, Troina, Italy
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17
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Sarhan M, Land WG, Tonnus W, Hugo CP, Linkermann A. Origin and Consequences of Necroinflammation. Physiol Rev 2018; 98:727-780. [PMID: 29465288 DOI: 10.1152/physrev.00041.2016] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
When cells undergo necrotic cell death in either physiological or pathophysiological settings in vivo, they release highly immunogenic intracellular molecules and organelles into the interstitium and thereby represent the strongest known trigger of the immune system. With our increasing understanding of necrosis as a regulated and genetically determined process (RN, regulated necrosis), necrosis and necroinflammation can be pharmacologically prevented. This review discusses our current knowledge about signaling pathways of necrotic cell death as the origin of necroinflammation. Multiple pathways of RN such as necroptosis, ferroptosis, and pyroptosis have been evolutionary conserved most likely because of their differences in immunogenicity. As the consequence of necrosis, however, all necrotic cells release damage associated molecular patterns (DAMPs) that have been extensively investigated over the last two decades. Analysis of necroinflammation allows characterizing specific signatures for each particular pathway of cell death. While all RN-pathways share the release of DAMPs in general, most of them actively regulate the immune system by the additional expression and/or maturation of either pro- or anti-inflammatory cytokines/chemokines. In addition, DAMPs have been demonstrated to modulate the process of regeneration. For the purpose of better understanding of necroinflammation, we introduce a novel classification of DAMPs in this review to help detect the relative contribution of each RN-pathway to certain physiological and pathophysiological conditions.
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Affiliation(s)
- Maysa Sarhan
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University Vienna , Vienna , Austria ; INSERM UMR_S 1109, Laboratory of Excellence Transplantex, University of Strasbourg , Strasbourg , France ; German Academy of Transplantation Medicine, Munich , Germany ; and Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus at the Technische Universität Dresden , Dresden , Germany
| | - Walter G Land
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University Vienna , Vienna , Austria ; INSERM UMR_S 1109, Laboratory of Excellence Transplantex, University of Strasbourg , Strasbourg , France ; German Academy of Transplantation Medicine, Munich , Germany ; and Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus at the Technische Universität Dresden , Dresden , Germany
| | - Wulf Tonnus
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University Vienna , Vienna , Austria ; INSERM UMR_S 1109, Laboratory of Excellence Transplantex, University of Strasbourg , Strasbourg , France ; German Academy of Transplantation Medicine, Munich , Germany ; and Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus at the Technische Universität Dresden , Dresden , Germany
| | - Christian P Hugo
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University Vienna , Vienna , Austria ; INSERM UMR_S 1109, Laboratory of Excellence Transplantex, University of Strasbourg , Strasbourg , France ; German Academy of Transplantation Medicine, Munich , Germany ; and Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus at the Technische Universität Dresden , Dresden , Germany
| | - Andreas Linkermann
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University Vienna , Vienna , Austria ; INSERM UMR_S 1109, Laboratory of Excellence Transplantex, University of Strasbourg , Strasbourg , France ; German Academy of Transplantation Medicine, Munich , Germany ; and Division of Nephrology, Department of Internal Medicine III, University Hospital Carl Gustav Carus at the Technische Universität Dresden , Dresden , Germany
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18
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Metabotropic glutamate receptor subtype 7 in the dorsal striatum oppositely modulates pain in sham and neuropathic rats. Neuropharmacology 2018; 135:86-99. [PMID: 29505788 DOI: 10.1016/j.neuropharm.2018.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 02/23/2018] [Accepted: 03/01/2018] [Indexed: 11/24/2022]
Abstract
The study investigated the role of the metabotropic glutamate receptor subtype 7 (mGluR7) in pain signalling in the dorsal striatum of sham and neuropathic rats. Supraspinal circuitries involved in the dorsal striatum control of pain were also explored. In the sham rats, microinjection of N,N'-bis(diphenylmethyl)-1,2-ethanediamine (AMN082), a selective mGluR7 positive allosteric modulator, into the dorsal striatum, facilitated pain, increased the activity of the ON cells and inhibited the activity of the OFF cells in the rostral ventromedial medulla, and decreased glutamate levels in the dorsal striatum. Conversely, AMN082 inhibited pain and the activity of the ON cells while increased the activity of the OFF cells in rats with spared nerve injury (SNI) of the sciatic nerve. AMN082 also decreased glutamate levels in the dorsal striatum of SNI rats. The effect of AMN082 on mechanical allodynia and glutamate release was blocked by 6-(2,4-dimethylphenyl)-2-ethyl-6,7-dihydro-4(5H)-benzoxazolone (ADX71743), a selective mGluR7 negative allosteric modulator. Moreover, in the sham rats, AMN082 increased the activity of total nociceptive convergent neurons in the dorsal reticular nucleus while in the SNI rats, such activity was decreased. The administration of lidocaine into the subthalamic nucleus abolished the effect of AMN082 on the total nociceptive convergent neurons in the sham rats but not in the SNI rats. Thus, the dual effect of mGluR7 in facilitating or inhibiting pain responses may be due to the recruitment of different pathways of the basal ganglia, the indirect or direct pathway, in physiological or pathological conditions, respectively.
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19
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Zhuo M. New mechanisms for pain: From neurons to glia; from spinal cord to cortex. J Neurochem 2017; 141:484-485. [PMID: 28332187 DOI: 10.1111/jnc.13985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 02/09/2017] [Indexed: 11/30/2022]
Abstract
This is the Preface for the special article series "Pain". Cover Image for this issue: doi: 10.1111/jnc.13799.
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Affiliation(s)
- Min Zhuo
- Center for Neuron and Disease, Frontier Institutes of Science and Technology, Xi'an Jiaotong University, Xi'an, Shanxi, China.,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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