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Waataja JJ, Honda CN, Asp AJ, Nihilani RK, Farajidavar A. The Duration and Intensity of High Frequency Alternating Current Influences the Degree and Recovery of Nerve Conduction Block. IEEE Trans Biomed Eng 2024; 71:2170-2179. [PMID: 38335073 DOI: 10.1109/tbme.2024.3364350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2024]
Abstract
OBJECTIVE The purpose of this paper is to investigate the persistence of nerve blockade beyond the duration of applying high frequency alternating current (HFAC) to thinly myelinated and non-myelinated fibers, also termed a "carry-over effect". METHODS In this study, we used electrically-evoked compound action potentials from isolated rat vagus nerves to assess the influence of 5 kHz HFAC amplitude and duration on the degree of the carry-over effect. Current amplitudes from 1-10 mA and 5 kHz durations from 10-120 seconds were tested. RESULTS By testing 20 different combinations of 5 kHz amplitude and duration, we found a significant interaction between 5 kHz amplitude and duration on influencing the carry-over effect. CONCLUSION The degree of carry-over effect was dependent on 5 kHz amplitude, as well as duration. SIGNIFICANCE Utilizing the carry-over effect may be useful in designing energy efficient nerve blocking algorithms for the treatment of diseases influenced by nerve activity.
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Berthon A, Wernisch L, Stoukidi M, Thornton M, Tessier-Lariviere O, Fortier-Poisson P, Mamen J, Pinkney M, Lee S, Sarkans E, Annecchino L, Appleton B, Garsed P, Patterson B, Gonshaw S, Jakopec M, Shunmugam S, Edwards T, Tukiainen A, Jennings J, Lajoie G, Hewage E, Armitage O. Using neural biomarkers to personalize dosing of vagus nerve stimulation. Bioelectron Med 2024; 10:15. [PMID: 38880906 PMCID: PMC11181600 DOI: 10.1186/s42234-024-00147-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/17/2024] [Indexed: 06/18/2024] Open
Abstract
BACKGROUND Vagus nerve stimulation (VNS) is an established therapy for treating a variety of chronic diseases, such as epilepsy, depression, obesity, and for stroke rehabilitation. However, lack of precision and side-effects have hindered its efficacy and extension to new conditions. Achieving a better understanding of the relationship between VNS parameters and neural and physiological responses is therefore necessary to enable the design of personalized dosing procedures and improve precision and efficacy of VNS therapies. METHODS We used biomarkers from recorded evoked fiber activity and short-term physiological responses (throat muscle, cardiac and respiratory activity) to understand the response to a wide range of VNS parameters in anaesthetised pigs. Using signal processing, Gaussian processes (GP) and parametric regression models we analyse the relationship between VNS parameters and neural and physiological responses. RESULTS Firstly, we illustrate how considering multiple stimulation parameters in VNS dosing can improve the efficacy and precision of VNS therapies. Secondly, we describe the relationship between different VNS parameters and the evoked fiber activity and show how spatially selective electrodes can be used to improve fiber recruitment. Thirdly, we provide a detailed exploration of the relationship between the activations of neural fiber types and different physiological effects. Finally, based on these results, we discuss how recordings of evoked fiber activity can help design VNS dosing procedures that optimize short-term physiological effects safely and efficiently. CONCLUSION Understanding of evoked fiber activity during VNS provide powerful biomarkers that could improve the precision, safety and efficacy of VNS therapies.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Guillaume Lajoie
- Université de Montréal and Mila-Quebec AI Institute, Montréal, Canada
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Verma N, Knudsen B, Gholston A, Skubal A, Blanz S, Settell M, Frank J, Trevathan J, Ludwig K. Microneurography as a minimally invasive method to assess target engagement during neuromodulation. J Neural Eng 2023; 20:10.1088/1741-2552/acc35c. [PMID: 36898148 PMCID: PMC10587909 DOI: 10.1088/1741-2552/acc35c] [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: 09/20/2022] [Accepted: 03/10/2023] [Indexed: 03/12/2023]
Abstract
Objective.Peripheral neural signals recorded during neuromodulation therapies provide insights into local neural target engagement and serve as a sensitive biomarker of physiological effect. Although these applications make peripheral recordings important for furthering neuromodulation therapies, the invasive nature of conventional nerve cuffs and longitudinal intrafascicular electrodes (LIFEs) limit their clinical utility. Furthermore, cuff electrodes typically record clear asynchronous neural activity in small animal models but not in large animal models. Microneurography, a minimally invasive technique, is already used routinely in humans to record asynchronous neural activity in the periphery. However, the relative performance of microneurography microelectrodes compared to cuff and LIFE electrodes in measuring neural signals relevant to neuromodulation therapies is not well understood.Approach.To address this gap, we recorded cervical vagus nerve electrically evoked compound action potentials (ECAPs) and spontaneous activity in a human-scaled large animal model-the pig. Additionally, we recorded sensory evoked activity and both invasively and non-invasively evoked CAPs from the great auricular nerve. In aggregate, this study assesses the potential of microneurography electrodes to measure neural activity during neuromodulation therapies with statistically powered and pre-registered outcomes (https://osf.io/y9k6j).Main results.The cuff recorded the largest ECAP signal (p< 0.01) and had the lowest noise floor amongst the evaluated electrodes. Despite the lower signal to noise ratio, microneurography electrodes were able to detect the threshold for neural activation with similar sensitivity to cuff and LIFE electrodes once a dose-response curve was constructed. Furthermore, the microneurography electrodes recorded distinct sensory evoked neural activity.Significance.The results show that microneurography electrodes can measure neural signals relevant to neuromodulation therapies. Microneurography could further neuromodulation therapies by providing a real-time biomarker to guide electrode placement and stimulation parameter selection to optimize local neural fiber engagement and study mechanisms of action.
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Affiliation(s)
- Nishant Verma
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute for Translational Neuroengineering (WITNe), Madison, WI, United States of America
| | - Bruce Knudsen
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute for Translational Neuroengineering (WITNe), Madison, WI, United States of America
| | - Aaron Gholston
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute for Translational Neuroengineering (WITNe), Madison, WI, United States of America
| | - Aaron Skubal
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute for Translational Neuroengineering (WITNe), Madison, WI, United States of America
| | - Stephan Blanz
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute for Translational Neuroengineering (WITNe), Madison, WI, United States of America
| | - Megan Settell
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute for Translational Neuroengineering (WITNe), Madison, WI, United States of America
| | - Jennifer Frank
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
| | - James Trevathan
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute for Translational Neuroengineering (WITNe), Madison, WI, United States of America
| | - Kip Ludwig
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute for Translational Neuroengineering (WITNe), Madison, WI, United States of America
- Department of Neurosurgery, University of Wisconsin-Madison, Madison, WI, United States of America
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Zou T, Chen H, Wang PC, Sun HH, Feng XM. Predictive factors for residual leg numbness after decompression surgery for lumbar degenerative diseases. BMC Musculoskelet Disord 2022; 23:910. [PMID: 36224568 PMCID: PMC9559037 DOI: 10.1186/s12891-022-05848-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 09/19/2022] [Indexed: 11/10/2022] Open
Abstract
Background The purpose of this study is to evaluate the change patterns of leg numbness (LN) after lumbar decompression surgery (LDS), and to find the predictive factors that affect the recovery of numbness. Methods Patients who underwent LDS in our institution between August 2020 and July 2021 were prospectively enrolled in this study, and were followed by a 12-month follow-up. The degree of LN, leg pain (LP) and the disability were assessed using the visual analog scale (VAS) and oswestry disability index (ODI). Results A total of 314 patients finished the 12-month follow-up. The preoperative mean VAS-LN score was 3.49 ± 2.44, which decreased to 1.91 ± 1.30 at 3 months, to 1.29 ± 0.97 at 6 months and to 1.26 ± 0.96 at 12 months after surgery. The preoperative mean VAS-LP score was 6.05 ± 1.30, which decreased to 2.00 ± 0.86 at 3 months, to 1.02 ± 0.80 at 6 months, and to 0.49 ± 0.71 at 12 months after surgery. The preoperative mean ODI score was 27.90 ± 7.08, which decreased to 9.73 ± 3.09 at 3 months, to 6.72 ± 2.98 at 6 months, and to 4.57 ± 2.76 at 12 months after surgery. Via multivariate logistic regression analysis, only preoperative VAS-LN score (p < 0.001*) was identified as a significantly independent predictive factor for residual LN after operation. Conclusion Clinically significant improvement in LN was observed in the majority of patients within 6 months after LDS, and the improvement of VAS-LN was slower than the VAS-LP. High pre-operative VAS-LN score can independently predict the presence of residual LN after surgery at 12-month follow up.
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Affiliation(s)
- Tao Zou
- Department of Orthopedics, Clinical Medical College of Yangzhou University, No.98 Nantong West Road, 225001, Yangzhou, Jiangsu province, China
| | - Hao Chen
- Department of Orthopedics, Clinical Medical College of Yangzhou University, No.98 Nantong West Road, 225001, Yangzhou, Jiangsu province, China
| | - Ping-Chuan Wang
- Department of Orthopedics, Clinical Medical College of Yangzhou University, No.98 Nantong West Road, 225001, Yangzhou, Jiangsu province, China
| | - Hui-Hui Sun
- Department of Orthopedics, Clinical Medical College of Yangzhou University, No.98 Nantong West Road, 225001, Yangzhou, Jiangsu province, China.
| | - Xin-Min Feng
- Department of Orthopedics, Clinical Medical College of Yangzhou University, No.98 Nantong West Road, 225001, Yangzhou, Jiangsu province, China.
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Sun Q, Li G, Liu D, Xie W, Xiao W, Li Y, Cai M. Peripheral nerves in the tibial subchondral bone : the role of pain and homeostasis in osteoarthritis. Bone Joint Res 2022; 11:439-452. [PMID: 35775136 PMCID: PMC9350689 DOI: 10.1302/2046-3758.117.bjr-2021-0355.r1] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Osteoarthritis (OA) is a highly prevalent degenerative joint disorder characterized by joint pain and physical disability. Aberrant subchondral bone induces pathological changes and is a major source of pain in OA. In the subchondral bone, which is highly innervated, nerves have dual roles in pain sensation and bone homeostasis regulation. The interaction between peripheral nerves and target cells in the subchondral bone, and the interplay between the sensory and sympathetic nervous systems, allow peripheral nerves to regulate subchondral bone homeostasis. Alterations in peripheral innervation and local transmitters are closely related to changes in nociception and subchondral bone homeostasis, and affect the progression of OA. Recent literature has substantially expanded our understanding of the physiological and pathological distribution and function of specific subtypes of neurones in bone. This review summarizes the types and distribution of nerves detected in the tibial subchondral bone, their cellular and molecular interactions with bone cells that regulate subchondral bone homeostasis, and their role in OA pain. A comprehensive understanding and further investigation of the functions of peripheral innervation in the subchondral bone will help to develop novel therapeutic approaches to effectively prevent OA, and alleviate OA pain. Cite this article: Bone Joint Res 2022;11(7):439–452.
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Affiliation(s)
- Qi Sun
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University, School of Medicine, Shanghai, China
| | - Gen Li
- Department of Orthopedics, Shanghai Institute of Traumatology and Orthopedics, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai, China
| | - Di Liu
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, China
| | - Wenqing Xie
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, China
| | - Wenfeng Xiao
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yusheng Li
- Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Ming Cai
- Department of Orthopedics, Shanghai Tenth People's Hospital, Tongji University, School of Medicine, Shanghai, China
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Mohan PR, chowdary S, Siva Kumar A, Maruthy K, Mahesh kumar K. Quantification of heat threshold and tolerance to evaluate small fiber neuropathy- an indigenously developed thermal model of pain. CLINICAL EPIDEMIOLOGY AND GLOBAL HEALTH 2021. [DOI: 10.1016/j.cegh.2021.100760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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7
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Rega D, Aiko M, Peñaranda N, Urios A, Gallego JJ, Giménez-Garzó C, Casanova F, Fiorillo A, Cabrera-Pastor A, San-Miguel T, Ipiens C, Escudero-García D, Tosca J, Montón C, Ballester MP, Ballester J, Aparicio L, Ríos MP, Durbán L, Mir A, Kosenko E, Cases P, Felipo V, Montoliu C. Patients with Minimal Hepatic Encephalopathy Show Altered Thermal Sensitivity and Autonomic Function. J Clin Med 2021; 10:jcm10020239. [PMID: 33440769 PMCID: PMC7826803 DOI: 10.3390/jcm10020239] [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: 10/28/2020] [Revised: 12/30/2020] [Accepted: 01/05/2021] [Indexed: 12/21/2022] Open
Abstract
Cirrhotic patients may experience alterations in the peripheral nervous system and in somatosensory perception. Impairment of the somatosensory system could contribute to cognitive and motor alterations characteristic of minimal hepatic encephalopathy (MHE), which affects up to 40% of cirrhotic patients. We assessed the relationship between MHE and alterations in thermal, vibration, and/or heat pain sensitivity in 58 cirrhotic patients (38 without and 20 with MHE according to Psychometric Hepatic Encephalopathy Score) and 39 controls. All participants underwent attention and coordination tests, a nerve conduction study, autonomic function testing, and evaluation of sensory thresholds (vibration, cooling, and heat pain detection) by electromyography and quantitative sensory testing. The detection thresholds for cold and heat pain on the foot were higher in patients with, than those without MHE. This hyposensitivity was correlated with attention deficits. Reaction times in the foot were longer in patients with, than without MHE. Patients with normal sural nerve amplitude showed altered thermal sensitivity and autonomic function, with stronger alterations in patients with, than in those without MHE. MHE patients show a general decrease in cognitive and sensory abilities. Small fibers of the autonomic nervous system and thermal sensitivity are altered early on in MHE, before large sensory fibers. Quantitative sensory testing could be used as a marker of MHE.
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Affiliation(s)
- Dalia Rega
- INCLIVA, Health Research Institute, 46010 Valencia, Spain (A.U.); (J.-J.G.); (F.C.); (A.F.); (A.C.-P.); (M.-P.B.)
| | - Mika Aiko
- Servicio de Neurofisiología, Hospital Clínico de Valencia, 46010 Valencia, Spain; (M.A.); (N.P.); (C.I.); (P.C.)
| | - Nicolás Peñaranda
- Servicio de Neurofisiología, Hospital Clínico de Valencia, 46010 Valencia, Spain; (M.A.); (N.P.); (C.I.); (P.C.)
| | - Amparo Urios
- INCLIVA, Health Research Institute, 46010 Valencia, Spain (A.U.); (J.-J.G.); (F.C.); (A.F.); (A.C.-P.); (M.-P.B.)
| | - Juan-José Gallego
- INCLIVA, Health Research Institute, 46010 Valencia, Spain (A.U.); (J.-J.G.); (F.C.); (A.F.); (A.C.-P.); (M.-P.B.)
| | - Carla Giménez-Garzó
- Laboratorio de Neurobiología. Centro Investigación Príncipe Felipe, 46012 Valencia, Spain; (C.G.-G.); (V.F.)
| | - Franc Casanova
- INCLIVA, Health Research Institute, 46010 Valencia, Spain (A.U.); (J.-J.G.); (F.C.); (A.F.); (A.C.-P.); (M.-P.B.)
| | - Alessandra Fiorillo
- INCLIVA, Health Research Institute, 46010 Valencia, Spain (A.U.); (J.-J.G.); (F.C.); (A.F.); (A.C.-P.); (M.-P.B.)
| | - Andrea Cabrera-Pastor
- INCLIVA, Health Research Institute, 46010 Valencia, Spain (A.U.); (J.-J.G.); (F.C.); (A.F.); (A.C.-P.); (M.-P.B.)
| | - Teresa San-Miguel
- Departamento de Patología, Facultad de Medicina, Universidad de Valencia, 46010 Valencia, Spain;
| | - Cristina Ipiens
- Servicio de Neurofisiología, Hospital Clínico de Valencia, 46010 Valencia, Spain; (M.A.); (N.P.); (C.I.); (P.C.)
| | - Desamparados Escudero-García
- Servicio de Medicina Digestiva, Hospital Clinico de Valencia, 46010 Valencia, Spain; (D.E.-G.); (J.T.); (C.M.); (J.B.)
- Departamento de Medicina, Universidad de Valencia, 46010 Valencia, Spain;
| | - Joan Tosca
- Servicio de Medicina Digestiva, Hospital Clinico de Valencia, 46010 Valencia, Spain; (D.E.-G.); (J.T.); (C.M.); (J.B.)
| | - Cristina Montón
- Servicio de Medicina Digestiva, Hospital Clinico de Valencia, 46010 Valencia, Spain; (D.E.-G.); (J.T.); (C.M.); (J.B.)
| | - María-Pilar Ballester
- INCLIVA, Health Research Institute, 46010 Valencia, Spain (A.U.); (J.-J.G.); (F.C.); (A.F.); (A.C.-P.); (M.-P.B.)
- Servicio de Medicina Digestiva, Hospital Clinico de Valencia, 46010 Valencia, Spain; (D.E.-G.); (J.T.); (C.M.); (J.B.)
| | - José Ballester
- Servicio de Medicina Digestiva, Hospital Clinico de Valencia, 46010 Valencia, Spain; (D.E.-G.); (J.T.); (C.M.); (J.B.)
| | - Luis Aparicio
- Departamento de Anatomía y Embriología, Universidad Valencia, 46010 Valencia, Spain;
| | - María-Pilar Ríos
- Servicio de Digestivo, Hospital Arnau de Vilanova, 46015 Valencia, Spain; (M.-P.R.); (L.D.)
| | - Lucía Durbán
- Servicio de Digestivo, Hospital Arnau de Vilanova, 46015 Valencia, Spain; (M.-P.R.); (L.D.)
| | - Amparo Mir
- Departamento de Medicina, Universidad de Valencia, 46010 Valencia, Spain;
| | - Elena Kosenko
- Institute of Theoretical and Experimental Biophysics of Russian Academy of Sciences, 142290 Pushchino, Russia;
| | - Paula Cases
- Servicio de Neurofisiología, Hospital Clínico de Valencia, 46010 Valencia, Spain; (M.A.); (N.P.); (C.I.); (P.C.)
| | - Vicente Felipo
- Laboratorio de Neurobiología. Centro Investigación Príncipe Felipe, 46012 Valencia, Spain; (C.G.-G.); (V.F.)
| | - Carmina Montoliu
- INCLIVA, Health Research Institute, 46010 Valencia, Spain (A.U.); (J.-J.G.); (F.C.); (A.F.); (A.C.-P.); (M.-P.B.)
- Departamento de Patología, Facultad de Medicina, Universidad de Valencia, 46010 Valencia, Spain;
- Correspondence: ; Tel.: +34-963-864-381
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Carmichael J, Fadavi H, Ishibashi F, Shore AC, Tavakoli M. Advances in Screening, Early Diagnosis and Accurate Staging of Diabetic Neuropathy. Front Endocrinol (Lausanne) 2021; 12:671257. [PMID: 34122344 PMCID: PMC8188984 DOI: 10.3389/fendo.2021.671257] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/17/2021] [Indexed: 12/14/2022] Open
Abstract
The incidence of both type 1 and type 2 diabetes is increasing worldwide. Diabetic peripheral neuropathy (DPN) is among the most distressing and costly of all the chronic complications of diabetes and is a cause of significant disability and poor quality of life. This incurs a significant burden on health care costs and society, especially as these young people enter their peak working and earning capacity at the time when diabetes-related complications most often first occur. DPN is often asymptomatic during the early stages; however, once symptoms and overt deficits have developed, it cannot be reversed. Therefore, early diagnosis and timely intervention are essential to prevent the development and progression of diabetic neuropathy. The diagnosis of DPN, the determination of the global prevalence, and incidence rates of DPN remain challenging. The opinions vary about the effectiveness of the expansion of screenings to enable early diagnosis and treatment initiation before disease onset and progression. Although research has evolved over the years, DPN still represents an enormous burden for clinicians and health systems worldwide due to its difficult diagnosis, high costs related to treatment, and the multidisciplinary approach required for effective management. Therefore, there is an unmet need for reliable surrogate biomarkers to monitor the onset and progression of early neuropathic changes in DPN and facilitate drug discovery. In this review paper, the aim was to assess the currently available tests for DPN's sensitivity and performance.
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Affiliation(s)
- Josie Carmichael
- Diabetes and Vascular Research Centre, National Institute for Health Research, Exeter Clinical Research Facility, University of Exeter Medical School, Exeter, United Kingdom
| | - Hassan Fadavi
- Peripheral Neuropathy Group, Imperial College, London, United Kingdom
| | - Fukashi Ishibashi
- Internal Medicine, Ishibashi Medical and Diabetes Centre, Hiroshima, Japan
| | - Angela C Shore
- Diabetes and Vascular Research Centre, National Institute for Health Research, Exeter Clinical Research Facility, University of Exeter Medical School, Exeter, United Kingdom
| | - Mitra Tavakoli
- Diabetes and Vascular Research Centre, National Institute for Health Research, Exeter Clinical Research Facility, University of Exeter Medical School, Exeter, United Kingdom
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Abe G, Oyama H, Liao Z, Honda K, Yashima K, Asao A, Izumi SI. Difference in Pain and Discomfort of Comparable Wrist Movements Induced by Magnetic or Electrical Stimulation for Peripheral Nerves in the Dorsal Forearm. MEDICAL DEVICES-EVIDENCE AND RESEARCH 2020; 13:439-447. [PMID: 33376417 PMCID: PMC7755354 DOI: 10.2147/mder.s271258] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/29/2020] [Indexed: 11/23/2022] Open
Abstract
Purpose Both repetitive peripheral magnetic stimulation (rPMS) and transcutaneous electrical current stimulation (TES) could elicit the limb movements; it is still unclear how subjective sensation is changed according to the amount of limb movements. We investigated the pain and discomfort induced by newly developed rPMS and TES of peripheral nerves in the dorsal forearm. Methods The subjects were 12 healthy adults. The stimulus site was the right dorsal forearm; thus, when stimulated, wrist dorsiflexion was induced. The rPMS was delivered by the new stimulator, Pathleader at 10 stimulus intensity levels, and TES intensity was in 1-mA increments. The duration of each stimulation was 2 s. The analysis parameters were subjective pain and discomfort, measured by a numerical rating scale. The rating scale at corresponding levels of integrated range of movement (iROM) induced by rPMS or TES was compared. The subjective values were analyzed by two-way repeated measures ANOVA with the stimulus conditions (rPMS, TES) and the seven levels of iROM (20-140 ºs). Results In the rPMS experiments, stimuli were administered to all subjects at all stimulus intensities. In the TES experiments, none of the subjects dropped out between 1 and 16 mA, but there were dropouts at each of the intensities as follows: 1 subject at 17 mA, 20 mA, 22 mA, 23 mA, 27 mA, 29 mA and 2 subjects at 21 mA, 24 mA, 26 mA. The main effects of the stimulus conditions and iROM were significant for pain and discomfort. Post hoc analysis demonstrated that pain and discomfort in rPMS were significantly lower compared to TES when the iROM was above 60 ºs and 80 ºs, respectively. Conclusion New rPMS stimulator, Pathleader, caused less pain and discomfort than TES, but this was only evident when comparatively large joint movements occurred.
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Affiliation(s)
- Genji Abe
- Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Rehabilitation, Faculty of Medical Science and Welfare, Tohoku Bunka Gakuen University, Sendai, Miyagi, Japan
| | - Hideki Oyama
- Department of Physical Medicine and Rehabilitation, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi, Japan
| | - Zhenyi Liao
- Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Keita Honda
- Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | | | - Akihiko Asao
- Department of Occupational Therapy, Niigata University of Health and Welfare, Niigata, Japan
| | - Shin-Ichi Izumi
- Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.,Department of Physical Medicine and Rehabilitation, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi, Japan
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Lin Q, Shivdasani MN, Tsai D, Chang YC, Jayaprakash N, Zanos S, Lovell NH, Dokos S, Guo T. A Computational Model of Functionally-distinct Cervical Vagus Nerve Fibers. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:2475-2478. [PMID: 33018508 DOI: 10.1109/embc44109.2020.9175855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cervical vagus nerve stimulation (VNS) is a neuromodulation therapy used in the treatment of several chronic disorders. In order to maximize the therapeutic effectiveness of VNS, it has become increasingly important to deliver fiber-specific neurostimulation, so that undesired effects can be minimized. Assessing the activation of different vagal fiber types through electrical stimulation is therefore essential for developing fiber-selective VNS therapies. Towards this goal, we conducted in silico investigations using a generic model of functionally distinct nerve fibers and clinically relevant cuff electrodes using COMSOL. Our model is constrained by histological observations from rat cervical vagus nerves and its outputs are validated against averaged compound nerve action potentials (CNAPs) obtained from rat vagus nerve recordings. We propose this model as an effective tool to design fiber-specific stimulation protocols before testing them in experimental animals.
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Nicolai EN, Settell ML, Knudsen BE, McConico AL, Gosink BA, Trevathan JK, Baumgart IW, Ross EK, Pelot NA, Grill WM, Gustafson KJ, Shoffstall AJ, Williams JC, Ludwig KA. Sources of off-target effects of vagus nerve stimulation using the helical clinical lead in domestic pigs. J Neural Eng 2020; 17:046017. [PMID: 32554888 PMCID: PMC7717671 DOI: 10.1088/1741-2552/ab9db8] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Objective Clinical data suggest that efficacious vagus nerve stimulation (VNS) is limited by side effects such as cough and dyspnea that have stimulation thresholds lower than those for therapeutic outcomes. VNS side effects are putatively caused by activation of nearby muscles within the neck, via direct muscle activation or activation of nerve fibers innervating those muscles. Our goal was to determine the thresholds at which various VNS-evoked effects occur in the domestic pig—an animal model with vagus anatomy similar to human—using the bipolar helical lead deployed clinically. Approach Intrafascicular electrodes were placed within the vagus nerve to record electroneurographic (ENG) responses, and needle electrodes were placed in the vagal-innervated neck muscles to record electromyographic (EMG) responses. Main results Contraction of the cricoarytenoid muscle occurred at low amplitudes (~0.3 mA) and resulted from activation of motor nerve fibers in the cervical vagus trunk within the electrode cuff which bifurcate into the recurrent laryngeal branch of the vagus. At higher amplitudes (~1.4 mA), contraction of the cricoarytenoid and cricothyroid muscles was generated by current leakage outside the cuff to activate motor nerve fibers running within the nearby superior laryngeal branch of the vagus. Activation of these muscles generated artifacts in the ENG recordings that may be mistaken for compound action potentials representing slowly conducting Aδ-, B-, and C-fibers. Significance Our data resolve conflicting reports of the stimulation amplitudes required for C-fiber activation in large animal studies (>10 mA) and human studies (<250 μA). After removing muscle-generated artifacts, ENG signals with post-stimulus latencies consistent with Aδ- and B-fibers occurred in only a small subset of animals, and these signals had similar thresholds to those that caused bradycardia. By identifying specific neuroanatomical pathways that cause off-target effects and characterizing the stimulation dose-response curves for on- and off-target effects, we hope to guide interpretation and optimization of clinical VNS.
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Affiliation(s)
- Evan N Nicolai
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Mayo Clinic, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, United States of America
- Wisconsin Institute of Neuroengineering (WITNe), University of Wisconsin-Madison, WI, United States of America
| | - Megan L Settell
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Mayo Clinic, Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, United States of America
- Wisconsin Institute of Neuroengineering (WITNe), University of Wisconsin-Madison, WI, United States of America
| | - Bruce E Knudsen
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Department of Neurosurgery, Mayo Clinic, Rochester, MN, United States of America
- Wisconsin Institute of Neuroengineering (WITNe), University of Wisconsin-Madison, WI, United States of America
| | - Andrea L McConico
- Department of Neurosurgery, Mayo Clinic, Rochester, MN, United States of America
| | - Brian A Gosink
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Department of Neurosurgery, University of Wisconsin-Madison, Madison, WI, United States of America
| | - James K Trevathan
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute of Neuroengineering (WITNe), University of Wisconsin-Madison, WI, United States of America
| | - Ian W Baumgart
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Erika K Ross
- Abbott Neuromodulation, Plano, TX, United States of America
| | - Nicole A Pelot
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
| | - Warren M Grill
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
| | - Kenneth J Gustafson
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America
- Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States of America
| | - Andrew J Shoffstall
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States of America
- Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States of America
| | - Justin C Williams
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Department of Neurosurgery, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute of Neuroengineering (WITNe), University of Wisconsin-Madison, WI, United States of America
| | - Kip A Ludwig
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
- Department of Neurosurgery, University of Wisconsin-Madison, Madison, WI, United States of America
- Wisconsin Institute of Neuroengineering (WITNe), University of Wisconsin-Madison, WI, United States of America
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Risk Factors for Postsurgical Foot Complaints One Year Following Degenerative Lumbar Spinal Surgery. Spine (Phila Pa 1976) 2020; 45:E533-E541. [PMID: 31703052 DOI: 10.1097/brs.0000000000003315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
UNLABELLED MINI: Postsurgical foot complaints occurred frequently in 853 degenerative lumbar surgeries (prevalence, 20.6%; n = 176). Risk factor analysis showed that the incidence of postsurgical foot complaint was significantly higher in patients with preoperative foot symptoms (adjusted odds ratio, 5.532) and in those with preoperative sensory deficits on the leg (adjusted odds ratio, 1.904). STUDY DESIGN Retrospective. OBJECTIVE To investigate the prevalence and risk factors of postsurgical foot complaints (PFCs) following spinal surgery by using a modified pain drawing (PD) instrument. SUMMARY OF BACKGROUND DATA Although many patients report nonspecific foot symptoms with various clinical presentation, there is not a well defined diagnostic criterion. PDs are essential for measuring spinal surgery outcomes. We created a modified patient-physician communication-based PD instrument to overcome the limitations of the previous system. METHODS We included 853 consecutive patients who underwent decompression with or without fusion. PFCs were defined as sensory foot symptoms, including ambiguous sensations that were not clearly due to spinal pathology. Patients who complained of postoperative foot symptoms at more than two consecutive visits were assigned to the PFC group. The remaining patients were assigned to the asymptomatic group. We collected medical records using our PD instrument and compared variables between the two groups. RESULTS In total, 176 (20.6%) of the 853 patients had PFCs. The duration of preoperative leg pain was significantly longer in the PFC group than in the asymptomatic group (2.8 vs. 2.2 years; P = 0.048). The proportions of preoperative foot symptoms (82.9% vs. 43.3%) and sensory deficits on the leg (48.6% vs. 27%) were significantly greater in the PFC group than in the asymptomatic group (P < 0.001). Multivariable logistic regression analysis revealed two independent risk factors: the presence of preoperative foot symptoms (adjusted odds ratio, 5.532) and preoperative sensory deficits on the leg (adjusted odds ratio, 1.904). CONCLUSION PFCs occurred frequently after degenerative lumbar spinal surgery (prevalence, 20.6%). Based on our data using PD instrument, it can help reduce the incidence of PFCs if patients are informed and educated that preoperatively existing foot symptom and sensory deficits on the leg are significant risk factors for PFC development. LEVEL OF EVIDENCE 4.
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Numbness and Weakness Recovered at a Less Extent in Patients with Lumbar Disc Herniation after Percutaneous Endoscopic Lumbar Discectomy. Pain Res Manag 2019; 2019:4642701. [PMID: 31949548 PMCID: PMC6942906 DOI: 10.1155/2019/4642701] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 09/23/2019] [Accepted: 10/08/2019] [Indexed: 12/13/2022]
Abstract
Background Patients with lumbar disc herniation (LDH) may present with motor disorders and various sensory disorders, among which pain and numbness are the most common ones. Percutaneous endoscopic lumbar discectomy (PELD) is reported to be both safe and effective. However, most of the previous studies focused on the recovery of pain, and the relief extent of numbness and weakness has rarely been reported. The Sciatica Bothersomeness Index (SBI) is a self-assessment tool for LDH patients. It has demonstrated acceptable reliability, construct validity, and responsiveness. Objectives Our aim was to explore the curative effect of percutaneous endoscopic lumbar discectomy and to compare the various extent of relief among pain, numbness, and weakness. Methods The medical records of patients admitted for LDH from September 2016 to December 2018 were collected, and the patients were followed up for 3 months to evaluate the relief of their clinical symptoms. Preoperative and postoperative total scores and subitem scores of SBI were compared to evaluate the relief of pain, numbness, and weakness. Surgical outcomes of PELD were evaluated by the Nakai score, and patients were divided into two groups accordingly, which were the relief group (excellent and good in the Nakai score) and the less relief group (fair and poor in the Nakai score). Risk factors for PELD outcomes and preoperative presence of numbness and/or weakness were analyzed by the logistic model, and p value less than 0.05 was considered significant. Results A total of 86 patients met the inclusion criteria and acquired 3 months follow-up. Relief extent of pain, numbness, and weakness, was 82%, 41%, and 21%, respectively. There were 71 cases in the relief group and 15 cases in the less relief group. Results of the logistic regression analysis showed that the preoperative pain score of SBI (p=0.002; OR: 1.647 (1.199-2.261)) was a relatively independent risk factor for PELD outcomes, and multiplicativity of duration of preoperative symptoms and imaging grade [p=0.004; OR: 1.015 (1.005-1.026)] was a relatively independent risk factor for preoperative presence of numbness and/or weakness. Conclusions PELD had a good curative effect in the treatment of LDH. Patients of LDH recovered best from pain, followed by numbness and weakness after PELD. Higher level of patients self-reported preoperative pain indicated a better surgical outcome for LDH patients, and preoperative long duration of symptoms together with a severe compression of nerve root significantly increased the risk of presenting numbness and/or weakness.
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Vidondo B, Stettler S, Stojiljkovic A, Mogel H, Gaschen V, Spadavecchia C, Casoni D, Stoffel MH. Assessment of potential neuropathic changes in cattle after cautery disbudding. Res Vet Sci 2019; 126:9-16. [PMID: 31419617 DOI: 10.1016/j.rvsc.2019.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 07/07/2019] [Accepted: 08/02/2019] [Indexed: 02/02/2023]
Abstract
Disbudding of calves is a standard husbandry procedure to reduce the risk of injuries to other cattle and to workers. Whereas acute pain resulting from disbudding has been studied extensively, little is known about chronic pain as a potential long-term consequence. The goal of the present study was to investigate possible morphological changes in the cornual nerve as a function of disbudding. Samples were collected from 17 randomly selected bulls and from 21 calves from a prospective clinical study. Among the calves, 13 were disbudded and 8 were sham-disbudded. Out of the disbudded calves, 4 showed signs of chronic pain. In all the animals, the infraorbital nerve was used as a methodological check. Morphological analysis included measuring minimal diameters of the axons present in both the cornual and infraorbital nerves. Sympathetic fibers were identified as based on the presence of Tyroxine hydroxylase (TH). TH-negative fibers were considered afferents. Trigeminal ganglia from the calves were immunostained for glial fibrillary acidic protein (GFAP) and Activating transcription factor 3 (ATF3). R. cornualis and N. infraorbitalis differed in terms of axon diameters and proportion of TH-positive fibers. Weak evidence (p > .091) of a difference in axon diameters between control and disbudded calves was found in R. cornualis, but the proportion of TH-positive fibers was alike in both groups. Average glial envelope and the percentages of ATF3-positive neurons revealed no difference between calves with and without signs of pain. Thus, available evidence is insufficient to support neuropathic changes as a result of disbudding in calves.
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Affiliation(s)
- B Vidondo
- Veterinary Public Health Institute, Vetsuisse Faculty, University of Bern, POB 3350, CH - 3001 Bern, Switzerland
| | - S Stettler
- Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, POB 3350, CH - 3001 Bern, Switzerland
| | - A Stojiljkovic
- Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, POB 3350, CH - 3001 Bern, Switzerland.
| | - H Mogel
- Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, POB 3350, CH - 3001 Bern, Switzerland.
| | - V Gaschen
- Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, POB 3350, CH - 3001 Bern, Switzerland.
| | - C Spadavecchia
- Division of Veterinary Anesthesia, Vetsuisse Faculty, University of Bern, POB 3350, CH - 3001 Bern, Switzerland.
| | - D Casoni
- Division of Veterinary Anesthesia, Vetsuisse Faculty, University of Bern, POB 3350, CH - 3001 Bern, Switzerland.
| | - M H Stoffel
- Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, POB 3350, CH - 3001 Bern, Switzerland.
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Yu H, Wang D, Li Q. Periotic sensory dysfunction via postauricular approach after otitis media surgery. Laryngoscope 2018; 129:454-458. [PMID: 30325498 DOI: 10.1002/lary.27318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 01/10/2018] [Accepted: 05/08/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Huiqian Yu
- ENT Institute and Otorhinolaryngology Department; Affiliated Eye and ENT Hospital of Fudan University and Key Laboratory of Hearing Medicine, National Health Commission of the People's Republic of China (NHCPRC); Shanghai People's Republic of China
| | - Dan Wang
- ENT Institute and Otorhinolaryngology Department; Affiliated Eye and ENT Hospital of Fudan University and Key Laboratory of Hearing Medicine, National Health Commission of the People's Republic of China (NHCPRC); Shanghai People's Republic of China
| | - Qingzhong Li
- ENT Institute and Otorhinolaryngology Department; Affiliated Eye and ENT Hospital of Fudan University and Key Laboratory of Hearing Medicine, National Health Commission of the People's Republic of China (NHCPRC); Shanghai People's Republic of China
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Blom JHG, Van der Lubbe RHJ. Endogenous spatial attention directed to intracutaneous electrical stimuli on the forearms involves an external reference frame. Int J Psychophysiol 2017; 121:1-11. [PMID: 28847743 DOI: 10.1016/j.ijpsycho.2017.08.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 06/05/2017] [Accepted: 08/23/2017] [Indexed: 10/19/2022]
Abstract
In the present study, we examined whether the direction of attention while anticipating intracutaneous electrical stimuli on the left or right forearm occurs within an internal somatotopic or an external body-based reference frame. Participants placed their hands on a table in front of them in a normal position or in a crossed-hands position. A symbolic cue with a validity of 80% instructed participants to attend to either the left or the right side, which varied from trial to trial. Crossing the hands induces a conflict of internal and external reference frames which allows to determine the dominating reference frame(s). Analyses of the electroencephalogram (EEG) during the orienting phase revealed that crossing the arms did not induce a reversal of neural activity over central sites as a late direction attention-related positivity and increased ipsilateral alpha power over occipital and central sites was observed in both conditions. Hand position influenced the processing of the electrical stimuli as no effect of cue validity was observed on the P3a component in the crossed-hands position. Our results indicate that endogenous spatial attention to intracutaneous electrical stimuli primarily occurs within an external reference frame.
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Affiliation(s)
- Jorian H G Blom
- Cognitive Psychology and Ergonomics, University of Twente, The Netherlands
| | - Rob H J Van der Lubbe
- Cognitive Psychology and Ergonomics, University of Twente, The Netherlands; Cognitive Psychology, University of Finance and Management, Warszawa, Poland.
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Wu JR, Chen H, Yao YY, Zhang MM, Jiang K, Zhou B, Zhang DX, Wang J. Local injection to sciatic nerve of dexmedetomidine reduces pain behaviors, SGCs activation, NGF expression and sympathetic sprouting in CCI rats. Brain Res Bull 2017; 132:118-128. [DOI: 10.1016/j.brainresbull.2017.04.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 04/27/2017] [Indexed: 12/17/2022]
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Žužek MC, Rozman J, Pečlin P, Vrecl M, Frangež R. Analysis of compound action potentials elicited with specific current stimulating pulses in an isolated rat sciatic nerve. ACTA ACUST UNITED AC 2017; 62:37-48. [DOI: 10.1515/bmt-2015-0167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/26/2016] [Indexed: 11/15/2022]
Abstract
AbstractThe ability to selectively stimulate Aα, Aβ-fibers and Aδ-fibers in an isolated rat sciatic nerve (SNR) was assessed. The stimulus used was a current, biphasic pulse with a quasitrapezoidal cathodic phase and rectangular anodic phase where parameters were systematically varied: intensity of the cathodic phase (i
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Pečlin P, Mehle A, Karpe B, Rozman J. Electrochemical and Electrophysiological Performance of Platinum Electrodes Within the Ninety-Nine-Electrode Stimulating Nerve Cuff. Artif Organs 2015; 39:886-96. [DOI: 10.1111/aor.12625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Polona Pečlin
- Center for Implantable Technology and Sensors; ITIS d. o. o. Ljubljana; Ljubljana Slovenia
| | - Andraž Mehle
- Center for Implantable Technology and Sensors; ITIS d. o. o. Ljubljana; Ljubljana Slovenia
| | - Blaž Karpe
- Department of Materials and Metallurgy; Faculty of Natural Sciences and Engineering; University of Ljubljana; Ljubljana Slovenia
| | - Janez Rozman
- Center for Implantable Technology and Sensors; ITIS d. o. o. Ljubljana; Ljubljana Slovenia
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Li Y, Lao J, Zhao X, Tian D, Zhu Y, Wei X. The optimal distance between two electrode tips during recording of compound nerve action potentials in the rat median nerve. Neural Regen Res 2014; 9:171-8. [PMID: 25206798 PMCID: PMC4146167 DOI: 10.4103/1673-5374.125346] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2013] [Indexed: 11/25/2022] Open
Abstract
The distance between the two electrode tips can greatly influence the parameters used for recording compound nerve action potentials. To investigate the optimal parameters for these recordings in the rat median nerve, we dissociated the nerve using different methods and compound nerve action potentials were orthodromically or antidromically recorded with different electrode spacings. Compound nerve action potentials could be consistently recorded using a method in which the middle part of the median nerve was intact, with both ends dissociated from the surrounding fascia and a ground wire inserted into the muscle close to the intact part. When the distance between two stimulating electrode tips was increased, the threshold and supramaximal stimulating intensity of compound nerve action potentials were gradually decreased, but the amplitude was not changed significantly. When the distance between two recording electrode tips was increased, the amplitude was gradually increased, but the threshold and supramaximal stimulating intensity exhibited no significant change. Different distances between recording and stimulating sites did not produce significant effects on the aforementioned parameters. A distance of 5 mm between recording and stimulating electrodes and a distance of 10 mm between recording and stimulating sites were found to be optimal for compound nerve action potential recording in the rat median nerve. In addition, the orthodromic compound action potential, with a biphasic waveform that was more stable and displayed less interference (however also required a higher threshold and higher supramaximal stimulus), was found to be superior to the antidromic compound action potential.
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Affiliation(s)
- Yongping Li
- Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China ; Department of Orthopedics, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, China
| | - Jie Lao
- Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China
| | - Xin Zhao
- Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China
| | - Dong Tian
- Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China
| | - Yi Zhu
- Department of Hand Surgery of HuaShan Hospital, Fudan University; Key Laboratory of Hand Reconstruction, Ministry of Healthy; Shanghai Key Laboratory of Peripheral Nerve and Microsurgery, Shanghai, China
| | - Xiaochun Wei
- Department of Orthopedics, the Second Hospital of Shanxi Medical University, Taiyuan, Shanxi Province, China
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Richner M, Ulrichsen M, Elmegaard SL, Dieu R, Pallesen LT, Vaegter CB. Peripheral nerve injury modulates neurotrophin signaling in the peripheral and central nervous system. Mol Neurobiol 2014; 50:945-70. [PMID: 24752592 DOI: 10.1007/s12035-014-8706-9] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 04/01/2014] [Indexed: 12/21/2022]
Abstract
Peripheral nerve injury disrupts the normal functions of sensory and motor neurons by damaging the integrity of axons and Schwann cells. In contrast to the central nervous system, the peripheral nervous system possesses a considerable capacity for regrowth, but regeneration is far from complete and functional recovery rarely returns to pre-injury levels. During development, the peripheral nervous system strongly depends upon trophic stimulation for neuronal differentiation, growth and maturation. The perhaps most important group of trophic substances in this context is the neurotrophins (NGF, BDNF, NT-3 and NT-4/5), which signal in a complex spatial and timely manner via the two structurally unrelated p75(NTR) and tropomyosin receptor kinase (TrkA, Trk-B and Trk-C) receptors. Damage to the adult peripheral nerves induces cellular mechanisms resembling those active during development, resulting in a rapid and robust increase in the synthesis of neurotrophins in neurons and Schwann cells, guiding and supporting regeneration. Furthermore, the injury induces neurotrophin-mediated changes in the dorsal root ganglia and in the spinal cord, which affect the modulation of afferent sensory signaling and eventually may contribute to the development of neuropathic pain. The focus of this review is on the expression patterns of neurotrophins and their receptors in neurons and glial cells of the peripheral nervous system and the spinal cord. Furthermore, injury-induced changes of expression patterns and the functional consequences in relation to axonal growth and remyelination as well as to neuropathic pain development will be reviewed.
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Affiliation(s)
- Mette Richner
- Danish Research Institute of Translational Neuroscience DANDRITE, Nordic EMBL Partnership, and Lundbeck Foundation Research Center MIND, Department of Biomedicine, Aarhus University, Ole Worms Allé 3, 8000, Aarhus C, Denmark
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How fast pain, numbness, and paresthesia resolves after lumbar nerve root decompression: a retrospective study of patient's self-reported computerized pain drawing. Spine (Phila Pa 1976) 2014; 39:E529-36. [PMID: 24480941 DOI: 10.1097/brs.0000000000000240] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A single-center retrospective study. OBJECTIVE To compare the speed of recovery of different sensory symptoms, pain, numbness, and paresthesia, after lumbar nerve root decompression. SUMMARY OF BACKGROUND DATA Lumbar radiculopathy is characterized by different sensory symptoms like pain, numbness, and paresthesia, which may resolve at different rates after surgical decompression. METHODS Eighty-five cases with predominant lumbar radiculopathy treated surgically were reviewed. Oswestry Disability Index score, 36-Item Short Form Health Survey scores (Physical Component Summary and Mental Component Summary), and pain drawing at preoperative and at 6 weeks, 3 months, 6 months, and 1-year follow-up were reviewed. Recovery rate between different sensory symptoms were compared in all patients, and between the short-term compression (<6 mo) and long-term compression groups. RESULTS At baseline, 73 (85.8%) patients had pain, 63 (74.1%) had numbness, and 38 (44.7%) had paresthesia; 28 (32.9%) had all these 3 component of sensory symptoms. Mean pain score improved fastest (55.3% at 6 wk); further resolution until 1 year was slow and not significant compared with each previous visit. Both numbness and paresthesia scores showed a trend of faster recovery during the initial 6-week period (20.5% and 24%, respectively); paresthesia recovery reached a plateau at 3 months postoperatively, but numbness continued a slow recovery until 1-year follow-up. Both Oswestry Disability Index score and Physical Component Summary scores (54.02 ± 1.87 and 26.29 ± 0.93, respectively, at baseline) improved significantly compared with each previous visits at 6 weeks and 3 months postoperatively, but further improvement was insignificant. Mental Component Summary showed a similar trend but smaller improvement. The short-term compression group had faster recovery of pain than the long-term compression group. CONCLUSION In lumbar radiculopathy patients after surgical decompression, pain recovers fastest, in the first 6 weeks postoperatively, followed by paresthesia recovery that plateaus at 3 months postoperatively. Numbness recovers at a slower pace but continues until 1 year. LEVEL OF EVIDENCE 4.
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Alternative paradigm of selective vagus nerve stimulation tested on an isolated porcine vagus nerve. ScientificWorldJournal 2014; 2014:310283. [PMID: 24683328 PMCID: PMC3933024 DOI: 10.1155/2014/310283] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/02/2013] [Indexed: 11/18/2022] Open
Abstract
Alternative paradigm for spatial and fibre-type selective vagus nerve stimulation (VNS) was developed using realistic structural topography and tested in an isolated segment of a porcine cervical left vagus nerve (LVN). A spiral cuff (cuff) containing a matrix of ninety-nine electrodes was developed for selective VNS. A quasitrapezoidal stimulating pulse (stimulus) was applied to the LVN via an appointed group of three electrodes (triplet). The triplet and stimulus were configured to predominantly stimulate the B-fibres, minimizing stimulation of the A-fibres and by-passing the stimulation of the C-fibres. To assess which fibres made the most probable contribution to the neural response (NR) during selective VNS, the distribution of conduction velocity (CV) within the LVN was considered. Experimental testing of the paradigm showed the existence of certain parameters and waveforms of the stimulus, for which the contribution of the A-fibres to the NR was slightly reduced and that of the B-fibres was slightly enlarged. The cuff provided satisfactory fascicle discrimination in selective VNS as well as satisfactory fascicle discrimination during NR recording. However, in the present stage of development, fibre-type VNS remained rather limited.
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Alfieri A, Rampp S, Strauss C, Fleischhammer J, Rachinger J, Scheller C, Prell J. The relationship between nervus intermedius anatomy, ultrastructure, electrophysiology, and clinical function. Usefulness in cerebellopontine microsurgery. Acta Neurochir (Wien) 2014; 156:403-8. [PMID: 24287684 DOI: 10.1007/s00701-013-1952-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 11/13/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND Although previous studies have described the clinical features of the nervus intermedius (NI), no attempt has yet been made to describe the relationship between the ultrastructural and electrophysiological characteristics of the nervus intermedius and its motor competence. OBJECTIVE In this study, we analyzed the intraoperative electrophysiological response obtained during vestibular schwannoma surgery. The ultrastructure was studied using electron microscopy. MATERIALS AND METHODS Thirty-six consecutive patients underwent microsurgery for vestibular schwannoma with cerebellopontine angle tumors. The patients were extensively monitored intraoperatively. Selective stimulation of the nervus intermedius was attempted in all cases. The patients were then examined postoperatively and followed for a minimum of 1 year. Forty-three isolated human brainstems were analyzed to collect the ultrastructural NI data. RESULTS We found a correlation between the NI motor responses in the perinasal and perioral regions and the ultrastructure characteristics, with few (0.5 %) but large myelinated motor fibers (diameters >12 μm). Both characteristics are consistent with the clinical observation of transient weakness of the levator anguli oris muscle. These observations indicate a relationship between the intraoperative electrophysiological identification of the NI nervus intermedius and its clinical and ultrastructural characteristics. CONCLUSIONS Identifying the NI in the deformed anatomy of tumors could provide a fixed landmark during cerebellopontine surgery and help prevent damage of the facial nerve.
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Affiliation(s)
- Alex Alfieri
- Neurosurgery and Spinal Surgery, Ruppiner Kliniken Fehrbelliner Strasse, 39, D-16816, Neuruppin, Germany,
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Moldovan M, Alvarez S, Romer Rosberg M, Krarup C. Axonal voltage-gated ion channels as pharmacological targets for pain. Eur J Pharmacol 2013; 708:105-12. [PMID: 23500193 DOI: 10.1016/j.ejphar.2013.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 03/04/2013] [Indexed: 12/19/2022]
Abstract
Upon peripheral nerve injury (caused by trauma or disease process) axons of the dorsal root ganglion (DRG) somatosensory neurons have the ability to sprout and regrow/remyelinate to reinnervate distant target tissue or form a tangled scar mass called a neuroma. This regenerative response can become maladaptive leading to a persistent and debilitating pain state referred to as chronic pain corresponding to the clinical description of neuropathic/chronic inflammatory pain. There is little agreement to what causes peripheral chronic pain other than hyperactivity of the nociceptive DRG neurons which ultimately depends on the function of voltage-gated ion channels. This review focuses on the pharmacological modulators of voltage-gated ion channels known to be present on axonal membrane which represents by far the largest surface of DRG neurons. Blockers of voltage-gated Na(+) channels, openers of voltage-gated K(+) channels and blockers of hyperpolarization-activated cyclic nucleotide-gated channels that were found to reduce neuronal activity were also found to be effective in neuropathic and inflammatory pain states. The isoforms of these channels present on nociceptive axons have limited specificity. The rationale for considering axonal voltage-gated ion channels as targets for pain treatment comes from the accumulating evidence that chronic pain states are associated with a dysregulation of these channels that could alter their specificity and make them more susceptible to pharmacological modulation. This drives the need for further development of subtype-specific voltage-gated ion channels modulators, as well as clinically available neurophysiological techniques for monitoring axonal ion channel function in peripheral nerves.
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Affiliation(s)
- Mihai Moldovan
- Institute of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
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n5-STZ Diabetic Model Develops Alterations in Sciatic Nerve and Dorsal Root Ganglia Neurons of Wistar Rats. ISRN ENDOCRINOLOGY 2013; 2013:638028. [PMID: 23476801 PMCID: PMC3588209 DOI: 10.1155/2013/638028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 12/18/2012] [Indexed: 12/20/2022]
Abstract
One experimental model of diabetes mellitus (DM) similar to type
II DM, called n5-STZ, is obtained by a single injection (via i.p.)
of streptozotocin (STZ) in the 5th day of life of newborn rats.
The present investigation aimed to characterize alterations in
excitability of rat peripheral neurons in n5-STZ model. n5-STZ DM
was induced, and electrophysiological evaluation was done at 12th
week of rat life. Rats developed glucose intolerance, sensory
alteration, and hyperglycemia or near-normoglycemia (21.2 ± 1.6 and 7.4 ± 0.4 mmol/L). In near-normoglycemia group the significant
electrophysiological alteration observed was decreased in
amplitude of 2nd wave (2nd component, conduction velocity:
48.8 m/s) of compound action potential (CAP) of sciatic nerve. For
hyperglycemic rats, decreased excitability, amplitude, and
conduction velocity of 2nd CAP component of sciatic nerve were
found; a depolarization of resting potential (4-5 mV) and reduction
in maximum ascendant and descendant inclinations of action
potential were found in DRG neurons but no alteration on
Na+ current (INa+).
Thus, n5-STZ rats develop alterations in
excitability which were related to glycemic levels but were not
likely attributable to changes on INa+. Our data confirm that
n5-STZ model is a useful model to study type II DM.
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Rodrigues Júnior IA, Silva ICC, Gresta LT, Lyon S, Villarroel MDF, Arantes RME. Degree of skin denervation and its correlation to objective thermal sensory test in leprosy patients. PLoS Negl Trop Dis 2012; 6:e1975. [PMID: 23272267 PMCID: PMC3521713 DOI: 10.1371/journal.pntd.0001975] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 11/04/2012] [Indexed: 12/20/2022] Open
Abstract
Background Leprosy is an infectious disease affecting skin and peripheral nerves resulting in increased morbidity and physical deformities. Early diagnosis provides opportune treatment and reduces its complications, relying fundamentally on the demonstration of impaired sensation in suggestive cutaneous lesions. The loss of tactile sensitivity in the lesions is preceded by the loss of thermal sensitivity, stressing the importance of the thermal test in the suspicious lesions approach. The gold-standard method for the assessment of thermal sensitivity is the quantitative sensory test (QST). Morphological study may be an alternative approach to access the thin nerve fibers responsible for thermal sensitivity transduction. The few studies reported in leprosy patients pointed out a rarefaction of thin dermo-epidermal fibers in lesions, but used semi-quantitative evaluation methods. Methodology/Principal Findings This work aimed to study the correlation between the degree of thermal sensitivity impairment measured by QST and the degree of denervation in leprosy skin lesions, evaluated by immunohistochemistry anti-PGP 9.5 and morphometry. Twenty-two patients were included. There were significant differences in skin thermal thresholds among lesions and contralateral skin (cold, warm, cold induced pain and heat induced pain). The mean reduction in the density of intraepidermal and subepidermal fibers in lesions was 79.5% (SD = 19.6) and 80.8% (SD = 24.9), respectively. Conclusions/Significance We observed a good correlation between intraepidermal and subepidermal fibers deficit, but no correlation between these variables and those accounting for the degree of impairment in thermal thresholds, since the thin fibers rarefaction was homogeneously intense in all patients, regardless of the degree of sensory deficit. We believe that the homogeneously intense denervation in leprosy lesions should be objective of further investigations focused on its diagnostic applicability, particularly in selected cases with only discrete sensory impairment, patients unable to perform the sensory test and especially those with nonspecific histopathological finds. Our study has addressed objectively the rarefaction of cutaneous thin nerve fibers density and its correlation with quantitative thermal sensory test in leprosy patients. Thermal sensitivity evaluation is crucial to the early diagnosis of leprosy, since it is the first type of cutaneous sensitivity lost in the lesions. However, some patients are unable to perform thermal tests, like children and patients with cognitive impairment. The pathological study of those lesions is also fundamental and it is the gold standard method to diagnose and classify leprosy patients. However, it may also be unspecific, especially in the indeterminate form of leprosy. Our findings show that even in lesions with slight thermal sensitivity impairment, there is a homogeneously intense denervation, specifically in the superficial skin layers. We believe that our findings pave the way to future studies focused on the diagnostic applicability of the cutaneous thin nerve fibers density quantification in leprosy suspected lesions.
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Affiliation(s)
- Ismael Alves Rodrigues Júnior
- Departamento de Patologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Isabel Cristina Costa Silva
- Departamento de Patologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Letícia Trivellato Gresta
- Departamento de Patologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sandra Lyon
- Departamento de Dermatologia, Hospital Eduardo de Menezes, Fundação Hospitalar do Estado de Minas Gerais, Belo Horizonte, Brazil
| | | | - Rosa Maria Esteves Arantes
- Departamento de Patologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- * E-mail:
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Bucher D, Goaillard JM. Beyond faithful conduction: short-term dynamics, neuromodulation, and long-term regulation of spike propagation in the axon. Prog Neurobiol 2011; 94:307-46. [PMID: 21708220 PMCID: PMC3156869 DOI: 10.1016/j.pneurobio.2011.06.001] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 05/27/2011] [Accepted: 06/07/2011] [Indexed: 12/13/2022]
Abstract
Most spiking neurons are divided into functional compartments: a dendritic input region, a soma, a site of action potential initiation, an axon trunk and its collaterals for propagation of action potentials, and distal arborizations and terminals carrying the output synapses. The axon trunk and lower order branches are probably the most neglected and are often assumed to do nothing more than faithfully conducting action potentials. Nevertheless, there are numerous reports of complex membrane properties in non-synaptic axonal regions, owing to the presence of a multitude of different ion channels. Many different types of sodium and potassium channels have been described in axons, as well as calcium transients and hyperpolarization-activated inward currents. The complex time- and voltage-dependence resulting from the properties of ion channels can lead to activity-dependent changes in spike shape and resting potential, affecting the temporal fidelity of spike conduction. Neural coding can be altered by activity-dependent changes in conduction velocity, spike failures, and ectopic spike initiation. This is true under normal physiological conditions, and relevant for a number of neuropathies that lead to abnormal excitability. In addition, a growing number of studies show that the axon trunk can express receptors to glutamate, GABA, acetylcholine or biogenic amines, changing the relative contribution of some channels to axonal excitability and therefore rendering the contribution of this compartment to neural coding conditional on the presence of neuromodulators. Long-term regulatory processes, both during development and in the context of activity-dependent plasticity may also affect axonal properties to an underappreciated extent.
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Affiliation(s)
- Dirk Bucher
- The Whitney Laboratory and Department of Neuroscience, University of Florida, St. Augustine, FL 32080, USA.
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