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Veshchitskii A, Merkulyeva N. Calcium-binding protein parvalbumin in the spinal cord and dorsal root ganglia. Neurochem Int 2023; 171:105634. [PMID: 37967669 DOI: 10.1016/j.neuint.2023.105634] [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: 05/13/2023] [Revised: 09/20/2023] [Accepted: 10/26/2023] [Indexed: 11/17/2023]
Abstract
Parvalbumin is one of the calcium-binding proteins. In the spinal cord, it is mainly expressed in inhibitory neurons; in the dorsal root ganglia, it is expressed in proprioceptive neurons. In contrast to in the brain, weak systematization of parvalbumin-expressing neurons occurs in the spinal cord. The aim of this paper is to provide a systematic review of parvalbumin-expressing neuronal populations throughout the spinal cord and the dorsal root ganglia of mammals, regarding their mapping, co-expression with some functional markers. The data reviewed are mostly concerning rodentia species because they are predominantly presented in literature.
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Affiliation(s)
- Aleksandr Veshchitskii
- Neuromorphology Lab, Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia
| | - Natalia Merkulyeva
- Neuromorphology Lab, Pavlov Institute of Physiology Russian Academy of Sciences, Saint Petersburg, Russia.
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2
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Pereira-Silva R, Serrão P, Lourença Neto F, Martins I. Diffuse noxious inhibitory controls in chronic joint inflammatory Pain: Study of the descending serotonergic modulation mediated through 5HT3 receptors. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2023; 13:100123. [PMID: 36915290 PMCID: PMC10006856 DOI: 10.1016/j.ynpai.2023.100123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 02/27/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023]
Abstract
The loss of diffuse noxious inhibitory controls (DNIC) is recognized as a predictor of chronic pain. Mechanistically, DNIC produces analgesia by a heterotopically applied conditioning-noxious stimulus (CS) and yet underexplored descending modulatory inputs. Here, we aimed at studying DNIC in monoarthritis (MA) by exploring the spinal component of the descending serotonergic system, specifically 5-hydroxytryptamine 3 receptors (5-HT3R). MA was induced in male Wistar rats by tibiotarsal injection of complete Freund's adjuvant. Mechanical hyperalgesia and DNIC were assessed weekly by the Randall-Selitto test. Immunohistochemistry was used to quantify spinal 5-HT3R, and tryptophan hydroxylase (TPH) colocalization with phosphorylated extracellular signal-regulated protein kinases 1/2 at the rostroventromedial medulla (RVM). Spinal serotonin (5-HT) was quantified by HPLC. The effects of intrathecal ondansetron, a 5-HT3R antagonist, were assessed on mechanical hyperalgesia and DNIC. MA resulted in a prolonged steady-state mechanical hyperalgesia. In contrast, DNIC peaked after 28 days, decreasing afterwards until extinction at 42 days. At this later timepoint, MA rats showed increased: (i) spinal 5-HT3R and 5-HT levels, (ii) neuronal serotonergic activation and TPH expression at the RVM. Ondansetron reversed mechanical hyperalgesia and restored DNIC, regardless of being administered before or after CS. However, data variability was higher upon administration before CS in MA-animals. Prolonged MA upregulates the descending serotonergic modulation, which simultaneously results in increased nociception and DNIC extinction, through 5-HT3R. Our data suggest a role for spinal 5-HT3R in the top-down modulation of DNIC. Additionally, these receptors may also be involved in the bottom-up circuitry implicated in the trigger of DNIC.
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Affiliation(s)
- Raquel Pereira-Silva
- Instituto de Investigação e Inovação em Saúde da Universidade do Porto (I3S). Rua Alfredo Allen 208, 4200 393 Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto. Rua Alfredo Allen 208, 4200-393 Porto, Portugal.,Departamento de Biomedicina - Unidade de Biologia Experimental, Faculdade de Medicina, Universidade do Porto. Alameda Prof. Hernâni Monteiro 4200-319 Porto, Portugal
| | - Paula Serrão
- Departamento de Biomedicina - Unidade de Farmacologia e Terapêutica, Faculdade de Medicina, Universidade do Porto. Alameda Prof. Hernâni Monteiro 4200-319 Porto, Portugal.,MedInUP - Center for Drug Discovery and Innovative Medicines, University of Porto. Alameda Prof. Hernâni Monteiro 4200-319 Porto, Portugal
| | - Fani Lourença Neto
- Instituto de Investigação e Inovação em Saúde da Universidade do Porto (I3S). Rua Alfredo Allen 208, 4200 393 Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto. Rua Alfredo Allen 208, 4200-393 Porto, Portugal.,Departamento de Biomedicina - Unidade de Biologia Experimental, Faculdade de Medicina, Universidade do Porto. Alameda Prof. Hernâni Monteiro 4200-319 Porto, Portugal
| | - Isabel Martins
- Instituto de Investigação e Inovação em Saúde da Universidade do Porto (I3S). Rua Alfredo Allen 208, 4200 393 Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto. Rua Alfredo Allen 208, 4200-393 Porto, Portugal.,Departamento de Biomedicina - Unidade de Biologia Experimental, Faculdade de Medicina, Universidade do Porto. Alameda Prof. Hernâni Monteiro 4200-319 Porto, Portugal
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3
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Satiamurthy R, Yaakob NS, Shah NM, Azmi N, Omar MS. Potential Roles of 5-HT 3 Receptor Antagonists in Reducing Chemotherapy-induced Peripheral Neuropathy (CIPN). Curr Mol Med 2023; 23:341-349. [PMID: 35549869 DOI: 10.2174/1566524022666220512122525] [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: 08/12/2021] [Revised: 01/10/2022] [Accepted: 01/20/2022] [Indexed: 11/22/2022]
Abstract
5-HT3 receptor antagonists corresponding to ondansetron, granisetron, tropisetron, and palonosetron are clinically accustomed to treating nausea and emesis in chemotherapy patients. However, current and previous studies reveal novel potentials of those ligands in other diseases involving the nervous system, such as addiction, pruritus, and neurological disorders, such as anxiety, psychosis, nociception, and cognitive function. This review gathers existing studies to support the role of 5-HT3 receptors in CIPN modulation. It has been reported that chemotherapy drugs increase the 5-HT content that binds with the 5-HT3 receptor, which later induces pain. As also shown in pre-clinical and clinical studies that various neuropathic pains could be blocked by the 5-HT3 receptor antagonists, we proposed that 5-HT3 receptor antagonists via 5- HT3 receptors may also inhibit neuropathic pain induced by chemotherapy. Our review suggests that future studies focus more on the 5-HT3 receptor antagonists and their modulation in CIPN to reduce the gap in the current pharmacotherapy for cancer-related pain.
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Affiliation(s)
- Raajeswari Satiamurthy
- Centre for Drug and Herbal Development, Faculty of Pharmacy, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Nor Syafinaz Yaakob
- Centre for Drug and Herbal Development, Faculty of Pharmacy, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Noraida Mohamed Shah
- Centre for Quality Management of Medicines, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Norazrina Azmi
- Centre for Drug and Herbal Development, Faculty of Pharmacy, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Marhanis Salihah Omar
- Centre for Quality Management of Medicines, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
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4
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Martinello K, Sucapane A, Fucile S. 5-HT3 Receptors in Rat Dorsal Root Ganglion Neurons: Ca 2+ Entry and Modulation of Neurotransmitter Release. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081178. [PMID: 36013357 PMCID: PMC9409985 DOI: 10.3390/life12081178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 07/29/2022] [Accepted: 07/31/2022] [Indexed: 11/16/2022]
Abstract
Rat dorsal root ganglion (DRG) neurons express 5-hydroxytryptamine receptors (5-HT3Rs). To elucidate their physiological role in the modulation of sensory signaling, we aimed to quantify their functional expression in newborn and adult rat DRG neurons, as well as their ability to modulate the Ca2+-dependent neurotransmitter release, by means of electrophysiological techniques combined with fluorescence-based Ca2+ imaging. The selective 5-HT3R agonist mCPBG (10 μM) elicited whole-cell currents in 92.5% of adult DRG neurons with a significantly higher density current than in responding newborn cells (52.2%), suggesting an increasing serotoninergic modulation on primary afferent cells during development. Briefly, 5-HT3Rs expressed by adult DRG neurons are permeable to Ca2+ ions, with a measured fractional Ca2+ current (i.e., the percentage of total current carried by Ca2+ ions, Pf) of 1.0%, similar to the value measured for the human heteromeric 5-HT3A/B receptor (Pf = 1.1%), but lower than that of the human homomeric 5-HT3A receptor (Pf = 3.5%). mCPBG applied to co-cultures of newborn DRG and spinal neurons significantly increased the miniature excitatory postsynaptic currents (mEPSCs) frequency in a subset of recorded spinal neurons, even in the presence of Cd2+, a voltage-activated Ca2+ channel blocker. Considered together, our findings indicate that the Ca2+ influx through heteromeric 5-HT3Rs is sufficient to increase the spontaneous neurotransmitter release from DRG to spinal neurons.
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Affiliation(s)
| | - Antonietta Sucapane
- Department of Physiology and Pharmacology, Sapienza University of Rome, P.le Aldo Moro, 5, 00185 Rome, Italy;
| | - Sergio Fucile
- IRCCS Neuromed, Via Atinense, 86077 Pozzilli, Italy;
- Department of Physiology and Pharmacology, Sapienza University of Rome, P.le Aldo Moro, 5, 00185 Rome, Italy;
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5
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Costa EV, Alencar Menezes LR, Dutra LM, Pinheiro MLB, Lavor ÉM, Silva MG, Alves CDSC, Almeida JRGS, da Silva FMA, Koolen HHF, Barison A. A novel eudesmol derivative from the leaf essential oil of Guatteria friesiana (Annonaceae) and evaluation of the antinociceptive activity. Z NATURFORSCH C 2022; 78:169-177. [PMID: 35579663 DOI: 10.1515/znc-2022-0059] [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: 04/09/2021] [Accepted: 03/22/2022] [Indexed: 11/15/2022]
Abstract
In the present study, it was evaluated the chemical composition and the antinociceptive activity of the essential oil obtained from the leaves of Guatteria friesiana. Seven compounds corresponding to 96.2% of the crude essential oil were identified. The main components identified were the mixture of β-eudesmol and α-eudesmol (58.1%), and γ-eudesmol (16.8%). A new α-eudesmol derivative, named 5-hydroxy-α-eudesmol, was isolated together with the known compounds β-eudesmol and a mixture of α-eudesmol, β-eudesmol and γ-eudesmol of the essential oil. The chemical structures were determined by 1D and 2D NMR, and MS experiments. Essential oil has significant antinociceptive properties, which are related probably with the involvement of the opioid receptors and K+-ATP channels.
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Affiliation(s)
- Emmanoel V Costa
- Department of Chemistry, Federal University of Amazonas, Manaus, Amazonas, 69080-900, Brazil
| | | | - Lívia M Dutra
- NMR Center, Federal University of Paraná, Curitiba, Paraná, 81531-990, Brazil.,Center for Studies and Research of Medicinal Plants (NEPLAME), Federal University of San Francisco Valley, Petrolina, Pernambuco, 56304-205, Brazil
| | - Maria Lúcia B Pinheiro
- Department of Chemistry, Federal University of Amazonas, Manaus, Amazonas, 69080-900, Brazil
| | - Érica M Lavor
- Center for Studies and Research of Medicinal Plants (NEPLAME), Federal University of San Francisco Valley, Petrolina, Pernambuco, 56304-205, Brazil
| | - Mariana G Silva
- Center for Studies and Research of Medicinal Plants (NEPLAME), Federal University of San Francisco Valley, Petrolina, Pernambuco, 56304-205, Brazil
| | - Cristiane Dos S C Alves
- Center for Studies and Research of Medicinal Plants (NEPLAME), Federal University of San Francisco Valley, Petrolina, Pernambuco, 56304-205, Brazil
| | - Jackson R G S Almeida
- Center for Studies and Research of Medicinal Plants (NEPLAME), Federal University of San Francisco Valley, Petrolina, Pernambuco, 56304-205, Brazil
| | - Felipe Moura A da Silva
- Department of Chemistry, Federal University of Amazonas, Manaus, Amazonas, 69080-900, Brazil
| | - Hector H F Koolen
- Dempster Mass Spectrometry Group, Amazonas State University, Manaus, Amazonas, 69065-001, Brazil
| | - Andersson Barison
- NMR Center, Federal University of Paraná, Curitiba, Paraná, 81531-990, Brazil
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6
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de Kort AR, Joosten EA, Patijn J, Tibboel D, van den Hoogen NJ. Selective Targeting of Serotonin 5-HT1a and 5-HT3 Receptors Attenuates Acute and Long-Term Hypersensitivity Associated With Neonatal Procedural Pain. FRONTIERS IN PAIN RESEARCH 2022; 3:872587. [PMID: 35571143 PMCID: PMC9091564 DOI: 10.3389/fpain.2022.872587] [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: 02/09/2022] [Accepted: 03/30/2022] [Indexed: 11/13/2022] Open
Abstract
Neonatal painful procedures causes acute pain and trigger long-term changes in nociceptive processing and anxiety behavior, highlighting the need for adequate analgesia during this critical time. Spinal serotonergic receptors 5-HT1a and 5-HT3 play an important role in modulating incoming nociceptive signals in neonates. The current study aims to attenuate acute and long-term hypersensitivity associated with neonatal procedural pain using ondansetron (a 5-HT3 antagonist) and buspirone (a 5-HT1a agonist) in a well-established rat model of repetitive needle pricking. Sprague-Dawley rat pups of both sexes received ondansetron (3 mg/kg), buspirone (3 mg/kg) or saline prior to repetitive needle pricks into the left hind-paw from postnatal day 0-7. Control animals received tactile stimulation or were left undisturbed. Acute, long-term, and post-operative mechanical sensitivity as well as adult anxiety were assessed. Neonatal 5-HT1a receptor agonism completely reverses acute hypersensitivity from P0-7. The increased duration of postoperative hypersensitivity after re-injury in adulthood is abolished by 5-HT3 receptor antagonism during neonatal repetitive needle pricking, without affecting baseline sensitivity. Moreover, 5-HT1a and 5-HT3 receptor modulation decreases adult state anxiety. Altogether, our data suggests that targeted pharmacological treatment based on the modulation of spinal serotonergic network via the 5-HT1a and 5-HT3 receptors in neonates may be of use in treatment of neonatal procedural pain and its long-term consequences. This may result in a new mechanism-based therapeutic venue in treatment of procedural pain in human neonates.
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Affiliation(s)
- Anne R. de Kort
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, Netherlands
- Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Elbert A. Joosten
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, Netherlands
- Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Jacob Patijn
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, Netherlands
- Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Dick Tibboel
- Intensive Care and Department of Pediatric Surgery, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
| | - Nynke J. van den Hoogen
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, Netherlands
- Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
- Department of Comparative Biology and Experimental Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
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7
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Hiroki T, Suto T, Ohta J, Saito S, Obata H. Spinal γ-Aminobutyric Acid Interneuron Plasticity Is Involved in the Reduced Analgesic Effects of Morphine on Neuropathic Pain. THE JOURNAL OF PAIN 2022; 23:547-557. [PMID: 34678470 DOI: 10.1016/j.jpain.2021.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/16/2021] [Accepted: 10/05/2021] [Indexed: 12/25/2022]
Abstract
Systemic administration of morphine increases serotonin (5-HT) in the spinal dorsal horn (SDH), which attenuates the analgesic effects of morphine on neuropathic pain through spinal 5-HT3 receptors. We hypothesized that dysfunction of the descending serotonergic system, including the periaqueductal gray (PAG), contributes to attenuate the efficacy of morphine on neuropathic pain through spinal 5-HT3 receptors and GABA neurons. Morphine (100 ng) injected into the PAG produced analgesic effects in normal rats, but not in spinal nerve ligation (SNL) rats. In vivo microdialysis showed that PAG morphine increased the SDH 5-HT concentration in both groups. Intrathecal injection of the 5-HT3 receptor antagonist ondansetron and the GABAA receptor antagonist bicuculline attenuated the analgesic effects of PAG morphine in normal rats, but increased the effects in SNL rats. The increased analgesic effect of PAG morphine induced by bicuculline was reversed by pretreatment with the tropomyosin receptor kinase B (TrkB) antagonist K252a. Activation of spinal 5-HT3 receptors by 2-methyl-5-HT increased the GABA concentration in both groups. Morphine activates GABAergic interneurons in the SDH by activating descending serotonergic neurons. Functional changes in GABAA receptors from inhibitory to facilitatory through the activation of TrkB receptors may contribute to the attenuated efficacy of morphine against neuropathic pain. PERSPECTIVE: Although morphine provides strong analgesia against acute pain, it has limited efficacy against neuropathic pain. This article demonstrates that functional changes in GABAA receptors in the spinal dorsal horn after nerve injury might strongly contribute to the attenuation of opioid-induced analgesia for neuropathic pain.
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Affiliation(s)
- Tadanao Hiroki
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan.
| | - Takashi Suto
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Jo Ohta
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Shigeru Saito
- Department of Anesthesiology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hideaki Obata
- Department of Anesthesiology, Saitama Medical Center, Saitama Medical University, Kawagoe, Japan
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Involvement of Serotonergic System in Oxaliplatin-Induced Neuropathic Pain. Biomedicines 2021; 9:biomedicines9080970. [PMID: 34440174 PMCID: PMC8394518 DOI: 10.3390/biomedicines9080970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/29/2021] [Accepted: 08/03/2021] [Indexed: 12/27/2022] Open
Abstract
Oxaliplatin is a chemotherapeutic agent widely used against colorectal and breast cancers; however, it can also induce peripheral neuropathy that can rapidly occur even after a single infusion in up to 80–90% of treated patients. Numerous efforts have been made to understand the underlying mechanism and find an effective therapeutic agent that could diminish pain without damaging its anti-tumor effect. However, its mechanism is not yet clearly understood. The serotonergic system, as part of the descending pain inhibitory system, has been reported to be involved in different types of pain. The malfunction of serotonin (5-hydroxytryptamine; 5-HT) or its receptors has been associated with the development and maintenance of pain. However, its role in oxaliplatin-induced neuropathy has not been clearly elucidated. In this review, 16 in vivo studies focused on the role of the serotonergic system in oxaliplatin-induced neuropathic pain were analyzed. Five studies analyzed the involvement of 5-HT, while fourteen studies observed the role of its receptors in oxaliplatin-induced allodynia. The results show that 5-HT is not involved in the development of oxaliplatin-induced allodynia, but increasing the activity of the 5-HT1A, 5-HT2A, and 5-HT3 receptors and decreasing the action of 5-HT2C and 5-HT6 receptors may help inhibit pain.
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9
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WeiWei Y, WenDi F, Mengru C, Tuo Y, Chen G. The cellular mechanism by which the rostral ventromedial medulla acts on the spinal cord during chronic pain. Rev Neurosci 2021; 32:545-558. [PMID: 33565739 DOI: 10.1515/revneuro-2020-0121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 12/18/2020] [Indexed: 11/15/2022]
Abstract
Clinical therapies for chronic pain are limited. While targeted drugs are promising therapies for chronic pain, they exhibit insufficient efficacy and poor targeting. The occurrence of chronic pain partly results from central changes caused by alterations in neurons in the rostral ventromedial medulla (RVM) in the brainstem regulatory pathway. The RVM, which plays a key role in the descending pain control pathway, greatly contributes to the development and maintenance of pain. However, the exact roles of the RVM in chronic pain remain unclear, making it difficult to develop new drugs targeting the RVM and related pathways. Here, we first discuss the roles of the RVM and related circuits in chronic pain. Then, we analyze synaptic transmission between RVM neurons and spinal cord neurons, specifically focusing on the release of neurotransmitters, to explore the cellular mechanisms by which the RVM regulates chronic pain. Finally, we propose some ideas for the development of drugs targeting the RVM.
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Affiliation(s)
- Yu WeiWei
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong226001, China
| | - Fei WenDi
- Key Laboratory of Neuroregeneration of Jiangsu and the Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong226001, China
| | - Cui Mengru
- Department of Anesthesiology, Affiliated Hospital of Nantong University, Nantong226001, China
| | - Yang Tuo
- Department of Hand Surgery, China-Japan Union Hospital of Jilin University, Changchun130033, China
| | - Gang Chen
- Department of Anesthesiology, Affiliated Hospital of Nantong University, Nantong226001, China.,Department of Tissue and Embryology, Medical School of Nantong University, Co-innovation Center of Neuroregeneration, Nantong University, Nantong226001, China
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10
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Heijmans L, Mons MR, Joosten EA. A systematic review on descending serotonergic projections and modulation of spinal nociception in chronic neuropathic pain and after spinal cord stimulation. Mol Pain 2021; 17:17448069211043965. [PMID: 34662215 PMCID: PMC8527581 DOI: 10.1177/17448069211043965] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/01/2021] [Accepted: 08/16/2021] [Indexed: 12/11/2022] Open
Abstract
Chronic neuropathic pain is a debilitating ordeal for patients worldwide and pharmacological treatment efficacy is still limited. As many pharmacological interventions for neuropathic pain often fail, insights into the underlying mechanism and role of identified receptors is of utmost importance. An important target for improving treatment of neuropathic pain is the descending serotonergic system as these projections modulate nociceptive signaling in the dorsal horn. Also with use of last resort treatments like spinal cord stimulation (SCS), the descending serotonergic projections are known to be involved in the pain relieving effect. This systematic review summarizes the involvement of the serotonergic system on nociceptive modulation in the healthy adult rodent and the chronic neuropathic rodent and summarizes all available literature on the serotonergic system in the SCS-treated neuropathic rodent. Medline, Embase and Pubmed databases were used in the search for articles. Descending serotonergic modulation of nociceptive signaling in spinal dorsal horn in normal adult rat is mainly inhibitory and mediated by 5-HT1a, 5-HT1b, 5-HT2c, 5-HT3 and 5-HT4 receptors. Upon injury and in the neuropathic rat, this descending serotonergic modulation becomes facilitatory via activation of the 5-HT2a, 5-HT2b and 5-HT3 receptors. Analgesia due to neuromodulatory intervention like SCS restores the inhibitory function of the descending serotonergic system and involves 5-HT2, 5-HT3 and 5-HT4 receptors. The results of this systematic review provide insights and suggestions for further pharmacological and or neuromodulatory treatment of neuropathic pain based on targeting selected serotonergic receptors related to descending modulation of nociceptive signaling in spinal dorsal horn. With the novel developed SCS paradigms, the descending serotonergic system will be an important target for mechanism-based stimulation induced analgesia.
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Affiliation(s)
- Lonne Heijmans
- Department of Anesthesiology and Pain Management, Maastricht
University Medical Centre, the Netherlands
- Department of Translational Neuroscience, School of Mental
Health and Neuroscience, Maastricht University, the Netherlands
| | - Martijn R Mons
- Department of Anesthesiology and Pain Management, Maastricht
University Medical Centre, the Netherlands
- Department of Translational Neuroscience, School of Mental
Health and Neuroscience, Maastricht University, the Netherlands
| | - Elbert A Joosten
- Department of Anesthesiology and Pain Management, Maastricht
University Medical Centre, the Netherlands
- Department of Translational Neuroscience, School of Mental
Health and Neuroscience, Maastricht University, the Netherlands
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11
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Liu QQ, Yao XX, Gao SH, Li R, Li BJ, Yang W, Cui RJ. Role of 5-HT receptors in neuropathic pain: potential therapeutic implications. Pharmacol Res 2020; 159:104949. [PMID: 32464329 DOI: 10.1016/j.phrs.2020.104949] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 10/24/2022]
Abstract
5-HT plays a crucial role in the progress and adjustment of pain both centrally and peripherally. The therapeutic action of the 5-HT receptors` agonist and antagonist in neuropathic pain have been widely reported in many studies. However, the specific roles of 5-HT subtype receptors have not been reviewed comprehensively. Therefore, we summarized the recent findings on multiple subtypes of 5-HT receptors in both central and peripheral nervous system in neuropathic pain, particularly, 5-HT1, 5-HT2, 5-HT3 and 5-HT7 receptors. In addition, 5-HT4, 5-HT5 and 5-HT6 receptors were also reviewed. Most of studies focused on the function of 5-HT subtype receptors in spinal level compared to brain areas. Based on these evidences, the pain process can be facilitated or inhibited that depending on the specific subtypes and the distribution of 5-HT receptors. Therefore, this review may provide potential therapeutic implications in treatment of neuropathic pain.
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Affiliation(s)
- Qian Qian Liu
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China; Hand Surgery Department, The Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Xiao Xiao Yao
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
| | - Shuo Hui Gao
- Department of Gastrointestinal Colorectal Surgery, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Rui Li
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China; Hand Surgery Department, The Second Hospital of Jilin University, Changchun, Jilin Province, China
| | - Bing Jin Li
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
| | - Wei Yang
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
| | - Ran Ji Cui
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China.
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12
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Bardoni R. Serotonergic Modulation of Nociceptive Circuits in Spinal Cord Dorsal Horn. Curr Neuropharmacol 2020; 17:1133-1145. [PMID: 31573888 PMCID: PMC7057206 DOI: 10.2174/1570159x17666191001123900] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/28/2019] [Accepted: 09/26/2019] [Indexed: 01/12/2023] Open
Abstract
Background: Despite the extensive number of studies performed in the last 50 years, aimed at describing the role of serotonin and its receptors in pain modulation at the spinal cord level, several aspects are still not entirely understood. The interpretation of these results is often complicated by the use of different pain models and animal species, together with the lack of highly selective agonists and antagonists binding to serotonin receptors. Method: In this review, a search has been conducted on studies investigating the modulatory action exerted by serotonin on specific neurons and circuits in the spinal cord dorsal horn. Particular attention has been paid to studies employing electro-physiological techniques, both in vivo and in vitro. Conclusion: The effects of serotonin on pain transmission in dorsal horn depend on several factors, including the type of re-ceptors activated and the populations of neurons involved. Recently, studies performed by activating and/or recording from identified neurons have importantly contributed to the understanding of serotonergic modulation on dorsal horn circuits.
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Affiliation(s)
- Rita Bardoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, 41125, Italy
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13
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Costa‐Pereira JT, Serrão P, Martins I, Tavares I. Serotoninergic pain modulation from the rostral ventromedial medulla (RVM) in chemotherapy‐induced neuropathy: The role of spinal 5‐HT3 receptors. Eur J Neurosci 2019; 51:1756-1769. [DOI: 10.1111/ejn.14614] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/03/2019] [Accepted: 10/30/2019] [Indexed: 01/31/2023]
Affiliation(s)
- José Tiago Costa‐Pereira
- Department of Biomedicine Unit of Experimental Biology Faculty of Medicine University of Porto Porto Portugal
- IBMC‐Institute of Molecular and Cell Biology University of Porto Porto Portugal
- I3S‐ Institute of Investigation and Innovation in Health University of Porto Porto Portugal
| | - Paula Serrão
- Department of Biomedicine Unit of Pharmacology and Therapeutics Faculty of Medicine University of Porto Porto Portugal
- MedInUP ‐ Center for Drug Discovery and Innovative Medicines University of Porto Porto Portugal
| | - Isabel Martins
- Department of Biomedicine Unit of Experimental Biology Faculty of Medicine University of Porto Porto Portugal
- IBMC‐Institute of Molecular and Cell Biology University of Porto Porto Portugal
- I3S‐ Institute of Investigation and Innovation in Health University of Porto Porto Portugal
| | - Isaura Tavares
- Department of Biomedicine Unit of Experimental Biology Faculty of Medicine University of Porto Porto Portugal
- IBMC‐Institute of Molecular and Cell Biology University of Porto Porto Portugal
- I3S‐ Institute of Investigation and Innovation in Health University of Porto Porto Portugal
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14
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Colitis-induced alterations in response properties of visceral nociceptive neurons in the rat caudal medulla oblongata and their modulation by 5-HT3 receptor blockade. Brain Res Bull 2018; 142:183-196. [PMID: 30031817 DOI: 10.1016/j.brainresbull.2018.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 06/15/2018] [Accepted: 07/17/2018] [Indexed: 12/17/2022]
Abstract
There is considerable clinical and experimental evidence that intestinal inflammation is associated with altered visceral nociceptive processing in the spinal cord and brain, but the underlying neuronal mechanisms, especially acting at the supraspinal level, remain unclear. Considering that the caudal ventrolateral medulla (CVLM) and the nucleus tractus solitarius (NTS) are the first sites for supraspinal processing of visceral pain signals, in the present study we evaluated the experimental colitis-induced changes in response properties of CVLM and NTS medullary neurons to noxious colorectal distension (CRD) in urethane-anesthetized adult male Wistar rats. To determine if gut inflammation alters the 5-HT3 receptor-dependent modulation of visceral pain-related CVLM and NTS cells, we examined the effects of intravenously administered selective 5-HT3 antagonist granisetron on ongoing and CRD-evoked activity of CVLM and NTS neurons in healthy control and colitic animals. In the absence of colonic pathology, the CVLM neurons were more excited by noxious CRD that the NTS cells, which demonstrated a greater tendency to be inhibited by the stimulation. The difference was eliminated after the development of colitis due to the increase in the proportion of CRD-excited neurons in both medullary regions associated with enhanced magnitude of the neuronal nociceptive responses. Intravenous granisetron (1 or 2 mg/kg) produced the dose-dependent suppression of the ongoing and evoked firing of CRD-excited cells within both the CVLM and NTS in normal conditions as well as was able to substantially reduce excitability of the caudal medullary neurons in the presence of colonic inflammation, arguing for the potential efficacy of the 5-HT3 receptor blockade with granisetron against both acute and inflammatory abdominal pain. Taken together, the data obtained can contribute to a deeper understanding of supraspinal serotonergic mechanisms responsible for the persistence of visceral hypersensitivity and hyperalgesia triggered by colonic inflammation.
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15
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Shiao R, Lee-Kubli CA. Neuropathic Pain After Spinal Cord Injury: Challenges and Research Perspectives. Neurotherapeutics 2018; 15:635-653. [PMID: 29736857 PMCID: PMC6095789 DOI: 10.1007/s13311-018-0633-4] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neuropathic pain is a debilitating consequence of spinal cord injury (SCI) that remains difficult to treat because underlying mechanisms are not yet fully understood. In part, this is due to limitations of evaluating neuropathic pain in animal models in general, and SCI rodents in particular. Though pain in patients is primarily spontaneous, with relatively few patients experiencing evoked pains, animal models of SCI pain have primarily relied upon evoked withdrawals. Greater use of operant tasks for evaluation of the affective dimension of pain in rodents is needed, but these tests have their own limitations such that additional studies of the relationship between evoked withdrawals and operant outcomes are recommended. In preclinical SCI models, enhanced reflex withdrawal or pain responses can arise from pathological changes that occur at any point along the sensory neuraxis. Use of quantitative sensory testing for identification of optimal treatment approach may yield improved identification of treatment options and clinical trial design. Additionally, a better understanding of the differences between mechanisms contributing to at- versus below-level neuropathic pain and neuropathic pain versus spasticity may shed insights into novel treatment options. Finally, the role of patient characteristics such as age and sex in pathogenesis of neuropathic SCI pain remains to be addressed.
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Affiliation(s)
- Rani Shiao
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines, La Jolla, California, 92073, USA
| | - Corinne A Lee-Kubli
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines, La Jolla, California, 92073, USA.
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16
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Yu Y, Zhu W, Liang Q, Liu J, Yang X, Sun G. Tropisetron attenuates lipopolysaccharide induced neuroinflammation by inhibiting NF-κB and SP/NK1R signaling pathway. J Neuroimmunol 2018; 320:80-86. [PMID: 29759144 DOI: 10.1016/j.jneuroim.2018.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 05/02/2018] [Accepted: 05/02/2018] [Indexed: 12/22/2022]
Abstract
Tropisetron, an antagonist of serotonin type 3 receptors (5-HT3Rs), has been investigated in colonic inflammatory process. Since substance P/neurokinin 1 receptor (SP/NK1R) signaling pathway plays a key role in several sensory neuronal inflammatory. We evaluated the anti-inflammatory activity of tropisetron in mice cerebral cortex, and discovered that it was a potential inhibitor in LPS-mediated neuron inflammation through SP/NK1R signaling pathway. We found that tropisetron significantly reduced the increased number of iba-1 positive microglia, down-regulated the gene transcription and protein expression of IL-1β,IL-6 and TNF-α in LPS stimulated cerebral cortex. To characterize the inhibitory mechanism of tropisetron at the SP response in inflammation, we further examined the effect of tropisetron on NF-κB and SP/NK1R signaling pathway in the process of mice cerebral cortex inflammation. We found that tropisetron inhibited the gene transcription and protein expression of NF-κB, SP, NK1R via inhibiting 5-HT3R activity. These findings might provide new insights into the anti-inflammatory activities of 5-HT3R inhibitor tropisetron, which would be the interaction of serotonin receptor signaling and SP/NK1R pathway. These might highlight their potential to design novel therapeutic strategies to manage inflammatory diseases.
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Affiliation(s)
- Yan Yu
- Department of pharmacy, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China
| | - Wanhu Zhu
- Department of pharmacy, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China
| | - Qing Liang
- Department of pharmacy, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China
| | - Jing Liu
- Department of pharmacy, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China
| | - Xu Yang
- Department of pharmacy, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China
| | - Guangchun Sun
- Department of pharmacy, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China.
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17
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The developmental emergence of differential brainstem serotonergic control of the sensory spinal cord. Sci Rep 2017; 7:2215. [PMID: 28533557 PMCID: PMC5440407 DOI: 10.1038/s41598-017-02509-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 04/12/2017] [Indexed: 12/29/2022] Open
Abstract
Descending connections from brainstem nuclei are known to exert powerful control of spinal nociception and pain behaviours in adult mammals. Here we present evidence that descending serotonergic fibres not only inhibit nociceptive activity, but also facilitate non-noxious tactile activity in the healthy adult rat spinal dorsal horn via activation of spinal 5-HT3 receptors (5-HT3Rs). We further show that this differential serotonergic control in the adult emerges from a non-modality selective system in young rats. Serotonergic fibres exert background 5-HT3R mediated facilitation of both tactile and nociceptive spinal activity in the first three postnatal weeks. Thus, differential descending serotonergic control of spinal touch and pain processing emerges in late postnatal life to allow flexible and context-dependent brain control of somatosensation.
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18
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Tramadol and Tramadol+Caffeine Synergism in the Rat Formalin Test Are Mediated by Central Opioid and Serotonergic Mechanisms. BIOMED RESEARCH INTERNATIONAL 2015; 2015:686424. [PMID: 26146627 PMCID: PMC4471251 DOI: 10.1155/2015/686424] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 05/15/2015] [Accepted: 05/17/2015] [Indexed: 01/08/2023]
Abstract
Different analgesic combinations with caffeine have shown this drug to be capable of increasing the analgesic effect. Many combinations with nonsteroidal anti-inflammatory drugs (NSAIDs) have been carried out, but, in regard to opioids, only combinations with morphine and tramadol have been reported. The antinociceptive synergism mechanism of these combinations is not well understood. The purpose of the present study was to determine the participation of spinal and supraspinal opioidergic and serotonergic systems in the synergic effect of the tramadol+caffeine combination in the rat formalin test. At the supraspinal level, the opioid antagonist, naloxone, completely reversed the effect of the drug combination, whereas ketanserin, a 5-HT2 receptor antagonist, inhibited the effect by 60%; however, ondansetron, a 5-HT3 receptor antagonist, did not alter the combination effect. When the antagonists were intrathecally administered, there was a significant reduction in all tramadol-caffeine combination effects. With respect to tramadol alone, there was significant participation of the opioid system at the supraspinal level, whereas it was the serotonergic system that participated at the spinal level by means of the two receptors studied. In conclusion, the tramadol+caffeine combination synergically activated the opioid and serotonergic systems at the supraspinal level, as well as at the spinal level, to produce the antinociception.
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19
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Okamoto K, Katagiri A, Rahman M, Thompson R, Bereiter DA. Inhibition of temporomandibular joint input to medullary dorsal horn neurons by 5HT3 receptor antagonist in female rats. Neuroscience 2015; 299:35-44. [PMID: 25913635 DOI: 10.1016/j.neuroscience.2015.04.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/17/2015] [Accepted: 04/16/2015] [Indexed: 12/19/2022]
Abstract
Repeated forced swim (FS) conditioning enhances nociceptive responses to temporomandibular joint (TMJ) stimulation in female rats. The basis for FS-induced TMJ hyperalgesia remains unclear. To test the hypothesis that serotonin 3 receptor (5HT3R) mechanisms contribute to enhanced TMJ nociception after FS, ovariectomized female rats were treated with estradiol and subjected to FS for three days. On day 4, rats were anesthetized with isoflurane and TMJ-responsive neurons were recorded from superficial and deep laminae at the trigeminal subnucleus caudalis/upper cervical (Vc/C1-2) region and electromyographic (EMG) activity was recorded from the masseter muscle. Only Vc/C1-2 neurons activated by intra-TMJ injections of ATP were included for further analysis. Although neurons in both superficial and deep laminae were activated by ATP, only neurons in deep laminae displayed enhanced responses after FS. Local application of the 5HT3R antagonist, ondansetron (OND), at the Vc/C1-2 region reduced the ATP-evoked responses of neurons in superficial and deep laminae and reduced the EMG response in both sham and FS rats. OND also decreased the spontaneous firing rate of neurons in deep laminae and reduced the high-threshold convergent cutaneous receptive field area of neurons in superficial and deep laminae in both sham and FS rats. These results revealed that central application of a 5HT3R antagonist, had widespread effects on the properties of TMJ-responsive neurons at the Vc/C1-2 region and on jaw muscle reflexes under sham and FS conditions. It is concluded that 5HT3R does not play a unique role in mediating stress-induced hyperalgesia related to TMJ nociception.
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Affiliation(s)
- K Okamoto
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, MN 55455, United States.
| | - A Katagiri
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, MN 55455, United States
| | - M Rahman
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, MN 55455, United States
| | - R Thompson
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, MN 55455, United States
| | - D A Bereiter
- Department of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, Minneapolis, MN 55455, United States
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20
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The inhibitory effect of granisetron on ventrolateral medulla neuron responses to colorectal distension in rats. Eur J Pharmacol 2015; 749:49-55. [DOI: 10.1016/j.ejphar.2015.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 12/23/2014] [Accepted: 01/06/2015] [Indexed: 01/17/2023]
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21
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Guo W, Miyoshi K, Dubner R, Gu M, Li M, Liu J, Yang J, Zou S, Ren K, Noguchi K, Wei F. Spinal 5-HT3 receptors mediate descending facilitation and contribute to behavioral hypersensitivity via a reciprocal neuron-glial signaling cascade. Mol Pain 2014; 10:35. [PMID: 24913307 PMCID: PMC4067691 DOI: 10.1186/1744-8069-10-35] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 05/30/2014] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND It has been recently recognized that the descending serotonin (5-HT) system from the rostral ventromedial medulla (RVM) in the brainstem and the 5-HT3 receptor subtype in the spinal dorsal horn are involved in enhanced descending pain facilitation after tissue and nerve injury. However, the mechanisms underlying the activation of the 5-HT3 receptor and its contribution to facilitation of pain remain unclear. RESULTS In the present study, activation of spinal 5-HT3 receptors by intrathecal injection of a selective 5-HT3 receptor agonist SR 57227 induced spinal glial hyperactivity, neuronal hyperexcitability and pain hypersensitivity in rats. We found that there was neuron-to-microglia signaling via the chemokine fractalkine, microglia to astrocyte signaling via cytokine IL-18, astrocyte to neuronal signaling by IL-1β, and enhanced activation of NMDA receptors in the spinal dorsal horn. Glial hyperactivation in spinal dorsal horn after hindpaw inflammation was also attenuated by molecular depletion of the descending 5-HT system by intra-RVM Tph-2 shRNA interference. CONCLUSIONS These findings offer new insights into the cellular and molecular mechanisms at the spinal level responsible for descending 5-HT-mediated pain facilitation during the development of persistent pain after tissue and nerve injury. New pain therapies should focus on prime targets of descending facilitation-induced glial involvement, and in particular the blocking of intercellular signaling transduction between neurons and glia.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Feng Wei
- Department of Neural and Pain Sciences, Dental School; Program in Neuroscience, University of Maryland, 650 W, Baltimore St, Baltimore, Maryland 21201, USA.
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García-Ramírez DL, Calvo JR, Hochman S, Quevedo JN. Serotonin, dopamine and noradrenaline adjust actions of myelinated afferents via modulation of presynaptic inhibition in the mouse spinal cord. PLoS One 2014; 9:e89999. [PMID: 24587177 PMCID: PMC3938568 DOI: 10.1371/journal.pone.0089999] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 01/29/2014] [Indexed: 01/20/2023] Open
Abstract
Gain control of primary afferent neurotransmission at their intraspinal terminals occurs by several mechanisms including primary afferent depolarization (PAD). PAD produces presynaptic inhibition via a reduction in transmitter release. While it is known that descending monoaminergic pathways complexly regulate sensory processing, the extent these actions include modulation of afferent-evoked PAD remains uncertain. We investigated the effects of serotonin (5HT), dopamine (DA) and noradrenaline (NA) on afferent transmission and PAD. Responses were evoked by stimulation of myelinated hindlimb cutaneous and muscle afferents in the isolated neonatal mouse spinal cord. Monosynaptic responses were examined in the deep dorsal horn either as population excitatory synaptic responses (recorded as extracellular field potentials; EFPs) or intracellular excitatory postsynaptic currents (EPSCs). The magnitude of PAD generated intraspinally was estimated from electrotonically back-propagating dorsal root potentials (DRPs) recorded on lumbar dorsal roots. 5HT depressed the DRP by 76%. Monosynaptic actions were similarly depressed by 5HT (EFPs 54%; EPSCs 75%) but with a slower time course. This suggests that depression of monosynaptic EFPs and DRPs occurs by independent mechanisms. DA and NA had similar depressant actions on DRPs but weaker effects on EFPs. IC50 values for DRP depression were 0.6, 0.8 and 1.0 µM for 5HT, DA and NA, respectively. Depression of DRPs by monoamines was nearly-identical in both muscle and cutaneous afferent-evoked responses, supporting a global modulation of the multimodal afferents stimulated. 5HT, DA and NA produced no change in the compound antidromic potentials evoked by intraspinal microstimulation indicating that depression of the DRP is unrelated to direct changes in the excitability of intraspinal afferent fibers, but due to metabotropic receptor activation. In summary, both myelinated afferent-evoked DRPs and monosynaptic transmission in the dorsal horn are broadly reduced by descending monoamine transmitters. These actions likely integrate with modulatory actions elsewhere to reconfigure spinal circuits during motor behaviors.
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Affiliation(s)
- David L García-Ramírez
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, D.F., México
| | - Jorge R Calvo
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, D.F., México
| | - Shawn Hochman
- Department of Physiology, Emory University, Atlanta, Georgia, United States of America
| | - Jorge N Quevedo
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, D.F., México
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Tomoyose O, Kodama D, Ono H, Tanabe M. Presynaptic Inhibitory Effects of Fluvoxamine, a Selective Serotonin Reuptake Inhibitor, on Nociceptive Excitatory Synaptic Transmission in Spinal Superficial Dorsal Horn Neurons of Adult Mice. J Pharmacol Sci 2014; 126:136-45. [DOI: 10.1254/jphs.14127fp] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Chang EY, Chen X, Sandhu A, Li CY, Luo ZD. Spinal 5-HT3 receptors facilitate behavioural hypersensitivity induced by elevated calcium channel alpha-2-delta-1 protein. Eur J Pain 2013; 17:505-13. [PMID: 23065867 PMCID: PMC3548964 DOI: 10.1002/j.1532-2149.2012.00221.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2012] [Indexed: 12/31/2022]
Abstract
BACKGROUND Peripheral nerve injury induces up-regulation of the calcium channel alpha-2-delta-1 proteins in the dorsal root ganglia and dorsal spinal cord that correlates with neuropathic pain development. Similar behavioural hypersensitivity was also observed in injury-free transgenic (TG) mice over-expressing the alpha-2-delta-1 proteins in neuronal tissues. To investigate pathways regulating alpha-2-delta-1 protein-mediated behavioural hypersensitivity, we examined whether spinal serotonergic 5-HT3 receptors are involved similarly in the modulation of behavioural hypersensitivity induced by either peripheral nerve injury in a nerve injury model or neuronal alpha-2-delta-1 over-expression in the TG model. METHODS The effects of blocking behavioural hypersensitivity in these two models by intrathecal or systemic injections of 5-HT3 receptor antagonist, ondansetron, were compared. RESULTS Our data indicated that the TG mice displayed similar behavioural hypersensitivities to non-painful mechanical stimulation (tactile allodynia) and painful thermal stimulation (thermal hyperalgesia) as that observed in the nerve injury model. Interestingly, tactile allodynia and thermal hyperalgesia in both models can be blocked similarly by intrathecal, but not systemic, injection of ondansetron. CONCLUSIONS Our data suggest that spinal 5-HT3 receptors are likely to play a role in alpha-2-delta-1-mediated behavioural hypersensitivities through a descending serotonergic facilitation.
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Affiliation(s)
- E Y Chang
- Department of Anesthesiology & Perioperative Care School of Medicine, University of California, Irvine, USA
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25
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Abstract
In addition to analgesia, opioids may also produce paradoxical pain amplification [opioid-induced hyperalgesia (OIH)] either on abrupt withdrawal or during continuous long-term application. Here, we assessed antinociceptive and pronociceptive effects of three clinically used opioids at C-fiber synapses in the rat spinal dorsal horn in vivo. During 60 min of intravenous infusions of remifentanil (450 μg·kg⁻¹·h⁻¹), fentanyl (48 μg·kg⁻¹·h⁻¹), or morphine (14 mg·kg⁻¹·h⁻¹), C-fiber-evoked field potentials were depressed and paired-pulse ratios (PPR) were increased, indicating a presynaptic inhibition by all three opioids. After withdrawal, postsynaptic responses were enhanced substantially for the remaining of the recording periods of at least 3 h. Withdrawal from remifentanil led to long-term potentiation (LTP) of synaptic strength in C-fibers via activation of spinal μ-opioid receptors (MORs) and spinal NMDA receptors (NMDARs). Fentanyl and morphine caused an enhancement of synaptic transmission at C-fibers, which involved two distinct mechanisms: (1) an opioid withdrawal LTP that also required activation of spinal MORs and NMDARs and that was associated with a decrease in PPR suggestive of a presynaptic mechanism of its expression, and (2) an immediate-onset, descending facilitation of C-fiber-evoked field potentials during and after intravenous infusion of fentanyl and morphine. Immediate-onset, descending facilitation was mediated by the activation of extraspinal MORs, descending serotonergic pathways, and spinal 5-hydroxytryptamine-3 receptors (5-HT₃Rs). Our study identified fundamentally different pronociceptive effects of clinically used opioids and suggests that OIH can be prevented by the combined use of NMDAR and 5-HT₃R antagonists.
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26
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Gu M, Miyoshi K, Dubner R, Guo W, Zou S, Ren K, Noguchi K, Wei F. Spinal 5-HT(3) receptor activation induces behavioral hypersensitivity via a neuronal-glial-neuronal signaling cascade. J Neurosci 2011; 31:12823-36. [PMID: 21900561 PMCID: PMC3199304 DOI: 10.1523/jneurosci.1564-11.2011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 07/15/2011] [Accepted: 07/18/2011] [Indexed: 01/15/2023] Open
Abstract
Recent studies indicate that the descending serotonin (5-HT) system from the rostral ventromedial medulla (RVM) in the brainstem and the 5-HT(3) receptor subtype in the spinal dorsal horn are involved in enhanced descending pain facilitation after tissue and nerve injury. However, the mechanisms underlying the activation of the 5-HT(3) receptor and its contribution to facilitation of pain remain unclear. In the present study, activation of spinal 5-HT(3) receptor by intrathecal injection of a selective 5-HT(3) receptor agonist, SR57227, induced spinal glial hyperactivity, neuronal hyperexcitability, and pain hypersensitivity in rats. We found that there was neuron-to-microglia signaling via chemokine fractalkine, microglia to astrocyte signaling via the cytokine IL-18, astrocyte to neuronal signaling by IL-1β, and enhanced activation of GluN (NMDA) receptors in the spinal dorsal horn. In addition, exogenous brain-derived neurotrophic factor-induced descending pain facilitation was accompanied by upregulation of CD11b and GFAP expression in the spinal dorsal horn after microinjection in the RVM, and these events were significantly prevented by functional blockade of spinal 5-HT(3) receptors. Enhanced expression of spinal CD11b and GFAP after hindpaw inflammation was also attenuated by molecular depletion of the descending 5-HT system by intra-RVM Tph-2 shRNA interference. Thus, these findings offer new insights into the cellular and molecular mechanisms at the spinal level responsible for descending 5-HT-mediated pain facilitation during the development of persistent pain after tissue and nerve injury. New pain therapies should focus on prime targets of descending facilitation-induced glial involvement, and in particular the blocking of intercellular signaling transduction between neuron and glia.
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Affiliation(s)
- Ming Gu
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201 and
| | - Kan Miyoshi
- Department of Anatomy and Neuroscience, Institute for Advanced Medical Sciences, Hyogo University, Hyogo 663-8501, Japan
| | - Ronald Dubner
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201 and
| | - Wei Guo
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201 and
| | - Shiping Zou
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201 and
| | - Ke Ren
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201 and
| | - Koichi Noguchi
- Department of Anatomy and Neuroscience, Institute for Advanced Medical Sciences, Hyogo University, Hyogo 663-8501, Japan
| | - Feng Wei
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201 and
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27
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Yin H, Park SA, Han SK, Park SJ. Effects of 5-hydroxytryptamine on substantia gelatinosa neurons of the trigeminal subnucleus caudalis in immature mice. Brain Res 2010; 1368:91-101. [PMID: 20971089 DOI: 10.1016/j.brainres.2010.10.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 10/11/2010] [Accepted: 10/14/2010] [Indexed: 12/21/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) is involved in the descending modulation of nociceptive transmission in the spinal dorsal horn. The trigeminal subnucleus caudalis (Vc; medullary dorsal horn) processes nociceptive input from the orofacial region, and 5-HT-containing axons are numerous in the superficial layers of the Vc. This study examined the actions of 5-HT on the substantia gelatinosa (SG) neurons of the Vc, using gramicidin-perforated patch-clamp recording in brainstem slice preparations from immature mice. In order to clarify the possible mechanisms underlying 5-HT actions in the SG of the Vc, the direct membrane effects of 5-HT and effects of 5-HT receptor subtype agonists were examined. 5-HT induced a hyperpolarization in the majority (64/115, 56%) of the SG neurons tested. Thirty nine (34%) SG neurons showed no response, and 12 (10%) neurons responded with depolarization. The hyperpolarizing response to 5-HT was concentration-dependent (0.1-30 μM; n=7), not desensitized by repeated application (n=22), and significantly attenuated by Ba(2+) (K(+) channel blocker; n=8). The 5-HT-induced hyperpolarization was maintained in the presence of TTX (Na(+) channel blocker), CNQX (non-NMDA glutamate receptor antagonist), AP5 (NMDA glutamate receptor antagonist), picrotoxin (GABA(A) receptor antagonist), and strychnine (glycine receptor antagonist), indicating direct postsynaptic action of 5-HT on SG neurons (n=7). The 5-HT-induced hyperpolarizing effects were mimicked by 8-OH-DPAT (5-HT(1A) receptor agonist) and α-methyl-5-HT (5-HT(2) receptor agonist) and blocked by WAY-100635 (5-HT(1A) receptor antagonist) and ketanserin (5-HT(2) receptor antagonist). Single-cell RT-PCR also revealed the presence of mRNA for 5-HT(1A) and 5-HT(2C) subtypes in the SG neurons. These results suggest that 5-HT acts directly on SG neurons and 5-HT-induced hyperpolarization is mediated, in part, by 5-HT(1A) receptors and 5-HT(2) receptors, as well as by the activation of K(+) channels, indicating an important role for 5-HT in the modulation of orofacial nociceptive processing at the level of the SG of the Vc in mice.
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Affiliation(s)
- Hua Yin
- Department of Oral Physiology and Institute of Oral Bioscience, School of Dentistry, Chonbuk National University, Jeonju, Jeonbuk, 561-756, Republic of Korea
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Spinal cord mechanisms mediating behavioral hyperalgesia induced by neurokinin-1 tachykinin receptor activation in the rostral ventromedial medulla. Neuroscience 2010; 171:1341-56. [PMID: 20888891 DOI: 10.1016/j.neuroscience.2010.09.040] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 08/24/2010] [Accepted: 09/22/2010] [Indexed: 11/23/2022]
Abstract
Hyperalgesia in animal injury models is linked to activation of descending raphespinal modulatory circuits originating in the rostral ventromedial medulla (RVM). A neurokinin-1 (NK-1) receptor antagonist microinjected into the RVM before or after inflammation produced by complete Freund's adjuvant (CFA) resulted in an attenuation of thermal hyperalgesia. A transient (acute) or a continuous infusion of Substance P (SP) microinjected into the RVM of non-inflamed animals led to similar pain hypersensitivity. Intrathecal pretreatment or post-treatment of a 5-HT3 receptor antagonist (Y-25130 or ondansetron) blocked the SP-induced hyperalgesia. The SP-induced hyperalgesia was both GABA(A) and NMDA receptor-dependent after pre- and post-treatment with selective antagonists at the spinal level. A microinjection of SP into the RVM also led to increased NMDA NR1 receptor subunit phosphorylation in spinal cord tissue. The GABA(A) receptor-mediated hyperalgesia involved a shift in the anionic gradient in dorsal horn nociceptive neurons and an increase in phosphorylated NKCC1 protein (isoform of the Na-K-Cl cotransporter). Following a low dose of SP infused into the RVM, intrathecal muscimol (GABA(A) agonist) increased SP-induced thermal hyperalgesia, phosphorylated NKCC1 protein expression, and NMDA NR1 subunit phosphorylation in the spinal cord. The thermal hyperalgesia was blocked by intrathecal gabazine, the GABA(A) receptor antagonist, and MK-801, the NMDA receptor channel blocker. These findings indicate that NK-1 receptors in the RVM are involved in SP-induced thermal hyperalgesia, this hyperalgesia is 5-HT3-receptor dependent at the spinal level, and involves the functional interaction of spinal GABA(A) and NMDA receptors.
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Asante CO, Dickenson AH. Descending serotonergic facilitation mediated by spinal 5-HT3 receptors engages spinal rapamycin-sensitive pathways in the rat. Neurosci Lett 2010; 484:108-12. [PMID: 20709148 PMCID: PMC3098387 DOI: 10.1016/j.neulet.2010.08.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 08/06/2010] [Accepted: 08/06/2010] [Indexed: 11/25/2022]
Abstract
We have recently reported the importance of spinal rapamycin-sensitive pathways in maintaining persistent pain-like states. A descending facilitatory drive mediated through spinal 5-HT3 receptors (5-HT3Rs) originating from superficial dorsal horn NK1-expressing neurons and that relays through the parabrachial nucleus and the rostroventral medial medulla to act on deep dorsal horn neurons is known be important in maintaining these pain-like states. To determine if spinal rapamycin-sensitive pathways are activated by a descending serotonergic drive, we investigated the effects of spinally administered rapamycin on responses of deep dorsal horn neurons that had been pre-treated with the selective 5-HT3R antagonist ondansetron. We also investigated the effects of spinally administered cell cycle inhibitor (CCI)-779 (a rapamycin ester analogue) on deep dorsal horn neurons from rats with carrageenan-induced inflammation of the hind paw. Unlike some other models of persistent pain, this model does not involve an altered 5-HT3R-mediated descending serotonergic drive. We found that the inhibitory effects of rapamycin were significantly reduced for neuronal responses to mechanical and thermal stimuli when the spinal cord was pre-treated with ondansetron. Furthermore, CCI-779 was found to be ineffective in attenuating spinal neuronal responses to peripheral stimuli in carrageenan-treated rats. Therefore, we conclude that 5-HT3R-mediated descending facilitation is one requirement for activation of rapamycin-sensitive pathways that contribute to persistent pain-like states.
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Affiliation(s)
- Curtis O Asante
- Department of Neuroscience Physiology and Pharmacology, University College London, Gower Street, London WC1E6BT, UK.
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Lack of analgesic efficacy of spinal ondansetron on thermal and mechanical hypersensitivity following spinal nerve ligation in the rat. Brain Res 2010; 1352:83-93. [PMID: 20637741 DOI: 10.1016/j.brainres.2010.07.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 07/06/2010] [Accepted: 07/09/2010] [Indexed: 12/31/2022]
Abstract
The balance between descending inhibition and facilitation is thought to be disturbed in chronic pain states. Increased facilitation by spinally released serotonin has been suggested by demonstration that mechanically evoked neuronal responses of wide dynamic range neurons are inhibited by 5-HT3 receptor antagonists in rats following spinal nerve ligation (SNL) but not sham operation. Despite these physiologic data, the effects of spinal 5-HT3 receptor blockade on behavioral hypersensitivity and neurochemical alterations in spinal serotonergic system have not been thoroughly investigated following spinal nerve ligation in the rat. To test this, we acutely injected intrathecal ondansetron in rats between 14 and 30 days after SNL and assessed effects on thermal and mechanical hypersensitivity. We also determined the density of serotonergic nerve fibers, serotonin content and the levels of 5-HT3 receptors within the spinal cord at this time point. Intrathecal ondansetron (1, 3, 10, 30, and 100microg) produced no effect on behavioral measures of thermal or mechanical hypersensitivity whereas intrathecal morphine (1microg) and gabapentin (200microg) partially reversed thermal and mechanical hypersensitivity following SNL. In addition, SNL did not alter the density of serotonergic fibers or 5-HT3 receptor immunoreactivity or spinal tissue content of 5-HT within the dorsal horn. These results do not support anatomic plasticity of descending serotonergic pathways or tonic 5-HT3 receptor activity in maintaining hypersensitivity after nerve injury and in contrast to previous studies fail to demonstrate an anti-hypersensitivity effect of intrathecal injection of the 5-HT3 receptor antagonist ondansetron. Importantly, behavioral measures of mechanical hypersensitivity assess threshold responses whereas physiological studies of mechanically evoked neuronal responses involve application of suprathreshold stimuli. Thus, suprathreshold or more intense stimuli may be necessary to recruit descending serotonergic facilitatory drive required to observe the inhibitory effects of ondansetron on spinal neuronal excitability and behavioral hypersensitivity.
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Wu SX, Wang W, Li H, Wang YY, Feng YP, Li YQ. The synaptic connectivity that underlies the noxious transmission and modulation within the superficial dorsal horn of the spinal cord. Prog Neurobiol 2010; 91:38-54. [DOI: 10.1016/j.pneurobio.2010.01.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 12/10/2009] [Accepted: 01/14/2010] [Indexed: 01/27/2023]
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Fukushima T, Ohtsubo T, Tsuda M, Yanagawa Y, Hori Y. Facilitatory actions of serotonin type 3 receptors on GABAergic inhibitory synaptic transmission in the spinal superficial dorsal horn. J Neurophysiol 2009; 102:1459-71. [PMID: 19369358 DOI: 10.1152/jn.91160.2008] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Analgesic effects of serotonin (5-hydroxytryptamine [5-HT]) type 3 (5-HT3) receptors may involve the release of gamma-aminobutyric acid (GABA) in the spinal dorsal horn. However, the precise synaptic mechanisms for 5-HT3 receptor-mediated spinal analgesia are not clear. In this study, we investigated whether GABAergic neurons in the superficial dorsal horn (SDH) express functional 5-HT3 receptors and how these 5-HT3 receptors affect GABAergic inhibitory synaptic transmission in the SDH, by using slice preparations from adult glutamate decarboxylase 67-green fluorescent protein (GAD67-GFP) knock-in mice. Tight-seal whole cell recordings from GFP-positive and -negative neurons showed that 5-HT3 receptor-specific agonist 2-methyl-serotonin (2-Me-5-HT) induced inward currents in a substantial population of both GFP-positive and -negative neurons. Additionally, we confirmed expression of 5-HT3 receptors in both types of neurons by single-cell reverse transcription-polymerase chain reaction (RT-PCR) analysis. Further, GABAA receptor-mediated inhibitory postsynaptic currents (IPSCs)-both those evoked by electrical stimulation and those occurring spontaneously in tetrodotoxin (i.e., miniature IPSCs [mIPSCs])-were recorded from GFP-negative neurons. 2-Me-5-HT increased the amplitude of the evoked IPSCs and the frequency of mIPSCs. The amplitude of mIPSCs was not affected by 2-Me-5-HT, suggesting that 5-HT augments GABAergic synaptic transmission via presynaptic mechanisms. The present observations indicate that 5-HT3 receptors are expressed on both somadendritic regions and presynaptic terminals of GABAergic neurons and regulate GABAA receptor-mediated inhibitory synaptic transmission in the SDH. Taken together, these results provide clues for the underlying mechanisms of the antinociceptive actions of 5-HT3 receptors in the spinal dorsal horn.
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Affiliation(s)
- Teruyuki Fukushima
- Department of Physiology and Biological Information, Dokkyo Medical University School of Medicine, Kitakobayashi 880, Mibu, Tochigi 321-0293, Japan
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Abe K, Kato G, Katafuchi T, Tamae A, Furue H, Yoshimura M. Responses to 5-HT in morphologically identified neurons in the rat substantia gelatinosa in vitro. Neuroscience 2008; 159:316-24. [PMID: 19141313 DOI: 10.1016/j.neuroscience.2008.12.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2008] [Revised: 12/10/2008] [Accepted: 12/12/2008] [Indexed: 10/21/2022]
Abstract
Bath application of 5-HT (1-1000 muM) induced a tetrodotoxin (TTX)-resistant outward current at the holding membrane potential (V(H)) of -50 mV in 104/162 (64.2%) of substantia gelatinosa (SG) neurons from the rat spinal cord in vitro. The 5-HT-induced outward current was suppressed by an external solution containing Ba(2+), or a pipette solution containing Cs(2)SO(4) and tetraethylammonium. It was reversed near the equilibrium potential of the K(+) channel. The response to 5-HT was abolished 30 min after patch formation with a pipette solution containing guanosine-5-O-(2-thiodiphosphate)-S. The 5-HT-induced outward current was mimicked by a 5-HT(1A) agonist, (+/-)-8-hydroxy-2-(di-n-propylamino) tetralin hydrobromide, and suppressed by a 5-HT(1A) antagonist, WAY100635, suggesting the 5HT(1A) receptor-mediated activation of K(+) channels in the outward current. In 11/162 (6.8%) SG neurons, 5-HT produced an inward current, which was mimicked by a 5-HT(3) agonist, 1-(m-chlorophenyl)-biguanide (mCPBG). The 5-HT-induced outward currents were observed in vertical cells (21/34) and small islet cells (11/34), while inward currents were induced in islet cells (1/5) and small islet (4/5) cells, but not in vertical cells. It is known that most vertical cells and islet cells in the SG are excitatory (glutamatergic) and inhibitory interneurons, respectively, while small islet cells consist of both excitatory and inhibitory neurons. Bath application of 5-HT or mCPBG increased the amplitude and the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs), but no neurons showed a decrease in sIPSC. Furthermore, frequency, but not amplitude, of miniature IPSCs increased with perfusion with 5-HT in the presence of TTX. These findings, taken together, suggest that 5-HT induces outward currents through 5-HT(1A) receptors in excitatory SG neurons. These findings also suggest that the inward currents are post- and presynaptically evoked through 5-HT(3) receptors, probably in inhibitory neurons.
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Affiliation(s)
- K Abe
- Department of Integrative Physiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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Faerber L, Drechsler S, Ladenburger S, Gschaidmeier H, Fischer W. The neuronal 5-HT3 receptor network after 20 years of research — Evolving concepts in management of pain and inflammation. Eur J Pharmacol 2007; 560:1-8. [PMID: 17316606 DOI: 10.1016/j.ejphar.2007.01.028] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2006] [Accepted: 01/09/2007] [Indexed: 11/19/2022]
Abstract
The 5-HT3 receptor is a pentameric ligand-gated cation channel which is found in the central and peripheral nervous system and on extraneuronal locations like lymphocytes, monocytes and fetal tissue. Five monomer subtypes, the 5-HT(3A-E) subunits, have been identified which show differences in the amino-terminal and the transmembrane region. The functional relevance of different receptor compositions is not yet clarified. 5-HT3 receptors are located predominantly in CNS regions that are involved in the integration of the vomiting reflex, pain processing, the reward system and anxiety control. The preferential localization on nerve endings is consistent with a physiological role of 5-HT3 receptors in the control of neurotransmitter release such as dopamine, cholecystokinin, glutamate, acetylcholine, GABA, substance P, or serotonin itself. 5-HT3-receptor agonists cause unpleasant effects like nausea and anxiety, and no clinical use has been considered. In contrast, the introduction of 5-HT3-receptor antagonists for chemotherapy-induced vomiting was extremely successful. After development of other gastrointestinal indications like postoperative vomiting and diarrhea-predominant irritable bowel syndrome recent research focuses on rheumatological indications such as fibromyalgia, rheumatoid arthritis and tendinopathies. Positive effects have also been observed for pain syndromes such as chronic neuropathic pain and migraine. These effects seem to be related to substance P-mediated inflammation and hyperalgesia. Furthermore, antiinflammatory and immunomodulatory properties have been observed for 5-HT3-receptor antagonists which might explain promising findings in systemic sclerosis and other immunological conditions. For all of these innovative indications the optimal dosing schedule is a crucial issue, since a bell-shaped dose-response curve has been observed repeatedly for 5-HT3-receptor antagonists, particularly in CNS effects.
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Affiliation(s)
- Lothar Faerber
- Department of Pharmacology, Regensburg Medical School, Universitaetsstr. 31, 93053 Regensburg, Germany.
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Abstract
Digestion and absorption of a meal are time-intensive processes. To optimize digestion and absorption, transit of the meal through the gastrointestinal tract is regulated by a complex integration of neuropeptidergic signals generated as the jejunal brake and ileal brake response to nutrients. Mediators involved in the slowing of transit responses include peptide YY (PYY), chemosensitive afferent neurons, intestinofugal nerves, noradrenergic nerves, myenteric serotonergic neurons, and opioid neurons. The activation of this circuitry modifies the peristaltic reflex to convert the intestinal motility pattern from propagative to segmenting. Fat is the most potent trigger of these transit control mechanisms. The integrated circuitry of gut peptides and neurons involved in transit control in response to nutrients is described in this review.
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Affiliation(s)
- Gregg W Van Citters
- Division of Gastroinestinal and Liver Diseases, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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Bradesi S, Lao L, McLean PG, Winchester WJ, Lee K, Hicks GA, Mayer EA. Dual role of 5-HT3 receptors in a rat model of delayed stress-induced visceral hyperalgesia. Pain 2006; 130:56-65. [PMID: 17161536 DOI: 10.1016/j.pain.2006.10.028] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Revised: 09/22/2006] [Accepted: 10/26/2006] [Indexed: 11/20/2022]
Abstract
Despite its beneficial effect in IBS patients, the mechanism of action of the 5-HT3 receptor (5-HT3R) antagonist alosetron is still incompletely understood. We aimed to characterize the effect and site(s) of action in a model of stress-induced sensitization of visceral nociception in rats. Adult male Wistar rats were equipped for recording of visceromotor response (VMR) to phasic colorectal distension (CRD; 10-60 mmHg). VMR to CRD was recorded 24 h after an acute session of water avoidance (WA) stress (post-WA). Baseline and post-WA responses were measured in rats exposed to WA or sham-WA, treated with alosetron at 0.3 mg/kg subcutaneously (s.c.) 25 nmol intrathecally (i.t.) or vehicle before post-WA CRD. Some rats were treated with capsaicin/vehicle on the cervical vagus nerve and received alosetron (0.3 mg/kg, s.c.) 15 min before post-WA CRD. WA stress led to visceral hyperalgesia 24 h later. Alosetron (0.3 mg/kg, s.c.), failed to inhibit WA-induced exacerbation of VMR to CRD. Stress-induced visceral hyperalgesia was abolished when alosetron was injected intrathecally (P<0.05) in intact rats or subcutaneously (0.3 mg/kg) in capsaicin-pretreated animals (P<0.05). Capsaicin-pretreatment did not affect the exacerbating effect of stress on visceral sensitivity. Alosetron had no inhibitory effect on normal visceral pain responses when administered subcutaneously or intrathecally. We demonstrated that 5-HT3Rs on central terminals of spinal afferents are engaged in the facilitatory effect of stress on visceral sensory information processing. In addition, we showed that stress-induced sensitization of visceral nociception is independent of 5-HT3R activation on vagal afferents.
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Affiliation(s)
- Sylvie Bradesi
- Center for Neurovisceral Sciences and Women's Health, Department of Medicine, VAGLAHS CURE Building 115, Room 223, 11301 Wilshire Boulevard, Los Angeles, CA 90073, USA
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Okamoto K, Kimura A, Donishi T, Imbe H, Nishie Y, Matsushita H, Tamai Y, Senba E. Contribution of peripheral 5-HT2A or 5-HT3 receptors to Fos expression in the trigeminal spinal nucleus produced by acute injury to the masseter muscle during persistent temporomandibular joint inflammation in rats. Neuroscience 2006; 143:597-606. [PMID: 16979827 DOI: 10.1016/j.neuroscience.2006.08.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Revised: 07/17/2006] [Accepted: 08/07/2006] [Indexed: 12/30/2022]
Abstract
We investigated the contribution of peripheral 5-HT2A or 5-HT3 receptors to Fos expression in the trigeminal spinal nucleus (VSP) following acute masseter muscle injury in male rats with or without temporomandibular joint (TMJ) inflammation persisting for 7 days. TMJ inflammation was evoked by an injection of complete Freund's adjuvant (CFA). Two hours after formalin injection into the masseter muscle produced Fos-like immunoreactivity (Fos-LI) in several regions of the VSP and upper cervical spinal cord (C2), such as ventrolateral (vl) area of the trigeminal subnucleus caudalis (Vc)/subnucleus interpolaris (Vi) transition (vl-Vi/Vc), paratrigeminal nucleus (dPa5), middle portion of the Vc (mid-Vc) and Vc/C2 transition (Vc/C2) regions in both groups. Significant increases in the number of Fos-LI were observed in these areas in CFA group compared with non-CFA group. TMJ inflammation alone did not induce a significant level of Fos-LI in the VSP. In order to assess the effect of antagonizing 5-HT2A or 5-HT3 receptors on formalin-induced Fos-LI, rats were pre-treated with local (masseter muscle) administration of ketanserin or tropisetron (0.01, 0.1 mg/rat) 20 min prior to formalin injection. In CFA group, these antagonists given locally reduced the Fos-LI response in the laminae I-II at the mid-Vc and Vc/C2 regions. These antagonists reduced the Fos-LI response in the dPa5, but not in the vl-Vi/Vc region. The Fos-LI response was not affected by i.v. administration of ketanserin (0.01, 0.1 mg/rat) or tropisetron (0.01 mg/rat). In non-CFA group, these antagonists given locally did not reduce the Fos-LI response. These results suggest that peripheral 5-HT2A and 5-HT3 receptors contribute to nociceptive processing in the masseter muscle in TMJ inflammatory conditions.
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Affiliation(s)
- K Okamoto
- Department of Physiology, Wakayama Medical University, Wakayama City 641-8509, Japan.
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Svensson CI, Tran TK, Fitzsimmons B, Yaksh TL, Hua XY. Descending serotonergic facilitation of spinal ERK activation and pain behavior. FEBS Lett 2006; 580:6629-34. [PMID: 17113581 PMCID: PMC2291024 DOI: 10.1016/j.febslet.2006.11.012] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 10/31/2006] [Accepted: 11/04/2006] [Indexed: 11/25/2022]
Abstract
Serotonin (5-HT) derived from bulbo-spinal projection is released by nociceptive input into the spinal dorsal horn. Here we report that formalin injection in the paw produced pain behavior (flinching) and phosphorylation of spinal ERK1/2 (P-ERK1/2, indicating activation) in rats. Depletion of spinal 5-HT by intrathecal (IT) 5,7-DHT, a serotonergic neurotoxin, profoundly reduced formalin evoked flinching and the increase in P-ERK1/2. Ondansetron (a 5-HT3 receptor antagonist) at IT doses that inhibited flinching also attenuated spinal ERK activation. These findings reveal that primary afferent-evoked activation of spinal ERK requires the input from an excitatory 5-HT descending pathway.
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Affiliation(s)
- Camilla I Svensson
- Department of Anesthesiology, University of California - San Diego, 9500 Gilman drive, La Jolla, CA 92093-0818, USA
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Singh JN, Gupta R, Deshpande SB. Ptychodiscus brevis toxin-induced depression of spinal reflexes involves 5-HT via 5-HT3 receptors modulated by NMDA receptor. Neurosci Lett 2006; 409:70-4. [PMID: 17014958 DOI: 10.1016/j.neulet.2006.09.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2006] [Revised: 08/29/2006] [Accepted: 09/08/2006] [Indexed: 11/27/2022]
Abstract
The involvement of 5-hydroxytryptaminergic (5-HT) system for the Ptychodiscus brevis toxin (PbTx)-induced depression of spinal reflexes was evaluated. The reflex potentials were recorded at ventral root by stimulating the corresponding dorsal root in neonatal rat spinal cord in vitro. Superfusion of PbTx (2.8-84microM) depressed the monosynaptic (MSR) and polysynaptic (PSR) reflexes in a concentration-dependent manner. The depression of the reflexes was maximal with 84microM of the toxin. Ondansetron (0.1microM), a 5-HT(3) receptor antagonist, blocked the PbTx-induced depression of MSR and PSR. Spiperone (a 5-HT(2A) antagonist) or ketanserin (5-HT(2A/2C) antagonist and also at 5-HT(1B/1D)) failed to block the PbTx-induced depression of the reflexes. The 5-HT concentration of the cords was increased by four-fold after exposure to PbTx (28microM) and the increase was not seen in the cords pretreated with dl-2 amino-5-phosphonovaleric acid (APV, a NMDA receptor antagonist). Superfusion of 5-HT or phenylbiguanide (PBG, a 5-HT(3) receptor agonist) also produced depression of the spinal reflexes in a concentration-dependent manner. The 5-HT-induced depression of reflexes was blocked by ondansetron but not by spiperone. The results demonstrate that the PbTx-induced depression of spinal reflexes involves 5-hydroxytryptamine via 5-HT(3) receptors modulated by NMDA receptor.
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Affiliation(s)
- Jitendra N Singh
- Department of Physiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
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