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D'Alesio G, Stumpp LI, Sciarrone P, Navari A, Gentile F, Borrelli C, Ballanti S, Degl'Innocenti E, Carrasco A, Costa AC, Andrade A, Mannini A, Macefield VG, Emdin M, Passino C, Mazzoni A, Giannoni A, Oddo CM. An open computational toolbox to analyze multi- and single-unit sympathetic nerve activity in microneurography. BIOPHYSICS REVIEWS 2024; 5:021401. [PMID: 38895135 PMCID: PMC11184970 DOI: 10.1063/5.0202385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Accepted: 05/08/2024] [Indexed: 06/21/2024]
Abstract
Microelectrode recordings from human peripheral and cranial nerves provide a means to study both afferent and efferent axonal signals at different levels of detail, from multi- to single-unit activity. Their analysis can lead to advancements both in diagnostic and in the understanding of the genesis of neural disorders. However, most of the existing computational toolboxes for the analysis of microneurographic recordings are limited in scope or not open-source. Additionally, conventional burst-based metrics are not suited to analyze pathological conditions and are highly sensitive to distance of the microelectrode tip from the active axons. To address these challenges, we developed an open-source toolbox that offers advanced analysis capabilities for studying neuronal reflexes and physiological responses to peripheral nerve activity. Our toolbox leverages the observation of temporal sequences of action potentials within inherently cyclic signals, introducing innovative methods and indices to enhance analysis accuracy. Importantly, we have designed our computational toolbox to be accessible to novices in biomedical signal processing. This may include researchers and professionals in healthcare domains, such as clinical medicine, life sciences, and related fields. By prioritizing user-friendliness, our software application serves as a valuable resource for the scientific community, allowing to extract advanced metrics of neural activity in short time and evaluate their impact on other physiological variables in a consistent and standardized manner, with the final aim to widen the use of microneurography among researchers and clinicians.
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Affiliation(s)
- Giacomo D'Alesio
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | | | - Alessandro Navari
- Cardiovascular Medicine Department, Fondazione Toscana Gabriele Monasterio, Pisa, Italy
| | | | - Chiara Borrelli
- Medical Research Center, University of Iowa, Iowa City, Iowa, USA
| | - Sara Ballanti
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | | | | | - Alexandre Andrade
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
| | - Andrea Mannini
- Artificial Intelligence for Rehabilitation Laboratory, Fondazione Don Carlo Gnocchi IRCCS, Florence, Italy
| | | | | | | | - Alberto Mazzoni
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
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2
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Raabe W, Walk D. Multiple averaged records to identify Aδ-fibers in sensory nerves. J Neurosci Methods 2024; 405:110081. [PMID: 38369028 DOI: 10.1016/j.jneumeth.2024.110081] [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: 09/18/2023] [Revised: 01/08/2024] [Accepted: 02/15/2024] [Indexed: 02/20/2024]
Abstract
BACKGROUND Existing methods identify only ≈10 Aδ-fibers in human sensory nerves per recording. This study examines methods to increase the detection of Aδ-fibers. NEW METHOD Two to 20 averages of 500 replicate responses to epidermal nerve stimulation are obtained. Pairs of different averages are constructed. Each pair is analyzed with algorithms applied to amplitude and frequency to detect replication of responses to stimulation as "simultaneous similarities in two averages" (SS2AVs) at ≥99.5th percentile of control. In a pair of averages the latencies of amplitude and frequency SS2AVs for the same response to stimulation may differ by ≤0.25 ms. Therefore, Aδ-fibers are identified by the 0.25 ms moving sum of SS2AV latencies of the pairs of averages. RESULTS Increasing averages increases pairs of different averages and detection of Aδ-fibers: from 2 to 10 Aδ-fibers with two averages (one pair) to >50 Aδ-fibers with 12-20 averages (66-190 pairs). COMPARISON WITH EXISTING METHOD(S) Existing methods identify ≤10 Aδ-fibers in 10 averages/45 pairs with the medians of amplitude and frequency algorithms applied to all 45 pairs. This study identifies Aδ-fibers (i) by applying these algorithms at the 99.5th percentile of control, (ii) to each pair of averages and (iii) by the 0.25 ms sum of algorithm identified events (SS2AVs) in all pairs. These three changes significantly increase the detection of Aδ-fibers, e.g., in 10 averages/45pairs from 10 to 45. CONCLUSIONS Three modifications of existing methods can increase the detection of Aδ-fibers to an amount suitable (>50 with ≥12 averages) for statistical comparison of different nerves.
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Affiliation(s)
- W Raabe
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA.
| | - D Walk
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA
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3
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Robb KA, Perry SD. Capitalizing on skin in orthotics design: the effects of texture on plantar intrinsic foot muscles during locomotion. Exp Brain Res 2024; 242:403-416. [PMID: 38135819 DOI: 10.1007/s00221-023-06758-8] [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: 05/23/2023] [Accepted: 11/29/2023] [Indexed: 12/24/2023]
Abstract
Foot orthoses (FO) are a commonly prescribed intervention to alter foot function during walking although their effects have been primarily studied in the extrinsic muscles of the foot. Furthermore, enhancing sensory feedback under the foot sole has been recently shown to alter extrinsic muscle activity during gait; however, the effects of FOs with enhanced sensory feedback on plantar intrinsic foot muscles (PIFMs) remain unknown. Thus, the purpose of this study was to investigate the effect of FOs with and without sensory facilitation on PIFM activity during locomotion. Forty healthy adults completed a series of gait trials in non-textured and textured FOs when walking over hard and soft flooring. Outcome measures included bilateral joint kinematics and electromyography (EMG) of four PIFMs. Results of this study highlight the distinct onset and cessations of each PIFM throughout the stance phase of gait. PIFMs remained active during mid-stance when wearing FOs and textured FOs facilitated muscle activity across the stance phase of gait. Increasing cutaneous input from foot sole skin, via the addition of texture under the foot sole, appears to alter motor-neuron pool excitation of PIFMs. Future academics are encouraged to increase our understanding on which pathologies, diseases, and/or medical conditions would best benefit from textured FOs.
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Affiliation(s)
- Kelly A Robb
- Department of Kinesiology and Physical Education, Faculty of Science, Wilfrid Laurier University, 75 University Ave. West, Waterloo, ON, N2L 3C5, Canada.
| | - Stephen D Perry
- Department of Kinesiology and Physical Education, Faculty of Science, Wilfrid Laurier University, 75 University Ave. West, Waterloo, ON, N2L 3C5, Canada
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Ezquerra-Romano I, Clements MF, di Costa S, Iannetti GD, Haggard P. Revisiting a classical theory of sensory specificity: assessing consistency and stability of thermosensitive spots. J Neurophysiol 2023; 130:1567-1577. [PMID: 37964756 DOI: 10.1152/jn.00275.2023] [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: 07/20/2023] [Revised: 10/26/2023] [Accepted: 11/08/2023] [Indexed: 11/16/2023] Open
Abstract
Thermal sensitivity is not uniform across the skin, and is particularly high in small (∼1 mm2) regions termed "thermosensitive spots." These spots are thought to reflect the anatomical location of specialized thermosensitive nerve endings from single primary afferents. Thermosensitive spots provide foundational support for "labeled line" or specificity theory of sensory perception, which states that different sensory qualities are transmitted by separate and specific neural pathways. This theory predicts a highly stable relation between repetitions of a thermal stimulus and the resulting sensory quality, yet these predictions have rarely been tested systematically. Here, we present the qualitative, spatial, and repeatability properties of 334 thermosensitive spots on the dorsal forearm sampled across four separate sessions. In line with previous literature, we found that spots associated with cold sensations (112 cold spots, 34%) were more frequent than spots associated with warm sensations (41 warm spots, 12%). Still more frequent (165 spots, 49%) were spots that elicited inconsistent sensations when repeatedly stimulated by the same temperature. Remarkably, only 13 spots (4%) conserved their position between sessions. Overall, we show unexpected inconsistency of both the perceptual responses elicited by spot stimulation and of spot locations across time. These observations suggest reappraisals of the traditional view that thermosensitive spots reflect the location of individual thermosensitive, unimodal primary afferents serving as specific labeled lines for corresponding sensory qualities.NEW & NOTEWORTHY Thermosensitive spots are clustered rather than randomly distributed and have the highest density near the wrist. Surprisingly, we found that thermosensitive spots elicit inconsistent sensory qualities and are unstable over time. Our results question the widely believed notion that thermosensitive spots reflect the location of individual thermoreceptive, unimodal primary afferents that serve as labelled lines for corresponding sensory qualities.
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Affiliation(s)
- Ivan Ezquerra-Romano
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom
| | - Michael F Clements
- Department of Psychology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Steven di Costa
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom
| | | | - Patrick Haggard
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom
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5
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Rogers ER, Mirzakhalili E, Lempka SF. Model-based analysis of subthreshold mechanisms of spinal cord stimulation for pain. J Neural Eng 2023; 20:066003. [PMID: 37906966 PMCID: PMC10632558 DOI: 10.1088/1741-2552/ad0858] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/11/2023] [Accepted: 10/31/2023] [Indexed: 11/02/2023]
Abstract
Objective.Spinal cord stimulation (SCS) is a common treatment for chronic pain. For decades, SCS maximized overlap between stimulation-induced paresthesias and the patient's painful areas. Recently developed SCS paradigms relieve pain at sub-perceptible amplitudes, yet little is known about the neural response to these new waveforms or their analgesic mechanisms of action. Therefore, in this study, we investigated the neural response to multiple forms of paresthesia-free SCS.Approach.We used computational modeling to investigate the neurophysiological effects and the plausibility of commonly proposed mechanisms of three paresthesia-free SCS paradigms: burst, 1 kHz, and 10 kHz SCS. Specifically, in C- and Aβ-fibers, we investigated the effects of different SCS waveforms on spike timing and activation thresholds, as well as how stochastic ion channel gating affects the response of dorsal column axons. Finally, we characterized membrane polarization of superficial dorsal horn neurons.Main results.We found that none of the SCS waveforms activate nor modulate spike timing in C-fibers. Spike timing was modulated in Aβ-fibers only at suprathreshold amplitudes. Ion channel stochasticity had little effect on Aβ-fiber activation thresholds but produced heterogeneous spike timings at suprathreshold amplitudes. Finally, local cells were preferentially polarized in their axon terminals, and the magnitude of this polarization was dependent on cellular morphology and position relative to the stimulation electrodes.Significance.Overall, the mechanisms of action of subparesthetic SCS remain unclear. Our results suggest that no SCS waveforms directly activate C-fibers, and modulation of spike timing is unlikely at subthreshold amplitudes. We conclude that potential subthreshold neuromodulatory effects of SCS on local cells are likely to be presynaptic in nature, as axons are preferentially depolarized during SCS.
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Affiliation(s)
- Evan R Rogers
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Ehsan Mirzakhalili
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
| | - Scott F Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States of America
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, United States of America
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Bouhassira D, Attal N. Personalized treatment of neuropathic pain: Where are we now? Eur J Pain 2023; 27:1084-1098. [PMID: 37114461 DOI: 10.1002/ejp.2120] [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: 02/16/2023] [Revised: 04/07/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023]
Abstract
BACKGROUND The treatment of neuropathic pain remains a major unmet need that the development of personalized and refined treatment strategies may contribute to address. DATABASE In this narrative review, we summarize the various approaches based on objective biomarkers or clinical markers that could be used. RESULTS In principle, the validation of objective biomarkers would be the most robust approach. However, although promising results have been reported demonstrating a potential value of genomics, anatomical or functional markers, the clinical validation of these markers has only just begun. Thus, most of the strategies documented to date have been based on the development of clinical markers. In particular, many studies have suggested that the identification of specific subgroups of patients presenting with specific combinations of symptoms and signs would be a relevant approach. Two main approaches have been used to identify relevant sensory profiles: quantitative sensory testing and specific patients reported outcomes based on description of pain qualities. CONCLUSION We discuss here the advantages and limitations of these approaches, which are not mutually exclusive. SIGNIFICANCE Recent data indicate that various new treatment strategies based on predictive biological and/or clinical markers could be helpful to better personalized and therefore improve the management of neuropathic pain.
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Affiliation(s)
- Didier Bouhassira
- Inserm U987, UVSQ-Paris-Saclay University, Ambroise Pare Hospital, Boulogne-Billancourt, France
| | - Nadine Attal
- Inserm U987, UVSQ-Paris-Saclay University, Ambroise Pare Hospital, Boulogne-Billancourt, France
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Konradi P, Troglio A, Pérez Garriga A, Pérez Martín A, Röhrig R, Namer B, Kutafina E. PyDapsys: an open-source library for accessing electrophysiology data recorded with DAPSYS. Front Neuroinform 2023; 17:1250260. [PMID: 37780458 PMCID: PMC10539619 DOI: 10.3389/fninf.2023.1250260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/28/2023] [Indexed: 10/03/2023] Open
Abstract
In the field of neuroscience, a considerable number of commercial data acquisition and processing solutions rely on proprietary formats for data storage. This often leads to data being locked up in formats that are only accessible by using the original software, which may lead to interoperability problems. In fact, even the loss of data access is possible if the software becomes unsupported, changed, or otherwise unavailable. To ensure FAIR data management, strategies should be established to enable long-term, independent, and unified access to data in proprietary formats. In this work, we demonstrate PyDapsys, a solution to gain open access to data that was acquired using the proprietary recording system DAPSYS. PyDapsys enables us to open the recorded files directly in Python and saves them as NIX files, commonly used for open research in the electrophysiology domain. Thus, PyDapsys secures efficient and open access to existing and prospective data. The manuscript demonstrates the complete process of reverse engineering a proprietary electrophysiological format on the example of microneurography data collected for studies on pain and itch signaling in peripheral neural fibers.
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Affiliation(s)
- Peter Konradi
- Institute of Medical Informatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Alina Troglio
- Research Group Neuroscience, IZKF, RWTH Aachen, Aachen, Germany
| | - Ariadna Pérez Garriga
- Institute of Medical Informatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Aarón Pérez Martín
- Simulation and Data Lab Neuroscience, Jülich Supercomputing Centre (JSC), Institute for Advanced Simulation, JARA, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Rainer Röhrig
- Institute of Medical Informatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Barbara Namer
- Research Group Neuroscience, IZKF, RWTH Aachen, Aachen, Germany
- Department for Neurophysiology, University Hospital RWTH Aachen, Aachen, Germany
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ekaterina Kutafina
- Institute of Medical Informatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Wang Y, Sun K, Zhang Q, Yu SS, Han BS, Wang J, Zhao M, Meng X, Chen S, Zheng Y. Flexible integrated sensor with asymmetric structure for simultaneously 3D tactile and thermal sensing. Biosens Bioelectron 2023; 224:115054. [PMID: 36603284 DOI: 10.1016/j.bios.2022.115054] [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: 11/17/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 12/31/2022]
Abstract
The human body detects tactile stimuli through a combination of pressure force and temperature signals via various cutaneous receptors. The development of a multifunctional artificial tactile perception system has potential benefits for future robotic technologies, human-machine interfaces, artificial intelligence, and health monitoring devices. However, constructing systems beyond simple pressure sensing capabilities remains challenging. Here, we propose an artificial flexible and ultra-thin (50 μ m) skin system to simultaneously capture 3D tactile and thermal signals, which mimics the human tactile recognition process using customized sensor pairs and compact peripheral signal-converting circuits. The 3D tactile sensors have a flower-like asymmetric structure with 5-ports and 4 capacitive elements in pairs. Differential and average signals would reveal the curl and amplitude values of the fore field with a resolution of 0.18/mm. The resistive thermal sensors are fabricated with serpentine lines and possess stable heat-sensing performance (165 mV/°C) under shape deformation conditions. Real-time monitoring of the skin stimuli is displayed on the user interface and stored on mobile clients. This work offers broad capabilities relevant to practical applications ranging from assistant prosthetics to artificial electronic skins.
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Affiliation(s)
- Yongqing Wang
- School of Geophysics and Information Technology, China University of Geosciences, Beijing, 100084, China; School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Kun Sun
- Beijing Key Laboratory of Advanced Manufacturing Technology, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Qisheng Zhang
- School of Geophysics and Information Technology, China University of Geosciences, Beijing, 100084, China
| | | | - Boon Siew Han
- Schaeffler Hub for Advanced Research (SHARE@NTU), Nanyang Technological University, 61 Nanyang Dr, 637460, Singapore
| | - Jianpeng Wang
- Department of Critical CareMedicine, The First Affiliated Hospital of Harbin Medical University, Harbin, 150007, China
| | - Mingyan Zhao
- Department of Critical CareMedicine, The First Affiliated Hospital of Harbin Medical University, Harbin, 150007, China
| | - Xianglin Meng
- Department of Critical CareMedicine, The First Affiliated Hospital of Harbin Medical University, Harbin, 150007, China
| | - Sicheng Chen
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
| | - Yuanjin Zheng
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
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Kutafina E, Becker S, Namer B. Measuring pain and nociception: Through the glasses of a computational scientist. Transdisciplinary overview of methods. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:1099282. [PMID: 36926544 PMCID: PMC10013045 DOI: 10.3389/fnetp.2023.1099282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 01/04/2023] [Indexed: 02/12/2023]
Abstract
In a healthy state, pain plays an important role in natural biofeedback loops and helps to detect and prevent potentially harmful stimuli and situations. However, pain can become chronic and as such a pathological condition, losing its informative and adaptive function. Efficient pain treatment remains a largely unmet clinical need. One promising route to improve the characterization of pain, and with that the potential for more effective pain therapies, is the integration of different data modalities through cutting edge computational methods. Using these methods, multiscale, complex, and network models of pain signaling can be created and utilized for the benefit of patients. Such models require collaborative work of experts from different research domains such as medicine, biology, physiology, psychology as well as mathematics and data science. Efficient work of collaborative teams requires developing of a common language and common level of understanding as a prerequisite. One of ways to meet this need is to provide easy to comprehend overviews of certain topics within the pain research domain. Here, we propose such an overview on the topic of pain assessment in humans for computational researchers. Quantifications related to pain are necessary for building computational models. However, as defined by the International Association of the Study of Pain (IASP), pain is a sensory and emotional experience and thus, it cannot be measured and quantified objectively. This results in a need for clear distinctions between nociception, pain and correlates of pain. Therefore, here we review methods to assess pain as a percept and nociception as a biological basis for this percept in humans, with the goal of creating a roadmap of modelling options.
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Affiliation(s)
- Ekaterina Kutafina
- Institute of Medical Informatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
- Faculty of Applied Mathematics, AGH University of Science and Technology, Krakow, Poland
| | - Susanne Becker
- Clinical Psychology, Department of Experimental Psychology, Heinrich Heine University, Düsseldorf, Germany
- Integrative Spinal Research, Department of Chiropractic Medicine, University Hospital Balgrist, University of Zurich, Zurich, Switzerland
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Barbara Namer
- Junior Research Group Neuroscience, Interdisciplinary Center for Clinical Research Within the Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Institute of Physiology, Medical Faculty, RWTH Aachen University, Aachen, Germany
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10
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Álvarez DMC, Serrano-Muñoz D, Fernández-Pérez JJ, Gómez-Soriano J, Avendaño-Coy J. Effect of percutaneous electrical stimulation with high-frequency alternating currents at 30 kHz on the sensory-motor system. Front Neurosci 2023; 17:1048986. [PMID: 36845426 PMCID: PMC9947497 DOI: 10.3389/fnins.2023.1048986] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/24/2023] [Indexed: 02/11/2023] Open
Abstract
Background Unmodulated high-frequency alternating currents (HFAC) are employed for producing peripheral nerves block. HFAC have been applied in humans with frequencies up to 20 kHz, whether transcutaneously, percutaneously, or via surgically-implanted electrodes. The aim of this study was to assess the effect of percutaneous HFAC, applied with ultrasound-guided needles at 30 kHz, on the sensory-motor nerve conduction of healthy volunteers. Methods A parallel, double-blind, randomized clinical trial with a placebo control was conducted. Percutaneous HFAC at 30 kHz or sham stimulation was applied via ultrasound-guided needles in 48 healthy volunteers (n = 24 in each group) for 20 min. The assessed outcome variables were pressure pain threshold (PPT), mechanical detection threshold (MDT), maximal finger flexion strength (MFFS), antidromic sensory nerve action potential (SNAP), hand temperature, and subjective sensations by the participants. The measurements were recorded pre-intervention, during the stimulation (at 15 min), immediately post-intervention (at 20 min), and 15 min after the end of treatment. Results The PPT increased in the active group compared with sham stimulation, both during the intervention [14.7%; 95% confidence interval (CI): 4.4-25.0], immediately post-intervention (16.9%; 95% CI: -7.2-26.5), and 15 min after the end of the stimulation (14.3%; 95% CI: 4.4-24.3) (p < 0.01). The proportion of participants who reported feelings of numbness and heaviness was significantly higher in the active group (46 and 50%, respectively) than in the sham group (8 and 18%, respectively) (p < 0.05). No intergroup differences were observed in the remaining outcome variables. No unexpected adverse effects derived from the electrical stimulation were reported. Conclusion Percutaneous stimulation with HFAC at 30 kHz applied to the median nerve increased the PPT and subjective perception of numbness and heaviness. Future research should evaluate its potential therapeutic effect in people with pain. Clinical trial registration https://clinicaltrials.gov/ct2/show/NCT04884932, identifier NCT04884932.
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Affiliation(s)
- David Martín-Caro Álvarez
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing of Toledo, Universidad de Castilla-La Mancha, Toledo, Spain
| | | | - Juan José Fernández-Pérez
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing of Toledo, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Julio Gómez-Soriano
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing of Toledo, Universidad de Castilla-La Mancha, Toledo, Spain
| | - Juan Avendaño-Coy
- Toledo Physiotherapy Research Group (GIFTO), Faculty of Physiotherapy and Nursing of Toledo, Universidad de Castilla-La Mancha, Toledo, Spain
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11
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Crucianelli L, Chancel M, Ehrsson HH. Modeling affective touch pleasantness across skin types at the individual level reveals a reliable and stable basic function. J Neurophysiol 2022; 128:1435-1452. [PMID: 36260710 DOI: 10.1152/jn.00179.2022] [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: 01/06/2023] Open
Abstract
Touch is perceived most pleasant when delivered at velocities known to optimally activate the C-tactile afferent system. At the group level, pleasantness ratings of touch delivered at velocities in the range between 0.3 and 30 cm/s follow an inverted-U shape curve, with maximum pleasantness between 1 and 10 cm/s. However, the prevalence, reliability, and stability of this function at the individual level and across skin types based on hair density remains unknown. Here, we tested a range of seven velocities (0.3, 1, 3, 6, 9, 18, and 27 cm/s) delivered with a soft brush, on both hairy (forearm and dorsal hand) and nonhairy skin (palm) in 123 participants. Our results suggest that the relationship between pleasantness and velocity of touch is significantly best described by a negative quadratic model at the individual level in the majority of participants both on hairy (67.1%) and nonhairy (62.6%) skin, a larger extent than previously reported. Higher interoceptive accuracy and self-reported depression were related to a better fit of the quadratic model and the steepness of the curve, respectively. The prevalence of the quadratic model at the individual level was stable across body sites (62.6%, experiment 1), across two experimental sessions (73%-78%, experiment 2), and regardless of the number of repetitions of each velocity (experiment 3). Thus, the individual perception of tactile pleasantness follows a characteristic velocity-dependent function across skin types and shows trait characteristics. Future studies can investigate further the possibility to use affective touch as a behavioral biomarker for mental health disorders.NEW & NOTEWORTHY Touch is perceived as most pleasant when delivered at slow, caress-like velocities, known to activate C-tactile afferents. At the group level, tactile pleasantness and velocity of touch show a reliable pattern of relationship on hairy skin. Here, we found that the perception of tactile pleasantness follows a consistent pattern also at the individual level, across skin types and testing sessions. However, individual differences in interoceptive abilities and self-reported depression do play a role.
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Affiliation(s)
- Laura Crucianelli
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Marie Chancel
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - H Henrik Ehrsson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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12
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Hargreaves R, Akinsanya K, Ajit SK, Dhruv NT, Driscoll J, Farina P, Gavva N, Gill M, Houghton A, Iyengar S, Jones C, Kavelaars A, Kaykas A, Koroshetz WJ, Laeng P, Laird JM, Lo DC, Luthman J, Munro G, Oshinsky ML, Sittampalam GS, Woller SA, Tamiz AP. Preclinical target validation for non-addictive therapeutics development for pain. Expert Opin Ther Targets 2022; 26:811-822. [DOI: 10.1080/14728222.2022.2147063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
| | | | - Seena K. Ajit
- Department of Pharmacology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States
| | - Neel T. Dhruv
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States
| | - Jamie Driscoll
- National Institute of Mental Health, Bethesda, Maryland, United States
| | - Peter Farina
- Canaan Partners, Westport, Connecticut, United States
| | - Narender Gavva
- Drug Discovery Sciences, Takeda Pharmaceuticals, San Diego, California, United States
| | - Marie Gill
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States
| | | | - Smriti Iyengar
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States
| | - Carrie Jones
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, United States
| | - Annemieke Kavelaars
- The University of Texas MD Anderson Cancer Center, Houston, Texas, United States
| | | | - Walter J. Koroshetz
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States
| | - Pascal Laeng
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States
| | - Jennifer M. Laird
- Eli Lilly and Company, Windlesham, United Kingdom of Great Britain and Northern Ireland
| | - Donald C. Lo
- National Center for Advancing Translational Sciences, Bethesda, Maryland, United States
| | | | | | - Michael L. Oshinsky
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States
| | - G. Sitta Sittampalam
- National Center for Advancing Translational Sciences, Bethesda, Maryland, United States
| | - Sarah A. Woller
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States
| | - Amir P. Tamiz
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, United States
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13
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Kutafina E, Troglio A, de Col R, Röhrig R, Rossmanith P, Namer B. Decoding Neuropathic Pain: Can We Predict Fluctuations of Propagation Speed in Stimulated Peripheral Nerve? Front Comput Neurosci 2022; 16:899584. [PMID: 35966281 PMCID: PMC9366140 DOI: 10.3389/fncom.2022.899584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/22/2022] [Indexed: 11/17/2022] Open
Abstract
To understand neural encoding of neuropathic pain, evoked and resting activity of peripheral human C-fibers are studied via microneurography experiments. Before different spiking patterns can be analyzed, spike sorting is necessary to distinguish the activity of particular fibers of a recorded bundle. Due to single-electrode measurements and high noise contamination, standard methods based on spike shapes are insufficient and need to be enhanced with additional information. Such information can be derived from the activity-dependent slowing of the fiber propagation speed, which in turn can be assessed by introducing continuous "background" 0.125-0.25 Hz electrical stimulation and recording the corresponding responses from the fibers. Each fiber's speed propagation remains almost constant in the absence of spontaneous firing or additional stimulation. This way, the responses to the "background stimulation" can be sorted by fiber. In this article, we model the changes in the propagation speed resulting from the history of fiber activity with polynomial regression. This is done to assess the feasibility of using the developed models to enhance the spike shape-based sorting. In addition to human microneurography data, we use animal in-vitro recordings with a similar stimulation protocol as higher signal-to-noise ratio data example for the models.
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Affiliation(s)
- Ekaterina Kutafina
- Institute of Medical Informatics, Medical Faculty, RWTH Aachen University, Aachen, Germany,Faculty of Applied Mathematics, AGH University of Science and Technology, Krakow, Poland,*Correspondence: Ekaterina Kutafina
| | - Alina Troglio
- Junior Research Group Neuroscience, Interdisciplinary Center for Clinical Research Within the Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Roberto de Col
- Junior Research Group Neuroscience, Interdisciplinary Center for Clinical Research Within the Faculty of Medicine, RWTH Aachen University, Aachen, Germany,Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Rainer Röhrig
- Institute of Medical Informatics, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Peter Rossmanith
- Theoretical Computer Science, Department of Computer Science, RWTH Aachen University, Aachen, Germany
| | - Barbara Namer
- Junior Research Group Neuroscience, Interdisciplinary Center for Clinical Research Within the Faculty of Medicine, RWTH Aachen University, Aachen, Germany,Institute of Physiology, Medical Faculty, RWTH Aachen University, Aachen, Germany
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14
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15
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Ma Q. A functional subdivision within the somatosensory system and its implications for pain research. Neuron 2022; 110:749-769. [PMID: 35016037 PMCID: PMC8897275 DOI: 10.1016/j.neuron.2021.12.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 10/07/2021] [Accepted: 12/09/2021] [Indexed: 12/12/2022]
Abstract
Somatosensory afferents are traditionally classified by soma size, myelination, and their response specificity to external and internal stimuli. Here, we propose the functional subdivision of the nociceptive somatosensory system into two branches. The exteroceptive branch detects external threats and drives reflexive-defensive reactions to prevent or limit injury. The interoceptive branch senses the disruption of body integrity, produces tonic pain with strong aversive emotional components, and drives self-caring responses toward to the injured region to reduce suffering. The central thesis behind this functional subdivision comes from a reflection on the dilemma faced by the pain research field, namely, the use of reflexive-defensive behaviors as surrogate assays for interoceptive tonic pain. The interpretation of these assays is now being challenged by the discovery of distinct but interwoven circuits that drive exteroceptive versus interoceptive types of behaviors, with the conflation of these two components contributing partially to the poor translation of therapies from preclinical studies.
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Affiliation(s)
- Qiufu Ma
- Dana-Farber Cancer Institute and Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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16
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Themistocleous AC, Kristensen AG, Sola R, Gylfadottir SS, Bennedsgaard K, Itani M, Krøigård T, Ventzel L, Sindrup SH, Jensen TS, Bostock H, Serra J, Finnerup NB, Tankisi H, Bennett DLH. Axonal excitability does not differ between painful and painless diabetic or chemotherapy-induced distal symmetrical polyneuropathy in a multi-centre observational study. Ann Neurol 2022; 91:506-520. [PMID: 35150149 PMCID: PMC9313833 DOI: 10.1002/ana.26319] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 01/18/2022] [Accepted: 02/07/2022] [Indexed: 11/16/2022]
Abstract
Objective Axonal excitability reflects ion channel function, and it is proposed that this may be a biomarker in painful (vs painless) polyneuropathy. Our objective was to investigate the relationship between axonal excitability parameters and chronic neuropathic pain in deeply phenotyped cohorts with diabetic or chemotherapy‐induced distal symmetrical polyneuropathy. Methods Two hundred thirty‐nine participants with diabetic polyneuropathy were recruited from sites in the UK and Denmark, and 39 participants who developed chemotherapy‐induced polyneuropathy were recruited from Denmark. Participants were separated into those with probable or definite neuropathic pain and those without neuropathic pain. Axonal excitability of large myelinated fibers was measured with the threshold tracking technique. The stimulus site was the median nerve, and the recording sites were the index finger (sensory studies) and abductor pollicis brevis muscle (motor studies). Results Participants with painless and painful polyneuropathy were well matched across clinical variables. Sensory and motor axonal excitability measures, including recovery cycle, threshold electrotonus, strength–duration time constant, and current–threshold relationship, did not show differences between participants with painful and painless diabetic polyneuropathy, and there were only minor changes for chemotherapy‐induced polyneuropathy. Interpretation Axonal excitability did not significantly differ between painful and painless diabetic or chemotherapy‐induced polyneuropathy in a multicenter observational study. Threshold tracking assesses the excitability of myelinated axons; the majority of nociceptors are unmyelinated, and although there is some overlap of the "channelome" between these axonal populations, our results suggest that alternative measures such as microneurography are required to understand the relationship between sensory neuron excitability and neuropathic pain. ANN NEUROL 2022;91:506–520
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Affiliation(s)
| | - Alexander Gramm Kristensen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
| | - Roma Sola
- Neuroscience Technologies, Barcelona, Spain.,MC Mutual, Barcelona, Spain
| | - Sandra Sif Gylfadottir
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Kristine Bennedsgaard
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Mustapha Itani
- Department of Neurology, Odense University Hospital, Odense, Denmark
| | - Thomas Krøigård
- Department of Neurology, Odense University Hospital, Odense, Denmark
| | - Lise Ventzel
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - Troels Staehelin Jensen
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Hugh Bostock
- UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Jordi Serra
- Neuroscience Technologies, Barcelona, Spain.,MC Mutual, Barcelona, Spain
| | - Nanna B Finnerup
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Hatice Tankisi
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
| | - David L H Bennett
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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17
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Slow touch in non-human species: translational research into the C-tactile (CT) afferent system. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2021.10.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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18
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Van Puyvelde M, Mairesse O. Do C-tactile afferents go to sleep? A potential role for somatosensory stimulation in sleep regulation. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2021.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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19
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Roza C, Bernal L. Electrophysiological characterization of ectopic spontaneous discharge in axotomized and intact fibers upon nerve transection: a role in spontaneous pain? Pflugers Arch 2022; 474:387-396. [PMID: 35088129 DOI: 10.1007/s00424-021-02655-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022]
Abstract
Many patients experience positive symptoms after traumatic nerve injury. Despite the increasing number of experimental studies in models of peripheral neuropathy and the knowledge acquired, most of these patients lack an effective treatment for their chronic pain. One possible explanation might be that most of the preclinical studies focused on the development of mechanical or thermal allodynia/hyperalgesia, neglecting that most of the patients with peripheral neuropathies complain mostly about spontaneous forms of pains. Here, we summarize the aberrant electrophysiological behavior of peripheral nerve fibers recorded in experimental models, the underlying pathophysiological mechanisms, and their relationship with the symptoms reported by patients. Upon nerve section, axotomized but also intact fibers develop ectopic spontaneous activity. Most interestingly, a proportion of axotomized fibers might present receptive fields in the skin far beyond the site of damage, indicative of a functional cross talk between neuromatose and intact fibers. All these features can be linked with some of the symptoms that neuropathic patients experience. Furthermore, we spotlight the consequence of primary afferents with different patterns of spontaneous discharge on the neural code and its relationship with chronic pain states. With this article, readers will be able to understand the pathophysiological mechanisms that might underlie some of the symptoms that experience neuropathic patients, with a special focus on spontaneous pain.
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Affiliation(s)
- Carolina Roza
- Dpto. Biología de Sistemas, Edificio de Medicina Universidad de Alcalá, 28871, Alcalá de Henares, Madrid, Spain.
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20
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Raabe W, Walk D. Median amplitude and frequency analysis of sensory nerve responses to intraepidermal stimulation. J Neurosci Methods 2022; 365:109377. [PMID: 34634281 DOI: 10.1016/j.jneumeth.2021.109377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 09/30/2021] [Accepted: 10/01/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND In clinical practice, small myelinated sensory fibers conveying pain and other sensations, Aδ-fibers, cannot be examined with available nerve conduction study techniques. NEW METHOD Equipment available in clinical neurophysiology laboratories is used to record from human sensory nerves multiple averaged responses to non-painful stimulation of intraepidermal nerves. Ten averaged responses are analyzed in all possible pair combinations with an algorithm applied to a 0.45 ms period of amplitude and frequency (power spectrum). The median of the algorithms is compared to control data to identify potentials generated as response to intraepidermal stimulation. RESULTS Median analysis of the algorithm applied to amplitude and frequency of multiple record pairs identifies potentials with conduction velocities of Aδ-fibers. The analysis of frequency (power spectrum) adds data to the analysis of amplitude. Median analysis of multiple record pairs yields more data than analysis of one pair of alternate averages with the same algorithms. COMPARISON WITH EXISTING METHOD(S) At present, analysis of one pair of alternate average records with an algorithm is the only method to identify Aδ-fiber generated potentials. Median analysis of the same algorithm applied to the amplitude of multiple record pairs increases the number of Aδ-fiber generated potentials identified. Neither median analysis of amplitude nor frequency of multiple records pairs has ever been used for conduction studies of nerve fibers, including Aδ-fibers. CONCLUSIONS Stimulation, recording and data analysis methods used in this study can be applied in the clinical EMG laboratory to identify the conduction velocities of Aδ-fibers in human sensory nerves.
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Affiliation(s)
- W Raabe
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA.
| | - D Walk
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA
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21
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Verdugo RJ, Matamala JM, Inui K, Kakigi R, Valls-Solé J, Hansson P, Bernhard Nilsen K, Lombardi R, Lauria G, Petropoulos IN, Malik RA, Treede RD, Baumgärtner U, Jara PA, Campero M. Review of techniques useful for the assessment of sensory small fiber neuropathies: Report from an IFCN expert group. Clin Neurophysiol 2022; 136:13-38. [DOI: 10.1016/j.clinph.2022.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/04/2022] [Accepted: 01/06/2022] [Indexed: 02/09/2023]
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22
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Nguyen MQ, von Buchholtz LJ, Reker AN, Ryba NJ, Davidson S. Single-nucleus transcriptomic analysis of human dorsal root ganglion neurons. eLife 2021; 10:71752. [PMID: 34825887 PMCID: PMC8626086 DOI: 10.7554/elife.71752] [Citation(s) in RCA: 94] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 11/06/2021] [Indexed: 12/14/2022] Open
Abstract
Somatosensory neurons with cell bodies in the dorsal root ganglia (DRG) project to the skin, muscles, bones, and viscera to detect touch and temperature as well as to mediate proprioception and many types of interoception. In addition, the somatosensory system conveys the clinically relevant noxious sensations of pain and itch. Here, we used single nuclear transcriptomics to characterize transcriptomic classes of human DRG neurons that detect these diverse types of stimuli. Notably, multiple types of human DRG neurons have transcriptomic features that resemble their mouse counterparts although expression of genes considered important for sensory function often differed between species. More unexpectedly, we identified several transcriptomic classes with no clear equivalent in the other species. This dataset should serve as a valuable resource for the community, for example as means of focusing translational efforts on molecules with conserved expression across species.
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Affiliation(s)
- Minh Q Nguyen
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, United States
| | - Lars J von Buchholtz
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, United States
| | - Ashlie N Reker
- Department of Anesthesiology, College of Medicine, University of Cincinnati, Cincinnati, United States
| | - Nicholas Jp Ryba
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, United States
| | - Steve Davidson
- Department of Anesthesiology, College of Medicine, University of Cincinnati, Cincinnati, United States
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23
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Holmes SA, Karapanagou A, Staffa SJ, Zurakowski D, Borra R, Simons LE, Sieberg C, Lebel A, Borsook D. DTI and MTR Measures of Nerve Fiber Integrity in Pediatric Patients With Ankle Injury. Front Pediatr 2021; 9:656843. [PMID: 34660471 PMCID: PMC8511521 DOI: 10.3389/fped.2021.656843] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Acute peripheral nerve injury can lead to chronic neuropathic pain. Having a standardized, non-invasive method to evaluate pathological changes in a nerve following nerve injury would help with diagnostic and therapeutic assessments or interventions. The accurate evaluation of nerve fiber integrity after injury may provide insight into the extent of pathology and a patient's level of self-reported pain. The aim of this investigation was to evaluate the extent to which peripheral nerve integrity could be evaluated in an acute ankle injury cohort and how markers of nerve fiber integrity correlate with self-reported pain levels in afferent nerves. We recruited 39 pediatric participants with clinically defined neuropathic pain within 3 months of an ankle injury and 16 healthy controls. Participants underwent peripheral nerve MRI using diffusion tensor (DTI) and magnetization transfer imaging (MTI) of their injured and non-injured ankles. The imaging window was focused on the branching point of the sciatic nerve into the tibial and fibular division. Each participant completed the Pain Detection Questionnaire (PDQ). Findings demonstrated group differences in DTI and MTI in the sciatic, tibial and fibular nerve in the injured ankle relative to healthy control and contralateral non-injured nerve fibers. Only AD and RD from the injured fibular nerve correlated with PDQ scores which coincides with the inversion-dominant nature of this particular ankle injuruy cohort. Exploratory analyses highlight the potential remodeling stages of nerve injury from neuropathic pain. Future research should emphasize sub-acute time frames of injury to capture post-injury inflammation and nerve fiber recovery.
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Affiliation(s)
- Scott A. Holmes
- Center for Pain and the Brain, Boston Children's Hospital, Boston, MA, United States
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Anastasia Karapanagou
- Center for Pain and the Brain, Boston Children's Hospital, Boston, MA, United States
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Steven J. Staffa
- Center for Pain and the Brain, Boston Children's Hospital, Boston, MA, United States
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - David Zurakowski
- Center for Pain and the Brain, Boston Children's Hospital, Boston, MA, United States
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Ronald Borra
- Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Laura E. Simons
- Department of Anesthesia, Stanford University, Stanford, CA, United States
| | - Christine Sieberg
- Center for Pain and the Brain, Boston Children's Hospital, Boston, MA, United States
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Alyssa Lebel
- Center for Pain and the Brain, Boston Children's Hospital, Boston, MA, United States
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - David Borsook
- Center for Pain and the Brain, Boston Children's Hospital, Boston, MA, United States
- Departments of Psychiatry and Radiology, Massachusetts General Hospital, Boston, MA, United States
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24
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Role of the Novel Peptide Phoenixin in Stress Response and Possible Interactions with Nesfatin-1. Int J Mol Sci 2021; 22:ijms22179156. [PMID: 34502065 PMCID: PMC8431171 DOI: 10.3390/ijms22179156] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 12/23/2022] Open
Abstract
The novel peptide phoenixin was shown to be involved in several physiological processes ranging from reproduction to food intake. Interest in this protein has steadily increased over the last few years and its known implications have become much broader, playing a role in glucose homeostasis, anxiety, nociception, and pruritus. Phoenixin is expressed in a multitude of organs such as the small intestine, pancreas, and in the hypothalamus, as well as several other brain nuclei influencing numerous physiological functions. Its highly conserved amino-acid sequence amongst species leads to the assumption, that phoenixin might be involved in essential physiological functions. Its co-expression and opposing functionality to the extensively studied peptide nesfatin-1 has given rise to the idea of a possible counterbalancing role. Several recent publications focused on phoenixin’s role in stress reactions, namely restraint stress and lipopolysaccharide-induced inflammation response, in which also nesfatin-1 is known to be altered. This review provides an overview on the phoenixins and nesfatin-1 properties and putative effects, and especially highlights the recent developments on their role and interaction in the response to response.
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25
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Chen WG, Schloesser D, Arensdorf AM, Simmons JM, Cui C, Valentino R, Gnadt JW, Nielsen L, Hillaire-Clarke CS, Spruance V, Horowitz TS, Vallejo YF, Langevin HM. The Emerging Science of Interoception: Sensing, Integrating, Interpreting, and Regulating Signals within the Self. Trends Neurosci 2021; 44:3-16. [PMID: 33378655 DOI: 10.1016/j.tins.2020.10.007] [Citation(s) in RCA: 234] [Impact Index Per Article: 78.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/21/2020] [Accepted: 10/14/2020] [Indexed: 02/07/2023]
Abstract
Interoception refers to the representation of the internal states of an organism, and includes the processes by which it senses, interprets, integrates, and regulates signals from within itself. This review presents a unified research framework and attempts to offer definitions for key terms to describe the processes involved in interoception. We elaborate on these definitions through illustrative research findings, and provide brief overviews of central aspects of interoception, including the anatomy and function of neural and non-neural pathways, diseases and disorders, manipulations and interventions, and predictive modeling. We conclude with discussions about major research gaps and challenges.
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Affiliation(s)
- Wen G Chen
- National Center for Complementary and Integrative Health (NCCIH), National Institutes of Health (NIH), Bethesda, MD 20892, USA.
| | - Dana Schloesser
- Office of Behavioral and Social Sciences Research (OBSSR), NIH, Bethesda, MD 20892, USA
| | - Angela M Arensdorf
- National Center for Complementary and Integrative Health (NCCIH), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Janine M Simmons
- National Institute of Mental Health (NIMH), NIH, Bethesda, MD 20892, USA
| | - Changhai Cui
- National Institute on Alcohol Abuse and Alcoholism (NIAAA), NIH, Bethesda, MD 20892, USA
| | - Rita Valentino
- National Institute on Drug Abuse (NIDA), NIH, Bethesda, MD 20892, USA
| | - James W Gnadt
- National Institute of Neurological Disorders and Stroke (NINDS), NIH, Bethesda, MD 20892, USA
| | - Lisbeth Nielsen
- National Institute on Aging (NIA), NIH, Bethesda, MD 20892, USA
| | | | - Victoria Spruance
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD 20892, USA
| | - Todd S Horowitz
- National Cancer Institute (NCI), NIH, Bethesda, MD 20892, USA
| | - Yolanda F Vallejo
- National Institute of Dental and Craniofacial Research (NIDCR), NIH, Bethesda, MD 20892, USA
| | - Helene M Langevin
- National Center for Complementary and Integrative Health (NCCIH), National Institutes of Health (NIH), Bethesda, MD 20892, USA
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26
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Ege Cansev M, Nordheimer D, Andrea Kirchner E, Beckerle P. Feel-Good Requirements: Neurophysiological and Psychological Design Criteria of Affective Touch for (Assistive) Robots. Front Neurorobot 2021; 15:661207. [PMID: 34295234 PMCID: PMC8290122 DOI: 10.3389/fnbot.2021.661207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/04/2021] [Indexed: 11/13/2022] Open
Abstract
Previous research has shown the value of the sense of embodiment, i.e., being able to integrate objects into one's bodily self-representation, and its connection to (assistive) robotics. Especially, tactile interfaces seem essential to integrate assistive robots into one's body model. Beyond functional feedback, such as tactile force sensing, the human sense of touch comprises specialized nerves for affective signals, which transmit positive sensations during slow and low-force tactile stimulations. Since these signals are extremely relevant for body experience as well as social and emotional contacts but scarcely considered in recent assistive devices, this review provides a requirement analysis to consider affective touch in engineering design. By analyzing quantitative and qualitative information from engineering, cognitive psychology, and neuroscienctific research, requirements are gathered and structured. The resulting requirements comprise technical data such as desired motion or force/torque patterns and an evaluation of potential stimulation modalities as well as their relations to overall user experience, e.g., pleasantness and realism of the sensations. This review systematically considers the very specific characteristics of affective touch and the corresponding parts of the neural system to define design goals and criteria. Based on the analysis, design recommendations for interfaces mediating affective touch are derived. This includes a consideration of biological principles and human perception thresholds which are complemented by an analysis of technical possibilities. Finally, we outline which psychological factors can be satisfied by the mediation of affective touch to increase acceptance of assistive devices and outline demands for further research and development.
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Affiliation(s)
- Mehmet Ege Cansev
- Chair of Autonomous Systems and Mechatronics, Department of Electrical Engineering, Faculty of Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Daniel Nordheimer
- Elastic Lightweight Robotics Group, Institute of Robotics Research, Department of Electrical and Information Engineering, Technische Universität Dortmund, Dortmund, Germany
| | - Elsa Andrea Kirchner
- Robotics Research Group, Mathematics and Computer Science, University of Bremen, Bremen, Germany.,Robotics Innovation Center, German Research Center for Artificial Intelligence, Bremen, Germany
| | - Philipp Beckerle
- Chair of Autonomous Systems and Mechatronics, Department of Electrical Engineering, Faculty of Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Institute for Mechatronic Systems, Department of Mechanical Engineering, Technical University of Darmstadt, Darmstadt, Germany
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Middleton SJ, Barry AM, Comini M, Li Y, Ray PR, Shiers S, Themistocleous AC, Uhelski ML, Yang X, Dougherty PM, Price TJ, Bennett DL. Studying human nociceptors: from fundamentals to clinic. Brain 2021; 144:1312-1335. [PMID: 34128530 PMCID: PMC8219361 DOI: 10.1093/brain/awab048] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/26/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022] Open
Abstract
Chronic pain affects one in five of the general population and is the third most important cause of disability-adjusted life-years globally. Unfortunately, treatment remains inadequate due to poor efficacy and tolerability. There has been a failure in translating promising preclinical drug targets into clinic use. This reflects challenges across the whole drug development pathway, from preclinical models to trial design. Nociceptors remain an attractive therapeutic target: their sensitization makes an important contribution to many chronic pain states, they are located outside the blood-brain barrier, and they are relatively specific. The past decade has seen significant advances in the techniques available to study human nociceptors, including: the use of corneal confocal microscopy and biopsy samples to observe nociceptor morphology, the culture of human nociceptors (either from surgical or post-mortem tissue or using human induced pluripotent stem cell derived nociceptors), the application of high throughput technologies such as transcriptomics, the in vitro and in vivo electrophysiological characterization through microneurography, and the correlation with pain percepts provided by quantitative sensory testing. Genome editing in human induced pluripotent stem cell-derived nociceptors enables the interrogation of the causal role of genes in the regulation of nociceptor function. Both human and rodent nociceptors are more heterogeneous at a molecular level than previously appreciated, and while we find that there are broad similarities between human and rodent nociceptors there are also important differences involving ion channel function, expression, and cellular excitability. These technological advances have emphasized the maladaptive plastic changes occurring in human nociceptors following injury that contribute to chronic pain. Studying human nociceptors has revealed new therapeutic targets for the suppression of chronic pain and enhanced repair. Cellular models of human nociceptors have enabled the screening of small molecule and gene therapy approaches on nociceptor function, and in some cases have enabled correlation with clinical outcomes. Undoubtedly, challenges remain. Many of these techniques are difficult to implement at scale, current induced pluripotent stem cell differentiation protocols do not generate the full diversity of nociceptor populations, and we still have a relatively poor understanding of inter-individual variation in nociceptors due to factors such as age, sex, or ethnicity. We hope our ability to directly investigate human nociceptors will not only aid our understanding of the fundamental neurobiology underlying acute and chronic pain but also help bridge the translational gap.
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Affiliation(s)
- Steven J Middleton
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Allison M Barry
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Maddalena Comini
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Yan Li
- Department of Anesthesia and Pain Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Pradipta R Ray
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Stephanie Shiers
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Andreas C Themistocleous
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.,Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa
| | - Megan L Uhelski
- Department of Anesthesia and Pain Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xun Yang
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Patrick M Dougherty
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa
| | - Theodore J Price
- Department of Neuroscience and Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX 75080, USA
| | - David L Bennett
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
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Mouraux A, Bannister K, Becker S, Finn DP, Pickering G, Pogatzki-Zahn E, Graven-Nielsen T. Challenges and opportunities in translational pain research - An opinion paper of the working group on translational pain research of the European pain federation (EFIC). Eur J Pain 2021; 25:731-756. [PMID: 33625769 PMCID: PMC9290702 DOI: 10.1002/ejp.1730] [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] [Indexed: 12/12/2022]
Abstract
For decades, basic research on the underlying mechanisms of nociception has held promise to translate into efficacious treatments for patients with pain. Despite great improvement in the understanding of pain physiology and pathophysiology, translation to novel, effective treatments for acute and chronic pain has however been limited, and they remain an unmet medical need. In this opinion paper bringing together pain researchers from very different disciplines, the opportunities and challenges of translational pain research are discussed. The many factors that may prevent the successful translation of bench observations into useful and effective clinical applications are reviewed, including interspecies differences, limited validity of currently available preclinical disease models of pain, and limitations of currently used methods to assess nociception and pain in non-human and human models of pain. Many paths are explored to address these issues, including the backward translation of observations made in patients and human volunteers into new disease models that are more clinically relevant, improved generalization by taking into account age and sex differences, and the integration of psychobiology into translational pain research. Finally, it is argued that preclinical and clinical stages of developing new treatments for pain can be improved by better preclinical models of pathological pain conditions alongside revised methods to assess treatment-induced effects on nociception in human and non-human animals. Significance: For decades, basic research of the underlying mechanisms of nociception has held promise to translate into efficacious treatments for patients with pain. Despite great improvement in the understanding of pain physiology and pathophysiology, translation to novel, effective treatments for acute and chronic pain has however been limited, and they remain an unmet medical need.
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Affiliation(s)
- André Mouraux
- Institute of Neuroscience (IONS), UCLouvain, Brussels, Belgium
| | - Kirsty Bannister
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Susanne Becker
- Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - David P Finn
- Pharmacology and Therapeutics, Centre for Pain Research, School of Medicine, National University of Ireland Galway, Galway, Ireland
| | - Gisèle Pickering
- Department of Clinical Pharmacology, Inserm CIC 1405, University Hospital, CHU Clermont-Ferrand, France.,Fundamental and Clinical Pharmacology of Pain, University Clermont Auvergne, Clermont-Ferrand, France
| | - Esther Pogatzki-Zahn
- Department of Anesthesiology, Critical Care Medicine and Pain Therapy, University Hospital Muenster, Muenster, Germany
| | - Thomas Graven-Nielsen
- Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark
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29
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Ahn YH, Kang HR. Pathophysiology, diagnosis, and management of chronic pruritus. ALLERGY ASTHMA & RESPIRATORY DISEASE 2021. [DOI: 10.4168/aard.2021.9.4.189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Yoon Hae Ahn
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea
| | - Hye-Ryun Kang
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea
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30
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Raabe W, Walk D. Slowly conducting potentials in human sensory nerves. J Neurosci Methods 2020; 351:109045. [PMID: 33358850 DOI: 10.1016/j.jneumeth.2020.109045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/13/2020] [Accepted: 12/15/2020] [Indexed: 01/18/2023]
Abstract
BACKGROUND In clinical practice, small myelinated sensory fibers, Aδ-fibers, conveying mainly pain and temperature sensations, cannot be examined with available nerve conduction study techniques. Currently, these fibers can only be examined with experimental or very specialized and not commonly available nerve conduction techniques, or only indirectly with cerebral evoked potentials. NEW METHOD This study uses equipment and methods available in clinical neurophysiology laboratories to record from human sensory nerves ≥1000 averaged responses to focal, non-painful stimuli applied by a special electrode to epidermal nerves. The averaged responses to odd numbered stimuli are compared to the averaged responses to even numbered stimuli. An algorithm identifies potentials common in both averages. The 99th and 99.9th percentiles for this algorithm are obtained from control records without stimulation and applied to records with stimulation to identify potentials resulting from stimulation of intraepidermal nerves. RESULTS The algorithm identifies numerous negative and positive potentials as being different from controls at the 99th and 99.9th percentile levels. The conduction velocities of the potentials range from of 1.3-29.9 m/s and are compatible with conduction velocities of Aδ-fibers. COMPARISON WITH EXISTING METHOD(S) No existing methods. CONCLUSIONS The stimulation, recording and data analysis methods used in this study can be applied in the clinical EMG laboratory to identify Aδ-fibers in human sensory nerves.
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Affiliation(s)
- W Raabe
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States.
| | - D Walk
- Department of Neurology, University of Minnesota, Minneapolis, MN, United States
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31
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Watkins RH, Dione M, Ackerley R, Backlund Wasling H, Wessberg J, Löken LS. Evidence for sparse C-tactile afferent innervation of glabrous human hand skin. J Neurophysiol 2020; 125:232-237. [PMID: 33296618 DOI: 10.1152/jn.00587.2020] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
C-tactile (CT) afferents were long-believed to be lacking in humans, but these were subsequently shown to densely innervate the face and arm skin, and to a lesser extent the leg. Their firing frequency to stroking touch at different velocities has been correlated with ratings of tactile pleasantness. CT afferents were thought to be absent in human glabrous skin; however, tactile pleasantness can be perceived across the whole body, including glabrous hand skin. We used microneurography to investigate mechanoreceptive afferents in the glabrous skin of the human hand, during median and radial nerve recordings. We describe CTs found in the glabrous skin, with characteristics comparable with those in hairy arm skin, and detail recordings from three such afferents. CTs were infrequently encountered in the glabrous skin and we estimate that the ratio of recorded CTs relative to myelinated mechanoreceptors (1:80) corresponds to an absolute innervation density of around seven times lower than in hairy skin. This sparse innervation sheds light on discrepancies between psychophysical findings of touch perception on glabrous skin and hairy skin, although the role of these CT afferents in the glabrous skin remains subject to future work.NEW & NOTEWORTHY Human touch is encoded by low-threshold mechanoreceptors, including myelinated Aβ afferents and unmyelinated C-tactile (CT) afferents. CTs are abundant in hairy skin and are thought to code gentle, stroking touch that signals positive affective interactions. CTs have never been described in human glabrous skin, yet we show evidence of their existence on the hand, albeit at a relatively low density. Glabrous skin CTs may provide modulatory reinforcement of gentle tactile interactions during touch using the hands.
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Affiliation(s)
- Roger Holmes Watkins
- LNC (Laboratoire de Neurosciences Cognitives (UMR 7291), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Université, Marseille, France.,Department of Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Mariama Dione
- LNC (Laboratoire de Neurosciences Cognitives (UMR 7291), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Université, Marseille, France.,Department of Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Rochelle Ackerley
- LNC (Laboratoire de Neurosciences Cognitives (UMR 7291), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Université, Marseille, France.,Department of Physiology, University of Gothenburg, Gothenburg, Sweden
| | | | - Johan Wessberg
- Department of Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Line S Löken
- Department of Physiology, University of Gothenburg, Gothenburg, Sweden
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32
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Systematic Review and Synthesis of Mechanism-based Classification Systems for Pain Experienced in the Musculoskeletal System. Clin J Pain 2020; 36:793-812. [DOI: 10.1097/ajp.0000000000000860] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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33
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Davis KD, Aghaeepour N, Ahn AH, Angst MS, Borsook D, Brenton A, Burczynski ME, Crean C, Edwards R, Gaudilliere B, Hergenroeder GW, Iadarola MJ, Iyengar S, Jiang Y, Kong JT, Mackey S, Saab CY, Sang CN, Scholz J, Segerdahl M, Tracey I, Veasley C, Wang J, Wager TD, Wasan AD, Pelleymounter MA. Discovery and validation of biomarkers to aid the development of safe and effective pain therapeutics: challenges and opportunities. Nat Rev Neurol 2020; 16:381-400. [PMID: 32541893 PMCID: PMC7326705 DOI: 10.1038/s41582-020-0362-2] [Citation(s) in RCA: 190] [Impact Index Per Article: 47.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2020] [Indexed: 02/06/2023]
Abstract
Pain medication plays an important role in the treatment of acute and chronic pain conditions, but some drugs, opioids in particular, have been overprescribed or prescribed without adequate safeguards, leading to an alarming rise in medication-related overdose deaths. The NIH Helping to End Addiction Long-term (HEAL) Initiative is a trans-agency effort to provide scientific solutions to stem the opioid crisis. One component of the initiative is to support biomarker discovery and rigorous validation in collaboration with industry leaders to accelerate high-quality clinical research into neurotherapeutics and pain. The use of objective biomarkers and clinical trial end points throughout the drug discovery and development process is crucial to help define pathophysiological subsets of pain, evaluate target engagement of new drugs and predict the analgesic efficacy of new drugs. In 2018, the NIH-led Discovery and Validation of Biomarkers to Develop Non-Addictive Therapeutics for Pain workshop convened scientific leaders from academia, industry, government and patient advocacy groups to discuss progress, challenges, gaps and ideas to facilitate the development of biomarkers and end points for pain. The outcomes of this workshop are outlined in this Consensus Statement.
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Affiliation(s)
- Karen D Davis
- Department of Surgery and Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
- Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Toronto Western Hospital, University Health Network, Toronto, ON, Canada.
| | - Nima Aghaeepour
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Martin S Angst
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - David Borsook
- Center for Pain and the Brain, Harvard Medical School, Boston, MA, USA
| | | | | | | | - Robert Edwards
- Pain Management Center, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Brice Gaudilliere
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Georgene W Hergenroeder
- The Vivian L. Smith Department of Neurosurgery, The University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, USA
| | - Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, NIH, Rockville, MD, USA
| | - Smriti Iyengar
- Division of Translational Research, National Institute of Neurological Disorders and Stroke, NIH, Rockville, MD, USA
| | - Yunyun Jiang
- The Biostatistics Center, Milken Institute School of Public Health, The George Washington University, Washington, DC, USA
| | - Jiang-Ti Kong
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Sean Mackey
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Carl Y Saab
- Department of Neuroscience and Department of Neurosurgery, Carney Institute for Brain Science, Brown University, Providence, RI, USA
| | - Christine N Sang
- Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Joachim Scholz
- Neurocognitive Disorders, Pain and New Indications, Biogen, Cambridge, MA, USA
| | | | - Irene Tracey
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Jing Wang
- Department of Anesthesiology, Perioperative Care and Pain Medicine, NYU School of Medicine, New York, NY, USA
| | - Tor D Wager
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, USA
| | - Ajay D Wasan
- Anesthesiology and Perioperative Medicine and Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mary Ann Pelleymounter
- Division of Translational Research, National Institute of Neurological Disorders and Stroke, NIH, Rockville, MD, USA
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Lee Masson H, Op de Beeck H, Boets B. Reduced task-dependent modulation of functional network architecture for positive versus negative affective touch processing in autism spectrum disorders. Neuroimage 2020; 219:117009. [PMID: 32504816 DOI: 10.1016/j.neuroimage.2020.117009] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/28/2020] [Accepted: 06/01/2020] [Indexed: 02/08/2023] Open
Abstract
Individuals with autism spectrum disorders (ASD) experience impairments in social communication and interaction, and often show difficulties with receiving and offering touch. Despite the high prevalence of abnormal reactions to touch in ASD, and the importance of touch communication in human relationships, the neural mechanisms underlying atypical touch processing in ASD remain largely unknown. To answer this question, we provided both pleasant and unpleasant touch stimulation to male adults with and without ASD during functional neuroimaging. By employing generalized psychophysiological interaction analysis combined with an independent component analysis approach, we characterize stimulus-dependent changes in functional connectivity patterns for processing two tactile stimuli that evoke different emotions (i.e., pleasant vs. unpleasant touch). Results reveal that neurotypical male adults showed extensive stimulus-sensitive modulations of the functional network architecture in response to the different types of touch, both at the level of brain regions and large-scale networks. Conversely, far fewer stimulus-sensitive modulations were observed in the ASD group. These aberrant functional connectivity profiles in the ASD group were marked by hypo-connectivity of the parietal operculum and major pain networks and hyper-connectivity between the semantic and limbic networks. Lastly, individuals presenting more social deficits and a more negative attitude towards social touch showed greater hyper-connectivity between the limbic and semantic networks. These findings suggest that reduced stimulus-related modulation of this functional network architecture is associated with abnormal processing of touch in ASD.
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Affiliation(s)
- Haemy Lee Masson
- Brain and Cognition, KU Leuven, 3000, Leuven, Belgium; Center for Developmental Psychiatry, KU Leuven, 3000, Leuven, Belgium; Leuven Brain Institute, KU Leuven, 3000, Leuven, Belgium; Leuven Autism Research (LAuRes) Consortium, KU Leuven, 3000, Leuven, Belgium.
| | - Hans Op de Beeck
- Brain and Cognition, KU Leuven, 3000, Leuven, Belgium; Leuven Brain Institute, KU Leuven, 3000, Leuven, Belgium
| | - Bart Boets
- Center for Developmental Psychiatry, KU Leuven, 3000, Leuven, Belgium; Leuven Brain Institute, KU Leuven, 3000, Leuven, Belgium; Leuven Autism Research (LAuRes) Consortium, KU Leuven, 3000, Leuven, Belgium
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35
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Croy I, Bierling A, Sailer U, Ackerley R. Individual Variability of Pleasantness Ratings to Stroking Touch Over Different Velocities. Neuroscience 2020; 464:33-43. [PMID: 32224227 DOI: 10.1016/j.neuroscience.2020.03.030] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/10/2020] [Accepted: 03/19/2020] [Indexed: 12/28/2022]
Abstract
Many studies have investigated the perception of tactile pleasantness over a range of stroking velocities. On average, pleasantness is low at slow (e.g. 0.3 cm/s) and fast (e.g. 30 cm/s) stroking velocities, but is rated highest at velocities between 1 and 10 cm/s. On a group level, this results in an inverted-U shape pleasantness ratings curve, which is described statistically by a negative quadratic equation. We reanalyzed the data from five earlier studies to investigate whether the inverted-U shape pleasantness curve at the group level is also present at the level of the individual, - a precondition for using tactile pleasantness perception as a diagnostic marker. We pooled the data from five studies with a total of 127 participants. Each study included a 'standard condition' of stroking on the dorsal forearm over different velocities (0.3, 1, 3, 10, 30 cm/s) and participants rated the pleasantness. Factors other than stroking velocity were also varied in these studies. On the whole-group level and in each study, pleasantness ratings produced a significant negative quadratic pleasantness curve over the stroking velocities. In individual participants, ratings varied greatly and only 42% of the participants showed a significant negative quadratic curve. The steepness of the inverted-U correlated only moderately across other experimental conditions, showing that the experimental circumstances can influence pleasantness ratings. Our findings have important implications for future work, where differences in the tactile pleasantness curve should not be used to predict or diagnose issues at an individual level.
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Affiliation(s)
- Ilona Croy
- Department of Psychotherapy and Psychosomatic Medicine, Medical Faculty, Technical University of Dresden, Germany
| | - Antonie Bierling
- Department of Psychotherapy and Psychosomatic Medicine, Medical Faculty, Technical University of Dresden, Germany
| | - Uta Sailer
- Department of Behavioral Sciences in Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Rochelle Ackerley
- Aix Marseille Univ, CNRS, LNSC (Laboratoire de Neurosciences Sensorielles et Cognitives - UMR 7260), Marseille, France.
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36
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Cutaneous warmth, but not touch, increases muscle sympathetic nerve activity during a muscle fatigue hand-grip task. Exp Brain Res 2020; 238:1035-1042. [PMID: 32198543 PMCID: PMC7181540 DOI: 10.1007/s00221-020-05779-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 03/10/2020] [Indexed: 12/05/2022]
Abstract
In homeostasis, somatosensory C fibre afferents are hypothesised to mediate input to the brain about interactions with external stimuli and sympathetic efference provides the output that regulates bodily functions. We aimed to test this hypothesis and whether different types of innocuous somatosensory input have differential effects. Healthy volunteers performed a muscle fatigue (hand-grip) task to exhaustion, which produces increased muscle sympathetic nerve activity (MSNA), as measured through microneurography. Participants completed the muscle fatigue task without concurrent cutaneous sensory stimulation (control) or we applied skin warming (heat pack) as a C fibre stimulation, slow brush stroking as C and Aβ fibre stimulation, or vibration as Aβ fibre stimulation, to the participant’s forearm. We also measured heart rate, the duration of the hand-grip task, and ratings of pain at the end of the task. Concurrent skin warming showed increased MSNA compared to the other conditions. Tactile stimuli (brushing, vibration) were not significantly different to the control (no intervention) condition. Warming increased the pain from the muscle contraction, whereas the tactile stimuli did not. We interpret the effect of warming on MSNA as providing relevant afferent information during muscle contraction, which needed to be counteracted via vasoconstriction to maintain homeostasis. Brushing and vibration were less homeostatically relevant stimuli for the muscle contraction and hence had no significant effect. The findings add sensory specificity to our current understanding of homeostatic regulation through somatosensory afferent and sympathetic efferent pathways.
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37
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Dickenson AH, Patel R. Translational issues in precision medicine in neuropathic pain. CANADIAN JOURNAL OF PAIN-REVUE CANADIENNE DE LA DOULEUR 2020; 4:30-38. [PMID: 32258972 PMCID: PMC7077367 DOI: 10.1080/24740527.2020.1720502] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/14/2020] [Accepted: 01/21/2020] [Indexed: 02/08/2023]
Abstract
Neuropathic pain remains poorly treated, with most new drugs falling through the translational gap. The traditional model of bench-to-bedside research has relied on identifying new mechanisms/targets in animal models and then developing clinical applications. Several have advocated bridging the translational gap by beginning with clinical observations and back-translating to animal models for further investigation of mechanisms. There is good evidence that phenotyping of patients through quantitative sensory testing can lead to improved treatment selection and hence improved patient outcomes. This practice has been widely adopted in clinical investigations, but its application in preclinical research is not mainstream. In this review, we retrospectively examine our historical rodent data sets with the aim of reconsidering drug effects on sensory neuronal endpoints, their alignment with clinical observations, and how these might guide future clinical studies.
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Affiliation(s)
- Anthony H Dickenson
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Ryan Patel
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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38
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Ackerley R, Wiklund Fernström K, Backlund Wasling H, Watkins RH, Johnson RD, Vallbo Å, Wessberg J. Differential effects of radiant and mechanically applied thermal stimuli on human C-tactile afferent firing patterns. J Neurophysiol 2018; 120:1885-1892. [PMID: 30044679 DOI: 10.1152/jn.00940.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
C-tactile (CT) afferents respond to gentle tactile stimulation, but only a handful of studies in humans and animals have investigated whether their firing is modified by temperature. We describe the effects of radiant thermal stimuli, and of stationary and very slowly moving mechanothermal stimuli, on CT afferent responses. We find that CT afferents are primarily mechanoreceptors, as they fired little during radiant thermal stimuli, but they exhibited different patterns of firing during combined mechano-cool stimulation compared with warming. CTs fired optimally to gentle, very slowly moving, or stationary mechanothermal stimuli delivered at neutral temperature (~32°C, normal skin temperature), but they responded with fewer spikes (median 67% decrease) and at significantly lower rates (47% decrease) during warm (~42°C) tactile stimuli. During cool tactile stimuli (~18°C), their mean instantaneous firing frequency significantly decreased by 35%, but they often fired a barrage of afterdischarge spikes at a low frequency (~5 Hz) that outlasted the mechanical stimulus. These effects were observed under a variety of stimulus conditions, including during stationary and slowly moving touch (0.1 cm/s), and we complemented these tactile approaches using a combined electrical-thermal stimulation experiment where we found a suppression of spiking during warming. Overall, CT afferents are exquisitely sensitive to tactile events, and we show that their firing is modulated with touch temperatures above and below neutral skin temperature. Warm touch consistently decreased their propensity to fire, whereas cool touch produced lower firing rates but afterdischarge spiking. NEW & NOTEWORTHY C-tactile (CT) afferents are thought to underpin pleasant touch, and previous work has shown that they respond optimally to a slow caress delivered at typical (neutral) skin temperature. Here, we show that, although CTs are primarily mechanoreceptive afferents, they are modified by temperature: warm touch decreases their firing, whereas cool touch produces lower firing rates but long-lasting spiking, frequently seen as afterdischarges. This has implications for the encoding of affective sensory events in human skin.
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Affiliation(s)
- Rochelle Ackerley
- Aix Marseille Université, CNRS, LNSC (Laboratoire de Neurosciences Sensorielles et Cognitives - UMR 7260), Marseille , France.,Department of Physiology, University of Gothenburg , Gothenburg , Sweden
| | | | | | - Roger H Watkins
- Department of Physiology, University of Gothenburg , Gothenburg , Sweden
| | - Richard D Johnson
- Department of Physiology, University of Gothenburg , Gothenburg , Sweden.,Department of Physiological Sciences, University of Florida College of Veterinary Medicine , Gainesville, Florida
| | - Åke Vallbo
- Department of Physiology, University of Gothenburg , Gothenburg , Sweden
| | - Johan Wessberg
- Department of Physiology, University of Gothenburg , Gothenburg , Sweden
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