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Proske U. Joint receptors play a role in position sense after all! J Physiol 2024; 602:3609-3612. [PMID: 38857461 DOI: 10.1113/jp286961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Accepted: 05/29/2024] [Indexed: 06/12/2024] Open
Affiliation(s)
- Uwe Proske
- School of Biomedical Sciences, Monash University, Clayton, VIC, Australia
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2
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Bennett-Kennett R, Pace J, Lynch B, Domanov Y, Luengo GS, Potter A, Dauskardt RH. Sensory neuron activation from topical treatments modulates the sensorial perception of human skin. PNAS NEXUS 2023; 2:pgad292. [PMID: 37771342 PMCID: PMC10531117 DOI: 10.1093/pnasnexus/pgad292] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 08/22/2023] [Indexed: 09/30/2023]
Abstract
Neural signaling of skin sensory perception from topical treatments is often reported in subjective terms such as a sensation of skin "tightness" after using a cleanser or "softness" after applying a moisturizer. However, the mechanism whereby cutaneous mechanoreceptors and corresponding sensory neurons are activated giving rise to these perceptions has not been established. Here, we provide a quantitative approach that couples in vitro biomechanical testing and detailed computational neural stimulation modeling along with a comprehensive in vivo self-assessment survey to demonstrate how cutaneous biomechanical changes in response to treatments are involved in the sensorial perception of the human skin. Strong correlations are identified between reported perception up to 12 hours post treatment and changes in the computed neural stimulation from mechanoreceptors residing deep under the skin surface. The study reveals a quantitative framework for understanding the biomechanical neural activation mechanism and the subjective perception by individuals.
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Affiliation(s)
- Ross Bennett-Kennett
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Joseph Pace
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Barbara Lynch
- L’Oréal Research and Innovation, Aulnay-sous-Bois 93601, France
| | - Yegor Domanov
- L’Oréal Research and Innovation, Aulnay-sous-Bois 93601, France
| | | | - Anne Potter
- L’Oréal Research and Innovation, Aulnay-sous-Bois 93601, France
| | - Reinhold H Dauskardt
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
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3
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Loutit AJ, Wheat HE, Khamis H, Vickery RM, Macefield VG, Birznieks I. How Tactile Afferents in the Human Fingerpad Encode Tangential Torques Associated with Manipulation: Are Monkeys Better than Us? J Neurosci 2023; 43:4033-4046. [PMID: 37142429 PMCID: PMC10254986 DOI: 10.1523/jneurosci.1305-22.2023] [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: 06/23/2022] [Revised: 04/14/2023] [Accepted: 04/17/2023] [Indexed: 05/06/2023] Open
Abstract
Dexterous object manipulation depends critically on information about forces normal and tangential to the fingerpads, and also on torque associated with object orientation at grip surfaces. We investigated how torque information is encoded by human tactile afferents in the fingerpads and compared them to 97 afferents recorded in monkeys (n = 3; 2 females) in our previous study. Human data included slowly-adapting Type-II (SA-II) afferents, which are absent in the glabrous skin of monkeys. Torques of different magnitudes (3.5-7.5 mNm) were applied in clockwise and anticlockwise directions to a standard central site on the fingerpads of 34 human subjects (19 females). Torques were superimposed on a 2, 3, or 4 N background normal force. Unitary recordings were made from fast-adapting Type-I (FA-I, n = 39), and slowly-adapting Type-I (SA-I, n = 31) and Type-II (SA-II, n = 13) afferents supplying the fingerpads via microelectrodes inserted into the median nerve. All three afferent types encoded torque magnitude and direction, with torque sensitivity being higher with smaller normal forces. SA-I afferent responses to static torque were inferior to dynamic stimuli in humans, while in monkeys the opposite was true. In humans this might be compensated by the addition of sustained SA-II afferent input, and their capacity to increase or decrease firing rates with direction of rotation. We conclude that the discrimination capacity of individual afferents of each type was inferior in humans than monkeys which could be because of differences in fingertip tissue compliance and skin friction.SIGNIFICANCE STATEMENT We investigated how individual human tactile nerve fibers encode rotational forces (torques) and compared them to their monkey counterparts. Human hands, but not monkey hands, are innervated by a tactile neuron type (SA-II afferents) specialized to encode directional skin strain yet, so far, torque encoding has only been studied in monkeys. We find that human SA-I afferents were generally less sensitive and less able to discriminate torque magnitude and direction than their monkey counterparts, especially during the static phase of torque loading. However, this shortfall in humans could be compensated by SA-II afferent input. This indicates that variation in afferent types might complement each other signaling different stimulus features possibly providing computational advantage to discriminate stimuli.
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Affiliation(s)
- Alastair J Loutit
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Biomedical Sciences, UNSW Sydney, Sydney, New South Wales 2031, Australia
| | - Heather E Wheat
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Heba Khamis
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- Graduate School of Biomedical Engineering, UNSW Sydney, Sydney, New South Wales 2031, Australia
| | - Richard M Vickery
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Biomedical Sciences, UNSW Sydney, Sydney, New South Wales 2031, Australia
- Bionics and Bio-robotics, Tyree Foundation Institute of Health Engineering, UNSW Sydney, Sydney, New South Wales 2031, Australia
| | - Vaughan G Macefield
- Baker Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria 3052, Australia
- Department of Neuroscience, Monash University, Melbourne, Victoria 3052, Australia
| | - Ingvars Birznieks
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Biomedical Sciences, UNSW Sydney, Sydney, New South Wales 2031, Australia
- Bionics and Bio-robotics, Tyree Foundation Institute of Health Engineering, UNSW Sydney, Sydney, New South Wales 2031, Australia
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4
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Bensmaia SJ, Tyler DJ, Micera S. Restoration of sensory information via bionic hands. Nat Biomed Eng 2023; 7:443-455. [PMID: 33230305 PMCID: PMC10233657 DOI: 10.1038/s41551-020-00630-8] [Citation(s) in RCA: 85] [Impact Index Per Article: 85.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 09/13/2020] [Indexed: 12/19/2022]
Abstract
Individuals who have lost the use of their hands because of amputation or spinal cord injury can use prosthetic hands to restore their independence. A dexterous prosthesis requires the acquisition of control signals that drive the movements of the robotic hand, and the transmission of sensory signals to convey information to the user about the consequences of these movements. In this Review, we describe non-invasive and invasive technologies for conveying artificial sensory feedback through bionic hands, and evaluate the technologies' long-term prospects.
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Affiliation(s)
- Sliman J Bensmaia
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL, USA.
- Committee on Computational Neuroscience, University of Chicago, Chicago, IL, USA.
- Grossman Institute for Neuroscience, Quantitative Biology, and Human Behavior, University of Chicago, Chicago, IL, USA.
| | - Dustin J Tyler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Silvestro Micera
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy.
- Translational Neural Engineering Laboratory, Center for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Federale de Lausanne, Lausanne, Switzerland.
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5
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A reassessment of the role of joint receptors in human position sense. Exp Brain Res 2023; 241:943-949. [PMID: 36869268 PMCID: PMC10082099 DOI: 10.1007/s00221-023-06582-0] [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: 01/11/2023] [Accepted: 02/22/2023] [Indexed: 03/05/2023]
Abstract
In the past, the peripheral sense organs responsible for generating human position sense were thought to be the slowly adapting receptors in joints. More recently, our views have changed and the principal position sensor is now believed to be the muscle spindle. Joint receptors have been relegated to the lesser role of acting as limit detectors when movements approach the anatomical limit of a joint. In a recent experiment concerned with position sense at the elbow joint, measured in a pointing task over a range of forearm angles, we have observed falls in position errors as the forearm was moved closer to the limit of extension. We considered the possibility that as the arm approached full extension, a population of joint receptors became engaged and that they were responsible for the changes in position errors. Muscle vibration selectively engages signals of muscle spindles. Vibration of elbow muscles undergoing stretch has been reported to lead to perception of elbow angles beyond the anatomical limit of the joint. The result suggests that spindles, by themselves, cannot signal the limit of joint movement. We hypothesise that over the portion of the elbow angle range where joint receptors become active, their signals are combined with those of spindles to produce a composite that contains joint limit information. As the arm is extended, the growing influence of the joint receptor signal is evidenced by the fall in position errors.
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6
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Valle G. Peripheral neurostimulation for encoding artificial somatosensations. Eur J Neurosci 2022; 56:5888-5901. [PMID: 36097134 PMCID: PMC9826263 DOI: 10.1111/ejn.15822] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/08/2022] [Accepted: 09/08/2022] [Indexed: 01/11/2023]
Abstract
The direct neural stimulation of peripheral or central nervous systems has been shown as an effective tool to treat neurological conditions. The electrical activation of the nervous sensory pathway can be adopted to restore the artificial sense of touch and proprioception in people suffering from sensory-motor disorders. The modulation of the neural stimulation parameters has a direct effect on the electrically induced sensations, both when targeting the somatosensory cortex and the peripheral somatic nerves. The properties of the artificial sensations perceived, as their location, quality and intensity are strongly dependent on the direct modulation of pulse width, amplitude and frequency of the neural stimulation. Different sensory encoding schemes have been tested in patients showing distinct effects and outcomes according to their impact on the neural activation. Here, I reported the most adopted neural stimulation strategies to artificially encode somatosensation into the peripheral nervous system. The real-time implementation of these strategies in bionic devices is crucial to exploit the artificial sensory feedback in prosthetics. Thus, neural stimulation becomes a tool to directly communicate with the human nervous system. Given the importance of adding artificial sensory information to neuroprosthetic devices to improve their control and functionality, the choice of an optimal neural stimulation paradigm could increase the impact of prosthetic devices on the quality of life of people with sensorimotor disabilities.
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Affiliation(s)
- Giacomo Valle
- Laboratory for Neuroengineering, Department of Health Sciences and TechnologyInstitute for Robotics and Intelligent Systems, ETH ZürichZürichSwitzerland
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7
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Wynands B, Zippenfennig C, Holowka NB, Lieberman DE, Milani TL. Does plantar skin abrasion affect cutaneous mechanosensation? Physiol Rep 2022; 10:e15479. [PMID: 36259120 PMCID: PMC9579735 DOI: 10.14814/phy2.15479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/31/2022] [Accepted: 09/06/2022] [Indexed: 06/16/2023] Open
Abstract
In humans, plantar cutaneous mechanoreceptors provide critical input signals for postural control during walking and running. Because these receptors are located within the dermis, the mechanical properties of the overlying epidermis likely affect the transmission of external stimuli. Epidermal layers are highly adaptable and can form hard and thick protective calluses, but their effects on plantar sensitivity are currently disputed. Some research has shown no effect of epidermal properties on sensitivity to vibrations, whereas other research suggests that vibration and touch sensitivity diminishes with a thicker and harder epidermis. To address this conflict, we conducted an intervention study where 26 participants underwent a callus abrasion while an age-matched control group (n = 16) received no treatment. Skin hardness and thickness as well as vibration perception thresholds and touch sensitivity thresholds were collected before and after the intervention. The Callus abrasion significantly decreased skin properties. The intervention group exhibited no change in vibration sensitivity but had significantly better touch sensitivity. We argue that touch sensitivity was impeded by calluses because hard skin disperses the monofilament's standardized pressure used to stimulate the mechanoreceptors over a larger area, decreasing indentation depth and therefore stimulus intensity. However, vibration sensitivity was unaffected because the vibrating probe was adjusted to reach specific indentation depths, and thus stimulus intensity was not affected by skin properties. Since objects underfoot necessarily indent plantar skin during weight-bearing, calluses should not affect mechanosensation during standing, walking, or running.
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Affiliation(s)
- Bert Wynands
- Department of Human Locomotion, Institute of Human Movement Science and HealthChemnitz University of TechnologyChemnitzGermany
| | - Claudio Zippenfennig
- Department of Human Locomotion, Institute of Human Movement Science and HealthChemnitz University of TechnologyChemnitzGermany
| | - Nicholas B. Holowka
- Department of Anthropology, College of Arts and SciencesUniversity at BuffaloBuffaloNew YorkUSA
| | - Daniel E. Lieberman
- Department of Human Evolutionary BiologyHarvard UniversityCambridgeMassachusettsUSA
| | - Thomas L. Milani
- Department of Human Locomotion, Institute of Human Movement Science and HealthChemnitz University of TechnologyChemnitzGermany
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8
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MS and GTO proprioceptor subtypes in the molecular genetic era: Opportunities for new advances and perspectives. Curr Opin Neurobiol 2022; 76:102597. [DOI: 10.1016/j.conb.2022.102597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 05/22/2022] [Accepted: 05/24/2022] [Indexed: 11/21/2022]
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9
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Michael GA, Salgues S, Plancher G, Duran G. Cues to body-related distortions and hallucinations? Spontaneous sensations correlate with EEG oscillatory activity recorded at rest in the somatosensory cortices. Psychiatry Res Neuroimaging 2022; 324:111506. [PMID: 35688045 DOI: 10.1016/j.pscychresns.2022.111506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 09/18/2021] [Accepted: 05/29/2022] [Indexed: 11/17/2022]
Abstract
Body awareness may arise in the total absence of sensory input, as suggested by the spontaneous occurrence of normal and pathological (i.e., hallucinatory) bodily sensations. These phenomena may arise due to back-projections from higher-order cortical areas to the primary (SI) and secondary (SII) somatosensory cortices, and would appear to be reflected in cortical oscillatory activity in both SI and SII. Here, we set to investigate the relationship of SI and SII in SPS. Healthy participants underwent an EEG recording session at rest, and then completed an experiment on the perception of spontaneous sensations occurring on the hands. Cortical oscillatory activity was extracted from specified ROIs in the somatosensory cortices. The findings showed that (i) SPS perceived in the fingers correlated positively with alpha-band oscillations recorded in SI, and that (ii) SPS perceived in the palm correlated positively with gamma-band oscillations and negatively with beta-band oscillations recorded in SII. Apart from supporting the idea that the somatosensory cortices are involved in bodily awareness even in the absence of sensory input, these findings also suggest that default oscillatory activity in the somatosensory cortices reflects individual differences in bodily awareness. The results are interpreted in terms of neural and cognitive processes that may give rise to bodily awareness and modulate it, and their importance in understanding body perception distortions and bodily delusions and hallucinations is discussed.
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Affiliation(s)
- George A Michael
- Université de Lyon, Lyon, France; Université Lyon 2, Unité de Recherche EMC, Lyon, France; Université Lyon 2, Institut de Psychologie, Lyon, France.
| | - Sara Salgues
- Université de Lyon, Lyon, France; Université Lyon 2, Unité de Recherche EMC, Lyon, France; Université Lyon 2, Institut de Psychologie, Lyon, France
| | - Gaën Plancher
- Université de Lyon, Lyon, France; Université Lyon 2, Unité de Recherche EMC, Lyon, France; Université Lyon 2, Institut de Psychologie, Lyon, France
| | - Geoffrey Duran
- Université de Lyon, Lyon, France; Université Lyon 2, Unité de Recherche EMC, Lyon, France; Université Lyon 2, Institut de Psychologie, Lyon, France
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10
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Dimitriou M. Human muscle spindles are wired to function as controllable signal-processing devices. eLife 2022; 11:e78091. [PMID: 35829705 PMCID: PMC9278952 DOI: 10.7554/elife.78091] [Citation(s) in RCA: 16] [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] [Received: 02/22/2022] [Accepted: 06/29/2022] [Indexed: 12/26/2022] Open
Abstract
Muscle spindles are encapsulated sensory organs found in most of our muscles. Prevalent models of sensorimotor control assume the role of spindles is to reliably encode limb posture and movement. Here, I argue that the traditional view of spindles is outdated. Spindle organs can be tuned by spinal γ motor neurons that receive top-down and peripheral input, including from cutaneous afferents. A new model is presented, viewing γ motor activity as an intermediate coordinate transformation that allows multimodal information to converge on spindles, creating flexible coordinate representations at the level of the peripheral nervous system. That is, I propose that spindles play a unique overarching role in the nervous system: that of a peripheral signal-processing device that flexibly facilitates sensorimotor performance, according to task characteristics. This role is compatible with previous findings and supported by recent studies with naturalistically active humans. Such studies have so far shown that spindle tuning enables the independent preparatory control of reflex muscle stiffness, the selective extraction of information during implicit motor adaptation, and for segmental stretch reflexes to operate in joint space. Incorporation of advanced signal-processing at the periphery may well prove a critical step in the evolution of sensorimotor control theories.
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Affiliation(s)
- Michael Dimitriou
- Physiology Section, Department of Integrative Medical Biology, Umeå UniversityUmeåSweden
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11
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Watkins RH, Amante M, Wasling HB, Wessberg J, Ackerley R. Slowly-adapting type II afferents contribute to conscious touch sensation in humans: evidence from single unit intraneural microstimulation. J Physiol 2022; 600:2939-2952. [PMID: 35569041 PMCID: PMC9328136 DOI: 10.1113/jp282873] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/03/2022] [Indexed: 11/08/2022] Open
Abstract
NEW & NOTEWORTHY Slowly-adapting type II mechanoreceptive afferents (SA-II) in glabrous hand skin encode touch force, direction, and velocity, as well as skin stretch/tension. Using single unit intraneural microstimulation, via microneurography in humans, a single mechanoreceptive afferent can be electrically-stimulated, producing a clear percept, yet SA-II stimulation has produced ambiguous results. We show that selective SA-II stimulation produces large pressure sensations, which has implications for their role in perceived touch and generating realistic touch feedback from prosthetics. KEY POINTS Slowly adapting type II mechanoreceptors (SA-IIs) are primary sensory neurons in humans that respond to pressure and stretch applied to the skin. To date, no specific conscious correlate of touch has been linked to SA-II activation Using microneurography and intraneural microstimulation to stimulate single sensory neurons in human subjects, we find a specific sensation linked to the activation of single SA-II afferents. This sensation of touch was reported as gentle pressure and subjects could detect this with a high degree of accuracy. Methods of artificial tactile sensory feedback and computational models of touch should include SA-II s as meaningful contributors to the conscious sensation of touch. ABSTRACT Slowly-adapting type II (SA-II, Ruffini) mechanoreceptive afferents respond well to pressure and stretch, and are regularly encountered in human microneurography studies. Despite an understanding of SA-II response properties, their role in touch perception remains unclear. Specific roles of different myelinated Aβ mechanoreceptive afferents in tactile perception have been revealed using single unit intraneural microstimulation (INMS), via microneurography, recording from and then electrically stimulating individual afferents. This method directly links single afferent artificial activation to perception, where INMS produces specific 'quantal' touch percepts associated with different mechanoreceptive afferent types. However, SA-II afferent stimulation has been ambiguous, producing inconsistent, vague sensations or no clear percept. We physiologically characterized hundreds of individual Aβ mechanoreceptive afferents in the glabrous hand skin and examined the subsequent percepts evoked by trains of low amplitude INMS current pulses (<10 μA). We present 18 SA-II afferents where INMS resulted in a clear, electrically evoked sensation of large (∼36 mm2 ) diffuse pressure, which was projected precisely to their physiologically-defined receptive field in the skin. This sensation was felt as natural, distinctive from other afferents, and showed no indications of multi-afferent stimulation. Stimulus frequency modulated sensation intensity and even brief stimuli (4 pulses, 60 ms) were perceived. These results suggest SA-II afferents contribute to perceived tactile sensations, can signal this rapidly and precisely, and are relevant and important for computational models of touch sensation and artificial prosthetic feedback. Abstract figure legend Using microneurography, recordings were made from single mechanoreceptive afferents in the median nerve of human subjects. After fiber classification, low amplitude (<10 μA) intraneural microstimulation was delivered to evoke sensations of touch. Varied sensations were evoked that could be attributed to selective activation of the recorded afferents. We identify a consistent link between type II slowly adapting mechanoreceptive afferents (SA-IIs) and a specific sensation (light pressure). These sensations matched the afferent properties precisely, indicated sensations were evoked by stimulating single SA-II afferents, and were modified by stimulus train modulations. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Roger Holmes Watkins
- Aix Marseille Univ, CNRS, LNC (Laboratoire de Neurosciences Cognitives - UMR 7291), Marseille, France
| | - Mario Amante
- Department of Physiology, University of Gothenburg, Gothenburg, 40530, Sweden
| | | | - Johan Wessberg
- Department of Physiology, University of Gothenburg, Gothenburg, 40530, Sweden
| | - Rochelle Ackerley
- Aix Marseille Univ, CNRS, LNC (Laboratoire de Neurosciences Cognitives - UMR 7291), Marseille, France
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12
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Graczyk EL, Christie BP, He Q, Tyler DJ, Bensmaia SJ. Frequency Shapes the Quality of Tactile Percepts Evoked through Electrical Stimulation of the Nerves. J Neurosci 2022; 42:2052-2064. [PMID: 35074865 PMCID: PMC8916769 DOI: 10.1523/jneurosci.1494-21.2021] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/29/2021] [Accepted: 11/22/2021] [Indexed: 11/21/2022] Open
Abstract
Electrical stimulation of the peripheral nerves of human participants provides a unique opportunity to study the neural determinants of perceptual quality using a causal manipulation. A major challenge in the study of neural coding of touch has been to isolate the role of spike timing-at the scale of milliseconds or tens of milliseconds-in shaping the sensory experience. In the present study, we address this question by systematically varying the pulse frequency (PF) of electrical stimulation pulse trains delivered to the peripheral nerves of seven participants with upper and lower extremity limb loss via chronically implanted neural interfaces. We find that increases in PF lead to systematic increases in perceived frequency, up to ∼50 Hz, at which point further changes in PF have little to no impact on sensory quality. Above this transition frequency, ratings of perceived frequency level off, the ability to discriminate changes in PF is abolished, and verbal descriptors selected to characterize the sensation change abruptly. We conclude that sensation quality is shaped by temporal patterns of neural activation, even if these patterns are imposed on a fixed neural population, but this temporal patterning can only be resolved up to ∼50 Hz. These findings highlight the importance of spike timing in shaping the quality of a sensation and will contribute to the development of encoding strategies for conveying touch feedback through bionic hands and feet.SIGNIFICANCE STATEMENT A major challenge in the study of neural coding of touch has been to understand how temporal patterns in neuronal responses shape the sensory experience. We address this question by varying the pulse frequency (PF) of electrical pulse trains delivered through implanted nerve interfaces in seven amputees. We concomitantly vary pulse width to separate the effect of changing PF on sensory quality from its effect on perceived magnitude. We find that increases in PF lead to increases in perceived frequency, a qualitative dimension, up to ∼50 Hz, beyond which changes in PF have little impact on quality. We conclude that temporal patterning in the neuronal response can shape quality and discuss the implications for restoring touch via neural interfaces.
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Affiliation(s)
- Emily L Graczyk
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio 44106
| | - Breanne P Christie
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106
- Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland 20723
| | - Qinpu He
- Committee on Computational Neuroscience, University of Chicago, Chicago, Illinois 60637
| | - Dustin J Tyler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio 44106
| | - Sliman J Bensmaia
- Committee on Computational Neuroscience, University of Chicago, Chicago, Illinois 60637
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois 60637
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13
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Rogers ER, Zander HJ, Lempka SF. Neural Recruitment During Conventional, Burst, and 10-kHz Spinal Cord Stimulation for Pain. THE JOURNAL OF PAIN 2022; 23:434-449. [PMID: 34583022 PMCID: PMC8925309 DOI: 10.1016/j.jpain.2021.09.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/09/2021] [Accepted: 09/11/2021] [Indexed: 10/20/2022]
Abstract
Spinal cord stimulation (SCS) is a popular neurostimulation therapy for severe chronic pain. To improve stimulation efficacy, multiple modes are now used clinically, including conventional, burst, and 10-kHz SCS. Clinical observations have produced speculation that these modes target different neural elements and/or work via distinct mechanisms of action. However, in humans, these hypotheses cannot be conclusively answered via experimental methods. Therefore, we utilized computational modeling to assess the response of primary afferents, interneurons, and projection neurons to conventional, burst, and 10-kHz SCS. We found that local cell thresholds were always higher than afferent thresholds, arguing against direct recruitment of these local cells. Furthermore, although we observed relative threshold differences between conventional, burst, and 10-kHz SCS, the recruitment order was the same. Finally, contrary to previous reports, axon collateralization produced complex changes in activation thresholds of primary afferents. These results motivate future work to contextualize clinical observations across SCS paradigms. PERSPECTIVE: This article presents the first computational modeling study to investigate neural recruitment during conventional, burst, and 10-kilohertz spinal cord stimulation for chronic pain within a single modeling framework. The results provide insight into these treatments' unknown mechanisms of action and offer context to interpreting clinical observations.
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Affiliation(s)
- Evan R. Rogers
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Hans J. Zander
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Scott F. Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA,Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
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14
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Verma N, Graham RD, Mudge J, Trevathan JK, Franke M, Shoffstall AJ, Williams J, Dalrymple AN, Fisher LE, Weber DJ, Lempka SF, Ludwig KA. Augmented Transcutaneous Stimulation Using an Injectable Electrode: A Computational Study. Front Bioeng Biotechnol 2021; 9:796042. [PMID: 34988068 PMCID: PMC8722711 DOI: 10.3389/fbioe.2021.796042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 11/25/2021] [Indexed: 11/13/2022] Open
Abstract
Minimally invasive neuromodulation technologies seek to marry the neural selectivity of implantable devices with the low-cost and non-invasive nature of transcutaneous electrical stimulation (TES). The Injectrode® is a needle-delivered electrode that is injected onto neural structures under image guidance. Power is then transcutaneously delivered to the Injectrode using surface electrodes. The Injectrode serves as a low-impedance conduit to guide current to the deep on-target nerve, reducing activation thresholds by an order of magnitude compared to using only surface stimulation electrodes. To minimize off-target recruitment of cutaneous fibers, the energy transfer efficiency from the surface electrodes to the Injectrode must be optimized. TES energy is transferred to the Injectrode through both capacitive and resistive mechanisms. Electrostatic finite element models generally used in TES research consider only the resistive means of energy transfer by defining tissue conductivities. Here, we present an electroquasistatic model, taking into consideration both the conductivity and permittivity of tissue, to understand transcutaneous power delivery to the Injectrode. The model was validated with measurements taken from (n = 4) swine cadavers. We used the validated model to investigate system and anatomic parameters that influence the coupling efficiency of the Injectrode energy delivery system. Our work suggests the relevance of electroquasistatic models to account for capacitive charge transfer mechanisms when studying TES, particularly when high-frequency voltage components are present, such as those used for voltage-controlled pulses and sinusoidal nerve blocks.
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Affiliation(s)
- Nishant Verma
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, WI, United States
- Wisconsin Institute for Translational Neuroengineering (WITNe)–Madison, Madison, WI, United States
| | - Robert D. Graham
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States
| | - Jonah Mudge
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, WI, United States
- Wisconsin Institute for Translational Neuroengineering (WITNe)–Madison, Madison, WI, United States
| | - James K. Trevathan
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, WI, United States
- Wisconsin Institute for Translational Neuroengineering (WITNe)–Madison, Madison, WI, United States
| | | | - Andrew J Shoffstall
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Justin Williams
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, WI, United States
- Wisconsin Institute for Translational Neuroengineering (WITNe)–Madison, Madison, WI, United States
| | - Ashley N. Dalrymple
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
- Rehab Neural Engineering Labs (RNEL), Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States
| | - Lee E. Fisher
- Rehab Neural Engineering Labs (RNEL), Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States
| | - Douglas J. Weber
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
- Rehab Neural Engineering Labs (RNEL), Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States
| | - Scott F. Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI, United States
| | - Kip A. Ludwig
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, WI, United States
- Wisconsin Institute for Translational Neuroengineering (WITNe)–Madison, Madison, WI, United States
- Department of Neurosurgery, University of Wisconsin–Madison, Madison, WI, United States
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15
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Two senses of human limb position: methods of measurement and roles in proprioception. Exp Brain Res 2021; 239:3157-3174. [PMID: 34482421 DOI: 10.1007/s00221-021-06207-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/26/2021] [Indexed: 12/18/2022]
Abstract
The sense of position of the body and its limbs is a proprioceptive sense. Proprioceptors are concerned with monitoring the body's own actions. Position sense is important because it is believed to contribute to our self-awareness. This review discusses recent developments in the debate about the sources of peripheral afferent signals contributing to position sense and describes different methods of measurement of position sense under conditions where vision does not participate. These include pointing to or verbal reporting of the perceived position of a hidden body part, alignment of one body part with the perceived position of another, or using memory-based repositioning tasks. The evidence suggests that there are at least two different mechanisms involved in the generation of position sense, mechanisms using different central processing pathways. The principal sensory receptor responsible for position sense is believed to be the muscle spindle. One criterion for identifying mechanism is whether position sense can be manipulated by controlled changes in spindle discharge rates. Position sense measured in two-limb matching is altered in a predictable way by such changes, while values for pointing and verbal reporting remain unresponsive. It is proposed that in two-limb matching the sensation generated is limb position in postural space. In pointing or verbal reporting, information is provided about limb position in extrapersonal space. Here vision is believed to play a role. The evidence suggests that we are aware, at the same time, of sensations of limb position in postural space as well as in extrapersonal space.
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16
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Shokur S, Mazzoni A, Schiavone G, Weber DJ, Micera S. A modular strategy for next-generation upper-limb sensory-motor neuroprostheses. MED 2021; 2:912-937. [DOI: 10.1016/j.medj.2021.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 04/28/2021] [Accepted: 05/10/2021] [Indexed: 02/06/2023]
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17
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Raspopovic S, Valle G, Petrini FM. Sensory feedback for limb prostheses in amputees. NATURE MATERIALS 2021; 20:925-939. [PMID: 33859381 DOI: 10.1038/s41563-021-00966-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
Commercial prosthetic devices currently do not provide natural sensory information on the interaction with objects or movements. The subsequent disadvantages include unphysiological walking with a prosthetic leg and difficulty in controlling the force exerted with a prosthetic hand, thus creating health issues. Restoring natural sensory feedback from the prosthesis to amputees is an unmet clinical need. An optimal device should be able to elicit natural sensations of touch or proprioception, by delivering the complex signals to the nervous system that would be produced by skin, muscles and joints receptors. This Review covers the various neurotechnological approaches that have been proposed for the development of the optimal sensory feedback restoration device for arm and leg amputees.
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Affiliation(s)
- Stanisa Raspopovic
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, Zurich, Switzerland.
| | - Giacomo Valle
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, Zurich, Switzerland
| | - Francesco Maria Petrini
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, Zurich, Switzerland
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18
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Salgues S, Plancher G, Michael GA. Visuospatial working memory abilities and spontaneous sensations perception. Somatosens Mot Res 2021; 38:164-177. [PMID: 34180338 DOI: 10.1080/08990220.2021.1914018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aim: Body awareness arises when attending to and maintaining awareness of visuospatial body representations. By the same token, focussing on representations transfers them to working memory. Body awareness and working memory seemingly rely on similar processes and recruit common parietal areas involved in perception. Therefore, we asked whether visuospatial working memory abilities would define individual differences in the perception of spontaneous sensations (SPS), i.e., bodily sensations perceived in the absence of triggers (e.g., tactile stimulation or movement), when attending to the body.Method: Participants completed two visuospatial working memory tasks to assess various mechanisms: (i) the decay of representations was assessed through a Brown-Peterson task in which the delay between the memorandum presentation and its recall was manipulated, and (ii) the impact of distractors' interference and cognitive load (i.e., complexity) on recall performances were assessed through a complex span task that required the processing of distractors while maintaining a memorandum. A standard SPS task involving localization and characterization of SPS perceived on the hands was completed afterwards.Results: Low performance due to decay, distractors' interference and cognitive load in visuospatial working memory was associated with a decrease in the frequency of SPS. Additionally, low performance due to distractors' cognitive load predicted a decrease in the perception of surface-type sensations, and high performance despite distractors' interference led to a better perception of SPS on less sensitive areas of the hand.Conclusion: We discuss how visuospatial working memory processes might contribute to body awareness and perceptual distortions of the body.
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Affiliation(s)
- Sara Salgues
- Université de Lyon, Lyon, France.,Département de Sciences Cognitives, Psychologie Cognitive et Neuropsychologie, Laboratoire d'Étude des Mécanismes Cognitifs (EA 3082), Institut de Psychologie, Université Lyon 2, Lyon, France
| | - Gaën Plancher
- Université de Lyon, Lyon, France.,Département de Sciences Cognitives, Psychologie Cognitive et Neuropsychologie, Laboratoire d'Étude des Mécanismes Cognitifs (EA 3082), Institut de Psychologie, Université Lyon 2, Lyon, France
| | - George A Michael
- Université de Lyon, Lyon, France.,Département de Sciences Cognitives, Psychologie Cognitive et Neuropsychologie, Laboratoire d'Étude des Mécanismes Cognitifs (EA 3082), Institut de Psychologie, Université Lyon 2, Lyon, France
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19
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Lutz OJ, Bensmaia SJ. Proprioceptive representations of the hand in somatosensory cortex. CURRENT OPINION IN PHYSIOLOGY 2021. [DOI: 10.1016/j.cophys.2021.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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20
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Onishi Y, Hisato H, Maeda S, Minato Y, Kuwahara-Otani S, Yagi H. Relationship between lamellar sensory corpuscles distributed along the upper arm's deep arteries and pulsating sensation of blood vessels. J Anat 2021; 239:101-110. [PMID: 33527396 DOI: 10.1111/joa.13398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 12/27/2020] [Accepted: 01/08/2021] [Indexed: 11/29/2022] Open
Abstract
Vibration is detected by mechanoreceptors, including Pacinian corpuscles (PCs), which are widely distributed in the human body including the adventitia of large blood vessels. Although the distribution of PCs around large limb vessels has been previously reported, there remains no consensus on their distribution in the adventitia of the human deep blood vessels in the upper arm. In addition, the physiological functions of PCs located around the deep limb blood vessels remain largely unknown. This study aimed to elucidate detailed anatomical features and physiological function of lamellar sensory corpuscles structurally identified as PCs using the immunohistochemical methods around the deep vessels in the upper arm. We identified PCs in the connective tissue adjacent to the deep vessels in the upper arm using histological analysis and confirmed that PCs are located in the vascular sheath of the artery and its accompanying vein as well as in the connective tissue surrounding the vascular sheath and nerves. PCs were densely distributed on the distal side of deep vessels near the elbow. We also examined the relationship between vascular sound and pulsating sensation to evaluate the PCs functions around deep arteries and veins and found that the vascular sound made by pressing the brachial arteries in the upper arm was associated with the pulsating sensation of the examinee. Our results suggest that PCs, around deep vessels, function as bathyesthesia sensors by detecting vibration from blood vessels.
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Affiliation(s)
- Yoshiyuki Onishi
- Department of Anatomy and Cell Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Haruka Hisato
- Department of Anatomy and Cell Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Seishi Maeda
- Department of Anatomy and Cell Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Yusuke Minato
- Department of Anatomy and Cell Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Sachi Kuwahara-Otani
- Department of Anatomy and Cell Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Hideshi Yagi
- Department of Anatomy and Cell Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
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21
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Macefield VG. Recording and quantifying sympathetic outflow to muscle and skin in humans: methods, caveats and challenges. Clin Auton Res 2021; 31:59-75. [PMID: 32588247 PMCID: PMC7907024 DOI: 10.1007/s10286-020-00700-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 05/26/2020] [Indexed: 01/04/2023]
Abstract
The development of microneurography, in which the electrical activity of axons can be recorded via an intrafascicular microelectrode inserted through the skin into a peripheral nerve in awake human participants, has contributed a great deal to our understanding of sensorimotor control and the control of sympathetic outflow to muscle and skin. This review summarises the different approaches to recording muscle sympathetic nerve activity (MSNA) and skin sympathetic nerve activity (SSNA), together with discussion on the issues that determine the quality of a recording. Various analytical approaches are also described, with a primary emphasis on those developed by the author, aimed at maximizing the information content from recordings of postganglionic sympathetic nerve activity in awake humans.
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Affiliation(s)
- Vaughan G Macefield
- Human Autonomic Neurophysiology Laboratory, Baker Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia.
- Department of Physiology, University of Melbourne, Melbourne, VIC, Australia.
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22
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Michael GA, Guyot D, Tarroux E, Comte M, Salgues S. Feeling Oneself Requires Embodiment: Insights From the Relationship Between Own-Body Transformations, Schizotypal Personality Traits, and Spontaneous Bodily Sensations. Front Psychol 2021; 11:578237. [PMID: 33424690 PMCID: PMC7786119 DOI: 10.3389/fpsyg.2020.578237] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 12/07/2020] [Indexed: 12/25/2022] Open
Abstract
Subtle bodily sensations such as itching or fluttering that occur in the absence of any external trigger (i.e., spontaneous sensations, or SPS) may serve to locate the spatial boundaries of the body. They may constitute the normal counterpart of extreme conditions in which body-related hallucinations and perceptual aberrations are experienced. Previous investigations have suggested that situations in which the body is spontaneously experienced as being deformed are related to the ability to perform own-body transformations, i.e., mental rotations of the body requiring disembodiment. We therefore decided to consider whether the perception of SPS might relate to embodiment as assessed through (i) the ability to perform own-body transformations (OBT task) and (ii) schizotypal traits (Schizotypal Personality Questionnaire, or SPQ), since high degrees of schizotypy in the general population have been associated with more vivid perceptions and aberrant perceptual experiences. Then participants completed a standard SPS task. Our analysis revealed that the slower the response time in the OBT task, the more frequent the perception of SPS. This suggests that difficulties in disembodying and mentally transforming one's own body facilitate feeling oneself. Furthermore, a greater number of correct responses in the OBT task was associated with less frequent perception of SPS. This suggests that finding it easier to disembody and perform mental own-body transformations interferes with the ability to sense oneself. The results also show that higher schizotypal traits, as assessed through the SPQ, are associated with more frequent perception of SPS. Taken together, these results provide a coherent picture and suggest that embodiment is required in order to correctly feel oneself, as expressed through the perception of SPS. The ability to easily experience disembodiment reduces the sense of feeling oneself, and proneness to schizotypal traits produces body misperceptions that enhance and amplify this feeling. The results are discussed in the light of current knowledge and theories about body representations, taking into account attention and interoception as factors that influence body awareness. We offer explanations for perceptual aberrations, body-related delusions, and hallucinations based on misperceived or misinterpreted SPS, and we discuss possible mechanisms that may contribute to feeling and misperceiving oneself.
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Affiliation(s)
- George A Michael
- University of Lyon, Lyon, France.,University Lyon 2, Laboratoire EMC (Cognitive Mechanisms Research Laboratory) (EA 3082), Lyon, France.,University Lyon 2, Institute of Psychology, Lyon, France
| | - Deborah Guyot
- University of Lyon, Lyon, France.,University Lyon 2, Laboratoire EMC (Cognitive Mechanisms Research Laboratory) (EA 3082), Lyon, France.,University Lyon 2, Institute of Psychology, Lyon, France
| | - Emilie Tarroux
- University of Lyon, Lyon, France.,University Lyon 2, Laboratoire EMC (Cognitive Mechanisms Research Laboratory) (EA 3082), Lyon, France.,University Lyon 2, Institute of Psychology, Lyon, France
| | - Mylène Comte
- University of Lyon, Lyon, France.,University Lyon 2, Laboratoire EMC (Cognitive Mechanisms Research Laboratory) (EA 3082), Lyon, France.,University Lyon 2, Institute of Psychology, Lyon, France
| | - Sara Salgues
- University of Lyon, Lyon, France.,University Lyon 2, Laboratoire EMC (Cognitive Mechanisms Research Laboratory) (EA 3082), Lyon, France.,University Lyon 2, Institute of Psychology, Lyon, France
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23
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D'Anna E, Valle G, Mazzoni A, Strauss I, Iberite F, Patton J, Petrini FM, Raspopovic S, Granata G, Di Iorio R, Controzzi M, Cipriani C, Stieglitz T, Rossini PM, Micera S. A closed-loop hand prosthesis with simultaneous intraneural tactile and position feedback. Sci Robot 2021; 4:4/27/eaau8892. [PMID: 33137741 DOI: 10.1126/scirobotics.aau8892] [Citation(s) in RCA: 139] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 12/18/2018] [Indexed: 01/09/2023]
Abstract
Current myoelectric prostheses allow transradial amputees to regain voluntary motor control of their artificial limb by exploiting residual muscle function in the forearm. However, the overreliance on visual cues resulting from a lack of sensory feedback is a common complaint. Recently, several groups have provided tactile feedback in upper limb amputees using implanted electrodes, surface nerve stimulation, or sensory substitution. These approaches have led to improved function and prosthesis embodiment. Nevertheless, the provided information remains limited to a subset of the rich sensory cues available to healthy individuals. More specifically, proprioception, the sense of limb position and movement, is predominantly absent from current systems. Here, we show that sensory substitution based on intraneural stimulation can deliver position feedback in real time and in conjunction with somatotopic tactile feedback. This approach allowed two transradial amputees to regain high and close-to-natural remapped proprioceptive acuity, with a median joint angle reproduction precision of 9.1° and a median threshold to detection of passive movements of 9.5°, which was comparable with results obtained in healthy participants. The simultaneous delivery of position information and somatotopic tactile feedback allowed both amputees to discriminate the size and compliance of four objects with high levels of performance (75.5%). These results demonstrate that tactile information delivered via somatotopic neural stimulation and position information delivered via sensory substitution can be exploited simultaneously and efficiently by transradial amputees. This study paves a way to more sophisticated bidirectional bionic limbs conveying richer, multimodal sensations.
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Affiliation(s)
- Edoardo D'Anna
- Bertarelli Foundation Chair in Translational Neuroengineering, Centre for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Giacomo Valle
- Bertarelli Foundation Chair in Translational Neuroengineering, Centre for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.,The Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Alberto Mazzoni
- The Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Ivo Strauss
- Bertarelli Foundation Chair in Translational Neuroengineering, Centre for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.,The Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Jérémy Patton
- Bertarelli Foundation Chair in Translational Neuroengineering, Centre for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Francesco M Petrini
- Bertarelli Foundation Chair in Translational Neuroengineering, Centre for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Stanisa Raspopovic
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland
| | | | - Riccardo Di Iorio
- Institute of Neurology, Catholic University of The Sacred Heart, Policlinic A. Gemelli Foundation, Roma, Italy
| | - Marco Controzzi
- The Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Thomas Stieglitz
- Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering-IMTEK, University of Freiburg, Freiburg D-79110, Germany
| | - Paolo M Rossini
- Institute of Neurology, Catholic University of The Sacred Heart, Policlinic A. Gemelli Foundation, Roma, Italy.,Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Roma, Italy
| | - Silvestro Micera
- Bertarelli Foundation Chair in Translational Neuroengineering, Centre for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland. .,The Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
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24
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Cobo R, García‐Mesa Y, Cárcaba L, Martin‐Cruces J, Feito J, García‐Suárez O, Cobo J, García‐Piqueras J, Vega JA. Verification and characterisation of human digital Ruffini's sensory corpuscles. J Anat 2021; 238:13-19. [PMID: 32864772 PMCID: PMC7754963 DOI: 10.1111/joa.13301] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/05/2020] [Accepted: 08/05/2020] [Indexed: 01/03/2023] Open
Abstract
Ruffini's corpuscles are present as long fusiform encapsulated sensory structures in different tissues including the skin. Although physiological analyses strongly suggest their existence in glabrous digital skin, such localisation remains unconfirmed. Here, we have investigated the occurrence of typical Ruffini's corpuscles in 372 sections of human digital skin obtained from 186 subjects of both sexes and different ages (19-92 years). S100 protein, neuron-specific enolase and neurofilament proteins were detected, and the basic immunohistochemical profile of these corpuscles was analysed. Fewer than 0.3 Ruffini's corpuscles/mm2 were detected, with density distribution across the fingers being F4 > F3 > F2 > F1 > F5 and absolute values being F2 > F1 > F3 > F4 > F5. Axons displayed neuron-specific enolase immunoreactivity, glial cells forming the core contained S100 protein, and the capsule was positive for CD34 but not Glut1, demonstrating an endoneurial origin. Present results demonstrate the existence of Ruffini's corpuscles in human glabrous digital skin at very low densities. Moreover, the identified Ruffini's corpuscles share the basic immunohistochemical characteristics of other dermal sensory corpuscles.
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Affiliation(s)
- Ramón Cobo
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - Yolanda García‐Mesa
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - Lucía Cárcaba
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - José Martin‐Cruces
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - Jorge Feito
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain,Servicio de Anatomía PatológicaComplejo Hospitalario Universitario de SalamancaSalamancaSpain
| | - Olivia García‐Suárez
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - Juan Cobo
- Departamento de Cirugía y Especialidades Médico‐QuirúrgicasUniversidad de OviedoOviedoSpain,Instituto Asturiano de OdontologíaOviedoSpain
| | - Jorge García‐Piqueras
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain
| | - José A. Vega
- Departamento de Morfología y Biología CelularGrpo SINPOSUniversidad de OviedoOviedoSpain,Facultad de Ciencias de la SaludUniversidad Autónoma de ChileSantiagoChile
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25
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Dunn JS, Mahns DA, Nagi SS. Modulation of Muscle Pain Is Not Somatotopically Restricted: An Experimental Model Using Concurrent Hypertonic-Normal Saline Infusions in Humans. FRONTIERS IN PAIN RESEARCH 2020; 1:601544. [PMID: 35295695 PMCID: PMC8915694 DOI: 10.3389/fpain.2020.601544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/25/2020] [Indexed: 11/15/2022] Open
Abstract
We have previously shown that during muscle pain induced by infusion of hypertonic saline (HS), concurrent application of vibration and gentle brushing to overlying and adjacent skin regions increases the overall pain. In the current study, we focused on muscle-muscle interactions and tested whether HS-induced muscle pain can be modulated by innocuous/sub-perceptual stimulation of adjacent, contralateral, and remote muscles. Psychophysical observations were made in 23 healthy participants. HS (5%) was infused into a forearm muscle (flexor carpi ulnaris) to produce a stable baseline pain. In separate experiments, in each of the three test locations (n = 10 per site)—ipsilateral hand (abductor digiti minimi), contralateral forearm (flexor carpi ulnaris), and contralateral leg (tibialis anterior)—50 μl of 0.9% normal saline (NS) was infused (in triplicate) before, during, and upon cessation of HS-induced muscle pain in the forearm. In the absence of background pain, the infusion of NS was imperceptible to all participants. In the presence of HS-induced pain in the forearm, the concurrent infusion of NS into the ipsilateral hand, contralateral forearm, and contralateral leg increased the overall pain by 16, 12, and 15%, respectively. These effects were significant, reproducible, and time-locked to NS infusions. Further, the NS-evoked increase in pain was almost always ascribed to the forearm where HS was infused with no discernible percept attributed to the sites of NS infusion. Based on these observations, we conclude that intramuscular infusion of HS results in muscle hyperalgesia to sub-perceptual stimulation of muscle afferents in a somatotopically unrestricted manner, indicating the involvement of a central (likely supra-spinal) mechanism.
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Affiliation(s)
- James S. Dunn
- School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - David A. Mahns
- School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Saad S. Nagi
- School of Medicine, Western Sydney University, Penrith, NSW, Australia
- Department of Biomedical and Clinical Sciences, Center for Social and Affective Neuroscience, Linköping University, Linköping, Sweden
- *Correspondence: Saad S. Nagi
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To the self and beyond: Arousal and functional connectivity of the temporo-parietal junction contributes to spontaneous sensations perception. Behav Brain Res 2020; 396:112880. [PMID: 32910970 DOI: 10.1016/j.bbr.2020.112880] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 07/27/2020] [Accepted: 08/19/2020] [Indexed: 01/29/2023]
Abstract
The temporoparietal junction (TPJ), along with the anterior insula (AI) and the extrastriate body area (EBA), play a major part in embodiment and self-awareness. However, these connections also appear to be frequently engaged in arousal and attentional processing of external events. Considering that these networks may focus attention both toward and away from the self, we set to investigate how they contribute to the perception of spontaneous sensations (SPS), a common phenomenon related to self-awareness and mediated by both interoceptive and attentional processes. In Experiment 1, resting-state EEG was recorded, as well as arousal reported via a questionnaire, followed by a SPS task. Functional TPJ-AI and TPJ-EBA connectivity were computed using eLORETA. Spatial correlational analyses showed that less frequent SPS coincided with greater TPJ-AI and TPJ-EBA functional connectivity, especially in the theta and alpha frequency bands. High self-reported arousal predicted low intensity and low confidence in the location of SPS. Resting-state skin conductance level (SCL) was recorded in Experiment 2, followed by the SPS task. Less frequent SPS coincided with greater SCL. Findings are interpreted in terms of attention and self-related processes, and a discussion of the TPJ participation in self-awareness through SPS is presented.
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Martins PP, Porto JM, Vieira FT, Trimer IR, Capato LL, de Abreu DCC. The effect of unilateral muscle fatigue of hip abductor muscles on balance and functional capacity in community-dwelling older women. Arch Gerontol Geriatr 2020; 91:104222. [PMID: 32784078 DOI: 10.1016/j.archger.2020.104222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 07/30/2020] [Accepted: 08/01/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Hip abductor muscles are important for the maintenance of postural stability, mainly on the mediolateral direction and unipodal support conditions. The objective of the present study was to evaluate the effect of unilateral induced fatigue of hip abductor muscles on balance and functional capacity of older women. METHODS The study included physically independent women aged 60-75 years. We assessed static balance with the single limb stance test (SLS) and evaluated functional capacity with the maximum gait speed (MGS) and step test (ST). We ran the protocol of hip abductor muscle fatigue with a Biodex isokinetic dynamometer. Assessment of balance and functional capacity happened before and after the muscle fatigue protocol. We applied the t-test for repeated measures to determine whether unilateral hip abductor muscle fatigue influences the performance in the tests (SLS, MGS and ST). RESULTS The protocol of hip abductor muscle fatigue negatively affected all three evaluated tasks: SLS (p = 0.000), ST (p = 0.000) and MGS (p = 0.000). However, the single limb stance test was the most task affected (effect size = 0.51, pre- and post-fatigue difference = 28.1 %). CONCLUSION After the unilateral muscle fatigue of hip abductors, we observed the worst performance on clinical tests, mainly regarding the SLS test, which shows the involvement of hip abductors during usual motor tasks. However, the small magnitude of the limitation of functional tests (MGS and ST) suggests the presence of postural compensations.
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Affiliation(s)
- Pâmela Precinotto Martins
- Physiotherapy Course, Department of Health Sciences, Rehabilitation and Functional Performance Program, Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, 14049-900, SP Brazil.
| | - Jaqueline Mello Porto
- Physiotherapy Course, Department of Health Sciences, Rehabilitation and Functional Performance Program, Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, 14049-900, SP Brazil.
| | - Flávio Tavares Vieira
- Physiotherapy Course, Department of Health Sciences, Rehabilitation and Functional Performance Program, Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, 14049-900, SP Brazil.
| | - Isabella Ramirez Trimer
- Physiotherapy Course, Department of Health Sciences, Rehabilitation and Functional Performance Program, Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, 14049-900, SP Brazil.
| | - Luana Letícia Capato
- Physiotherapy Course, Department of Health Sciences, Rehabilitation and Functional Performance Program, Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, 14049-900, SP Brazil.
| | - Daniela Cristina Carvalho de Abreu
- Physiotherapy Course, Department of Health Sciences, Rehabilitation and Functional Performance Program, Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, 14049-900, SP Brazil.
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28
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Manzone DM, Tremblay L. Contributions of exercise-induced fatigue versus intertrial tendon vibration on visual-proprioceptive weighting for goal-directed movement. J Neurophysiol 2020; 124:802-814. [PMID: 32755335 DOI: 10.1152/jn.00263.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It has been argued that exercise-induced muscle fatigue and tendon vibration can alter proprioceptive estimates of limb position. While exercise-induced muscle fatigue may also affect central efferent processes related to limb position sense, tendon vibration specifically targets peripheral afferent signals. It is unclear, however, whether either of these perturbations (i.e., muscle fatigue or tendon vibration) can alter the multisensory weighting processes preceding goal-directed movements. The current study sought to specifically explore visual-proprioceptive weighting before or after eccentric exercise-induced antagonist muscle fatigue (experiment 1) versus with or without intertrial simultaneous agonist-antagonist tendon vibration (experiment 2). To assess sensory weighting, a visual-proprioceptive mismatch between the participant's actual initial starting position and the associated visual cursor position was employed. This method provides an estimate of the participant's reliance on the proprioceptive or visual starting limb position for their aiming movements. Although there was clear evidence of muscle fatigue, there was no systematic alteration of proprioceptive weighting after eccentric exercise and no relationship between sensory weighting and the level of fatigue. On the other hand, participants' reliance on their actual (proprioceptive) limb position was systematically reduced when exposed to agonist-antagonist tendon vibration before each aiming movement. These findings provide seminal evidence that intertrial tendon vibration, but not exercise-induced fatigue, can alter the reliability of proprioceptive estimates and the relative contributions of visual and proprioceptive information for goal-directed movement.NEW & NOTEWORTHY Previous work has used muscle fatigue or tendon vibration to perturb proprioceptive limb position estimates. This study sought to determine whether exercise-induced muscle fatigue versus intertrial tendon vibration can alter multisensory weighting for upper limb-aiming movements. By introducing a discrepancy between participants' actual proprioceptive and visual finger position, this study provides seminal evidence for the reduction of proprioceptive-to-visual weighting using intertrial tendon vibration but no evidence for a systematic reduction following exercise-induced fatigue.
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Affiliation(s)
- Damian M Manzone
- Perceptual Motor Behaviour Laboratory, Centre for Motor Control, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Luc Tremblay
- Perceptual Motor Behaviour Laboratory, Centre for Motor Control, Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
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29
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Viseux FJF, Martins DF, Villeneuve P, Charpentier P, de Sant'Anna E Silva L, Salgado ASI, Lemaire A. Effect of sensory stimulation applied under the great toe on postural ability in patients with fibromyalgia. Somatosens Mot Res 2020; 37:172-179. [PMID: 32419591 DOI: 10.1080/08990220.2020.1765767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Fibromyalgia (FM) is a chronic pain syndrome, characterised by several symptoms. One of the most prevalent symptoms in FM is balance impairment that compromise the autonomy, function and performance status of patients.Purpose: The main objective of the present study was to evaluate the effect of sensory stimulation provided by the use of a low additional thickness of 0.8 mm placed under the great toes bilaterally on the centre of pressure (CoP) measures in patients with FM. It was hypothesised that postural ability would change with a low focal additional thickness used to compute these measures.Materials and Method: Twenty-four patients with FM voluntarily participated in this study. Postural performance during quiet standing was investigated through the CoP displacements recorded using a force-plate. Sensory stimulation was provided by a small additional thickness of 0.8 mm placed under the great toe bilaterally and two conditions were compared: additional thickness 0 (control) and 0.8 mm.Results: An improvement of body balance through spatial parameters with sensory cutaneous stimulation applied under the great toe bilaterally were observed in patients with FM. Our results showed a significant decrease of surface area and mean speed of CoP, associated to a significant decrease of variance of speed. An additional observation is that sagittal (Y) mean position of the CoP gets more anterior (+ 5 mm) relative to control condition.Conclusion: These findings brings new clinical perspectives in the development of intervention strategies in the management of patients with FM and balance disorders, completing validated therapeutic strategies.
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Affiliation(s)
- Frederic J F Viseux
- Laboratoire d'Automatique, de Mécanique et d'Informatique industrielle et Humaine (LAMIH) - UMR CNRS 8201, Université Polytechnique des Hauts-de-France, Valenciennes, France.,Centre d'Evaluation et de Traitement de la Douleur (CETD), Centre hospitalier de Valenciennes, Valenciennes, France.,Posture Lab, Paris, France
| | - Daniel F Martins
- Experimental Neuroscience Laboratory (LaNEx), Postgraduate Program in Health Sciences, University of Southern Santa Catarina (UNISUL), Palhoça, Brazil
| | | | - Pascal Charpentier
- Centre d'Evaluation et de Traitement de la Douleur (CETD), Centre hospitalier de Valenciennes, Valenciennes, France
| | | | - Afonso S I Salgado
- Institute of Integral Health, Londrina, Brazil.,Experimental Neuroscience Laboratory (LaNEx), Postgraduate Program in Health Sciences, University of Southern Santa Catarina (UNISUL), Palhoça, Brazil
| | - Antoine Lemaire
- Centre d'Evaluation et de Traitement de la Douleur (CETD), Centre hospitalier de Valenciennes, Valenciennes, France
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Spontaneous sensations reveal distorted body perception in complex regional pain syndrome (CRPS). Brain Cogn 2020; 142:105568. [PMID: 32408059 DOI: 10.1016/j.bandc.2020.105568] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 04/01/2020] [Accepted: 04/10/2020] [Indexed: 01/30/2023]
Abstract
Distortions of body representation have been reported in Complex Regional Pain Syndrome (CRPS). The perception of sensations arising without external triggers (spontaneous sensations or SPS) was assessed here as a means of investigating distortions of body representation and awareness in CRPS. To avoid confounds between CRPS symptoms and SPS, lower-limb CRPS patients were included, whereas SPS were tested on the hands. Patients and controls were required to focus on their hands and to report the spatial and qualitative characteristics of SPS arising there. We found an ipsilateral decrease in the perception of thermal, pain-related and surface/mechanical SPS, as well as in the number of SPS-sensitive areas. The latter finding was predicted by decreased body awareness as assessed through questionnaires. A bilateral decrease in the perception of paresis-like SPS was also observed. Finally, the ipsilateral spatial distribution of SPS frequency and intensity underwent a shift from the fingers towards the lower parts of the palm. CRPS is likely to distort patient's body perception and awareness of the entire half-body ipsilateral to the affected limb, and even of both sides. Such disturbances are not manifested solely as a decrease in sensitivity, but sometimes as shifts in the spatial distribution of sensitivity.
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31
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Caprine Models of the Agonist-Antagonist Myoneural Interface Implemented at the Above- and Below-Knee Amputation Levels. Plast Reconstr Surg 2019; 144:218e-229e. [PMID: 31348345 DOI: 10.1097/prs.0000000000005864] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Traditional approaches to amputation are not capable of reproducing the dynamic muscle relationships that are essential for proprioceptive sensation and joint control. In this study, the authors present two caprine models of the agonist-antagonist myoneural interface (AMI), a surgical approach designed to improve bidirectional neural control of a bionic limb. The key advancement of the AMI is the surgical coaptation of natively innervated agonist-antagonist muscle pairs within the residual limb. METHODS One AMI was surgically created in the hindlimb of each of two African Pygmy goats at the time of primary transtibial amputation. Each animal was also implanted with muscle electrodes and sonomicrometer crystals to enable measurement of muscle activation and muscle state, respectively. Coupled agonist-antagonist excursion in the agonist-antagonist myoneural interface muscles was measured longitudinally for each animal. Fibrosis in the residual limb was evaluated grossly in each animal as part of a planned terminal procedure. RESULTS Electromyographic and muscle state measurements showed coupled agonist-antagonist motion within the AMI in the presence of both neural activation and artificial muscle stimulation. Gross observation of the residual limb during a planned terminal procedure revealed a thin fibrotic encapsulation of the AMI constructs, which was not sufficient to preclude coupled muscle excursion. CONCLUSIONS These findings highlight the AMI's potential to provide coupled motion of distal agonist-antagonist muscle pairs preserved during below- or above-knee amputation at nearly human scale. Guided by these findings, it is the authors' expectation that further development of the AMI architecture will improve neural control of advanced limb prostheses through incorporation of physiologically relevant muscle-tendon proprioception.
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32
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Turkmen C, Harput G, Kinikli GI, Kose N, Guney Deniz H. Correlation of force sense error test measured by a pressure biofeedback unit and EMG activity of quadriceps femoris in healthy individuals. J Electromyogr Kinesiol 2019; 49:102366. [PMID: 31678659 DOI: 10.1016/j.jelekin.2019.102366] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/23/2019] [Accepted: 10/23/2019] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Our study developed a force sense error test (FSET) method for use on the quadriceps muscle, which could be employed in clinical practice to correlate the results of quadriceps muscle activity levels determined by surface electromyography (sEMG). METHODS Twenty-four healthy individuals were included in the study. A pressure biofeedback unit (PBU) placed under the knee joint, was used for force sense error test (FSET) evaluation. First, a maximum contraction value was determined with the PBU. Next, 50% and 65% of the maximum contraction value were used for the analysis. Concurrently, norm values for the quadriceps muscle activity levels were determined by sEMG. Simultaneously, quadriceps muscle activity levels were recorded while testing the FSET using the PBU. Each measurement was repeated in triplicate, and the average constant errors observed by the PBU were recorded in mmHg. RESULTS The FSET for both 50% and 65% of the normal mmHg value determined using the PBU positively correlated with activity change levels in the quadriceps muscle determined by sEMG (p < 0.05). CONCLUSIONS The relationship between the FSET measured using PBU and changes in the level of activity in the quadriceps muscle showed that a PBU can be used in clinical practice for proprioceptive evaluation of the knee region.
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Affiliation(s)
- Ceyhun Turkmen
- Faculty of Physical Therapy and Rehabilitation, Hacettepe University, Ankara, Turkey.
| | - Gulcan Harput
- Faculty of Physical Therapy and Rehabilitation, Hacettepe University, Ankara, Turkey
| | - Gizem Irem Kinikli
- Faculty of Physical Therapy and Rehabilitation, Hacettepe University, Ankara, Turkey
| | - Nezire Kose
- Faculty of Physical Therapy and Rehabilitation, Hacettepe University, Ankara, Turkey
| | - Hande Guney Deniz
- Faculty of Physical Therapy and Rehabilitation, Hacettepe University, Ankara, Turkey
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33
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Cuberovic I, Gill A, Resnik LJ, Tyler DJ, Graczyk EL. Learning of Artificial Sensation Through Long-Term Home Use of a Sensory-Enabled Prosthesis. Front Neurosci 2019; 13:853. [PMID: 31496931 PMCID: PMC6712074 DOI: 10.3389/fnins.2019.00853] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/30/2019] [Indexed: 12/14/2022] Open
Abstract
Upper limb prostheses are specialized tools, and skilled operation is learned by amputees over time. Recently, neural prostheses using implanted peripheral nerve interfaces have enabled advances in artificial somatosensory feedback that can improve prosthesis outcomes. However, the effect of sensory learning on artificial somatosensation has not been studied, despite its known influence on intact somatosensation and analogous neuroprostheses. Sensory learning involves changes in the perception and interpretation of sensory feedback and may further influence functional and psychosocial outcomes. In this mixed methods case study, we examined how passive learning over 115 days of home use of a neural-connected, sensory-enabled prosthetic hand influenced perception of artificial sensory feedback in a participant with transradial amputation. We examined perceptual changes both within individual days of use and across the duration of the study. At both time scales, the reported percept locations became significantly more aligned with prosthesis sensor locations, and the phantom limb became significantly more extended toward the prosthesis position. Similarly, the participant’s ratings of intensity, naturalness, and contact touch significantly increased, while his ratings of vibration and movement significantly decreased across-days for tactile channels. These sensory changes likely resulted from engagement of cortical plasticity mechanisms as the participant learned to use the artificial sensory feedback. We also assessed psychosocial and functional outcomes through surveys and interviews, and found that self-efficacy, perceived function, prosthesis embodiment, social touch, body image, and prosthesis efficiency improved significantly. These outcomes typically improved within the first month of home use, demonstrating rapid benefits of artificial sensation. Participant interviews indicated that the naturalness of the experience and engagement with the prosthesis increased throughout the study, suggesting that artificial somatosensation may decrease prosthesis abandonment. Our data showed that prosthesis embodiment was intricately related to naturalness and phantom limb perception, and that learning the artificial sensation may have modified the body schema. As another indicator of successfully learning to use artificial sensation, the participant reported the emergence of stereognosis later in the study. This study provides the first evidence that artificial somatosensation can undergo similar learning processes as intact sensation and highlights the importance of sensory restoration in prostheses.
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Affiliation(s)
- Ivana Cuberovic
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States
| | - Anisha Gill
- Providence VA Medical Center, Providence, RI, United States
| | - Linda J Resnik
- Providence VA Medical Center, Providence, RI, United States.,Department of Health Services, Policy, and Practice, Brown University, Providence, RI, United States
| | - Dustin J Tyler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States
| | - Emily L Graczyk
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States
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Henry M, Baudry S. Age-related changes in leg proprioception: implications for postural control. J Neurophysiol 2019; 122:525-538. [PMID: 31166819 DOI: 10.1152/jn.00067.2019] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
In addition to being a prerequisite for many activities of daily living, the ability to maintain steady upright standing is a relevant model to study sensorimotor integrative function. Upright standing requires managing multimodal sensory inputs to produce finely tuned motor output that can be adjusted to accommodate changes in standing conditions and environment. The sensory information used for postural control mainly arises from the vestibular system of the inner ear, vision, and proprioception. Proprioception (sense of body position and movement) encompasses signals from mechanoreceptors (proprioceptors) located in muscles, tendons, and joint capsules. There is general agreement that proprioception signals from leg muscles provide the primary source of information for postural control. This is because of their exquisite sensitivity to detect body sway during unperturbed upright standing that mainly results from variations in leg muscle length induced by rotations around the ankle joint. However, aging is associated with alterations of muscle spindles and their neural pathways, which induce a decrease in the sensitivity, acuity, and integration of the proprioceptive signal. These alterations promote changes in postural control that reduce its efficiency and thereby may have deleterious consequences for the functional independence of an individual. This narrative review provides an overview of how aging alters the proprioceptive signal from the legs and presents compelling evidence that these changes modify the neural control of upright standing.
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Affiliation(s)
- Mélanie Henry
- Laboratory of Applied Biology and Research Unit in Applied Neurophysiology, ULB Neuroscience Institute, Université libre de Bruxelles, Brussels, Belgium
| | - Stéphane Baudry
- Laboratory of Applied Biology and Research Unit in Applied Neurophysiology, ULB Neuroscience Institute, Université libre de Bruxelles, Brussels, Belgium
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35
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Electrocorticographic changes in field potentials following natural somatosensory percepts in humans. Exp Brain Res 2019; 237:1155-1167. [PMID: 30796470 DOI: 10.1007/s00221-019-05495-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 02/15/2019] [Indexed: 01/06/2023]
Abstract
OBJECTIVE Restoration of somatosensory deficits in humans requires a clear understanding of the neural representations of percepts. To characterize the cortical response to naturalistic somatosensation, we examined field potentials in the primary somatosensory cortex of humans. METHODS Four patients with intractable epilepsy were implanted with subdural electrocorticography (ECoG) electrodes over the hand area of S1. Three types of stimuli were applied, soft-repetitive touch, light touch, and deep touch. Power in the alpha (8-15 Hz), beta (15-30 Hz), low-gamma (30-50 Hz), and high-gamma (50-125 Hz) frequency bands were evaluated for significance. RESULTS Seventy-seven percent of electrodes over the hand area of somatosensory cortex exhibited changes in these bands. High-gamma band power increased for all stimuli, with concurrent alpha and beta band power decreases. Earlier activity was seen in these bands in deep touch and light touch compared to soft touch. CONCLUSIONS These findings are consistent with prior literature and suggest a widespread response to focal touch, and a different encoding of deeper pressure touch than soft touch.
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36
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Viseux F, Lemaire A, Barbier F, Charpentier P, Leteneur S, Villeneuve P. How can the stimulation of plantar cutaneous receptors improve postural control? Review and clinical commentary. Neurophysiol Clin 2019; 49:263-268. [PMID: 30639034 DOI: 10.1016/j.neucli.2018.12.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 12/19/2018] [Accepted: 12/22/2018] [Indexed: 12/13/2022] Open
Abstract
Postural control requires constant and subconscious postural sway to manage balance and achieve postural stability. These movements of regulation are based in particular on cutaneous plantar information. The foot constitutes a functional whole that participates in the mechanisms of postural control and regulation. It represents the direct interface between the body and the ground during quiet standing, and plantar cutaneous information contributes to postural control. Upright balance mechanically depends on the gravitational torque produced by the forces of gravity and reaction of the ground. In this context, the foot behaves like a sensory system for postural regulation whose objective is to maintain a state of stability within a changing and constraining environment. There is a relation between balance improvement and the facilitation of sensory feedback related to the activation of the plantar cutaneous mechanoreceptors. From a clinical point of view, the application of additional tactile cues may have therapeutic benefits in relation to fall prevention, or to improve specific types of chronic pain.
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Affiliation(s)
- Frederic Viseux
- Laboratoire d'automatique, de mécanique et d'informatique industrielles et humaines (LAMIH), UMR CNRS 8201, université de Valenciennes et du Hainaut-Cambrésis (UVHC), 59313 Valenciennes, France; Centre d'évaluation et de traitement de la douleur (CETD), centre hospitalier de Valenciennes (CHV), 59322 Valenciennes, France; Posture Lab, 75012 Paris, France.
| | - Antoine Lemaire
- Centre d'évaluation et de traitement de la douleur (CETD), centre hospitalier de Valenciennes (CHV), 59322 Valenciennes, France
| | - Franck Barbier
- Laboratoire d'automatique, de mécanique et d'informatique industrielles et humaines (LAMIH), UMR CNRS 8201, université de Valenciennes et du Hainaut-Cambrésis (UVHC), 59313 Valenciennes, France
| | - Pascal Charpentier
- Centre d'évaluation et de traitement de la douleur (CETD), centre hospitalier de Valenciennes (CHV), 59322 Valenciennes, France
| | - Sebastien Leteneur
- Laboratoire d'automatique, de mécanique et d'informatique industrielles et humaines (LAMIH), UMR CNRS 8201, université de Valenciennes et du Hainaut-Cambrésis (UVHC), 59313 Valenciennes, France
| | - Philippe Villeneuve
- Laboratoire d'automatique, de mécanique et d'informatique industrielles et humaines (LAMIH), UMR CNRS 8201, université de Valenciennes et du Hainaut-Cambrésis (UVHC), 59313 Valenciennes, France; Posture Lab, 75012 Paris, France
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37
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Low additional thickness under the toes could change upright balance of healthy subjects. Neurophysiol Clin 2018; 48:397-400. [DOI: 10.1016/j.neucli.2018.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/13/2018] [Accepted: 08/08/2018] [Indexed: 11/24/2022] Open
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Knellwolf TP, Burton AR, Hammam E, Macefield VG. Firing properties of muscle spindles supplying the intrinsic foot muscles of humans in unloaded and freestanding conditions. J Neurophysiol 2018; 121:74-84. [PMID: 30427762 DOI: 10.1152/jn.00539.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
We recently developed an approach for recording from muscle spindles in the intrinsic muscles of the foot in freestanding humans by inserting a tungsten microelectrode into the posterior tibial nerve behind the medial malleolus of the ankle. Here we characterize the behavior of muscle spindles in the small muscles of the foot in 1) seated subjects with the leg horizontal and the foot naturally plantarflexed and 2) standing subjects. In the first study, recordings were made from 26 muscle spindle afferents located within flexor digiti minimi brevis ( n = 4), abductor digiti minimi ( n = 3), quadratus plantae ( n = 3), plantar interossei ( n = 4), flexor digitorum brevis ( n = 3), dorsal interossei ( n = 2), and lumbricals ( n = 2), with one each supplying abductor hallucis, adductor hallucis, and flexor hallucis brevis. The identity of another two muscle afferents was unknown. The majority of the units were silent at rest, only seven (27%) being spontaneously active. Because of the anatomic constraints of the foot, some spindles supplying muscles acting on the toes responded to movements of one or more digits. In the second study, 12 muscle spindle afferents were examined during standing. The ongoing discharge of eight spindle afferents covaried with changes in the center of pressure during postural sway. We conclude that the majority of spindle endings in the small muscles of the foot are silent at rest, which may allow them to encode changes in conformation of the foot when it is loaded during standing. Moreover, these muscle spindle afferents can provide useful proprioceptive information during standing and postural sway. NEW & NOTEWORTHY We have characterized the firing properties of muscle spindles in the intrinsic muscles of the human foot for the first time. The majority of the spindle endings are silent in seated subjects, and most fire tonically during standing, their discharge covarying with center of pressure during postural sway. We conclude that spindle endings in the intrinsic muscles of the foot provide useful proprioceptive information during free standing.
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Affiliation(s)
- T P Knellwolf
- School of Medicine, Western Sydney University , Sydney , Australia
| | - A R Burton
- School of Medicine, Western Sydney University , Sydney , Australia.,Neuroscience Research Institute , Sydney , Australia
| | - E Hammam
- School of Medicine, Western Sydney University , Sydney , Australia
| | - V G Macefield
- School of Medicine, Western Sydney University , Sydney , Australia.,Neuroscience Research Institute , Sydney , Australia.,Baker Heart and Diabetes Institute , Melbourne , Australia
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39
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Missitzi J, Geladas N, Misitzi A, Misitzis L, Classen J, Klissouras V. Heritability of proprioceptive senses. J Appl Physiol (1985) 2018. [PMID: 29517423 DOI: 10.1152/japplphysiol.00544.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heritability studies using the twin model have provided the basis to disentangle genetic and environmental factors that contribute to several complex human traits. However, the relative importance of these factors to individual differences in proprioception is largely unknown despite the fact that proprioceptive senses are of great importance, allowing us to respond to stimuli stemming from the space around us and react to altering circumstances. Hence, a total of 44 healthy male twins (11 MZ and 11 DZ pairs), 19-28 yr old, were examined for movement, position, and force sense at the elbow joint, and their heritability estimates were computed. Results showed that genetic factors explained 1) 72 and 76% of the total variance of movement sense at the start and the end of the movement, respectively, 2) 60 to 77% of the total variance of position sense, depending on the angle of elbow flexion and whether forearm positioning was active or passive, and 3) 73 and 70% of the total variance of the force sense at 90 and 60° of elbow flexion, respectively. It is concluded that proprioception assessed by these conscious sensations is to a substantial degree genetically dependent, with heritability indexes ranging from 0.60 to 0.77, depending on the task. NEW & NOTEWORTHY Proprioceptive acuity varies among people, but it is not known how much of this variability is due to differences in their genes. This study is the first to report that proprioception, expressed as movement sense, position sense, and force sense, is substantially heritable, and it is conceivable that this may have implications for motor learning and control, neural development, and neurorehabilitation.
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Affiliation(s)
- Julia Missitzi
- Ergophysiology Research Laboratory, Department of Sport Medicine and Biology of Physical Activity, National and Kapodistrian University of Athens , Athens , Greece
| | - Nickos Geladas
- Ergophysiology Research Laboratory, Department of Sport Medicine and Biology of Physical Activity, National and Kapodistrian University of Athens , Athens , Greece
| | - Angelica Misitzi
- School of Medicine, National and Kapodistrian University of Athens , Athens , Greece
| | | | - Joseph Classen
- Human Motor Control and Neuroplasticity Laboratory, Department of Neurology, University of Leipzig , Leipzig , Germany
| | - Vassilis Klissouras
- Ergophysiology Research Laboratory, Department of Sport Medicine and Biology of Physical Activity, National and Kapodistrian University of Athens , Athens , Greece
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Smith LJ, Norcliffe-Kaufmann L, Palma JA, Kaufmann H, Macefield VG. Impaired sensorimotor control of the hand in congenital absence of functional muscle spindles. J Neurophysiol 2018; 120:2788-2795. [PMID: 30230986 DOI: 10.1152/jn.00528.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Patients with hereditary sensory and autonomic neuropathy type III (HSAN III) exhibit marked ataxia, including gait disturbances. We recently showed that functional muscle spindle afferents in the leg, recorded via intraneural microelectrodes inserted into the peroneal nerve, are absent in HSAN III, although large-diameter cutaneous afferents are intact. Moreover, there is a tight correlation between loss of proprioceptive acuity at the knee and the severity of gait impairment. We tested the hypothesis that manual motor performance is also compromised in HSAN III, attributed to the predicted absence of muscle spindles in the intrinsic muscles of the hand. Manual performance in the Purdue pegboard task was assessed in 12 individuals with HSAN III and 11 age-matched healthy controls. The mean (±SD) pegboard score (number of pins inserted in 30 s) was 8.1 ± 1.9 and 8.6 ± 1.8 for the left and right hand, respectively, significantly lower than the scores for the controls (15.0 ± 1.3 and 16.0 ± 1.1; P < 0.0001). Performance was not improved after kinesiology tape was applied over the joints of the hand. In 5 patients we inserted a tungsten microelectrode into the ulnar nerve at the wrist. No spontaneous or stretch-evoked muscle afferent activity could be identified in any of the 11 fascicles supplying intrinsic muscles of the hand, whereas touch-evoked activity from low-threshold cutaneous mechanoreceptor afferents could readily be recorded from 4 cutaneous fascicles. We conclude that functional muscle spindles are absent in the short muscles of the hand and most likely absent in the long finger flexors and extensors, and that this largely accounts for the poor manual motor performance in HSAN III. NEW & NOTEWORTHY We describe the impaired manual motor performance in patients with hereditary sensory and autonomic neuropathy type III (Riley-Day syndrome), who exhibit congenital insensitivity to pain, poor proprioception, and marked gait ataxia. We show that functional muscle spindles are absent in the intrinsic muscles of the hand, which we argue contributes to their poor performance in a task involving the precision grip.
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Affiliation(s)
- Lyndon J Smith
- School of Medicine, Western Sydney University , Sydney , Australia
| | - Lucy Norcliffe-Kaufmann
- Dysautonomia Center, Department of Neurology, New York University School of Medicine , New York, New York
| | - Jose-Alberto Palma
- Dysautonomia Center, Department of Neurology, New York University School of Medicine , New York, New York
| | - Horacio Kaufmann
- Dysautonomia Center, Department of Neurology, New York University School of Medicine , New York, New York
| | - Vaughan G Macefield
- School of Medicine, Western Sydney University , Sydney , Australia.,Neuroscience Research Australia, Sydney , Australia.,Baker Heart & Diabetes Institute, Melbourne , Australia
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The effects of instrumental action on perceptual hand maps. Exp Brain Res 2018; 236:3113-3119. [DOI: 10.1007/s00221-018-5360-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 08/10/2018] [Indexed: 11/30/2022]
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Macefield VG, Knellwolf TP. Functional properties of human muscle spindles. J Neurophysiol 2018; 120:452-467. [DOI: 10.1152/jn.00071.2018] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Muscle spindles are ubiquitous encapsulated mechanoreceptors found in most mammalian muscles. There are two types of endings, primary and secondary, and both are sensitive to changes in muscle length and velocity, with the primary endings having a greater dynamic sensitivity. Unlike other mechanoreceptors in the somatosensory system, muscle spindles are unique in possessing motor innervation, via γ-motoneurons (fusimotor neurons), that control their sensitivity to stretch. Much of what we know about human muscles spindles comes from studying the behavior of their afferents via intraneural microelectrodes (microneurography) inserted into accessible peripheral nerves. We review the functional properties of human muscle spindles, comparing and contrasting with what we know about the functions of muscle spindles studied in experimental animals. As in the cat, many human muscle spindles possess a background discharge that is related to the degree of muscle stretch, but mean firing rates are much lower (~10 Hz). They can faithfully encode changes in muscle fascicle length in passive conditions, but higher level extraction of information is required by the central nervous system to measure changes in muscle length during muscle contraction. Moreover, although there is some evidence supporting independent control of human muscle spindles via fusimotor neurons, any effects are modest compared with the clearly independent control of fusimotor neurons observed in the cat.
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Affiliation(s)
- Vaughan G. Macefield
- School of Medicine, Western Sydney University, Sydney, Australia
- Neuroscience Research Institute, Sydney, Australia
- Baker Heart & Diabetes Institute, Melbourne, Australia
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Abstract
The kinesthetic senses are the senses of position and movement of the body, senses we are aware of only on introspection. A method used to study kinesthesia is muscle vibration, which engages afferents of muscle spindles to trigger illusions of movement and changed position. When vibrating elbow flexors, it generates sensations of forearm extension, when vibrating extensors, sensations of forearm flexion. Vibrating the elbow joint produces no illusion. Vibrating flexors and extensors together at the same frequency also produces no illusion, because what is perceived is the signal difference between antagonist muscles of each arm and between arms. The size of the illusion depends on how the muscle has been conditioned beforehand, due to a property of muscle called thixotropy. When measuring the illusion, blindfolded subjects may carry out a matching or pointing task. In pointing, signals from muscle spindles are less important than in matching. Afferent signals from kinesthetic receptors project to areas of somatosensory cortex to generate sensations of detection and location. This is referred to the body model, which provides information about size and shape of body parts. Kinesthesia, together with vision and touch, is associated with the sense of body ownership. All three can combine or each, on its own, can generate ownership. Related is the sense of agency, the sense of being responsible for one's own actions. In recent times, much progress has been made using neuroimaging techniques to identify the various areas of the brain likely to be responsible for generating these sensations. © 2017 American Physiological Society. Compr Physiol 8:1157-1183, 2018.
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Affiliation(s)
- Uwe Proske
- Department of Physiology, Monash University, Clayton, Victoria, Australia
| | - Simon C Gandevia
- Neuroscience Research Australia and University of New South Wales, New South Wales, Australia
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Clites TR, Carty MJ, Ullauri JB, Carney ME, Mooney LM, Duval JF, Srinivasan SS, Herr HM. Proprioception from a neurally controlled lower-extremity prosthesis. Sci Transl Med 2018; 10:10/443/eaap8373. [DOI: 10.1126/scitranslmed.aap8373] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/09/2017] [Accepted: 05/03/2018] [Indexed: 11/02/2022]
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Michael GA, Tapiero I, Gálvez-García G, Jacquot L. Thoughts and sensations, twin galaxies of the inner space: The propensity to mind-wander relates to spontaneous sensations arising on the hands. Conscious Cogn 2017; 55:223-231. [DOI: 10.1016/j.concog.2017.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 08/18/2017] [Accepted: 08/18/2017] [Indexed: 10/18/2022]
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Longo MR. Expansion of Perceptual Body Maps Near - But Not Across - The Wrist. Front Hum Neurosci 2017; 11:111. [PMID: 28326030 PMCID: PMC5339231 DOI: 10.3389/fnhum.2017.00111] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/22/2017] [Indexed: 11/13/2022] Open
Abstract
Perceiving the external spatial location of touch requires that tactile information about the stimulus location on the skin be integrated with proprioceptive information about the location of the body in external space, a process called tactile spatial remapping. Recent results have suggested that this process relies on a distorted representation of the hand. Here, I investigated whether similar distortions are also found on the forearm and how they are affected by the presence of the wrist joint, which forms a categorical, segmental boundary between the hand and the arm. Participants used a baton to judge the perceived location of touches applied to their left hand or forearm. Similar distortions were apparent on both body parts, with overestimation of distances in the medio-lateral axis compared to the proximo-distal axis. There was no perceptual expansion of distances that crossed the wrist boundary. However, there was increased overestimation of distances near the wrist in the medio-lateral orientation. These results replicate recent findings of a distorted representation of the hand underlying tactile spatial remapping, and show that this effect is not idiosyncratic to the hand, but also affects the forearm. These distortions may be a general characteristic of the mental representation of the arms.
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Affiliation(s)
- Matthew R Longo
- Department of Psychological Sciences, Birkbeck, University of London London, UK
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Clites TR, Carty MJ, Srinivasan S, Zorzos AN, Herr HM. A murine model of a novel surgical architecture for proprioceptive muscle feedback and its potential application to control of advanced limb prostheses. J Neural Eng 2017; 14:036002. [PMID: 28211795 DOI: 10.1088/1741-2552/aa614b] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Proprioceptive mechanisms play a critical role in both reflexive and volitional lower extremity control. Significant strides have been made in the development of bionic limbs that are capable of bi-directional communication with the peripheral nervous system, but none of these systems have been capable of providing physiologically-relevant muscle-based proprioceptive feedback through natural neural pathways. In this study, we present the agonist-antagonist myoneural interface (AMI), a surgical approach with the capacity to provide graded kinesthetic feedback from a prosthesis through mechanical activation of native mechanoreceptors within residual agonist-antagonist muscle pairs. APPROACH (1) Sonomicrometery and electroneurography measurement systems were validated using a servo-based muscle tensioning system. (2) A heuristic controller was implemented to modulate functional electrical stimulation of an agonist muscle, using sonomicrometric measurements of stretch from a mechanically-coupled antagonist muscle as feedback. (3) One AMI was surgically constructed in the hindlimb of each rat. (4) The gastrocnemius-soleus complex of the rat was cycled through a series of ramp-and-hold stretches in two different muscle architectures: native (physiologically-intact) and AMI (modified). Integrated electroneurography from the tibial nerve was compared across the two architectures. MAIN RESULTS Correlation between stretch and afferent signal demonstrated that the AMI is capable of provoking graded afferent signals in response to ramp-and-hold stretches, in a manner similar to the native muscle architecture. The response magnitude in the AMI was reduced when compared to the native architecture, likely due to lower stretch amplitudes. The closed-loop control system showed robustness at high stretch magnitudes, with some oscillation at low stretch magnitudes. SIGNIFICANCE These results indicate that the AMI has the potential to communicate meaningful kinesthetic feedback from a prosthetic limb by replicating the agonist-antagonist relationships that are fundamental to physiological proprioception.
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Affiliation(s)
- Tyler R Clites
- Center for Extreme Bionics, Massachusetts Institute of Technology, Cambridge, MA, United States of America
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Day J, Bent LR, Birznieks I, Macefield VG, Cresswell AG. Muscle spindles in human tibialis anterior encode muscle fascicle length changes. J Neurophysiol 2017; 117:1489-1498. [PMID: 28077660 DOI: 10.1152/jn.00374.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 12/23/2016] [Accepted: 01/05/2017] [Indexed: 11/22/2022] Open
Abstract
Muscle spindles provide exquisitely sensitive proprioceptive information regarding joint position and movement. Through passively driven length changes in the muscle-tendon unit (MTU), muscle spindles detect joint rotations because of their in-parallel mechanical linkage to muscle fascicles. In human microneurography studies, muscle fascicles are assumed to follow the MTU and, as such, fascicle length is not measured in such studies. However, under certain mechanical conditions, compliant structures can act to decouple the fascicles, and, therefore, the spindles, from the MTU. Such decoupling may reduce the fidelity by which muscle spindles encode joint position and movement. The aim of the present study was to measure, for the first time, both the changes in firing of single muscle spindle afferents and changes in muscle fascicle length in vivo from the tibialis anterior muscle (TA) during passive rotations about the ankle. Unitary recordings were made from 15 muscle spindle afferents supplying TA via a microelectrode inserted into the common peroneal nerve. Ultrasonography was used to measure the length of an individual fascicle of TA. We saw a strong correlation between fascicle length and firing rate during passive ankle rotations of varying rates (0.1-0.5 Hz) and amplitudes (1-9°). In particular, we saw responses observed at relatively small changes in muscle length that highlight the sensitivity of the TA muscle to small length changes. This study is the first to measure spindle firing and fascicle dynamics in vivo and provides an experimental basis for further understanding the link between fascicle length, MTU length, and spindle firing patterns.NEW & NOTEWORTHY Muscle spindles are exquisitely sensitive to changes in muscle length, but recordings from human muscle spindle afferents are usually correlated with joint angle rather than muscle fascicle length. In this study, we monitored both muscle fascicle length and spindle firing from the human tibialis anterior muscle in vivo. Our findings are the first to measure these signals in vivo and provide an experimental basis for exploring this link further.
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Affiliation(s)
- James Day
- School of Human Movement and Nutrition Sciences, University of Queensland, St. Lucia, Queensland, Australia
| | - Leah R Bent
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Ingvars Birznieks
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia.,School of Science and Health, Western Sydney University, Sydney, Australia.,Neuroscience Research Australia, Sydney, Australia
| | - Vaughan G Macefield
- School of Medicine, Western Sydney University, Sydney, Australia; and.,Neuroscience Research Australia, Sydney, Australia
| | - Andrew G Cresswell
- School of Human Movement and Nutrition Sciences, University of Queensland, St. Lucia, Queensland, Australia;
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Dunn JS, Mahns DA, Nagi SS. Why does a cooled object feel heavier? Psychophysical investigations into the Weber's Phenomenon. BMC Neurosci 2017; 18:4. [PMID: 28049434 PMCID: PMC5209941 DOI: 10.1186/s12868-016-0322-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 12/14/2016] [Indexed: 01/19/2023] Open
Abstract
Background It has long been known that a concomitantly cooled stimulus is perceived as heavier than the same object at a neutral temperature—termed Weber’s Phenomenon (WP). In the current study, we re-examined this phenomenon using well-controlled force and temperature stimuli to explore the complex interplay between thermal and tactile systems, and the peripheral substrates contributing to these interactions. A feedback-controlled apparatus was constructed using a mechanical stimulator attached to a 5- × 5-mm thermode. Force combinations of 0.5 and 1 N (superimposed on 1-N step) were applied to the ulnar territory of dorsal hand. One of the forces had a thermal component, being cooled from 32 to 28 °C at a rate of 2 °C/s with a 3-s static phase. The other stimulus was thermally neutral (32 °C). Participants were asked to report whether the first or the second stimulus was perceived heavier. These observations were obtained in the all-fibre-intact condition and following the preferential block of myelinated fibres by compression of ulnar nerve. Results In normal condition, when the same forces were applied, all subjects displayed a clear preference for the cooled tactile stimulus as being heavier than the tactile-only stimulus. The frequency of this effect was augmented by an additional ~17% when cooling was applied concurrently with the second stimulus. Following compression block, the mean incidence of WP was significantly reduced regardless of whether cooling was applied concurrently with the first or the second stimulus. However, while the effect was abolished in case of former (elicited in <50% of trials), the compression block had little effect in four out of nine participants in case of latter who reported WP in at least 80% of trials (despite abolition of vibration and cold sensations). Conclusions WP was found to be a robust tactile–thermal interaction in the all-fibre-intact condition. The emergence of inter-individual differences during myelinated block suggests that subjects may adopt strategies, unbeknownst to them, that focus on the dominant input (myelinated fibres, hence WP abolished by block) or the sum of convergent inputs (myelinated and C fibres, hence WP preserved during block) in order to determine differences in perceived heaviness. Electronic supplementary material The online version of this article (doi:10.1186/s12868-016-0322-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- James S Dunn
- School of Medicine, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - David A Mahns
- School of Medicine, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Saad S Nagi
- School of Medicine, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia. .,Department of Clinical and Experimental Medicine, Center for Social and Affective Neuroscience, Linköping University, 58183, Linköping, Sweden.
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Baghbani F, Woodhouse LJ, Gaeini AA. Dynamic Postural Control in Female Athletes and Nonathletes After a Whole-Body Fatigue Protocol. J Strength Cond Res 2016; 30:1942-7. [DOI: 10.1519/jsc.0000000000001275] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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