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Cai W, Haddad M, Haddad R, Kesten I, Hoffman T, Laan R, Westfall S, Defaye M, Abdullah NS, Wong C, Brown N, Tansley S, Lister KC, Hooshmandi M, Wang F, Lorenzo LE, Hovhannisyan V, Ho-Tieng D, Kumar V, Sharif B, Thurairajah B, Fan J, Sahar T, Clayton C, Wu N, Zhang J, Bar-Yoseph H, Pitashny M, Krock E, Mogil JS, Prager-Khoutorsky M, Séguéla P, Altier C, King IL, De Koninck Y, Brereton NJB, Gonzalez E, Shir Y, Minerbi A, Khoutorsky A. The gut microbiota promotes pain in fibromyalgia. Neuron 2025:S0896-6273(25)00252-1. [PMID: 40280127 DOI: 10.1016/j.neuron.2025.03.032] [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: 02/27/2024] [Revised: 02/09/2025] [Accepted: 03/28/2025] [Indexed: 04/29/2025]
Abstract
Fibromyalgia is a prevalent syndrome characterized by widespread pain in the absence of evident tissue injury or pathology, making it one of the most mysterious chronic pain conditions. The composition of the gut microbiota in individuals with fibromyalgia differs from that of healthy controls, but its functional role in the syndrome is unknown. Here, we show that fecal microbiota transplantation from fibromyalgia patients, but not from healthy controls, into germ-free mice induces pain and numerous molecular phenotypes that parallel known changes in fibromyalgia patients, including immune activation and metabolomic profile alterations. Replacing the fibromyalgia microbiota with a healthy microbiota substantially alleviated pain in mice. An open-label trial in women with fibromyalgia (Registry MOH_2021-11-04_010374) showed that transplantation of a healthy microbiota is associated with reduced pain and improved quality of life. We conclude that altered gut microbiota has a role in fibromyalgia pain, highlighting it as a promising target for therapeutic interventions.
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Affiliation(s)
- Weihua Cai
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - May Haddad
- Rambam Health Campus, Haifa, Israel; Ruth and Bruce Rapaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | | | - Inbar Kesten
- Rambam Health Campus, Haifa, Israel; Clinical Research Institute at Rambam (CRiR), Haifa, Israel
| | | | - Reut Laan
- Ruth and Bruce Rapaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Susan Westfall
- Department of Microbiology and Immunology, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada; McGill Centre for Microbiome Research, McGill University, Montreal, QC, Canada
| | - Manon Defaye
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Nasser S Abdullah
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Calvin Wong
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Nicole Brown
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Shannon Tansley
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Kevin C Lister
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Mehdi Hooshmandi
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Feng Wang
- Faculty of Dentistry, CERVO Brain Research Center, University Laval, Quebec City, QC, Canada
| | - Louis-Etienne Lorenzo
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, University Laval, Quebec City, QC, Canada
| | | | - David Ho-Tieng
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Vibhu Kumar
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Behrang Sharif
- Department of Neurology & Neurosurgery, McGill University, Montreal, QC, Canada
| | - Bavanitha Thurairajah
- Department of Microbiology and Immunology, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada; McGill Centre for Microbiome Research, McGill University, Montreal, QC, Canada
| | - Jonathan Fan
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Tali Sahar
- Alan Edwards Pain Management Unit, McGill University Health Centre, Montreal, QC, Canada
| | | | - Neil Wu
- Department of Anesthesia, McGill University, Montreal, QC, Canada
| | - Ji Zhang
- Department of Neurology & Neurosurgery, McGill University, Montreal, QC, Canada; Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada
| | - Haggai Bar-Yoseph
- Rambam Health Campus, Haifa, Israel; Ruth and Bruce Rapaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Clinical Research Institute at Rambam (CRiR), Haifa, Israel
| | - Milena Pitashny
- Rambam Health Campus, Haifa, Israel; Ruth and Bruce Rapaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Clinical Research Institute at Rambam (CRiR), Haifa, Israel
| | - Emerson Krock
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada
| | - Jeffrey S Mogil
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada; Departments of Psychology and Anesthesia, McGill University, Montreal, QC, Canada
| | | | - Philippe Séguéla
- Department of Neurology & Neurosurgery, McGill University, Montreal, QC, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada
| | - Christophe Altier
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Irah L King
- Department of Microbiology and Immunology, Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, QC, Canada; McGill Centre for Microbiome Research, McGill University, Montreal, QC, Canada
| | - Yves De Koninck
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, University Laval, Quebec City, QC, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada
| | - Nicholas J B Brereton
- School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Emmanuel Gonzalez
- McGill Centre for Microbiome Research, McGill University, Montreal, QC, Canada; Canadian Center for Computational Genomics, McGill University and Genome Quebec Innovation Center, Montreal, QC, Canada; Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Yoram Shir
- Department of Anesthesia, McGill University, Montreal, QC, Canada; Alan Edwards Pain Management Unit, McGill University Health Centre, Montreal, QC, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.
| | - Amir Minerbi
- Rambam Health Campus, Haifa, Israel; Ruth and Bruce Rapaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel; Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.
| | - Arkady Khoutorsky
- Department of Anesthesia, McGill University, Montreal, QC, Canada; McGill Centre for Microbiome Research, McGill University, Montreal, QC, Canada; Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, QC, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.
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Abd El Hay MY, Kamm GB, Tlaie Boria A, Siemens J. Diverging roles of TRPV1 and TRPM2 in warm-temperature detection. eLife 2025; 13:RP95618. [PMID: 40215103 PMCID: PMC11991700 DOI: 10.7554/elife.95618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2025] Open
Abstract
The perception of innocuous temperatures is crucial for thermoregulation. The TRP ion channels TRPV1 and TRPM2 have been implicated in warmth detection, yet their precise roles remain unclear. A key challenge is the low prevalence of warmth-sensitive sensory neurons, comprising fewer than 10% of rodent dorsal root ganglion (DRG) neurons. Using calcium imaging of >20,000 cultured mouse DRG neurons, we uncovered distinct contributions of TRPV1 and TRPM2 to warmth sensitivity. TRPV1's absence - and to a lesser extent absence of TRPM2 - reduces the number of neurons responding to warmth. Additionally, TRPV1 mediates the rapid, dynamic response to a warmth challenge. Behavioural tracking in a whole-body thermal preference assay revealed that these cellular differences shape nuanced thermal behaviours. Drift diffusion modelling of decision-making in mice exposed to varying temperatures showed that TRPV1 deletion impairs evidence accumulation, reducing the precision of thermal choice, while TRPM2 deletion increases overall preference for warmer environments that wildtype mice avoid. It remains unclear whether TRPM2 in DRG sensory neurons or elsewhere mediates thermal preference. Our findings suggest that different aspects of thermal information, such as stimulation speed and temperature magnitude, are encoded by distinct TRP channel mechanisms.
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Affiliation(s)
- Muad Y Abd El Hay
- Department of Pharmacology, Heidelberg UniversityHeidelbergGermany
- Ernst Strüngmann Institute for Neuroscience in Cooperation with the Max Planck SocietyFrankfurt am MainGermany
| | - Gretel B Kamm
- Department of Pharmacology, Heidelberg UniversityHeidelbergGermany
| | - Alejandro Tlaie Boria
- Ernst Strüngmann Institute for Neuroscience in Cooperation with the Max Planck SocietyFrankfurt am MainGermany
| | - Jan Siemens
- Department of Pharmacology, Heidelberg UniversityHeidelbergGermany
- Molecular Medicine Partnership Unit, European Molecular Biology Laboratory (EMBL)HeidelbergGermany
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Goodwin GL, Marin AC, Walker JV, Hobbs C, Denk F. Using in vivo calcium imaging to examine joint neuron spontaneous activity and home cage analysis to monitor activity changes in mouse models of arthritis. Arthritis Res Ther 2025; 27:67. [PMID: 40148904 PMCID: PMC11948904 DOI: 10.1186/s13075-025-03515-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2024] [Accepted: 02/21/2025] [Indexed: 03/29/2025] Open
Abstract
BACKGROUND Studying pain in rodent models of arthritis is challenging. For example, assessing functional changes in joint neurons is challenging due to their relative scarcity amongst all sensory neurons. Additionally, studying pain behaviors in rodent models of arthritis poses its own set of difficulties. Commonly used tests, such as static weight-bearing, often require restraint, which can induce stress and consequently alter nociception. The aim of this study was to evaluate two emerging techniques for investigating joint pain in mouse models of rheumatoid- and osteo-arthritis: In vivo calcium imaging to monitor joint afferent activity and group-housed home cage monitoring to assess pain-like behaviors. Specifically, we examined whether there was increased spontaneous activity in joint afferents and reduced locomotor activity following induction of arthritis. METHODS Antigen induced arthritis (AIA) was used to model rheumatoid arthritis and partial medial meniscectomy (PMX) was used to model osteoarthritis. Group-housed home cage monitoring was used to assess locomotor behavior in all mice, and weight bearing was assessed in PMX mice. In vivo calcium imaging with GCaMP6s was used to monitor spontaneous activity in L4 ganglion joint neurons retrogradely labelled with fast blue 2 days following AIA and 13-15 weeks following PMX model induction. Cartilage degradation was assessed in knee joint sections stained with Safranin O and fast green in PMX mice. RESULTS Antigen induced arthritis produced knee joint swelling and PMX caused degeneration of articular cartilage in the knee. In the first 46 h following AIA, mice travelled less distance and were less mobile compared to their control cage mates. In contrast, no such differences were found between PMX and sham mice when measured between 4-12 weeks post-surgery. A larger fraction of joint neurons showed spontaneous activity in AIA but not PMX mice. Spontaneous activity was mostly displayed by medium-sized neurons in AIA mice and was not correlated with any of the home cage behaviors. CONCLUSION Group-housed home cage monitoring revealed locomotor changes in AIA mice, but not PMX mice (with n = 10/group). In vivo calcium imaging can be used to assess activity in multiple retrogradely labelled joint afferents and revealed increased spontaneous activity in AIA but not PMX mice.
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Affiliation(s)
- George L Goodwin
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), King's College London, SE1 1UL, London, UK.
| | - Alina-Cristina Marin
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), King's College London, SE1 1UL, London, UK
| | - Julia Vlachaki Walker
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), King's College London, SE1 1UL, London, UK
| | - Carl Hobbs
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), King's College London, SE1 1UL, London, UK
| | - Franziska Denk
- Wolfson Sensory, Pain and Regeneration Centre (SPaRC), King's College London, SE1 1UL, London, UK
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Du L, Cheng H, Cui X, Cao Q, Li X, Wang S, Wang X, Liu Y, Zhu B, Gao X, Liu K. Mrgprb4-lineage neurons indispensable in pressure induced pleasant sensation are polymodal. iScience 2025; 28:111940. [PMID: 40034120 PMCID: PMC11872644 DOI: 10.1016/j.isci.2025.111940] [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: 09/25/2024] [Revised: 11/22/2024] [Accepted: 01/29/2025] [Indexed: 03/05/2025] Open
Abstract
Pharmacogenetic activation of the Mas-related G-protein-coupled receptor b4 (Mrgprb4) neurons in the dorsal root ganglia is positively reinforcing, and these neurons can be activated by innocuous or noxious mechanical stimuli. However, direct evidence regarding the role of these neurons and how they encode diverse somatic inputs remains unclear. To address this, the mild pressure conditioned place preference (MP-CPP) was conducted to evaluate the indispensability of Mrgprb4-lineage neurons in the pleasantness caused by pressure. Mice without Mrgprb4-lineage neurons lost the preference for pressure. The number of Mrgprb4-lineage neurons activated by pressure was significantly higher than that of brush and pinch. The Ca2+ transients activated by pressure and brush were higher than that of pinch. Further analysis of co-activating mechano-thermosensitive neurons showed that pressure evoked higher fluorescence than that of 0°C and 43°C. In brief, Mrgprb4-lineage neurons are needed to transmit pleasant sensation and exhibit functional polymodality.
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Affiliation(s)
- Longhua Du
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Hongyi Cheng
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiang Cui
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Qianan Cao
- Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi, China
| | - Xia Li
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Shuya Wang
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiaoxi Wang
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yun Liu
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Bing Zhu
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xinyan Gao
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Kun Liu
- Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
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5
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Liu L, Yin J, Meng Y, Ye C, Chen J, Wang S, Yin W, Gao P, Jiao Y, Yu W, Fan Y. Similarities and differences in the response and molecular characteristics of peripheral sensory neurons associated with pain and itch. Acta Biochim Biophys Sin (Shanghai) 2025. [PMID: 39953797 DOI: 10.3724/abbs.2024202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2025] Open
Abstract
Dorsal root ganglion (DRG) neurons are responsible for the primary detection and transmission of peripheral noxious stimuli, mainly pain and itch. However, as two distinct noxious sensations, how DRG neurons respond differently to and code pain and itch is still an attractive topic. Here, we investigate the response and activation spectrum of DRG neurons under peripheral pain and itch stimuli using in vivo two-photon calcium imaging and find differences in the response intensity to pain and itch between multisensory neurons (both pain and itch) and single-sensory neurons (either pain or itch). In addition, single-cell RNA sequencing (scRNA-seq) is used to reveal the heterogeneity of distinct subpopulations on the basis of their expressions of pain- or itch-related marker genes and to determine the similarities and differences in their transcriptomic changes under chronic pain and itch. Our results show that primary sensory neurons with different sensory patterns respond differently to the same nociceptive stimuli. Additionally, distinct clusters of neurons exhibit unique transcriptomic changes in the development of chronic pain and itch, which may offer new insights for treating these conditions.
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Affiliation(s)
- Li Liu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
| | - Jiemin Yin
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
| | - Youqiang Meng
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
- Department of Neurosurgery, Chongming Hospital Affiliated to Shanghai University of Medicine and Health Sciences, Shanghai 200127, China
| | - Congrui Ye
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
| | - Junhui Chen
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
| | - Sa Wang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
| | - Wen Yin
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
| | - Po Gao
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
| | - Yingfu Jiao
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
| | - Weifeng Yu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
| | - Yinghui Fan
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai 200127, China
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Semizoglou E, Lo Re L, Middleton SJ, Perez‐Sanchez J, Tufarelli T, Bennett DL, Chisholm KI. In vivo calcium imaging reveals directional sensitivity of C-low threshold mechanoreceptors. J Physiol 2025; 603:895-908. [PMID: 39810695 PMCID: PMC11826069 DOI: 10.1113/jp286631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 11/28/2024] [Indexed: 01/16/2025] Open
Abstract
C-low threshold mechanoreceptors (C-LTMRs) in animals (termed C-tactile (CT) fibres in humans) are a subgroup of C-fibre primary afferents, which innervate hairy skin and respond to low-threshold punctate indentations and brush stimuli. These afferents respond to gentle touch stimuli and are implicated in mediating pleasant/affective touch. These afferents have traditionally been studied using low-throughput, technically challenging approaches, including microneurography in humans and teased fibre electrophysiology in other mammals. Here we suggest a new approach to studying genetically labelled C-LTMRs using in vivo calcium imaging. We used an automated rotating brush stimulus and von Frey filaments, applied to the hairy skin of anaesthetized mice to mirror light and affective touch. Simultaneously we visualized changes in C-LTMR activity and confirmed that these neurons are sensitive to low-threshold punctate mechanical stimuli and brush stimuli with a strong preference for slow brushing speeds. We also reveal that C-LMTRs are directionally sensitive, showing more activity when brushed against the natural orientation of the hair. We present in vivo calcium imaging of genetically labelled C-LTMRs as a useful approach that can reveal new aspects of C-LTMR physiology. KEY POINTS: C-low threshold mechanoreceptors are sensitive to the directionality of a brush stimulus, being preferentially activated by brushing against the grain of the hair, compared with brushing with the grain of the hair. This is surprising as brushing against the grain of the hair is considered less pleasant. In vivo calcium imaging is a useful approach to the study of C-low threshold mechanoreceptors. While viral transfection, using systemic AAV9, is effective in labelling most sensory neuron populations in the dorsal root ganglion, it fails to label C-low threshold mechanoreceptors.
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Affiliation(s)
- Evangelia Semizoglou
- Department of NeurologyBrigham & Women's Hospital, Harvard Medical SchoolBostonUSA
| | - Laure Lo Re
- Tafalgie TherapeuticsCampus de LuminyMarseilleFrance
| | | | | | - Tommaso Tufarelli
- School of Mathematical SciencesThe University of NottinghamUniversity ParkNottinghamUK
| | - David L. Bennett
- Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
| | - Kim I. Chisholm
- School of Life SciencesThe University of NottinghamQueen's Medical CentreNottinghamUK
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Watanabe H, Shibuya S, Masuda Y, Sugi T, Saito K, Nagashima K. Spatial and temporal patterns of brain neural activity mediating human thermal sensations. Neuroscience 2025; 564:260-270. [PMID: 39586420 DOI: 10.1016/j.neuroscience.2024.11.045] [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: 02/01/2024] [Revised: 09/14/2024] [Accepted: 11/16/2024] [Indexed: 11/27/2024]
Abstract
This study aimed to elucidate the spatial and temporal patterns of brain neural activity that are associated with cold and hot sensations. Participants (n = 20) sat in a controlled room with their eyes closed and received local thermal stimuli to the right fingers using a Peltier apparatus. The thermal stimuli were repeated 40 times using a paired-thermal stimulus paradigm, comprising a 15 s-reference stimulus (32 °C), followed by 10 s-conditioned stimuli (24 °C and 40 °C, cold and hot conditions, respectively), for which 15-channel electroencephalography (EEG) signals were continuously monitored. To identify the patterns of brain neural activity, an independent component (IC) analysis was applied to the preprocessed EEG data. The equivalent current dipole locations were estimated, followed by clustering of the ICs with a dipole residual variance of <15 %. Subsequently, event-related spectral perturbations were analyzed in each identified cluster to calculate the power changes across specific frequency ranges. The right precentral gyrus, precuneus, medial frontal gyrus, middle frontal gyrus, superior frontal gyrus, cuneus, cingulate gyrus, left precentral gyrus, middle occipital gyrus, and cingulate gyrus were activated in both cold and hot conditions. In most activated regions, EEG power temporal changes were observed across the frequency ranges and were different between the two conditions. These results may suggest that cold and hot sensations are processed through different temporal brain neural activity patterns in overlapping brain regions.
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Affiliation(s)
- Hironori Watanabe
- Institute for Energy and Environmental System, Sustainable Energy and Environmental Society Open Innovation Research Organization, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 1698555, Japan; Advanced Research Center for Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 3591192, Japan; Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 3591192, Japan
| | - Satoshi Shibuya
- Department of Integrative Physiology, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo 1818611, Japan
| | - Yuta Masuda
- Laboratory of Animal Science, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5, Shimogamohangi, Kyoto, Kyoto 6068522, Japan
| | - Taisuke Sugi
- Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 3591192, Japan
| | - Kiyoshi Saito
- Institute for Energy and Environmental System, Sustainable Energy and Environmental Society Open Innovation Research Organization, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 1698555, Japan; Department of Applied Mechanics and Aerospace Engineering, School of Fundamental Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 1698555, Japan
| | - Kei Nagashima
- Institute for Energy and Environmental System, Sustainable Energy and Environmental Society Open Innovation Research Organization, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 1698555, Japan; Body Temperature and Fluid Laboratory, Faculty of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 3591192, Japan.
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Bokiniec P, Whitmire CJ, Poulet JFA. Bidirectionally responsive thermoreceptors encode cool and warm. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.11.28.625856. [PMID: 39651223 PMCID: PMC11623674 DOI: 10.1101/2024.11.28.625856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2024]
Abstract
Thermal sensation is a fundamental sense initiated by the activity of primary afferent thermoreceptors. While considerable attention has been paid to the encoding of noxious temperatures by thermoreceptors, it is far less clear how they encode innocuous cool and warm which are more commonly encountered in the environment. To address this, we sampled the entire thermoreceptor population using in vivo two-photon calcium imaging in the lumbar dorsal root ganglia of awake and anesthetized mice. We found that the vast majority of thermoreceptors respond bidirectionally, with an enhanced response to cool and a suppressed response to warm. Using in vivo pharmacology and computational modelling, we demonstrate that conductance changes in the cool-sensitive TRPM8 channel are sufficient to explain this bidirectional response type. Our comprehensive dataset reveals the fundamental principles of the peripheral encoding of innocuous temperatures and suggests that the same population of thermoreceptors underlie the distinct sensations of cool and warm.
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Frahm KS, Andersen OK, Arendt-Nielsen L, Gervasio S, Mørch CD. Topical capsaicin modulates the two-point discrimination threshold-Modulation depends on stimulation modality and intensity. Eur J Pain 2024; 28:1855-1865. [PMID: 39116004 DOI: 10.1002/ejp.4701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 06/07/2024] [Accepted: 07/04/2024] [Indexed: 08/10/2024]
Abstract
BACKGROUND Spatial acuity concerns the ability to localize and discriminate sensory input and is often tested using the two-point discrimination threshold (2PDT). Sensitization of the pain system can affect the spatial acuity, but it is unclear how 2PDTs of different testing modalities are affected. The aim was to investigate if the 2PDTs for mechanical and heat stimulation at different intensities were modulated by topical capsaicin sensitization. METHODS 30 healthy subjects were divided into either a capsaicin or a placebo group. The 2PDT was tested using two different modalities, mechanical and thermal (laser) delivered at innocuous and noxious intensities. The 2PDT were determined at baseline and re-assessed 48 h later. In the follow-up session, the subjects either had a capsaicin patch (8%) or placebo patch placed in the testing area for 30 min before re-testing the 2PDT. RESULTS The 2PDT was highly dependent on stimulation modality and intensity. The lowest 2PDT was found for innocuous mechanical stimuli (40.0 mm, 95% CI 38.1-41.9 mm), and the highest 2PDT was found for innocuous thermal stimuli (81.7 mm, 95% CI 73.9-89.5 mm). Topical capsaicin generally increased the 2PDT, but this was only significant for innocuous mechanical stimuli. The perceived intensity of the stimuli was increased following capsaicin and was generally higher for noxious stimuli than for innocuous stimuli (ANOVA, p < 0.001). CONCLUSIONS This study showed that capsaicin provoked pain sensitization increased the 2PDT. The 2PDT tested using innocuous mechanical stimuli showed less variable results indicating that this test is most suitable to detect this aspect of spatial acuity. SIGNIFICANCE STATEMENT This study investigated how the two-point discrimination threshold (2PDT) can be modulated by topical capsaicin. The 2PDT was assessed for two different modalities (thermal and mechanical) and for two different intensities (innocuous and noxious) before and after capsaicin. The results showed that the 2PDT was generally impaired following capsaicin, but this was only significant for mechanical innocuous stimuli. Furthermore, it was shown that mechanical innocuous stimuli assessed the 2PDT with lower variability than other combinations.
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Affiliation(s)
- Ken Steffen Frahm
- Integrative Neuroscience Group, CNAP-Center for Neuroplasticity and Pain, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Ole Kæseler Andersen
- Integrative Neuroscience Group, CNAP-Center for Neuroplasticity and Pain, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Lars Arendt-Nielsen
- Translational Pain Biomarkers, CNAP-Center for Neuroplasticity and Pain, SMI®, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
- Department of Gastroenterology & Hepatology, Mech-Sense, Department of Clinical Medicine, Aalborg University Hospital, Aalborg, Denmark
- Steno Diabetes Center North Denmark, Aalborg University Hospital, Aalborg, Denmark
| | - Sabata Gervasio
- Neural Engineering and Neurophysiology Group, SMI®, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Carsten Dahl Mørch
- Integrative Neuroscience Group, CNAP-Center for Neuroplasticity and Pain, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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10
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Ferron L, Harding EK, Gandini MA, Brideau C, Stys PK, Zamponi GW. Functional remodeling of presynaptic voltage-gated calcium channels in superficial layers of the dorsal horn during neuropathic pain. iScience 2024; 27:109973. [PMID: 38827405 PMCID: PMC11140212 DOI: 10.1016/j.isci.2024.109973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/29/2024] [Accepted: 05/10/2024] [Indexed: 06/04/2024] Open
Abstract
N- and P/Q-type voltage-gated Ca2+ channels are critical for synaptic transmission. While their expression is increased in the dorsal root ganglion (DRG) neuron cell bodies during neuropathic pain conditions, less is known about their synaptic remodeling. Here, we combined genetic tools with 2-photon Ca2+ imaging to explore the functional remodeling that occurs in central presynaptic terminals of DRG neurons during neuropathic pain. We imaged GCaMP6s fluorescence responses in an ex vivo spinal cord preparation from mice expressing GCaMP6s in Trpv1-Cre lineage nociceptors. We show that Ca2+ transient amplitude is increased in central terminals of these neurons after spared nerve injury, and that this increase is mediated by both N- and P/Q-type channels. We found that GABA-B receptor-dependent inhibition of Ca2+ transients was potentiated in the superficial layer of the dorsal horn. Our results provide direct evidence toward nerve injury-induced functional remodeling of presynaptic Ca2+ channels in Trpv1-lineage nociceptor terminals.
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Affiliation(s)
- Laurent Ferron
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Calgary Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Erika K. Harding
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Calgary Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Maria A. Gandini
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Calgary Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Craig Brideau
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Calgary Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Peter K. Stys
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Calgary Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Gerald W. Zamponi
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, Calgary Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
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11
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Ingram S, Chisholm KI, Wang F, De Koninck Y, Denk F, Goodwin GL. Assessing spontaneous sensory neuron activity using in vivo calcium imaging. Pain 2024; 165:1131-1141. [PMID: 38112748 PMCID: PMC11017743 DOI: 10.1097/j.pain.0000000000003116] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 09/01/2023] [Accepted: 09/23/2023] [Indexed: 12/21/2023]
Abstract
ABSTRACT Heightened spontaneous activity in sensory neurons is often reported in individuals living with chronic pain. It is possible to study this activity in rodents using electrophysiology, but these experiments require great skill and can be prone to bias. Here, we have examined whether in vivo calcium imaging with GCaMP6s can be used as an alternative approach. We show that spontaneously active calcium transients can be visualised in the fourth lumbar dorsal root ganglion (L4 DRG) through in vivo imaging in a mouse model of inflammatory pain. Application of lidocaine to the nerve, between the inflamed site and the DRG, silenced spontaneous firing and revealed the true baseline level of calcium for spontaneously active neurons. We used these data to train a machine learning algorithm to predict when a neuron is spontaneously active. We show that our algorithm is accurate in 2 different models of pain: intraplantar complete Freund adjuvant and antigen-induced arthritis, with accuracies of 90.0% ±1.2 and 85.9% ±2.1, respectively, assessed against visual inspection by an experienced observer. The algorithm can also detect neuronal activity in imaging experiments generated in a different laboratory using a different microscope configuration (accuracy = 94.0% ±2.2). We conclude that in vivo calcium imaging can be used to assess spontaneous activity in sensory neurons and provide a Google Colaboratory Notebook to allow anyone easy access to our novel analysis tool, for the assessment of spontaneous neuronal activity in their own imaging setups.
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Affiliation(s)
- Sonia Ingram
- Sonia Ingram, Data Scientist, Contract Researcher for King's College London, London, United Kingdom
| | - Kim I. Chisholm
- Pain Centre Versus Arthritis, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Feng Wang
- CERVO Brain Research Centre, Québec Mental Health Institute, Quebec City, QC, Canada
- Faculty of Dentistry, Laval University, Quebec, Canada
| | - Yves De Koninck
- CERVO Brain Research Centre, Québec Mental Health Institute, Quebec City, QC, Canada
| | - Franziska Denk
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - George L. Goodwin
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
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12
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Cai W, Zhang W, Zheng Q, Hor CC, Pan T, Fatima M, Dong X, Duan B, Xu XZS. The kainate receptor GluK2 mediates cold sensing in mice. Nat Neurosci 2024; 27:679-688. [PMID: 38467901 DOI: 10.1038/s41593-024-01585-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 01/23/2024] [Indexed: 03/13/2024]
Abstract
Thermosensors expressed in peripheral somatosensory neurons sense a wide range of environmental temperatures. While thermosensors detecting cool, warm and hot temperatures have all been extensively characterized, little is known about those sensing cold temperatures. Though several candidate cold sensors have been proposed, none has been demonstrated to mediate cold sensing in somatosensory neurons in vivo, leaving a knowledge gap in thermosensation. Here we characterized mice lacking the kainate-type glutamate receptor GluK2, a mammalian homolog of the Caenorhabditis elegans cold sensor GLR-3. While GluK2 knockout mice respond normally to heat and mechanical stimuli, they exhibit a specific deficit in sensing cold but not cool temperatures. Further analysis supports a key role for GluK2 in sensing cold temperatures in somatosensory DRG neurons in the periphery. Our results reveal that GluK2-a glutamate-sensing chemoreceptor mediating synaptic transmission in the central nervous system-is co-opted as a cold-sensing thermoreceptor in the periphery.
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Affiliation(s)
- Wei Cai
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Wenwen Zhang
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Qin Zheng
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Chia Chun Hor
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Tong Pan
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Mahar Fatima
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bo Duan
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
| | - X Z Shawn Xu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
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13
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Leva T, Whitmire CJ, Sauve I, Bokiniec P, Memler C, Horn BM, Vestergaard M, Carta M, Poulet JFA. The spatial representation of temperature in the thalamus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.13.580167. [PMID: 38405930 PMCID: PMC10888919 DOI: 10.1101/2024.02.13.580167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Although distinct thalamic nuclei encode sensory information for almost all sensory modalities, the existence of a thalamic representation of temperature is debated and the role of the thalamus in thermal perception remains unclear. To address this, we used high-density electrophysiological recordings across mouse forepaw somatosensory thalamus, and identified an anterior and a posterior representation of temperature that spans three thalamic nuclei. These parallel representations show fundamental differences in the cellular encoding of temperature that reflect their cortical output targets, with the anterior representation encoding cool only and the posterior both cool and warm. Moreover, their inactivation profoundly altered thermal perception. Together our data identifies a novel posterior thalamic representation of temperature and a principal role of the thalamus in thermal perception.
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14
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Sagalajev B, Zhang T, Abdollahi N, Yousefpour N, Medlock L, Al-Basha D, Ribeiro-da-Silva A, Esteller R, Ratté S, Prescott SA. Absence of paresthesia during high-rate spinal cord stimulation reveals importance of synchrony for sensations evoked by electrical stimulation. Neuron 2024; 112:404-420.e6. [PMID: 37972595 DOI: 10.1016/j.neuron.2023.10.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/24/2023] [Accepted: 10/18/2023] [Indexed: 11/19/2023]
Abstract
Electrically activating mechanoreceptive afferents inhibits pain. However, paresthesia evoked by spinal cord stimulation (SCS) at 40-60 Hz becomes uncomfortable at high pulse amplitudes, limiting SCS "dosage." Kilohertz-frequency SCS produces analgesia without paresthesia and is thought, therefore, not to activate afferent axons. We show that paresthesia is absent not because axons do not spike but because they spike asynchronously. In a pain patient, selectively increasing SCS frequency abolished paresthesia and epidurally recorded evoked compound action potentials (ECAPs). Dependence of ECAP amplitude on SCS frequency was reproduced in pigs, rats, and computer simulations and is explained by overdrive desynchronization: spikes desychronize when axons are stimulated faster than their refractory period. Unlike synchronous spikes, asynchronous spikes fail to produce paresthesia because their transmission to somatosensory cortex is blocked by feedforward inhibition. Our results demonstrate how stimulation frequency impacts synchrony based on axon properties and how synchrony impacts sensation based on circuit properties.
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Affiliation(s)
- Boriss Sagalajev
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Tianhe Zhang
- Boston Scientific Neuromodulation, Valencia, CA 25155, USA
| | - Nooshin Abdollahi
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Noosha Yousefpour
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Laura Medlock
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Dhekra Al-Basha
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Alfredo Ribeiro-da-Silva
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC H3G 1Y6, Canada; Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 0C7, Canada
| | | | - Stéphanie Ratté
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Steven A Prescott
- Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.
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15
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Negm A, Stobbe K, Ben Fradj S, Sanchez C, Landra-Willm A, Richter M, Fleuriot L, Debayle D, Deval E, Lingueglia E, Rovere C, Noel J. Acid-sensing ion channel 3 mediates pain hypersensitivity associated with high-fat diet consumption in mice. Pain 2024; 165:470-486. [PMID: 37733484 DOI: 10.1097/j.pain.0000000000003030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 07/07/2023] [Indexed: 09/23/2023]
Abstract
ABSTRACT Lipid-rich diet is the major cause of obesity, affecting 13% of the worldwide adult population. Obesity is a major risk factor for metabolic syndrome that includes hyperlipidemia and diabetes mellitus. The early phases of metabolic syndrome are often associated with hyperexcitability of peripheral small diameter sensory fibers and painful diabetic neuropathy. Here, we investigated the effect of high-fat diet-induced obesity on the activity of dorsal root ganglion (DRG) sensory neurons and pain perception. We deciphered the underlying cellular mechanisms involving the acid-sensing ion channel 3 (ASIC3). We show that mice made obese through consuming high-fat diet developed the metabolic syndrome and prediabetes that was associated with heat pain hypersensitivity, whereas mechanical sensitivity was not affected. Concurrently, the slow conducting C fibers in the skin of obese mice showed increased activity on heating, whereas their mechanosensitivity was not altered. Although ASIC3 knockout mice fed with high-fat diet became obese, and showed signs of metabolic syndrome and prediabetes, genetic deletion, and in vivo pharmacological inhibition of ASIC3, protected mice from obesity-induced thermal hypersensitivity. We then deciphered the mechanisms involved in the heat hypersensitivity of mice and found that serum from high-fat diet-fed mice was enriched in lysophosphatidylcholine (LPC16:0, LPC18:0, and LPC18:1). These enriched lipid species directly increased the activity of DRG neurons through activating the lipid sensitive ASIC3 channel. Our results identify ASIC3 channel in DRG neurons and circulating lipid species as a mechanism contributing to the hyperexcitability of nociceptive neurons that can cause pain associated with lipid-rich diet consumption and obesity.
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Affiliation(s)
- Ahmed Negm
- Université Côte d'Azur, CNRS, IPMC, LabEx ICST, FHU InovPain, Valbonne, France. Negm is now with the Université Clermont-Auvergne, Laboratoire Neurodol, UMR 1107 Inserm, Clermont-Ferrand, France
| | - Katharina Stobbe
- Université Côte d'Azur, CNRS, IPMC, LabEx SIGNALIFE, Valbonne, France
| | - Selma Ben Fradj
- Université Côte d'Azur, CNRS, IPMC, LabEx SIGNALIFE, Valbonne, France
| | - Clara Sanchez
- Université Côte d'Azur, CNRS, IPMC, LabEx SIGNALIFE, Valbonne, France
| | - Arnaud Landra-Willm
- Université Côte d'Azur, CNRS, IPMC, LabEx ICST, FHU InovPain, Valbonne, France. Negm is now with the Université Clermont-Auvergne, Laboratoire Neurodol, UMR 1107 Inserm, Clermont-Ferrand, France
| | - Margaux Richter
- Université Côte d'Azur, CNRS, IPMC, LabEx ICST, FHU InovPain, Valbonne, France. Negm is now with the Université Clermont-Auvergne, Laboratoire Neurodol, UMR 1107 Inserm, Clermont-Ferrand, France
| | | | | | - Emmanuel Deval
- Université Côte d'Azur, CNRS, IPMC, LabEx ICST, FHU InovPain, Valbonne, France. Negm is now with the Université Clermont-Auvergne, Laboratoire Neurodol, UMR 1107 Inserm, Clermont-Ferrand, France
| | - Eric Lingueglia
- Université Côte d'Azur, CNRS, IPMC, LabEx ICST, FHU InovPain, Valbonne, France. Negm is now with the Université Clermont-Auvergne, Laboratoire Neurodol, UMR 1107 Inserm, Clermont-Ferrand, France
| | - Carole Rovere
- Université Côte d'Azur, CNRS, IPMC, LabEx SIGNALIFE, Valbonne, France
| | - Jacques Noel
- Université Côte d'Azur, CNRS, IPMC, LabEx ICST, FHU InovPain, Valbonne, France. Negm is now with the Université Clermont-Auvergne, Laboratoire Neurodol, UMR 1107 Inserm, Clermont-Ferrand, France
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16
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Jager SE, Goodwin G, Chisholm KI, Denk F. In vivo calcium imaging shows that satellite glial cells have increased activity in painful states. Brain Commun 2024; 6:fcae013. [PMID: 38638153 PMCID: PMC11024818 DOI: 10.1093/braincomms/fcae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 11/22/2023] [Accepted: 01/17/2024] [Indexed: 04/20/2024] Open
Abstract
Satellite glial cells are important for proper neuronal function of primary sensory neurons for which they provide homeostatic support. Most research on satellite glial cell function has been performed with in vitro studies, but recent advances in calcium imaging and transgenic mouse models have enabled this first in vivo study of single-cell satellite glial cell function in mouse models of inflammation and neuropathic pain. We found that in naïve conditions, satellite glial cells do not respond in a time-locked fashion to neuronal firing. In painful inflammatory and neuropathic states, we detected time-locked signals in a subset of satellite glial cells, but only with suprathreshold stimulation of the sciatic nerve. Surprisingly, therefore, we conclude that most calcium signals in satellite glial cells seem to develop at arbitrary intervals not directly linked to neuronal activity patterns. More in line with expectations, our experiments also revealed that the number of active satellite glial cells was increased under conditions of inflammation or nerve injury. This could reflect the increased requirement for homeostatic support across dorsal root ganglion neuron populations, which are more active during such painful states.
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Affiliation(s)
- Sara E Jager
- Wolfson Centre for Age-related Diseases, King’s College London, Guy’s Campus, London SE1 1UL, UK
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - George Goodwin
- Wolfson Centre for Age-related Diseases, King’s College London, Guy’s Campus, London SE1 1UL, UK
| | - Kim I Chisholm
- Pain Centre Versus Arthritis, School of Life Sciences, University of Nottingham, Nottingham NG5 1PB, UK
| | - Franziska Denk
- Wolfson Centre for Age-related Diseases, King’s College London, Guy’s Campus, London SE1 1UL, UK
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17
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Eto K, Cheung DL, Nabekura J. Sensory Processing of Cutaneous Temperature in the Peripheral and Central Nervous System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1461:127-137. [PMID: 39289278 DOI: 10.1007/978-981-97-4584-5_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2024]
Abstract
Thermal perception is critical for sensing environmental temperature, keeping body temperature consistent, and avoiding thermal danger. Central to thermal perception is the detection of cutaneous (skin) temperature information by the peripheral nerves and its transmission to the spinal cord, thalamus, and downstream cortical areas including the insular cortex, primary somatosensory cortex, and secondary somatosensory cortex. Although much is still unknown about this process, advances in technology have enabled significant progress to be made in recent years.This chapter summarizes our current understanding of how the peripheral nerves, spinal cord, and brain process cutaneous temperature information to give rise to conscious thermal perception.
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Affiliation(s)
- Kei Eto
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Japan.
- Department of Physiology, School of Allied Health Sciences, Kitasato University, Tokyo, Japan.
| | - Dennis Lawrence Cheung
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, Japan
- Department of Physiological Sciences, The Graduate School for Advanced Study, Okazaki, Japan
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18
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Keramidis I, McAllister BB, Bourbonnais J, Wang F, Isabel D, Rezaei E, Sansonetti R, Degagne P, Hamel JP, Nazari M, Inayat S, Dudley JC, Barbeau A, Froux L, Paquet ME, Godin AG, Mohajerani MH, De Koninck Y. Restoring neuronal chloride extrusion reverses cognitive decline linked to Alzheimer's disease mutations. Brain 2023; 146:4903-4915. [PMID: 37551444 PMCID: PMC10690023 DOI: 10.1093/brain/awad250] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/23/2023] [Accepted: 07/09/2023] [Indexed: 08/09/2023] Open
Abstract
Disinhibition during early stages of Alzheimer's disease is postulated to cause network dysfunction and hyperexcitability leading to cognitive deficits. However, the underlying molecular mechanism remains unknown. Here we show that, in mouse lines carrying Alzheimer's disease-related mutations, a loss of neuronal membrane potassium-chloride cotransporter KCC2, responsible for maintaining the robustness of GABAA-mediated inhibition, occurs pre-symptomatically in the hippocampus and prefrontal cortex. KCC2 downregulation was inversely correlated with the age-dependent increase in amyloid-β 42 (Aβ42). Acute administration of Aβ42 caused a downregulation of membrane KCC2. Loss of KCC2 resulted in impaired chloride homeostasis. Preventing the decrease in KCC2 using long term treatment with CLP290 protected against deterioration of learning and cortical hyperactivity. In addition, restoring KCC2, using short term CLP290 treatment, following the transporter reduction effectively reversed spatial memory deficits and social dysfunction, linking chloride dysregulation with Alzheimer's disease-related cognitive decline. These results reveal KCC2 hypofunction as a viable target for treatment of Alzheimer's disease-related cognitive decline; they confirm target engagement, where the therapeutic intervention takes place, and its effectiveness.
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Affiliation(s)
- Iason Keramidis
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Graduate Program in Neuroscience, Faculty of Medicine, Université Laval, Québec, QC G1V 0A6, Canada
| | - Brendan B McAllister
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Julien Bourbonnais
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Feng Wang
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Faculty of Dentistry, Université Laval, Québec, QC G1V 0A6, Canada
| | - Dominique Isabel
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Edris Rezaei
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Romain Sansonetti
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Phil Degagne
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Justin P Hamel
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Mojtaba Nazari
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Samsoon Inayat
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Jordan C Dudley
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Annie Barbeau
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Lionel Froux
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
| | - Marie-Eve Paquet
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Department of Biochemistry, Microbiology, and Bio-informatics, Université Laval, Québec, QC G1V 0A6, Canada
| | - Antoine G Godin
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Graduate Program in Neuroscience, Faculty of Medicine, Université Laval, Québec, QC G1V 0A6, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec, QC G1V 0A6, Canada
| | - Majid H Mohajerani
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Yves De Koninck
- CERVO Brain Research Centre, Quebec Mental Health Institute, Québec, QC G1E 1T2, Canada
- Graduate Program in Neuroscience, Faculty of Medicine, Université Laval, Québec, QC G1V 0A6, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec, QC G1V 0A6, Canada
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19
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Haroun R, Gossage SJ, Luiz AP, Arcangeletti M, Sikandar S, Zhao J, Cox JJ, Wood JN. Chemogenetic Silencing of Na V1.8-Positive Sensory Neurons Reverses Chronic Neuropathic and Bone Cancer Pain in FLEx PSAM 4-GlyR Mice. eNeuro 2023; 10:ENEURO.0151-23.2023. [PMID: 37679042 PMCID: PMC10523839 DOI: 10.1523/eneuro.0151-23.2023] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/15/2023] [Accepted: 08/23/2023] [Indexed: 09/09/2023] Open
Abstract
Drive from peripheral neurons is essential in almost all pain states, but pharmacological silencing of these neurons to effect analgesia has proved problematic. Reversible gene therapy using long-lived chemogenetic approaches is an appealing option. We used the genetically activated chloride channel PSAM4-GlyR to examine pain pathways in mice. Using recombinant AAV9-based delivery to sensory neurons, we found a reversal of acute pain behavior and diminished neuronal activity using in vitro and in vivo GCaMP imaging on activation of PSAM4-GlyR with varenicline. A significant reduction in inflammatory heat hyperalgesia and oxaliplatin-induced cold allodynia was also observed. Importantly, there was no impairment of motor coordination, but innocuous von Frey sensation was inhibited. We generated a transgenic mouse that expresses a CAG-driven FLExed PSAM4-GlyR downstream of the Rosa26 locus that requires Cre recombinase to enable the expression of PSAM4-GlyR and tdTomato. We used NaV1.8 Cre to examine the role of predominantly nociceptive NaV1.8+ neurons in cancer-induced bone pain (CIBP) and neuropathic pain caused by chronic constriction injury (CCI). Varenicline activation of PSAM4-GlyR in NaV1.8-positive neurons reversed CCI-driven mechanical, thermal, and cold sensitivity. Additionally, varenicline treatment of mice with CIBP expressing PSAM4-GlyR in NaV1.8+ sensory neurons reversed cancer pain as assessed by weight-bearing. Moreover, when these mice were subjected to acute pain assays, an elevation in withdrawal thresholds to noxious mechanical and thermal stimuli was detected, but innocuous mechanical sensations remained unaffected. These studies confirm the utility of PSAM4-GlyR chemogenetic silencing in chronic pain states for mechanistic analysis and potential future therapeutic use.
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Affiliation(s)
- Rayan Haroun
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London WC1E 6BT, United Kingdom
| | - Samuel J Gossage
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London WC1E 6BT, United Kingdom
| | - Ana Paula Luiz
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London WC1E 6BT, United Kingdom
| | - Manuel Arcangeletti
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London WC1E 6BT, United Kingdom
| | - Shafaq Sikandar
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Jing Zhao
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London WC1E 6BT, United Kingdom
| | - James J Cox
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London WC1E 6BT, United Kingdom
| | - John N Wood
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, London WC1E 6BT, United Kingdom
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20
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Huerta TS, Haider B, Adamovich-Zeitlin R, Chen AC, Chaudhry S, Zanos TP, Chavan SS, Tracey KJ, Chang EH. Calcium imaging and analysis of the jugular-nodose ganglia enables identification of distinct vagal sensory neuron subsets. J Neural Eng 2023; 20:10.1088/1741-2552/acbe1e. [PMID: 36920156 PMCID: PMC10790314 DOI: 10.1088/1741-2552/acbe1e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 02/22/2023] [Indexed: 03/16/2023]
Abstract
Objective.Sensory nerves of the peripheral nervous system (PNS) transmit afferent signals from the body to the brain. These peripheral nerves are composed of distinct subsets of fibers and associated cell bodies, which reside in peripheral ganglia distributed throughout the viscera and along the spinal cord. The vagus nerve (cranial nerve X) is a complex polymodal nerve that transmits a wide array of sensory information, including signals related to mechanical, chemical, and noxious stimuli. To understand how stimuli applied to the vagus nerve are encoded by vagal sensory neurons in the jugular-nodose ganglia, we developed a framework for micro-endoscopic calcium imaging and analysis.Approach.We developed novel methods forin vivoimaging of the intact jugular-nodose ganglion using a miniature microscope (Miniscope) in transgenic mice with the genetically-encoded calcium indicator GCaMP6f. We adapted the Python-based analysis package Calcium Imaging Analysis (CaImAn) to process the resulting one-photon fluorescence data into calcium transients for subsequent analysis. Random forest classification was then used to identify specific types of neuronal responders.Results.We demonstrate that recordings from the jugular-nodose ganglia can be accomplished through careful surgical dissection and ganglia stabilization. Using a customized acquisition and analysis pipeline, we show that subsets of vagal sensory neurons respond to different chemical stimuli applied to the vagus nerve. Successful classification of the responses with a random forest model indicates that certain calcium transient features, such as amplitude and duration, are important for encoding these stimuli by sensory neurons.Significance.This experimental approach presents a new framework for investigating how individual vagal sensory neurons encode various stimuli on the vagus nerve. Our surgical and analytical approach can be applied to other PNS ganglia in rodents and other small animal species to elucidate previously unexplored roles for peripheral neurons in a diverse set of physiological functions.
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Affiliation(s)
- Tomás S Huerta
- Laboratory for Biomedical Sciences, Institute for Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States of America
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States of America
| | - Bilal Haider
- Laboratory for Biomedical Sciences, Institute for Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States of America
| | - Richard Adamovich-Zeitlin
- Laboratory for Biomedical Sciences, Institute for Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States of America
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States of America
| | - Adrian C Chen
- Laboratory for Biomedical Sciences, Institute for Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States of America
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States of America
| | - Saher Chaudhry
- Laboratory for Biomedical Sciences, Institute for Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States of America
| | - Theodoros P Zanos
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States of America
- Institute of Health System Science, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States of America
- Elmezzi Graduate School of Molecular Medicine, Manhasset, NY, United States of America
| | - Sangeeta S Chavan
- Laboratory for Biomedical Sciences, Institute for Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States of America
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States of America
- Elmezzi Graduate School of Molecular Medicine, Manhasset, NY, United States of America
| | - Kevin J Tracey
- Laboratory for Biomedical Sciences, Institute for Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States of America
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States of America
- Elmezzi Graduate School of Molecular Medicine, Manhasset, NY, United States of America
| | - Eric H Chang
- Laboratory for Biomedical Sciences, Institute for Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, United States of America
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States of America
- Elmezzi Graduate School of Molecular Medicine, Manhasset, NY, United States of America
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21
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Vestergaard M, Carta M, Güney G, Poulet JFA. The cellular coding of temperature in the mammalian cortex. Nature 2023; 614:725-731. [PMID: 36755097 PMCID: PMC9946826 DOI: 10.1038/s41586-023-05705-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 01/04/2023] [Indexed: 02/10/2023]
Abstract
Temperature is a fundamental sensory modality separate from touch, with dedicated receptor channels and primary afferent neurons for cool and warm1-3. Unlike for other modalities, however, the cortical encoding of temperature remains unknown, with very few cortical neurons reported that respond to non-painful temperature, and the presence of a 'thermal cortex' is debated4-8. Here, using widefield and two-photon calcium imaging in the mouse forepaw system, we identify cortical neurons that respond to cooling and/or warming with distinct spatial and temporal response properties. We observed a representation of cool, but not warm, in the primary somatosensory cortex, but cool and warm in the posterior insular cortex (pIC). The representation of thermal information in pIC is robust and somatotopically arranged, and reversible manipulations show a profound impact on thermal perception. Despite being positioned along the same one-dimensional sensory axis, the encoding of cool and that of warm are distinct, both in highly and broadly tuned neurons. Together, our results show that pIC contains the primary cortical representation of skin temperature and may help explain how the thermal system generates sensations of cool and warm.
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Affiliation(s)
- M Vestergaard
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany.
| | - M Carta
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany.
- Univ. Bordeaux, CNRS, IINS, UMR 5297, Bordeaux, France.
| | - G Güney
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Humboldt-Universität zu Berlin, Institut für Biologie, Berlin, Germany
| | - J F A Poulet
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany.
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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22
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Encoding of inflammatory hyperalgesia in mouse spinal cord. Pain 2023; 164:443-460. [PMID: 36149026 DOI: 10.1097/j.pain.0000000000002727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/21/2022] [Indexed: 02/06/2023]
Abstract
ABSTRACT Inflammation modifies the input-output properties of peripheral nociceptive neurons such that the same stimulus produces enhanced nociceptive firing. This increased nociceptive output enters the superficial dorsal spinal cord (SDH), an intricate neuronal network composed largely of excitatory and inhibitory interneurons and a small percentage of projection neurons. The SDH network comprises the first central nervous system network integrating noxious information. Using in vivo calcium imaging and a computational approach, we characterized the responsiveness of the SDH network in mice to noxious stimuli in normal conditions and investigated the changes in SDH response patterns after acute burn injury-induced inflammation. We show that the application of noxious heat stimuli to the hind paw of naïve mice results in an overall increase in SDH network activity. Single-cell response analysis reveals that 70% of recorded neurons increase or suppress their activity, while ∼30% of neurons remain nonresponsive. After acute burn injury and the development of inflammatory hyperalgesia, application of the same noxious heat stimuli leads to the activation of previously nonresponding neurons and desuppression of suppressed neurons. We further demonstrate that an increase in afferent activity mimics the response of the SDH network to noxious heat stimuli under inflammatory conditions. Using a computational model of the SDH network, we predict that the changes in SDH network activity result in overall increased activity of excitatory neurons, amplifying the output from SDH to higher brain centers. We suggest that during acute local peripheral inflammation, the SDH network undergoes dynamic changes promoting hyperalgesia.
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23
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Zhou Q, Liu C, Chen T, Liu Y, Cao R, Ni X, Yang WZ, Shen Q, Sun H, Shen WL. Cooling-activated dorsomedial hypothalamic BDNF neurons control cold defense in mice. J Neurochem 2022; 163:220-232. [PMID: 35862478 DOI: 10.1111/jnc.15666] [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: 06/17/2021] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 12/30/2022]
Abstract
BDNF and its expressing neurons in the brain critically control feeding and energy expenditure (EE) in both rodents and humans. However, whether BDNF neurons would function in thermoregulation during temperature challenges is unclear. Here, we show that BDNF neurons in the dorsomedial hypothalamus (DMHBDNF ) of mice are activated by afferent cooling signals. These cooling-activated BDNF neurons are mainly GABAergic. Activation of DMHBDNF neurons or the GABAergic subpopulations is sufficient to increase body temperature, EE, and physical activity. Conversely, blocking DMHBDNF neurons substantially impairs cold defense and reduces energy expenditure, physical activity, and UCP1 expression in BAT, which eventually results in bodyweight gain and glucose/insulin intolerance. Therefore, we identify a subset of DMHBDNF neurons as a novel type of cooling-activated neurons to promote cold defense. Thus, we reveal a critical role of BDNF circuitry in thermoregulation, which deepens our understanding of BDNF in controlling energy homeostasis and obesity.
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Affiliation(s)
- Qian Zhou
- School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Changhao Liu
- School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Ting Chen
- School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Yanyang Liu
- Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Ren Cao
- School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Xinyan Ni
- School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Wen Z Yang
- School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Qiwei Shen
- Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Hongbin Sun
- School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Wei L Shen
- School of Life Science and Technology, Shanghaitech University, Shanghai, China
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24
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Abstract
Sleep is a fundamental, evolutionarily conserved, plastic behavior that is regulated by circadian and homeostatic mechanisms as well as genetic factors and environmental factors, such as light, humidity, and temperature. Among environmental cues, temperature plays an important role in the regulation of sleep. This review presents an overview of thermoreception in animals and the neural circuits that link this process to sleep. Understanding the influence of temperature on sleep can provide insight into basic physiologic processes that are required for survival and guide strategies to manage sleep disorders.
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25
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Li J, Li S, Yu L, Wei J, Li S, Tan H. The Effects of Resistin Gene Polymorphism on Pain Thresholds and Postoperative Sufentanil Consumption in Gastric Cancer Patients. J Pain Res 2022; 15:1995-2004. [PMID: 35873952 PMCID: PMC9304898 DOI: 10.2147/jpr.s372845] [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: 04/29/2022] [Accepted: 07/06/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose As an adipocyte-secreted hormone, resistin is linked to inflammation, insulin resistance and atherosclerosis. Currently, resistin is proposed as a novel biomarker for postoperative pain intensity. However, due to the various types of surgery and limited numbers of studies, previous conclusions should be validated. This study aimed to explore the effect of resistin polymorphism (rs3745367) on pain thresholds and sufentanil consumption in gastric cancer patients. Patients and Methods A total of 148 gastric cancer patients enrolled in this study had their pain thresholds measured before surgery. After the exclusion of 16 patients, the characteristics of demography and clinic, numerical rating scale (NRS) and sufentanil consumption of 132 patients were recorded. Rs3745367 of resistin was identified by Sanger sequencing. Multivariate linear regression analysis was performed for sufentanil consumption and mechanical pain threshold. Results The distributions of the GG, AG, and AA genotypes of rs3745367 among the participants were 54 (40.9%), 65 (49.2%), and 13 (9.9%), respectively. The mechanical pain threshold (P=0.04) and postoperative sufentanil consumption in the 1st 24 h (P=0.03) were significantly different among GG, AG, and AA genotype carriers. There was no significant difference among the three genotypes for the heat pain threshold and cold pain threshold. Regarding the NRS, no statistically significant difference among the three different genotypes was found 24 h postoperatively. Conclusion Rs3745367 of resistin is associated with the mechanical pain threshold and postoperative sufentanil consumption in gastric cancer patients. Patients with the AA genotype of rs3745367 present an increased mechanical pain threshold and decreased postoperative sufentanil consumption.
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Affiliation(s)
- Jianing Li
- Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, People's Republic of China
| | - Shuo Li
- Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, People's Republic of China
| | - Ling Yu
- Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, People's Republic of China
| | - Jin Wei
- Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, People's Republic of China
| | - Shuang Li
- Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, People's Republic of China
| | - Hongyu Tan
- Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, People's Republic of China
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26
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Schaldemose EL, Andersen NT, Finnerup NB, Fardo F. When cooling of the skin is perceived as warmth: Enhanced paradoxical heat sensation by pre-cooling of the skin in healthy individuals. Temperature (Austin) 2022; 10:248-263. [PMID: 37332303 PMCID: PMC10274555 DOI: 10.1080/23328940.2022.2088028] [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: 02/25/2022] [Revised: 05/25/2022] [Accepted: 06/06/2022] [Indexed: 10/17/2022] Open
Abstract
A paradoxical heat sensation (PHS) is the misperception of warmth when the skin is cooled. PHS is uncommon in healthy individuals but common in patients with neuropathy and is associated with reduced thermal sensitivity. Identifying conditions that contribute to PHS may indirectly help us understand why some patients experience PHS. We hypothesized that pre-warming increased the number of PHS and that pre-cooling had minimal effect on PHS. We tested 100 healthy participants' thermal sensitivity on the dorsum of their feet by measuring detection and pain thresholds to cold and warm stimuli and PHS. PHS was measured using the thermal sensory limen (TSL) procedure from the quantitative sensory testing protocol of the German Research Network on Neuropathic Pain and by using a modified TSL protocol (mTSL). In the mTSL we examined the participants' thermal detection and PHS after pre-warming of 38°C and 44°C and pre-cooling of 26°C and 20°C. Compared to a baseline condition, the number of PHS responders was significantly increased after pre-cooling (20°C: RR = 1.9 (1.1; 3.3), p = 0.023 and 26°C: RR = 1.9 (1.2; 3.2), p = 0.017), but not significantly after pre-warming (38°C: RR = 1.5 (0.86; 2.8), p = 0.21 and 44°C: RR = 1.7 (.995; 2.9), p = 0.078). Pre-warming and pre-cooling increased the detection threshold of both cold and warm temperatures. We discussed these findings in relation to thermal sensory mechanisms and possible PHS mechanisms. In conclusion, PHS and thermosensation are closely related and pre-cooling can induce PHS responses in healthy individuals.
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Affiliation(s)
- Ellen L. Schaldemose
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Niels T. Andersen
- Biostatistics, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Nanna B. Finnerup
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Francesca Fardo
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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27
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Ma W, Sapio MR, Manalo AP, Maric D, Dougherty MK, Goto T, Mannes AJ, Iadarola MJ. Anatomical Analysis of Transient Potential Vanilloid Receptor 1 (Trpv1+) and Mu-Opioid Receptor (Oprm1+) Co-expression in Rat Dorsal Root Ganglion Neurons. Front Mol Neurosci 2022; 15:926596. [PMID: 35875671 PMCID: PMC9302591 DOI: 10.3389/fnmol.2022.926596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/09/2022] [Indexed: 11/29/2022] Open
Abstract
Primary afferent neurons of the dorsal root ganglia (DRG) transduce peripheral nociceptive signals and transmit them to the spinal cord. These neurons also mediate analgesic control of the nociceptive inputs, particularly through the μ-opioid receptor (encoded by Oprm1). While opioid receptors are found throughout the neuraxis and in the spinal cord tissue itself, intrathecal administration of μ-opioid agonists also acts directly on nociceptive nerve terminals in the dorsal spinal cord resulting in marked analgesia. Additionally, selective chemoaxotomy of cells expressing the TRPV1 channel, a nonselective calcium-permeable ion channel that transduces thermal and inflammatory pain, yields profound pain relief in rats, canines, and humans. However, the relationship between Oprm1 and Trpv1 expressing DRG neurons has not been precisely determined. The present study examines rat DRG neurons using high resolution multiplex fluorescent in situ hybridization to visualize molecular co-expression. Neurons positive for Trpv1 exhibited varying levels of expression for Trpv1 and co-expression of other excitatory and inhibitory ion channels or receptors. A subpopulation of densely labeled Trpv1+ neurons did not co-express Oprm1. In contrast, a population of less densely labeled Trpv1+ neurons did co-express Oprm1. This finding suggests that the medium/low Trpv1 expressing neurons represent a specific set of DRG neurons subserving the opponent processes of both transducing and inhibiting nociceptive inputs. Additionally, the medium/low Trpv1 expressing neurons co-expressed other markers implicated in pathological pain states, such as Trpa1 and Trpm8, which are involved in chemical nociception and cold allodynia, respectively, as well as Scn11a, whose mutations are implicated in familial episodic pain. Conversely, none of the Trpv1+ neurons co-expressed Spp1, which codes for osteopontin, a marker for large diameter proprioceptive neurons, validating that nociception and proprioception are governed by separate neuronal populations. Our findings support the hypothesis that the population of Trpv1 and Oprm1 coexpressing neurons may explain the remarkable efficacy of opioid drugs administered at the level of the DRG-spinal synapse, and that this subpopulation of Trpv1+ neurons is responsible for registering tissue damage.
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Affiliation(s)
- Wenting Ma
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Matthew R. Sapio
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Allison P. Manalo
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Dragan Maric
- National Institute of Neurological Disorders and Stroke, Flow and Imaging Cytometry Core Facility, Bethesda, MD, United States
| | - Mary Kate Dougherty
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Taichi Goto
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States
- Symptoms Biology Unit, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Andrew J. Mannes
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States
| | - Michael J. Iadarola
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, United States
- *Correspondence: Michael J. Iadarola
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28
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Goodwin G, McMurray S, Stevens EB, Denk F, McMahon SB. Examination of the contribution of Nav1.7 to axonal propagation in nociceptors. Pain 2022; 163:e869-e881. [PMID: 34561392 DOI: 10.1097/j.pain.0000000000002490] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/09/2021] [Indexed: 11/25/2022]
Abstract
ABSTRACT Nav1.7 is a promising drug target for the treatment of pain. However, there is a mismatch between the analgesia produced by Nav1.7 loss-of-function and the peripherally restricted Nav1.7 inhibitors, which may reflect a lack of understanding of the function of Nav1.7 in the transmission of nociceptive information. In the periphery, the role of Nav1.7 in transduction at nociceptive peripheral terminals has been comprehensively examined, but its role in axonal propagation in these neurons is less clearly defined. In this study, we examined the contribution of Nav1.7 to axonal propagation in nociceptors using sodium channel blockers in in vivo electrophysiological and calcium imaging recordings in mice. Using the sodium channel blocker tetrodotoxin (TTX) (1-10 µM) to inhibit Nav1.7 and other tetrodotoxin-sensitive sodium channels along the sciatic nerve, we first showed that around two-thirds of nociceptive L4 dorsal root ganglion neurons innervating the skin, but a lower proportion innervating the muscle (45%), are blocked by TTX. By contrast, nearly all large-sized cutaneous afferents (95%-100%) were blocked by axonal TTX. Many cutaneous nociceptors resistant to TTX were polymodal (57%) and capsaicin sensitive (57%). Next, we applied PF-05198007 (300 nM-1 µM) to the sciatic nerve between stimulating and recording sites to selectively block axonal Nav1.7 channels. One hundred to three hundred nanomolar PF-05198007 blocked propagation in 63% of C-fiber sensory neurons, whereas similar concentrations produced minimal block (5%) in rapidly conducting A-fiber neurons. We conclude that Nav1.7 is essential for axonal propagation in around two-thirds of nociceptive cutaneous C-fiber neurons and a lower proportion (≤45%) of nociceptive neurons innervating muscle.
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Affiliation(s)
- George Goodwin
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, United Kingdom
| | | | | | - Franziska Denk
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, United Kingdom
| | - Stephen B McMahon
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, United Kingdom
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29
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Wong C, Barkai O, Wang F, Thörn Pérez C, Lev S, Cai W, Tansley S, Yousefpour N, Hooshmandi M, Lister KC, Latif M, Cuello AC, Prager-Khoutorsky M, Mogil JS, Séguéla P, De Koninck Y, Ribeiro-da-Silva A, Binshtok AM, Khoutorsky A. mTORC2 mediates structural plasticity in distal nociceptive endings that contributes to pain hypersensitivity following inflammation. J Clin Invest 2022; 132:152635. [PMID: 35579957 PMCID: PMC9337825 DOI: 10.1172/jci152635] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 05/13/2022] [Indexed: 11/29/2022] Open
Abstract
The encoding of noxious stimuli into action potential firing is largely mediated by nociceptive free nerve endings. Tissue inflammation, by changing the intrinsic properties of the nociceptive endings, leads to nociceptive hyperexcitability and thus to the development of inflammatory pain. Here, we showed that tissue inflammation–induced activation of the mammalian target of rapamycin complex 2 (mTORC2) triggers changes in the architecture of nociceptive terminals and leads to inflammatory pain. Pharmacological activation of mTORC2 induced elongation and branching of nociceptor peripheral endings and caused long-lasting pain hypersensitivity. Conversely, nociceptor-specific deletion of the mTORC2 regulatory protein rapamycin-insensitive companion of mTOR (Rictor) prevented inflammation-induced elongation and branching of cutaneous nociceptive fibers and attenuated inflammatory pain hypersensitivity. Computational modeling demonstrated that mTORC2-mediated structural changes in the nociceptive terminal tree are sufficient to increase the excitability of nociceptors. Targeting mTORC2 using a single injection of antisense oligonucleotide against Rictor provided long-lasting alleviation of inflammatory pain hypersensitivity. Collectively, we showed that tissue inflammation–induced activation of mTORC2 causes structural plasticity of nociceptive free nerve endings in the epidermis and inflammatory hyperalgesia, representing a therapeutic target for inflammatory pain.
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Affiliation(s)
- Calvin Wong
- Department of Anesthesia, McGill University, Montreal, Canada
| | - Omer Barkai
- Department of Medical Neurobiology, The Hebrew University, Jerusalem, Israel
| | - Feng Wang
- Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Canada
| | | | - Shaya Lev
- Department of Medical Neurobiology, The Hebrew University, Jerusalem, Israel
| | - Weihua Cai
- Department of Anesthesia, McGill University, Montreal, Canada
| | - Shannon Tansley
- Department of Psychology, McGill University, Montreal, Canada
| | - Noosha Yousefpour
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | | | - Kevin C Lister
- Department of Anesthesia, McGill University, Montreal, Canada
| | - Mariam Latif
- Department of Anesthesia, McGill University, Montreal, Canada
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | | | - Jeffrey S Mogil
- Department of Psychology, McGill University, Montreal, Canada
| | - Philippe Séguéla
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Yves De Koninck
- Department of Psychiatry and Neuroscience, Université Laval, Quebec City, Canada
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30
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Wang H, Chen W, Dong Z, Xing G, Cui W, Yao L, Zou WJ, Robinson HL, Bian Y, Liu Z, Zhao K, Luo B, Gao N, Zhang H, Ren X, Yu Z, Meixiong J, Xiong WC, Mei L. A novel spinal neuron connection for heat sensation. Neuron 2022; 110:2315-2333.e6. [PMID: 35561677 DOI: 10.1016/j.neuron.2022.04.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 03/14/2022] [Accepted: 04/19/2022] [Indexed: 12/30/2022]
Abstract
Heat perception enables acute avoidance responses to prevent tissue damage and maintain body thermal homeostasis. Unlike other modalities, how heat signals are processed in the spinal cord remains unclear. By single-cell gene profiling, we identified ErbB4, a transmembrane tyrosine kinase, as a novel marker of heat-sensitive spinal neurons in mice. Ablating spinal ErbB4+ neurons attenuates heat sensation. These neurons receive monosynaptic inputs from TRPV1+ nociceptors and form excitatory synapses onto target neurons. Activation of ErbB4+ neurons enhances the heat response, while inhibition reduces the heat response. We showed that heat sensation is regulated by NRG1, an activator of ErbB4, and it involves dynamic activity of the tyrosine kinase that promotes glutamatergic transmission. Evidence indicates that the NRG1-ErbB4 signaling is also engaged in hypersensitivity of pathological pain. Together, these results identify a spinal neuron connection consisting of ErbB4+ neurons for heat sensation and reveal a regulatory mechanism by the NRG1-ErbB4 signaling.
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Affiliation(s)
- Hongsheng Wang
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Wenbing Chen
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Zhaoqi Dong
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Guanglin Xing
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Wanpeng Cui
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Lingling Yao
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Wen-Jun Zou
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Heath L Robinson
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Yaoyao Bian
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Zhipeng Liu
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Kai Zhao
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Bin Luo
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Nannan Gao
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Hongsheng Zhang
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Xiao Ren
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Zheng Yu
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - James Meixiong
- Solomon H. Snyder Department of Neuroscience and Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Wen-Cheng Xiong
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA
| | - Lin Mei
- Department of Neurosciences, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA; Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH 44106, USA.
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31
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Graham RD, Sankarasubramanian V, Lempka SF. Dorsal Root Ganglion Stimulation for Chronic Pain: Hypothesized Mechanisms of Action. THE JOURNAL OF PAIN 2022; 23:196-211. [PMID: 34425252 PMCID: PMC8943693 DOI: 10.1016/j.jpain.2021.07.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/28/2021] [Accepted: 07/20/2021] [Indexed: 02/03/2023]
Abstract
Dorsal root ganglion stimulation (DRGS) is a neuromodulation therapy for chronic pain that is refractory to conventional medical management. Currently, the mechanisms of action of DRGS-induced pain relief are unknown, precluding both our understanding of why DRGS fails to provide pain relief to some patients and the design of neurostimulation technologies that directly target these mechanisms to maximize pain relief in all patients. Due to the heterogeneity of sensory neurons in the dorsal root ganglion (DRG), the analgesic mechanisms could be attributed to the modulation of one or many cell types within the DRG and the numerous brain regions that process sensory information. Here, we summarize the leading hypotheses of the mechanisms of DRGS-induced analgesia, and propose areas of future study that will be vital to improving the clinical implementation of DRGS. PERSPECTIVE: This article synthesizes the evidence supporting the current hypotheses of the mechanisms of action of DRGS for chronic pain and suggests avenues for future interdisciplinary research which will be critical to fully elucidate the analgesic mechanisms of the therapy.
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Affiliation(s)
- Robert D. Graham
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States,Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, United States
| | - Vishwanath Sankarasubramanian
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States,Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, United States
| | - Scott F. Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, United States,Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, United States,Department of Anesthesiology, University of Michigan, Ann Arbor, MI 48109, United States,Corresponding author: Scott F. Lempka, PhD, Department of Biomedical Engineering, University of Michigan, 2800 Plymouth Road, NCRC 14-184, Ann Arbor, MI 48109-2800,
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32
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Zheng Q, Xie W, Lückemeyer DD, Lay M, Wang XW, Dong X, Limjunyawong N, Ye Y, Zhou FQ, Strong JA, Zhang JM, Dong X. Synchronized cluster firing, a distinct form of sensory neuron activation, drives spontaneous pain. Neuron 2022; 110:209-220.e6. [PMID: 34752775 PMCID: PMC8776619 DOI: 10.1016/j.neuron.2021.10.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 09/01/2021] [Accepted: 10/13/2021] [Indexed: 01/21/2023]
Abstract
Spontaneous pain refers to pain occurring without external stimuli. It is a primary complaint in chronic pain conditions and remains difficult to treat. Moreover, the mechanisms underlying spontaneous pain remain poorly understood. Here we employed in vivo imaging of dorsal root ganglion (DRG) neurons and discovered a distinct form of abnormal spontaneous activity following peripheral nerve injury: clusters of adjacent DRG neurons firing synchronously and sporadically. The level of cluster firing correlated directly with nerve injury-induced spontaneous pain behaviors. Furthermore, we demonstrated that cluster firing is triggered by activity of sympathetic nerves, which sprout into DRGs after injury, and identified norepinephrine as a key neurotransmitter mediating this unique firing. Chemogenetic and pharmacological manipulations of sympathetic activity and norepinephrine receptors suggest that they are necessary and sufficient for DRG cluster firing and spontaneous pain behavior. Therefore, blocking sympathetically mediated cluster firing may be a new paradigm for treating spontaneous pain.
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Affiliation(s)
- Qin Zheng
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA
| | - Wenrui Xie
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Debora D Lückemeyer
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Mark Lay
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA
| | - Xue-Wei Wang
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA
| | - Xintong Dong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA
| | - Nathachit Limjunyawong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA
| | - Yaqing Ye
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA
| | - Feng-Quan Zhou
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA
| | - Judith A Strong
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Jun-Ming Zhang
- Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA.
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33
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Körner J, Lampert A. Functional subgroups of rat and human sensory neurons: a systematic review of electrophysiological properties. Pflugers Arch 2022; 474:367-385. [PMID: 35031856 PMCID: PMC8924089 DOI: 10.1007/s00424-021-02656-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/23/2021] [Accepted: 12/14/2021] [Indexed: 11/15/2022]
Abstract
Sensory neurons are responsible for the generation and transmission of nociceptive signals from the periphery to the central nervous system. They encompass a broadly heterogeneous population of highly specialized neurons. The understanding of the molecular choreography of individual subpopulations is essential to understand physiological and pathological pain states. Recently, it became evident that species differences limit transferability of research findings between human and rodents in pain research. Thus, it is necessary to systematically compare and categorize the electrophysiological data gained from human and rodent dorsal root ganglia neurons (DRGs). In this systematic review, we condense the available electrophysiological data defining subidentities in human and rat DRGs. A systematic search on PUBMED yielded 30 studies on rat and 3 studies on human sensory neurons. Defined outcome parameters included current clamp, voltage clamp, cell morphology, pharmacological readouts, and immune reactivity parameters. We compare evidence gathered for outcome markers to define subgroups, offer electrophysiological parameters for the definition of neuronal subtypes, and give a framework for the transferability of electrophysiological findings between species. A semiquantitative analysis revealed that for rat DRGs, there is an overarching consensus between studies that C-fiber linked sensory neurons display a lower action potential threshold, higher input resistance, a larger action potential overshoot, and a longer afterhyperpolarization duration compared to other sensory neurons. They are also more likely to display an infliction point in the falling phase of the action potential. This systematic review points out the need of more electrophysiological studies on human sensory neurons.
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Affiliation(s)
- Jannis Körner
- Institute of Physiology, Uniklinik RWTH Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany.,Clinic of Anesthesiology, Uniklinik RWTH Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany
| | - Angelika Lampert
- Institute of Physiology, Uniklinik RWTH Aachen, Pauwelsstrasse 30, 52074, Aachen, Germany.
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34
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Iseppon F, Linley JE, Wood JN. Calcium imaging for analgesic drug discovery. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2022; 11:100083. [PMID: 35079661 PMCID: PMC8777277 DOI: 10.1016/j.ynpai.2021.100083] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/17/2021] [Accepted: 12/27/2021] [Indexed: 11/24/2022]
Abstract
Somatosensation and pain are complex phenomena involving a rangeofspecialised cell types forming different circuits within the peripheral and central nervous systems. In recent decades, advances in the investigation of these networks, as well as their function in sensation, resulted from the constant evolution of electrophysiology and imaging techniques to allow the observation of cellular activity at the population level both in vitro and in vivo. Genetically encoded indicators of neuronal activity, combined with recent advances in DNA engineering and modern microscopy, offer powerful tools to dissect and visualise the activity of specific neuronal subpopulations with high spatial and temporal resolution. In recent years various groups developed in vivo imaging techniques to image calcium transients in the dorsal root ganglia, the spinal cord and the brain of anesthetised and awake, behaving animals to address fundamental questions in both the physiology and pathophysiology of somatosensation and pain. This approach, besides giving unprecedented details on the circuitry of innocuous and painful sensation, can be a very powerful tool for pharmacological research, from the characterisation of new potential drugs to the discovery of new, druggable targets within specific neuronal subpopulations. Here we summarise recent developments in calcium imaging for pain research, discuss technical challenges and advances, and examine the potential positive impact of this technique in early preclinical phases of the analgesic drug discovery process.
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Affiliation(s)
- Federico Iseppon
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, WC1E 6BT London, UK
- Discovery UK, Neuroscience, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - John E. Linley
- Discovery UK, Neuroscience, Biopharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - John N. Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, WC1E 6BT London, UK
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35
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Maksymchuk N, Sakurai A, Cox DN, Cymbalyuk G. Transient and Steady-State Properties of Drosophila Sensory Neurons Coding Noxious Cold Temperature. Front Cell Neurosci 2022; 16:831803. [PMID: 35959471 PMCID: PMC9358291 DOI: 10.3389/fncel.2022.831803] [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: 12/08/2021] [Accepted: 06/09/2022] [Indexed: 12/04/2022] Open
Abstract
Coding noxious cold signals, such as the magnitude and rate of temperature change, play essential roles in the survival of organisms. We combined electrophysiological and computational neuroscience methods to investigate the neural dynamics of Drosophila larva cold-sensing Class III (CIII) neurons. In response to a fast temperature change (-2 to -6°C/s) from room temperature to noxious cold, the CIII neurons exhibited a pronounced peak of a spiking rate with subsequent relaxation to a steady-state spiking. The magnitude of the peak was higher for a higher rate of temperature decrease, while slow temperature decrease (-0.1°C/s) evoked no distinct peak of the spiking rate. The rate of the steady-state spiking depended on the magnitude of the final temperature and was higher at lower temperatures. For each neuron, we characterized this dependence by estimating the temperature of the half activation of the spiking rate by curve fitting neuron's spiking rate responses to a Boltzmann function. We found that neurons had a temperature of the half activation distributed over a wide temperature range. We also found that CIII neurons responded to decrease rather than increase in temperature. There was a significant difference in spiking activity between fast and slow returns from noxious cold to room temperature: The CIII neurons usually stopped activity abruptly in the case of the fast return and continued spiking for some time in the case of the slow return. We developed a biophysical model of CIII neurons using a generalized description of transient receptor potential (TRP) current kinetics with temperature-dependent activation and Ca2+-dependent inactivation. This model recapitulated the key features of the spiking rate responses found in experiments and suggested mechanisms explaining the transient and steady-state activity of the CIII neurons at different cold temperatures and rates of their decrease and increase. We conclude that CIII neurons encode at least three types of cold sensory information: the rate of temperature decrease by a peak of the firing rate, the magnitude of cold temperature by the rate of steady spiking activity, and direction of temperature change by spiking activity augmentation or suppression corresponding to temperature decrease and increase, respectively.
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Affiliation(s)
- Natalia Maksymchuk
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Akira Sakurai
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Daniel N Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Gennady Cymbalyuk
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States.,Department of Physics and Astronomy, Georgia State University, Atlanta, GA, United States
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36
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Abstract
Itch is one of the most primal sensations, being both ubiquitous and important for the well-being of animals. For more than a century, a desire to understand how itch is encoded by the nervous system has prompted the advancement of many theories. Within the past 15 years, our understanding of the molecular and neural mechanisms of itch has undergone a major transformation, and this remarkable progress continues today without any sign of abating. Here I describe accumulating evidence that indicates that itch is distinguished from pain through the actions of itch-specific neuropeptides that relay itch information to the spinal cord. According to this model, classical neurotransmitters transmit, inhibit and modulate itch information in a context-, space- and time-dependent manner but do not encode itch specificity. Gastrin-releasing peptide (GRP) is proposed to be a key itch-specific neuropeptide, with spinal neurons expressing GRP receptor (GRPR) functioning as a key part of a convergent circuit for the conveyance of peripheral itch information to the brain.
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37
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Carozzi VA, Salio C, Rodriguez-Menendez V, Ciglieri E, Ferrini F. 2D <em>vs</em> 3D morphological analysis of dorsal root ganglia in health and painful neuropathy. Eur J Histochem 2021; 65. [PMID: 34664808 PMCID: PMC8547168 DOI: 10.4081/ejh.2021.3276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/16/2021] [Indexed: 11/23/2022] Open
Abstract
Dorsal root ganglia (DRGs) are clusters of sensory neurons that transmit the sensory information from the periphery to the central nervous system, and satellite glial cells (SGCs), their supporting trophic cells. Sensory neurons are pseudounipolar neurons with a heterogeneous neurochemistry reflecting their functional features. DRGs, not protected by the blood brain barrier, are vulnerable to stress and damage of different origin (i.e., toxic, mechanical, metabolic, genetic) that can involve sensory neurons, SGCs or, considering their intimate intercommunication, both cell populations. DRG damage, primary or secondary to nerve damage, produces a sensory peripheral neuropathy, characterized by neurophysiological abnormalities, numbness, paraesthesia and dysesthesia, tingling and burning sensations and neuropathic pain. DRG stress can be morphologically detected by light and electron microscope analysis with alterations in cell size (swelling/atrophy) and in different subcellular compartments (i.e., mitochondria, endoplasmic reticulum, and nucleus) of neurons and/or SGCs. In addition, neurochemical changes can be used to portray abnormalities of neurons and SGC. Conventional immunostaining, i.e., immunohistochemical detection of specific molecules in tissue slices, can be employed to detect, localize and quantify particular markers of damage in neurons (i.e., nuclear expression of ATF3) or SGCs (i.e., increased expression of GFAP), markers of apoptosis (i.e., caspases), markers of mitochondrial suffering and oxidative stress (i.e., 8-OHdG), markers of tissue inflammation (i.e., CD68 for macrophage infiltration) etc. However classical (2D) methods of immunostaining disrupt the overall organization of the DRG, thus resulting in the loss of some crucial information. Whole-mount (3D) methods have been recently developed to investigate DRG morphology and neurochemistry without tissue slicing, giving the opportunity to study the intimate relationship between SGCs and sensory neurons in health and disease. Here, we aim to compare classical (2D) vs whole-mount (3D) approaches to highlight “pros” and “cons” of the two methodologies when analysing neuropathy-induced alterations in DRGs.
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Affiliation(s)
- Valentina Alda Carozzi
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca, Monza (MB).
| | - Chiara Salio
- Department of Veterinary Sciences, University of Turin, Grugliasco (TO).
| | | | | | - Francesco Ferrini
- Department of Veterinary Sciences, University of Turin, Grugliasco (TO).
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38
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Middleton SJ, Perez-Sanchez J, Dawes JM. The structure of sensory afferent compartments in health and disease. J Anat 2021; 241:1186-1210. [PMID: 34528255 PMCID: PMC9558153 DOI: 10.1111/joa.13544] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/12/2021] [Accepted: 08/30/2021] [Indexed: 12/20/2022] Open
Abstract
Primary sensory neurons are a heterogeneous population of cells able to respond to both innocuous and noxious stimuli. Like most neurons they are highly compartmentalised, allowing them to detect, convey and transfer sensory information. These compartments include specialised sensory endings in the skin, the nodes of Ranvier in myelinated axons, the cell soma and their central terminals in the spinal cord. In this review, we will highlight the importance of these compartments to primary afferent function, describe how these structures are compromised following nerve damage and how this relates to neuropathic pain.
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Affiliation(s)
- Steven J Middleton
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - John M Dawes
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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39
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Chisholm KI, Lo Re L, Polgár E, Gutierrez-Mecinas M, Todd AJ, McMahon SB. Encoding of cutaneous stimuli by lamina I projection neurons. Pain 2021; 162:2405-2417. [PMID: 33769365 PMCID: PMC8374708 DOI: 10.1097/j.pain.0000000000002226] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/11/2020] [Accepted: 01/04/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT Lamina I of the dorsal horn, together with its main output pathway, lamina I projection neurons, has long been implicated in the processing of nociceptive stimuli, as well as the development of chronic pain conditions. However, the study of lamina I projection neurons is hampered by technical challenges, including the low throughput and selection biases of traditional electrophysiological techniques. Here we report on a technique that uses anatomical labelling strategies and in vivo imaging to simultaneously study a network of lamina I projection neurons in response to electrical and natural stimuli. Although we were able to confirm the nociceptive involvement of this group of cells, we also describe an unexpected preference for innocuous cooling stimuli. We were able to characterize the thermal responsiveness of these cells in detail and found cooling responses decline when exposed to stable cold temperatures maintained for more than a few seconds, as well as to encode the intensity of the end temperature, while heating responses showed an unexpected reliance on adaptation temperatures.
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Affiliation(s)
- Kim I. Chisholm
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Laure Lo Re
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Erika Polgár
- Spinal Cord Group, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Maria Gutierrez-Mecinas
- Spinal Cord Group, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Andrew J. Todd
- Spinal Cord Group, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Stephen B. McMahon
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
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40
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Abstract
In animals, proper locomotion is crucial to find mates and foods and avoid predators or dangers. Multiple sensory systems detect external and internal cues and integrate them to modulate motor outputs. Proprioception is the internal sense of body position, and proprioceptive control of locomotion is essential to generate and maintain precise patterns of movement or gaits. This proprioceptive feedback system is conserved in many animal species and is mediated by stretch-sensitive receptors called proprioceptors. Recent studies have identified multiple proprioceptive neurons and proprioceptors and their roles in the locomotion of various model organisms. In this review we describe molecular and neuronal mechanisms underlying proprioceptive feedback systems in C. elegans, Drosophila, and mice.
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Affiliation(s)
- Kyeong Min Moon
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
| | - Jimin Kim
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
| | - Yurim Seong
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
| | - Byung-Chang Suh
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
| | - KyeongJin Kang
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
- KBRI (Korea Brain Research Institute), Daegu 41068, Korea
| | - Han Kyoung Choe
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
- KBRI (Korea Brain Research Institute), Daegu 41068, Korea
| | - Kyuhyung Kim
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea
- KBRI (Korea Brain Research Institute), Daegu 41068, Korea
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41
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Schorscher-Petcu A, Takács F, Browne LE. Scanned optogenetic control of mammalian somatosensory input to map input-specific behavioral outputs. eLife 2021; 10:62026. [PMID: 34323214 PMCID: PMC8428846 DOI: 10.7554/elife.62026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 07/28/2021] [Indexed: 11/13/2022] Open
Abstract
Somatosensory stimuli guide and shape behavior, from immediate protective reflexes to longer-term learning and higher-order processes related to pain and touch. However, somatosensory inputs are challenging to control in awake mammals due to the diversity and nature of contact stimuli. Application of cutaneous stimuli is currently limited to relatively imprecise methods as well as subjective behavioral measures. The strategy we present here overcomes these difficulties, achieving 'remote touch' with spatiotemporally precise and dynamic optogenetic stimulation by projecting light to a small defined area of skin. We mapped behavioral responses in freely behaving mice with specific nociceptor and low-threshold mechanoreceptor inputs. In nociceptors, sparse recruitment of single-action potentials shapes rapid protective pain-related behaviors, including coordinated head orientation and body repositioning that depend on the initial body pose. In contrast, activation of low-threshold mechanoreceptors elicited slow-onset behaviors and more subtle whole-body behaviors. The strategy can be used to define specific behavioral repertoires, examine the timing and nature of reflexes, and dissect sensory, motor, cognitive, and motivational processes guiding behavior.
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Affiliation(s)
- Ara Schorscher-Petcu
- Wolfson Institute for Biomedical Research, and Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Flóra Takács
- Wolfson Institute for Biomedical Research, and Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Liam E Browne
- Wolfson Institute for Biomedical Research, and Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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MacDonald DI, Luiz AP, Iseppon F, Millet Q, Emery EC, Wood JN. Silent cold-sensing neurons contribute to cold allodynia in neuropathic pain. Brain 2021; 144:1711-1726. [PMID: 33693512 PMCID: PMC8320254 DOI: 10.1093/brain/awab086] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/29/2020] [Accepted: 12/17/2020] [Indexed: 11/25/2022] Open
Abstract
Patients with neuropathic pain often experience innocuous cooling as excruciating pain. The cell and molecular basis of this cold allodynia is little understood. We used in vivo calcium imaging of sensory ganglia to investigate how the activity of peripheral cold-sensing neurons was altered in three mouse models of neuropathic pain: oxaliplatin-induced neuropathy, partial sciatic nerve ligation, and ciguatera poisoning. In control mice, cold-sensing neurons were few in number and small in size. In neuropathic animals with cold allodynia, a set of normally silent large diameter neurons became sensitive to cooling. Many of these silent cold-sensing neurons responded to noxious mechanical stimuli and expressed the nociceptor markers Nav1.8 and CGRPα. Ablating neurons expressing Nav1.8 resulted in diminished cold allodynia. The silent cold-sensing neurons could also be activated by cooling in control mice through blockade of Kv1 voltage-gated potassium channels. Thus, silent cold-sensing neurons are unmasked in diverse neuropathic pain states and cold allodynia results from peripheral sensitization caused by altered nociceptor excitability.
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Affiliation(s)
- Donald Iain MacDonald
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Ana P Luiz
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Federico Iseppon
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Queensta Millet
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Edward C Emery
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
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43
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Wercberger R, Braz JM, Weinrich JA, Basbaum AI. Pain and itch processing by subpopulations of molecularly diverse spinal and trigeminal projection neurons. Proc Natl Acad Sci U S A 2021; 118:e2105732118. [PMID: 34234018 PMCID: PMC8285968 DOI: 10.1073/pnas.2105732118] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
A remarkable molecular and functional heterogeneity of the primary sensory neurons and dorsal horn interneurons transmits pain- and or itch-relevant information, but the molecular signature of the projection neurons that convey the messages to the brain is unclear. Here, using retro-TRAP (translating ribosome affinity purification) and RNA sequencing, we reveal extensive molecular diversity of spino- and trigeminoparabrachial projection neurons. Among the many genes identified, we highlight distinct subsets of Cck+ -, Nptx2+ -, Nmb+ -, and Crh+ -expressing projection neurons. By combining in situ hybridization of retrogradely labeled neurons with Fos-based assays, we also demonstrate significant functional heterogeneity, including both convergence and segregation of pain- and itch-provoking inputs into molecularly diverse subsets of NK1R- and non-NK1R-expressing projection neurons.
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Affiliation(s)
- Racheli Wercberger
- Department of Anatomy, University of California, San Francisco, CA 94158
| | - Joao M Braz
- Department of Anatomy, University of California, San Francisco, CA 94158
| | - Jarret A Weinrich
- Department of Anatomy, University of California, San Francisco, CA 94158
| | - Allan I Basbaum
- Department of Anatomy, University of California, San Francisco, CA 94158
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44
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Diminished Cold Avoidance Behaviours after Chronic Cold Exposure - Potential Involvement of TRPM8. Neuroscience 2021; 469:17-30. [PMID: 34139303 DOI: 10.1016/j.neuroscience.2021.06.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 06/02/2021] [Accepted: 06/08/2021] [Indexed: 11/22/2022]
Abstract
Ambient temperature changes trigger plastic biological responses. Cold temperature is detected by the somatosensory system and evokes perception of cold together with adaptive physiological responses. We addressed whether chronic cold exposure induces adaptive adjustments of (1) thermosensory behaviours, and (2) the principle molecular cold sensor in the transduction machinery, transient receptor potential melastatin subtype 8 (TRPM8). Mice in two groups were exposed to either cold (6 °C) or thermoneutral (27 °C) ambient temperatures for 4 weeks and subjected to thermosensory behavioural testing. Cold group mice behaved different from Thermoneutral group in the Thermal Gradient Test: the former occupied a wider temperature range and was less cold avoidant. Furthermore, subcutaneous injection of the TRPM8 agonist icilin, enhanced cold avoidance in both groups in the Thermal Gradient Test, but Cold group mice were significantly less affected by icilin. Primary sensory neuron soma are located in dorsal root ganglia (DRGs), and western blotting showed diminished TRPM8 levels in DRGs of Cold group mice, as compared to the Thermoneutral group. We conclude that acclimation to chronic cold altered thermosensory behaviours, so that mice appeared less cold sensitive, and potentially, TRPM8 is involved.
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45
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Huang T, Ohman LC, Clements AV, Whiddon ZD, Krimm RF. Variable Branching Characteristics of Peripheral Taste Neurons Indicates Differential Convergence. J Neurosci 2021; 41:4850-4866. [PMID: 33875572 PMCID: PMC8260161 DOI: 10.1523/jneurosci.1935-20.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 03/26/2021] [Accepted: 04/10/2021] [Indexed: 11/21/2022] Open
Abstract
Taste neurons are functionally and molecularly diverse, but their morphologic diversity remains completely unexplored. Using sparse cell genetic labeling, we provide the first reconstructions of peripheral taste neurons. The branching characteristics across 96 taste neurons show surprising diversity in their complexities. Individual neurons had 1-17 separate arbors entering between one and seven taste buds, 18 of these neurons also innervated non-taste epithelia. Axon branching characteristics are similar in gustatory neurons from male and female mice. Cluster analysis separated the neurons into four groups according to branch complexity. The primary difference between clusters was the amount of the nerve fiber within the taste bud available to contact taste-transducing cells. Consistently, we found that the maximum number of taste-transducing cells capable of providing convergent input onto individual gustatory neurons varied with a range of 1-22 taste-transducing cells. Differences in branching characteristics across neurons indicate that some neurons likely receive input from a larger number of taste-transducing cells than other neurons (differential convergence). By dividing neurons into two groups based on the type of taste-transducing cell most contacted, we found that neurons contacting primarily sour transducing cells were more heavily branched than those contacting primarily sweet/bitter/umami transducing cells. This suggests that neuron morphologies may differ across functional taste quality. However, the considerable remaining variability within each group also suggests differential convergence within each functional taste quality. Each possibility has functional implications for the system.SIGNIFICANCE STATEMENT Taste neurons are considered relay cells, communicating information from taste-transducing cells to the brain, without variation in morphology. By reconstructing peripheral taste neuron morphologies for the first time, we found that some peripheral gustatory neurons are simply branched, and can receive input from only a few taste-transducing cells. Other taste neurons are heavily branched, contacting many more taste-transducing cells than simply branched neurons. Based on the type of taste-transducing cell contacted, branching characteristics are predicted to differ across (and within) quality types (sweet/bitter/umami vs sour). Therefore, functional differences between neurons likely depends on the number of taste-transducing cells providing input and not just the type of cell providing input.
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Affiliation(s)
- Tao Huang
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
| | - Lisa C Ohman
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
| | - Anna V Clements
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
| | - Zachary D Whiddon
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
| | - Robin F Krimm
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202
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46
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Bouali-Benazzouz R, Landry M, Benazzouz A, Fossat P. Neuropathic pain modeling: Focus on synaptic and ion channel mechanisms. Prog Neurobiol 2021; 201:102030. [PMID: 33711402 DOI: 10.1016/j.pneurobio.2021.102030] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 02/22/2021] [Indexed: 12/28/2022]
Abstract
Animal models of pain consist of modeling a pain-like state and measuring the consequent behavior. The first animal models of neuropathic pain (NP) were developed in rodents with a total lesion of the sciatic nerve. Later, other models targeting central or peripheral branches of nerves were developed to identify novel mechanisms that contribute to persistent pain conditions in NP. Objective assessment of pain in these different animal models represents a significant challenge for pre-clinical research. Multiple behavioral approaches are used to investigate and to validate pain phenotypes including withdrawal reflex to evoked stimuli, vocalizations, spontaneous pain, but also emotional and affective behaviors. Furthermore, animal models were very useful in investigating the mechanisms of NP. This review will focus on a detailed description of rodent models of NP and provide an overview of the assessment of the sensory and emotional components of pain. A detailed inventory will be made to examine spinal mechanisms involved in NP-induced hyperexcitability and underlying the current pharmacological approaches used in clinics with the possibility to present new avenues for future treatment. The success of pre-clinical studies in this area of research depends on the choice of the relevant model and the appropriate test based on the objectives of the study.
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Affiliation(s)
- Rabia Bouali-Benazzouz
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.
| | - Marc Landry
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Abdelhamid Benazzouz
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
| | - Pascal Fossat
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France
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47
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MacDonald DI, Sikandar S, Weiss J, Pyrski M, Luiz AP, Millet Q, Emery EC, Mancini F, Iannetti GD, Alles SRA, Arcangeletti M, Zhao J, Cox JJ, Brownstone RM, Zufall F, Wood JN. A central mechanism of analgesia in mice and humans lacking the sodium channel Na V1.7. Neuron 2021; 109:1497-1512.e6. [PMID: 33823138 PMCID: PMC8110947 DOI: 10.1016/j.neuron.2021.03.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 02/05/2020] [Accepted: 03/08/2021] [Indexed: 11/18/2022]
Abstract
Deletion of SCN9A encoding the voltage-gated sodium channel NaV1.7 in humans leads to profound pain insensitivity and anosmia. Conditional deletion of NaV1.7 in sensory neurons of mice also abolishes pain, suggesting that the locus of analgesia is the nociceptor. Here we demonstrate, using in vivo calcium imaging and extracellular recording, that NaV1.7 knockout mice have essentially normal nociceptor activity. However, synaptic transmission from nociceptor central terminals in the spinal cord is greatly reduced by an opioid-dependent mechanism. Analgesia is also reversed substantially by central but not peripheral application of opioid antagonists. In contrast, the lack of neurotransmitter release from olfactory sensory neurons is opioid independent. Male and female humans with NaV1.7-null mutations show naloxone-reversible analgesia. Thus, inhibition of neurotransmitter release is the principal mechanism of anosmia and analgesia in mouse and human Nav1.7-null mutants.
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Affiliation(s)
- Donald Iain MacDonald
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK.
| | - Shafaq Sikandar
- Centre for Experimental Medicine & Rheumatology, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Jan Weiss
- Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - Martina Pyrski
- Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - Ana P Luiz
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Queensta Millet
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Edward C Emery
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Flavia Mancini
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - Gian D Iannetti
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK; Neuroscience and Behaviour Laboratory, Istituto Italiano di Tecnologia, Rome, Italy
| | - Sascha R A Alles
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Manuel Arcangeletti
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - Jing Zhao
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | - James J Cox
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK
| | | | - Frank Zufall
- Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, UK.
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48
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Goodwin G, McMahon SB. The physiological function of different voltage-gated sodium channels in pain. Nat Rev Neurosci 2021; 22:263-274. [PMID: 33782571 DOI: 10.1038/s41583-021-00444-w] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2021] [Indexed: 02/01/2023]
Abstract
Evidence from human genetic pain disorders shows that voltage-gated sodium channel α-subtypes Nav1.7, Nav1.8 and Nav1.9 are important in the peripheral signalling of pain. Nav1.7 is of particular interest because individuals with Nav1.7 loss-of-function mutations are congenitally insensitive to acute and chronic pain, and there is considerable hope that phenocopying these effects with a pharmacological antagonist will produce a new class of analgesic drug. However, studies in these rare individuals do not reveal how and where voltage-gated sodium channels contribute to pain signalling, which is of critical importance for drug development. More than a decade of research utilizing rodent genetic models and pharmacological tools to study voltage-gated sodium channels in pain has begun to unravel the role of different subtypes. Here, we review the contribution of individual channel subtypes in three key physiological processes necessary for transmission of sensory information to the CNS: transduction of stimuli at peripheral nerve terminals, axonal transmission of action potentials and neurotransmitter release from central terminals. These data suggest that drugs seeking to recapitulate the analgesic effects of loss of function of Nav1.7 will need to be brain-penetrant - which most of those developed to date are not.
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Affiliation(s)
- George Goodwin
- Pain and Neurorestoration Group, King's College London, London, UK.
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49
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Yu L, Li S, Wei J, Sun H, Yang C, Tan H. Association of serotonin transporter-linked polymorphic region (5-HTTLPR) with heat pain stimulation and postoperative pain in gastric cancer patients. Mol Pain 2021; 17:17448069211006606. [PMID: 33882731 PMCID: PMC8071976 DOI: 10.1177/17448069211006606] [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] [Indexed: 11/15/2022] Open
Abstract
Background The aim of this study was to assess whether the genotype of the serotonin transporter-linked polymorphic region (5-HTTLPR) in gastric cancer patients is associated with postoperative pain and pain threshold. Methods We conducted a prospective cohort study of 251 patients scheduled for gastrectomy from May to September 2019. All patients enrolled in the study were asked to complete the Hospital Anxiety and Depression Scale questionnaire. Heat pain threshold (HPT), cold pain threshold (CPT) and Pressure pain threshold (PPT) were measured for all participants one day prior to surgery. Blood samples were collected for genetic testing. All patients were connected to a patient-controlled intravenous analgesia (PCIA) pump at the end of the surgery. After exclusion of 15 patients, the postoperative conditions of 236 patients were recorded. Results Distribution of homozygous long (L/L), heterozygous (L/S), and homozygous short (S/S) 5-HTTLPR genotypes among participants were 26 (11.0%), 91 (38.6%), and 119 (50.4%), respectively. Heat pain threshold (P = 0.038) and Numerical rating scale (NRS) in the 1st postoperative 24 h (P = 0.026) were significantly different between long (L/L) and short (S/S) genotype carriers. Conclusions In patients with gastric cancer, heat pain stimulation is associated with 5-HTTLPR polymorphism, and postoperative pain may be related to 5-HTTLPR polymorphism.
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Affiliation(s)
- Ling Yu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Shuo Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Jin Wei
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Hongwei Sun
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Caixia Yang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Hongyu Tan
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education, Beijing), Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing, China
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50
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Ohman LC, Krimm RF. Variation in taste ganglion neuron morphology: insights into taste function and plasticity. CURRENT OPINION IN PHYSIOLOGY 2021; 20:134-139. [DOI: 10.1016/j.cophys.2020.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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