701
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The Cellular and Synaptic Architecture of the Mechanosensory Dorsal Horn. Cell 2016; 168:295-310.e19. [PMID: 28041852 PMCID: PMC5236062 DOI: 10.1016/j.cell.2016.12.010] [Citation(s) in RCA: 235] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/18/2016] [Accepted: 12/06/2016] [Indexed: 11/20/2022]
Abstract
The deep dorsal horn is a poorly characterized spinal cord region implicated in processing low-threshold mechanoreceptor (LTMR) information. We report an array of mouse genetic tools for defining neuronal components and functions of the dorsal horn LTMR-recipient zone (LTMR-RZ), a role for LTMR-RZ processing in tactile perception, and the basic logic of LTMR-RZ organization. We found an unexpectedly high degree of neuronal diversity in the LTMR-RZ: seven excitatory and four inhibitory subtypes of interneurons exhibiting unique morphological, physiological, and synaptic properties. Remarkably, LTMRs form synapses on between four and 11 LTMR-RZ interneuron subtypes, while each LTMR-RZ interneuron subtype samples inputs from at least one to three LTMR classes, as well as spinal cord interneurons and corticospinal neurons. Thus, the LTMR-RZ is a somatosensory processing region endowed with a neuronal complexity that rivals the retina and functions to pattern the activity of ascending touch pathways that underlie tactile perception. Convergent LTMR and cortical inputs define the mechanosensory dorsal horn A dorsal horn molecular-genetic toolbox defines 11 interneuron subtypes Dorsal horn interneurons receive specific patterns of cortical and LTMR inputs Dorsal horn interneurons modulate output pathways and tactile perception
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702
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Alonso-Perez JL, Lopez-Lopez A, La Touche R, Lerma-Lara S, Suarez E, Rojas J, Bishop MD, Villafañe JH, Fernández-Carnero J. Hypoalgesic effects of three different manual therapy techniques on cervical spine and psychological interaction: A randomized clinical trial. J Bodyw Mov Ther 2016; 21:798-803. [PMID: 29037630 DOI: 10.1016/j.jbmt.2016.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 11/16/2016] [Accepted: 12/12/2016] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the extent to which psychological factors interact with a particular manual therapy (MT) technique to induce hypoalgesia in healthy subjects. METHODS Seventy-five healthy volunteers (36 female, 39 males), were recruited in this double-blind, controlled and parallel study. Subjects were randomly assigned to receive: High velocity low amplitude technique (HVLA), joint mobilization, or Cervical Lateral glide mobilization (CLGM). Pressure pain threshold (PPT) over C7 unilaterally, trapezius muscle and lateral epicondyle bilaterally, were measured prior to single technique MT was applied and immediately after to applied MT. Pain catastrophizing, depression, anxiety and kinesiophobia were evaluated before treatment. RESULTS The results indicate that hypoalgesia was observed in all groups after treatment in the neck and elbow region (P < 0.05), but mobilization induces more hypoalgesic effects. Catastrophizing interacted with change over time in PPT, for changes in C7 and in manipulation group. CONCLUSIONS All the MT techniques studied produced local and segmental hypoalgesic effects, supporting the results of previous studies studying the individual interventions. Interaction between catastrophizing and HVLA technique suggest that whether catastrophizing level is low or medium, the chance of success is high, but high levels of catastrophizing may result in poor outcome after HVLA intervention. TRIAL REGISTRATION ClinicalTrials.gov Registration Number: NCT02782585.
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Affiliation(s)
| | | | - Roy La Touche
- Departamento de Fisioterapia, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Spain.
| | - Sergio Lerma-Lara
- Departamento de Fisioterapia, Centro Superior de Estudios Universitarios La Salle, Universidad Autónoma de Madrid, Spain.
| | - Emilio Suarez
- Department of Psychology, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain.
| | - Javier Rojas
- Department of Psychology, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain.
| | - Mark D Bishop
- Department of Physical Therapy, University of Florida, USA.
| | | | - Josué Fernández-Carnero
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain; Grupo de Excelencia Investigadora, URJC-Banco de Santander:Grupo Multidisciplinar en investigación y tratamiento del dolor (I-dol), Avenida de Atenas s/n, Alcorcón, 28922 Madrid, Spain; Hospital La Paz Institute for Health Research, IdiPAZ, Madrid, Spain.
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703
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Arcourt A, Gorham L, Dhandapani R, Prato V, Taberner FJ, Wende H, Gangadharan V, Birchmeier C, Heppenstall PA, Lechner SG. Touch Receptor-Derived Sensory Information Alleviates Acute Pain Signaling and Fine-Tunes Nociceptive Reflex Coordination. Neuron 2016; 93:179-193. [PMID: 27989460 DOI: 10.1016/j.neuron.2016.11.027] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 08/01/2016] [Accepted: 11/07/2016] [Indexed: 11/25/2022]
Abstract
Painful mechanical stimuli activate multiple peripheral sensory afferent subtypes simultaneously, including nociceptors and low-threshold mechanoreceptors (LTMRs). Using an optogenetic approach, we demonstrate that LTMRs do not solely serve as touch receptors but also play an important role in acute pain signaling. We show that selective activation of neuropeptide Y receptor-2-expressing (Npy2r) myelinated A-fiber nociceptors evokes abnormally exacerbated pain, which is alleviated by concurrent activation of LTMRs in a frequency-dependent manner. We further show that spatial summation of single action potentials from multiple NPY2R-positive afferents is sufficient to trigger nocifensive paw withdrawal, but additional simultaneous sensory input from LTMRs is required for normal well-coordinated execution of this reflex. Thus, our results show that combinatorial coding of noxious and tactile sensory input is required for normal acute mechanical pain signaling. Additionally, we established a causal link between precisely defined neural activity in functionally identified sensory neuron subpopulations and nocifensive behavior and pain.
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Affiliation(s)
- Alice Arcourt
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Louise Gorham
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | | | - Vincenzo Prato
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Francisco J Taberner
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Hagen Wende
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany; Max-Delbrueck-Center (MDC) for Molecular Medicine, Robert-Roessle-Strasse 10, 13125 Berlin, Germany
| | - Vijayan Gangadharan
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Carmen Birchmeier
- Max-Delbrueck-Center (MDC) for Molecular Medicine, Robert-Roessle-Strasse 10, 13125 Berlin, Germany
| | | | - Stefan G Lechner
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany.
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704
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Morley SJ, Qi Y, Iovino L, Andolfi L, Guo D, Kalebic N, Castaldi L, Tischer C, Portulano C, Bolasco G, Shirlekar K, Fusco CM, Asaro A, Fermani F, Sundukova M, Matti U, Reymond L, De Ninno A, Businaro L, Johnsson K, Lazzarino M, Ries J, Schwab Y, Hu J, Heppenstall PA. Acetylated tubulin is essential for touch sensation in mice. eLife 2016; 5. [PMID: 27976998 PMCID: PMC5158137 DOI: 10.7554/elife.20813] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 11/29/2016] [Indexed: 01/11/2023] Open
Abstract
At its most fundamental level, touch sensation requires the translation of mechanical energy into mechanosensitive ion channel opening, thereby generating electro-chemical signals. Our understanding of this process, especially how the cytoskeleton influences it, remains unknown. Here we demonstrate that mice lacking the α-tubulin acetyltransferase Atat1 in sensory neurons display profound deficits in their ability to detect mechanical stimuli. We show that all cutaneous afferent subtypes, including nociceptors have strongly reduced mechanosensitivity upon Atat1 deletion, and that consequently, mice are largely insensitive to mechanical touch and pain. We establish that this broad loss of mechanosensitivity is dependent upon the acetyltransferase activity of Atat1, which when absent leads to a decrease in cellular elasticity. By mimicking α-tubulin acetylation genetically, we show both cellular rigidity and mechanosensitivity can be restored in Atat1 deficient sensory neurons. Hence, our results indicate that by influencing cellular stiffness, α-tubulin acetylation sets the force required for touch. DOI:http://dx.doi.org/10.7554/eLife.20813.001
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Affiliation(s)
- Shane J Morley
- EMBL Mouse Biology Unit, Monterotondo, Italy.,Molecular Medicine Partnership Unit (MMPU), Heidelberg, Germany
| | - Yanmei Qi
- Centre for Integrative Neuroscience, Tuebingen, Germany
| | - Loredana Iovino
- EMBL Mouse Biology Unit, Monterotondo, Italy.,Molecular Medicine Partnership Unit (MMPU), Heidelberg, Germany
| | | | - Da Guo
- Centre for Integrative Neuroscience, Tuebingen, Germany
| | - Nereo Kalebic
- EMBL Mouse Biology Unit, Monterotondo, Italy.,Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | | | | | | | | | | | | | | | | | | | - Ulf Matti
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Luc Reymond
- Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | | | | | - Kai Johnsson
- Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | | | - Jonas Ries
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Yannick Schwab
- European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jing Hu
- Centre for Integrative Neuroscience, Tuebingen, Germany
| | - Paul A Heppenstall
- EMBL Mouse Biology Unit, Monterotondo, Italy.,Molecular Medicine Partnership Unit (MMPU), Heidelberg, Germany
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705
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Small-molecule inhibition of STOML3 oligomerization reverses pathological mechanical hypersensitivity. Nat Neurosci 2016; 20:209-218. [PMID: 27941788 DOI: 10.1038/nn.4454] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/03/2016] [Indexed: 12/15/2022]
Abstract
The skin is equipped with specialized mechanoreceptors that allow the perception of the slightest brush. Indeed, some mechanoreceptors can detect even nanometer-scale movements. Movement is transformed into electrical signals via the gating of mechanically activated ion channels at sensory endings in the skin. The sensitivity of Piezo mechanically gated ion channels is controlled by stomatin-like protein-3 (STOML3), which is required for normal mechanoreceptor function. Here we identify small-molecule inhibitors of STOML3 oligomerization that reversibly reduce the sensitivity of mechanically gated currents in sensory neurons and silence mechanoreceptors in vivo. STOML3 inhibitors in the skin also reversibly attenuate fine touch perception in normal mice. Under pathophysiological conditions following nerve injury or diabetic neuropathy, the slightest touch can produce pain, and here STOML3 inhibitors can reverse mechanical hypersensitivity. Thus, small molecules applied locally to the skin can be used to modulate touch and may represent peripherally available drugs to treat tactile-driven pain following neuropathy.
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706
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Strzalkowski NDJ, Incognito AV, Bent LR, Millar PJ. Cutaneous Mechanoreceptor Feedback from the Hand and Foot Can Modulate Muscle Sympathetic Nerve Activity. Front Neurosci 2016; 10:568. [PMID: 28008306 PMCID: PMC5143677 DOI: 10.3389/fnins.2016.00568] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/24/2016] [Indexed: 01/07/2023] Open
Abstract
Stimulation of high threshold mechanical nociceptors on the skin can modulate efferent sympathetic outflow. Whether low threshold mechanoreceptors from glabrous skin are similarly capable of modulating autonomic outflow is unclear. Therefore, the purpose of this study was to examine the effects of cutaneous afferent feedback from the hand palm and foot sole on efferent muscle sympathetic nerve activity (MSNA). Fifteen healthy young participants (9 male; 25 ± 3 years [range: 22-29]) underwent microneurographic recording of multi-unit MSNA from the right fibular nerve during 2 min of baseline and 2 min of mechanical vibration (150 Hz, 220 μm peak-to-peak) applied to the left hand or foot. Each participant completed three trials of both hand and foot stimulation, each separated by 5 min. MSNA burst frequency decreased similarly during the 2 min of both hand (20.8 ± 8.9 vs. 19.3 ± 8.6 bursts/minute [Δ -8%], p = 0.035) and foot (21.0 ± 8.3 vs. 19.5 ± 8.3 bursts/minute [Δ -8%], p = 0.048) vibration but did not alter normalized mean burst amplitude or area (All p > 0.05). Larger reductions in burst frequency were observed during the first 10 s (onset) of both hand (20.8 ± 8.9 vs. 17.0 ± 10.4 [Δ -25%], p < 0.001) and foot (21.0 ± 8.3 vs. 18.3 ± 9.4 [Δ -16%], p = 0.035) vibration, in parallel with decreases in normalized mean burst amplitude (hand: 0.45 ± 0.06 vs. 0.36 ± 0.14% [Δ -19%], p = 0.03; foot: 0.47 ± 0.07 vs. 0.34 ± 0.19% [Δ -27%], p = 0.02) and normalized mean burst area (hand: 0.42 ± 0.05 vs. 0.32 ± 0.12% [Δ -25%], p = 0.003; foot: 0.47 ± 0.05 vs. 0.34 ± 0.16% [Δ -28%], p = 0.01). These results demonstrate that tactile feedback from the hands and feet can influence efferent sympathetic outflow to skeletal muscle.
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Affiliation(s)
| | - Anthony V Incognito
- Department of Human Health and Nutritional Science, University of Guelph Guelph, ON, Canada
| | - Leah R Bent
- Department of Human Health and Nutritional Science, University of Guelph Guelph, ON, Canada
| | - Philip J Millar
- Department of Human Health and Nutritional Science, University of GuelphGuelph, ON, Canada; Toronto General Research Institute, Toronto General HospitalToronto, ON, Canada
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707
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Ikeda R, Gu JG. Electrophysiological property and chemical sensitivity of primary afferent neurons that innervate rat whisker hair follicles. Mol Pain 2016; 12:12/0/1744806916685570. [PMID: 27927797 PMCID: PMC5207362 DOI: 10.1177/1744806916685570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Whisker hair follicles are sensory organs that sense touch and perform tactile discrimination in animals, and they are sites where sensory impulses are initiated when whisker hairs touch an object. The sensory signals are then conveyed by whisker afferent fibers to the brain for sensory perception. Electrophysiological property and chemical sensitivity of whisker afferent fibers, important factors affecting whisker sensory processing, are largely not known. In the present study, we performed patch-clamp recordings from pre-identified whisker afferent neurons in whole-mount trigeminal ganglion preparations and characterized their electrophysiological property and sensitivity to ATP, serotonin and glutamate. Of 97 whisker afferent neurons examined, 67% of them are found to be large-sized (diameter ≥45 µm) cells and 33% of them are medium- to small-sized (diameter <45 µm) cells. Almost every large-sized whisker afferent neuron fires a single action potential but many (40%) small/medium-sized whisker afferent neurons fire multiple action potentials in response to prolonged stepwise depolarization. Other electrophysiological properties including resting membrane potential, action potential threshold, and membrane input resistance are also significantly different between large-sized and small/medium-sized whisker afferent neurons. Most large-sized and many small/medium-sized whisker afferent neurons are sensitive to ATP and/or serotonin, and ATP and/or serotonin could evoke strong inward currents in these cells. In contrast, few whisker afferent neurons are sensitive to glutamate. Our results raise a possibility that ATP and/or serotonin may be chemical messengers involving sensory signaling for different types of rat whisker afferent fibers.
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Affiliation(s)
- Ryo Ikeda
- Department of Anesthesiology, The University of Cincinnati College of Medicine, Cincinnati, OH, USA
- Department of Orthopaedic Surgery, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Jianguo G Gu
- Department of Orthopaedic Surgery, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, AL, USA
- Jianguo G Gu, Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, 901 19th Street South Birmingham, AL 35294, USA.
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708
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Croy I, Geide H, Paulus M, Weidner K, Olausson H. Affective touch awareness in mental health and disease relates to autistic traits - An explorative neurophysiological investigation. Psychiatry Res 2016; 245:491-496. [PMID: 27639880 DOI: 10.1016/j.psychres.2016.09.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 08/29/2016] [Accepted: 09/08/2016] [Indexed: 10/21/2022]
Abstract
Affective touch is important for social interaction within families and groups and there is evidence that unmyelinated C tactile fibers are involved in this process. Individuals with autism spectrum disorders show alterations in the perception and processing of affective touch. sThus, we hypothesized that affective touch awareness based on C tactile fiber activation is impaired in individuals with high levels of autistic trait. The pleasantness perception of optimal and suboptimal C tactile stimuli was tested in an explorative study in 70 patients recruited from an outpatient psychotherapy clinic and 69 healthy comparison subjects. All participants completed questionnaires about autistic traits, depressive symptomatology, childhood maltreatment, and about the daily amount of touch. Relative to comparison subjects, patients reported engaging in touch less frequently in daily life and rated touch less pleasant. Reduced valence ratings of touch were explained by childhood maltreatment but not by any particular disorder or depression severity. Among all tested variables, the affective touch awareness correlated with autistic traits only - in patients as well as in comparison subjects. Taken together, individuals with mental health issues have a lower baseline of expression and reception of affective touch. Autistic traits and childhood maltreatment modulate the experience of affective touch.
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Affiliation(s)
- Ilona Croy
- Department of Psychotherapy and Psychosomatic Medicine, Technische Universität Dresden, Germany; Center for Social and Affective Neuroscience, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
| | - Helen Geide
- Center for Social and Affective Neuroscience, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Martin Paulus
- Laureate Institute for Brain Research, Tulsa, OK, USA
| | - Kerstin Weidner
- Department of Psychotherapy and Psychosomatic Medicine, Technische Universität Dresden, Germany
| | - Håkan Olausson
- Center for Social and Affective Neuroscience, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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709
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Abstract
The mammalian nervous system encodes many different forms of pain, from those that arise as a result of short-term low-grade interactions with noxious thermal, chemical, or mechanical sources to more serious forms of pain induced by trauma and disease. In this Review, we highlight recent advances in our understanding of the neural circuits that encode these types of pain. Promising therapeutic strategies based on recent advances are also highlighted.
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Affiliation(s)
- Cedric Peirs
- Departments of Neurobiology and Otolaryngology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, BST3, Pittsburgh, PA 15213, USA
- Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15213, USA
| | - Rebecca P Seal
- Departments of Neurobiology and Otolaryngology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, BST3, Pittsburgh, PA 15213, USA.
- Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15213, USA
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710
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Kretzberg J, Pirschel F, Fathiazar E, Hilgen G. Encoding of Tactile Stimuli by Mechanoreceptors and Interneurons of the Medicinal Leech. Front Physiol 2016; 7:506. [PMID: 27840612 PMCID: PMC5083904 DOI: 10.3389/fphys.2016.00506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 10/14/2016] [Indexed: 12/29/2022] Open
Abstract
For many animals processing of tactile information is a crucial task in behavioral contexts like exploration, foraging, and stimulus avoidance. The leech, having infrequent access to food, developed an energy efficient reaction to tactile stimuli, avoiding unnecessary muscle movements: The local bend behavior moves only a small part of the body wall away from an object touching the skin, while the rest of the animal remains stationary. Amazingly, the precision of this localized behavioral response is similar to the spatial discrimination threshold of the human fingertip, although the leech skin is innervated by an order of magnitude fewer mechanoreceptors and each midbody ganglion contains only 400 individually identified neurons in total. Prior studies suggested that this behavior is controlled by a three-layered feed-forward network, consisting of four mechanoreceptors (P cells), approximately 20 interneurons and 10 individually characterized motor neurons, all of which encode tactile stimulus location by overlapping, symmetrical tuning curves. Additionally, encoding of mechanical force was attributed to three types of mechanoreceptors reacting to distinct intensity ranges: T cells for touch, P cells for pressure, and N cells for strong, noxious skin stimulation. In this study, we provide evidences that tactile stimulus encoding in the leech is more complex than previously thought. Combined electrophysiological, anatomical, and voltage sensitive dye approaches indicate that P and T cells both play a major role in tactile information processing resulting in local bending. Our results indicate that tactile encoding neither relies on distinct force intensity ranges of different cell types, nor location encoding is restricted to spike count tuning. Instead, we propose that P and T cells form a mixed type population, which simultaneously employs temporal response features and spike counts for multiplexed encoding of touch location and force intensity. This hypothesis is supported by our finding that previously identified local bend interneurons receive input from both P and T cells. Some of these interneurons seem to integrate mechanoreceptor inputs, while others appear to use temporal response cues, presumably acting as coincidence detectors. Further voltage sensitive dye studies can test these hypotheses how a tiny nervous system performs highly precise stimulus processing.
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Affiliation(s)
- Jutta Kretzberg
- Computational Neuroscience, Department of Neuroscience, University of OldenburgOldenburg, Germany; Cluster of Excellence Hearing4all, University of OldenburgOldenburg, Germany
| | - Friederice Pirschel
- Computational Neuroscience, Department of Neuroscience, University of OldenburgOldenburg, Germany; Department of Organismal Biology and Anatomy, University of ChicagoChicago, IL, USA
| | - Elham Fathiazar
- Computational Neuroscience, Department of Neuroscience, University of Oldenburg Oldenburg, Germany
| | - Gerrit Hilgen
- Computational Neuroscience, Department of Neuroscience, University of OldenburgOldenburg, Germany; Faculty of Medical Sciences, Institute of Neuroscience, Newcastle UniversityNewcastle upon Tyne, UK
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711
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Thermal referral: evidence for a thermoceptive uniformity illusion without touch. Sci Rep 2016; 6:35286. [PMID: 27775034 PMCID: PMC5075768 DOI: 10.1038/srep35286] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 09/23/2016] [Indexed: 11/13/2022] Open
Abstract
When warm thermal stimulators are placed on the ring and index fingers of one hand, and a neutral-temperature stimulator on the middle finger, all three fingers feel warm. This illusion is known as thermal referral (TR). On one interpretation, the heterogenous thermal signals are overridden by homogenous tactile signals. This cross-modal thermo-tactile interaction could reflect a process of object recognition, based on the prior that many objects are thermally homogenous. Interestingly, the illusion was reported to disappear when the middle digit was lifted off the thermal stimulator, suggesting that tactile stimulation is necessary. However, no study has investigated whether purely thermal stimulation might induce TR, without any tactile object to which temperature can be attributed. We used radiant thermal stimulation to deliver purely thermal stimuli, which either were or were not accompanied by simultaneous touch. We found identical TR effects in both the original thermo-tactile condition, and in a purely thermoceptive condition where no tactile object was present. Control experiments ruled out explanations based on poor spatial discrimination of warm signals. Our purely thermoceptive results suggest that TR could reflect low-level organization of the thermoceptive pathway, rather than a cognitive intermodal modulation based on tactile object perception.
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712
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Abstract
The ability of animals to flexibly navigate through complex environments depends on the integration of sensory information with motor commands. The sensory modality most tightly linked to motor control is mechanosensation. Adaptive motor control depends critically on an animal's ability to respond to mechanical forces generated both within and outside the body. The compact neural circuits of insects provide appealing systems to investigate how mechanical cues guide locomotion in rugged environments. Here, we review our current understanding of mechanosensation in insects and its role in adaptive motor control. We first examine the detection and encoding of mechanical forces by primary mechanoreceptor neurons. We then discuss how central circuits integrate and transform mechanosensory information to guide locomotion. Because most studies in this field have been performed in locusts, cockroaches, crickets, and stick insects, the examples we cite here are drawn mainly from these 'big insects'. However, we also pay particular attention to the tiny fruit fly, Drosophila, where new tools are creating new opportunities, particularly for understanding central circuits. Our aim is to show how studies of big insects have yielded fundamental insights relevant to mechanosensation in all animals, and also to point out how the Drosophila toolkit can contribute to future progress in understanding mechanosensory processing.
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Affiliation(s)
- John C Tuthill
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA.
| | - Rachel I Wilson
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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713
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Hernandez-Miranda LR, Müller T, Birchmeier C. The dorsal spinal cord and hindbrain: From developmental mechanisms to functional circuits. Dev Biol 2016; 432:34-42. [PMID: 27742210 DOI: 10.1016/j.ydbio.2016.10.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 09/07/2016] [Accepted: 10/10/2016] [Indexed: 11/29/2022]
Abstract
Neurons of the dorsal hindbrain and spinal cord are central in receiving, processing and relaying sensory perception and participate in the coordination of sensory-motor output. Numerous cellular and molecular mechanisms that underlie neuronal development in both regions of the nervous system are shared. We discuss here the mechanisms that generate neuronal diversity in the dorsal spinal cord and hindbrain, and emphasize similarities in patterning and neuronal specification. Insight into the developmental mechanisms has provided tools that can help to assign functions to small subpopulations of neurons. Hence, novel information on how mechanosensory or pain sensation is encoded under normal and neuropathic conditions has already emerged. Such studies show that the complex neuronal circuits that control perception of somatosensory and viscerosensory stimuli are becoming amenable to investigations.
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Affiliation(s)
- Luis R Hernandez-Miranda
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz-Association, Robert-Rössle-Str. 10, 13125 Berlin, Germany.
| | - Thomas Müller
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz-Association, Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Carmen Birchmeier
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz-Association, Robert-Rössle-Str. 10, 13125 Berlin, Germany.
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714
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Chesler AT, Szczot M, Bharucha-Goebel D, Čeko M, Donkervoort S, Laubacher C, Hayes LH, Alter K, Zampieri C, Stanley C, Innes AM, Mah JK, Grosmann CM, Bradley N, Nguyen D, Foley AR, Le Pichon CE, Bönnemann CG. The Role of PIEZO2 in Human Mechanosensation. N Engl J Med 2016; 375:1355-1364. [PMID: 27653382 PMCID: PMC5911918 DOI: 10.1056/nejmoa1602812] [Citation(s) in RCA: 245] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND The senses of touch and proprioception evoke a range of perceptions and rely on the ability to detect and transduce mechanical force. The molecular and neural mechanisms underlying these sensory functions remain poorly defined. The stretch-gated ion channel PIEZO2 has been shown to be essential for aspects of mechanosensation in model organisms. METHODS We performed whole-exome sequencing analysis in two patients who had unique neuromuscular and skeletal symptoms, including progressive scoliosis, that did not conform to standard diagnostic classification. In vitro and messenger RNA assays, functional brain imaging, and psychophysical and kinematic tests were used to establish the effect of the genetic variants on protein function and somatosensation. RESULTS Each patient carried compound-inactivating variants in PIEZO2, and each had a selective loss of discriminative touch perception but nevertheless responded to specific types of gentle mechanical stimulation on hairy skin. The patients had profoundly decreased proprioception leading to ataxia and dysmetria that were markedly worse in the absence of visual cues. However, they had the ability to perform a range of tasks, such as walking, talking, and writing, that are considered to rely heavily on proprioception. CONCLUSIONS Our results show that PIEZO2 is a determinant of mechanosensation in humans. (Funded by the National Institutes of Health Intramural Research Program.).
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Affiliation(s)
- Alexander T Chesler
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Marcin Szczot
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Diana Bharucha-Goebel
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Marta Čeko
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Sandra Donkervoort
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Claire Laubacher
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Leslie H Hayes
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Katharine Alter
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Cristiane Zampieri
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Christopher Stanley
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - A Micheil Innes
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Jean K Mah
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Carla M Grosmann
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Nathaniel Bradley
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - David Nguyen
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - A Reghan Foley
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Claire E Le Pichon
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
| | - Carsten G Bönnemann
- From the National Center for Complementary and Integrative Health (A.T.C., M.S., M.C., C.L.), the National Institute of Neurological Disorders and Stroke (D.B.-G., S.D., L.H.H., N.B., D.N., A.R.F., C.E.L.P., C.G.B.), and the Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, Clinical Center (K.A., C.Z., C.S.), National Institutes of Health, Bethesda, MD; the Division of Neurology, Children's National Health System, Washington, DC (D.B.-G.); the Department of Medical Genetics and Alberta Children's Hospital Research Institute, Cumming School of Medicine (A.M.I.), and the Department of Clinical Neurosciences and Department of Pediatrics, Alberta Children's Hospital Research Institute (J.K.M.), University of Calgary, Calgary, Canada; and the Departments of Neurosciences and Pediatrics, School of Medicine, University of California, San Diego, Rady Children's Hospital, San Diego, CA (C.M.G.)
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715
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Mechanical sensitivity and electrophysiological properties of acutely dissociated dorsal root ganglion neurons of rats. Neurosci Lett 2016; 634:70-75. [PMID: 27720807 DOI: 10.1016/j.neulet.2016.10.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 10/03/2016] [Accepted: 10/04/2016] [Indexed: 11/24/2022]
Abstract
Primary afferent fibers use mechanically activated (MA) currents to transduce innocuous and noxious mechanical stimuli. However, it is largely unknown about the differences in MA currents between the afferents for sensing innocuous and noxious stimuli. In the present study, we used dorsal root ganglion (DRG) neurons acutely dissociated from rats and studied their MA currents and also their intrinsic membrane properties. Recorded from small-sized DRG neurons, we found that most of these neurons were mechanically sensitive (MS) showing MA currents. The MS neurons could be classified into nociceptive-like mechanically sensitive (Noci-MS) and non-nociceptive-like mechanically sensitive (nonNoci-MS) neurons based on their action potential shapes. Noci-MS neurons responded to mechanical stimulation with three types of MA currents, rapidly adapting (RA), intermediately adapting (IA), and slowly adapting (SA) currents. In contrast, almost all nonNoci-MS neurons showed RA current type in response to mechanical stimulation. Mechanical thresholds had a broad range for both nonNoci-MS and Noci-MS neurons, and the thresholds were not significantly different between them. However, MA current densities were significantly smaller in Noci-MS than in nonNoci-MS neurons. Noci-MS and nonNoci-MS neurons also showed significant differences in their electrophysiological properties including action potential (AP) thresholds and AP firing patterns. These differences may contribute to the differential sensory encoding for innocuous and noxious mechanical stimuli.
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716
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Thaweerattanasinp T, Heckman CJ, Tysseling VM. Firing characteristics of deep dorsal horn neurons after acute spinal transection during administration of agonists for 5-HT1B/1D and NMDA receptors. J Neurophysiol 2016; 116:1644-1653. [PMID: 27486104 PMCID: PMC5144700 DOI: 10.1152/jn.00198.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 07/07/2016] [Indexed: 11/22/2022] Open
Abstract
Spinal cord injury (SCI) results in a loss of serotonin (5-HT) to the spinal cord and a loss of inhibition to deep dorsal horn (DDH) neurons, which produces an exaggerated excitatory drive to motoneurons. The mechanism of this excitatory drive could involve the DDH neurons triggering long excitatory postsynaptic potentials in motoneurons, which may ultimately drive muscle spasms. Modifying the activity of DDH neurons with drugs such as NMDA or the 5-HT1B/1D receptor agonist zolmitriptan could have a large effect on motoneuron activity and, therefore, on muscle spasms. In this study, we characterize the firing properties of DDH neurons after acute spinal transection in adult mice during administration of zolmitriptan and NMDA, using the in vitro sacral cord preparation and extracellular electrophysiology. DDH neurons can be categorized into three major types with distinct evoked and spontaneous firing characteristics: burst (bursting), simple (single spiking), and tonic (spontaneously tonic firing) neurons. The burst neurons likely contribute to muscle spasm mechanisms because of their bursting behavior. Only the burst neurons show significant changes in their firing characteristics during zolmitriptan and NMDA administration. Zolmitriptan suppresses the burst neurons by reducing their evoked spikes, burst duration, and spontaneous firing rate. Conversely, NMDA facilitates them by enhancing their burst duration and spontaneous firing rate. These results suggest that zolmitriptan may exert its antispastic effect on the burst neurons via activation of 5-HT1B/1D receptors, whereas activation of NMDA receptors may facilitate the burst neurons in contributing to muscle spasm mechanisms following SCI.
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Affiliation(s)
| | - Charles J Heckman
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; and Department of Physical Therapy and Human Movement Science, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Vicki M Tysseling
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Department of Physical Therapy and Human Movement Science, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
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717
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Senkowski D, Heinz A. Chronic pain and distorted body image: Implications for multisensory feedback interventions. Neurosci Biobehav Rev 2016; 69:252-9. [DOI: 10.1016/j.neubiorev.2016.08.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 08/01/2016] [Accepted: 08/06/2016] [Indexed: 12/14/2022]
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718
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Cavero I, Holzgrefe H. 15 th Annual Meeting of the Safety Pharmacology Society: Focus on traditional sensory systems. J Pharmacol Toxicol Methods 2016; 83:55-71. [PMID: 27659846 DOI: 10.1016/j.vascn.2016.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 08/30/2016] [Accepted: 09/14/2016] [Indexed: 12/12/2022]
Abstract
INTRODUCTION This report summarizes and comments key talks on the five traditional senses (ear, vestibular system, vision, taste, olfaction, and touch) which were delivered during the 2015 Annual Meeting of the Safety Pharmacology (SP) Society. AREAS COVERED The functional observational battery (FOB) can detect major candidate drug liabilities only on ear, touch and vision. Anatomy, physiology, pharmacology, and pathology notions on each sensory system introduce speaker talks. Techniques for evaluating drug effects on hearing functions are reviewed. Nonclinical approaches to assess vestibular toxicity leading to balance deficits are presented. Retinal explants studied with multielectrode arrays allow the identification of drug liability sites on the retina. Routinely performed Safety Pharmacology assays are not powered to address candidate drug-induced disturbances on taste and smell. This weakness needs correction since unintended pharmacological impairment of these sensorial functions may have serious health consequences. Neuropathy produced by chemotherapeutic agents may cause multiple sensorial perception distortions. CONCLUSIONS Safety Pharmacology studies should ensure the safety of any candidate drug on the five sensorial systems.
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719
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Nakamura M, Kim DY, Jang IS. Acid modulation of tetrodotoxin-sensitive Na + channels in large-sized trigeminal ganglion neurons. Brain Res 2016; 1651:44-52. [PMID: 27639809 DOI: 10.1016/j.brainres.2016.09.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 07/29/2016] [Accepted: 09/13/2016] [Indexed: 12/13/2022]
Abstract
Voltage-gated Na+ channels in primary afferent neurons can be divided into tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) Na+ channels. Although previous studies have shown the acid modulation of TTX-R Na+ channels, the effect of acidic pH on tetrodotoxin-sensitive (TTX-S) Na+ channels is still unknown. Here we report the effect of acidic pH on TTX-S Na+ channels expressed in large-sized trigeminal ganglion (TG) neurons using a whole-cell patch clamp technique. The application of acidic extracellular solution decreased the peak amplitude of TTX-S currents (INa) in a pH-dependent manner, but weak acid (≥pH 6.0) had no inhibitory effect on TTX-S INa. Acidic pH (pH 6.0) shifted both the activation and steady-state fast inactivation relationships of TTX-S Na+ channels toward depolarized potentials. However, acidic pH (pH 6.0) had no effect on use-dependent inhibition in response to high-frequency stimuli, development of inactivation, and accelerated the recovery from inactivation of TTX-S Na+ channels, suggesting that TTX-S Na+ channels in large-sized TG neurons are less sensitive to acidic pH. Given that voltage-gated Na+ channels play a pivotal role in the generation and conduction of action potentials in neural tissues, the insensitivity of TTX-S Na+ channels expressed in large-sized TG neurons to acidic pH would ensure transmission of innocuous tactile sensation from orofacial regions at acidic pH conditions.
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Affiliation(s)
- Michiko Nakamura
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 700-412, Republic of Korea; Brain Science & Engineering Institute, Kyungpook National University, Daegu 700-412, Republic of Korea
| | - Do-Yeon Kim
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 700-412, Republic of Korea; Brain Science & Engineering Institute, Kyungpook National University, Daegu 700-412, Republic of Korea
| | - Il-Sung Jang
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 700-412, Republic of Korea; Brain Science & Engineering Institute, Kyungpook National University, Daegu 700-412, Republic of Korea.
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720
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Cui L, Miao X, Liang L, Abdus-Saboor I, Olson W, Fleming MS, Ma M, Tao YX, Luo W. Identification of Early RET+ Deep Dorsal Spinal Cord Interneurons in Gating Pain. Neuron 2016; 91:1137-1153. [PMID: 27545714 PMCID: PMC5017914 DOI: 10.1016/j.neuron.2016.07.038] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 04/30/2016] [Accepted: 07/21/2016] [Indexed: 11/29/2022]
Abstract
The gate control theory (GCT) of pain proposes that pain- and touch-sensing neurons antagonize each other through spinal cord dorsal horn (DH) gating neurons. However, the exact neural circuits underlying the GCT remain largely elusive. Here, we identified a new population of deep layer DH (dDH) inhibitory interneurons that express the receptor tyrosine kinase Ret neonatally. These early RET+ dDH neurons receive excitatory as well as polysynaptic inhibitory inputs from touch- and/or pain-sensing afferents. In addition, they negatively regulate DH pain and touch pathways through both pre- and postsynaptic inhibition. Finally, specific ablation of early RET+ dDH neurons increases basal and chronic pain, whereas their acute activation reduces basal pain perception and relieves inflammatory and neuropathic pain. Taken together, our findings uncover a novel spinal circuit that mediates crosstalk between touch and pain pathways and suggest that some early RET+ dDH neurons could function as pain "gating" neurons.
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Affiliation(s)
- Lian Cui
- Department of Neuroscience, Perelman School of Medicine, the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Xuerong Miao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, the State University of New Jersey, Newark, NJ 07103, USA
| | - Lingli Liang
- Department of Anesthesiology, New Jersey Medical School, Rutgers, the State University of New Jersey, Newark, NJ 07103, USA
| | - Ishmail Abdus-Saboor
- Department of Neuroscience, Perelman School of Medicine, the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William Olson
- Department of Neuroscience, Perelman School of Medicine, the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael S Fleming
- Department of Neuroscience, Perelman School of Medicine, the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Minghong Ma
- Department of Neuroscience, Perelman School of Medicine, the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yuan-Xiang Tao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, the State University of New Jersey, Newark, NJ 07103, USA.
| | - Wenqin Luo
- Department of Neuroscience, Perelman School of Medicine, the University of Pennsylvania, Philadelphia, PA 19104, USA.
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721
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Neuronal networks and nociceptive processing in the dorsal horn of the spinal cord. Neuroscience 2016; 338:230-247. [PMID: 27595888 DOI: 10.1016/j.neuroscience.2016.08.048] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/23/2016] [Accepted: 08/28/2016] [Indexed: 12/31/2022]
Abstract
The dorsal horn (DH) of the spinal cord receives a variety of sensory information arising from the inner and outer environment, as well as modulatory inputs from supraspinal centers. This information is integrated by the DH before being forwarded to brain areas where it may lead to pain perception. Spinal integration of this information relies on the interplay between different DH neurons forming complex and plastic neuronal networks. Elements of these networks are therefore potential targets for new analgesics and pain-relieving strategies. The present review aims at providing an overview of the current knowledge on these networks, with a special emphasis on those involving interlaminar communication in both physiological and pathological conditions.
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722
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Chortos A, Liu J, Bao Z. Pursuing prosthetic electronic skin. NATURE MATERIALS 2016; 15:937-50. [PMID: 27376685 DOI: 10.1038/nmat4671] [Citation(s) in RCA: 858] [Impact Index Per Article: 107.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/19/2016] [Indexed: 05/18/2023]
Abstract
Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals.
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Affiliation(s)
- Alex Chortos
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
| | - Jia Liu
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA
| | - Zhenan Bao
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA
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723
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Morrison I. Keep Calm and Cuddle on: Social Touch as a Stress Buffer. ADAPTIVE HUMAN BEHAVIOR AND PHYSIOLOGY 2016. [DOI: 10.1007/s40750-016-0052-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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724
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Sterbing-D'Angelo SJ, Liu H, Yu M, Moss CF. Morphology and deflection properties of bat wing sensory hairs: scanning electron microscopy, laser scanning vibrometry, and mechanics model. BIOINSPIRATION & BIOMIMETICS 2016; 11:056008. [PMID: 27545727 DOI: 10.1088/1748-3190/11/5/056008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Bat wings are highly adaptive airfoils that enable demanding flight maneuvers, which are performed with astonishing robustness under turbulent conditions, and stability at slow flight velocities. The bat wing is sparsely covered with microscopically small, sensory hairs that are associated with tactile receptors. In a previous study we demonstrated that bat wing hairs are involved in sensing airflow for improved flight maneuverability. Here, we report physical measurements of these hairs and their distribution on the wing surface of the big brown bat, Eptesicus fuscus, based on scanning electron microscopy analyses. The wing hairs are strongly tapered, and are found on both the dorsal and ventral wing surfaces. Laser scanning vibrometry tests of 43 hairs from twelve locations across the wing of the big brown bat revealed that their natural frequencies inversely correlate with length and range from 3.7 to 84.5 kHz. Young's modulus of the average wing hair was calculated at 4.4 GPa, which is comparable with rat whiskers or arthropod airflow-sensing hairs.
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725
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Reed JL, Liao CC, Qi HX, Kaas JH. Plasticity and Recovery After Dorsal Column Spinal Cord Injury in Nonhuman Primates. J Exp Neurosci 2016; 10:11-21. [PMID: 27578996 PMCID: PMC4991577 DOI: 10.4137/jen.s40197] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 06/26/2016] [Accepted: 06/28/2016] [Indexed: 12/15/2022] Open
Abstract
Here, we review recent work on plasticity and recovery after dorsal column spinal cord injury in nonhuman primates. Plasticity in the adult central nervous system has been established and studied for the past several decades; however, capacities and limits of plasticity are still under investigation. Studies of plasticity include assessing multiple measures before and after injury in animal models. Such studies are particularly important for improving recovery after injury in patients. In summarizing work by our research team and others, we suggest how the findings from plasticity studies in nonhuman primate models may affect therapeutic interventions for conditions involving sensory loss due to spinal cord injury.
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Affiliation(s)
- Jamie L Reed
- Department of Psychology, Vanderbilt University, Nashville, TN, USA
| | - Chia-Chi Liao
- Department of Psychology, Vanderbilt University, Nashville, TN, USA
| | - Hui-Xin Qi
- Department of Psychology, Vanderbilt University, Nashville, TN, USA
| | - Jon H Kaas
- Department of Psychology, Vanderbilt University, Nashville, TN, USA
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726
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Qi HX, Wang F, Liao CC, Friedman RM, Tang C, Kaas JH, Avison MJ. Spatiotemporal trajectories of reactivation of somatosensory cortex by direct and secondary pathways after dorsal column lesions in squirrel monkeys. Neuroimage 2016; 142:431-453. [PMID: 27523450 DOI: 10.1016/j.neuroimage.2016.08.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/23/2016] [Accepted: 08/09/2016] [Indexed: 11/17/2022] Open
Abstract
After lesions of the somatosensory dorsal column (DC) pathway, the cortical hand representation can become unresponsive to tactile stimuli, but considerable responsiveness returns over weeks of post-lesion recovery. The reactivation suggests that preserved subthreshold sensory inputs become potentiated and axon sprouting occurs over time to mediate recovery. Here, we studied the recovery process in 3 squirrel monkeys, using high-resolution cerebral blood volume-based functional magnetic resonance imaging (CBV-fMRI) mapping of contralateral somatosensory cortex responsiveness to stimulation of distal finger pads with low and high level electrocutaneous stimulation (ES) before and 2, 4, and 6weeks after a mid-cervical level contralateral DC lesion. Both low and high intensity ES of digits revealed the expected somatotopy of the area 3b hand representation in pre-lesion monkeys, while in areas 1 and 3a, high intensity stimulation was more effective in activating somatotopic patterns. Six weeks post-lesion, and irrespective of the severity of loss of direct DC inputs (98%, 79%, 40%), somatosensory cortical area 3b of all three animals showed near complete recovery in terms of somatotopy and responsiveness to low and high intensity ES. However there was significant variability in the patterns and amplitudes of reactivation of individual digit territories within and between animals, reflecting differences in the degree of permanent and/or transient silencing of primary DC and secondary inputs 2weeks post-lesion, and their spatio-temporal trajectories of recovery between 2 and 6weeks. Similar variations in the silencing and recovery of somatotopy and responsiveness to high intensity ES in areas 3a and 1 are consistent with individual differences in damage to and recovery of DC and spinocuneate pathways, and possibly the potentiation of spinothalamic pathways. Thus, cortical deactivation and subsequent reactivation depends not only on the degree of DC lesion, but also on the severity and duration of loss of secondary as well as primary inputs revealed by low and high intensity ES.
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Affiliation(s)
- Hui-Xin Qi
- Department of Psychology, Vanderbilt University, Nashville, TN 37240, USA.
| | - Feng Wang
- Institute of Imaging Science, Vanderbilt University, Nashville, TN 37240, USA; Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN 37240, USA
| | - Chia-Chi Liao
- Department of Psychology, Vanderbilt University, Nashville, TN 37240, USA
| | - Robert M Friedman
- Department of Psychology, Vanderbilt University, Nashville, TN 37240, USA
| | - Chaohui Tang
- Institute of Imaging Science, Vanderbilt University, Nashville, TN 37240, USA; Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN 37240, USA
| | - Jon H Kaas
- Department of Psychology, Vanderbilt University, Nashville, TN 37240, USA; Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN 37240, USA
| | - Malcolm J Avison
- Institute of Imaging Science, Vanderbilt University, Nashville, TN 37240, USA; Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN 37240, USA; Pharmacology, Vanderbilt University, Nashville, TN 37240, USA
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727
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Multiplexed Population Coding of Stimulus Properties by Leech Mechanosensory Cells. J Neurosci 2016; 36:3636-47. [PMID: 27030751 DOI: 10.1523/jneurosci.1753-15.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 02/10/2016] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED Sensory coding has long been discussed in terms of a dichotomy between spike timing and rate coding. However, recent studies found that in primate mechanoperception and other sensory systems, spike rates and timing of cell populations complement each other. They simultaneously carry information about different stimulus properties in a multiplexed way. Here, we present evidence for multiplexed encoding of tactile skin stimulation in the tiny population of leech mechanoreceptors, consisting of only 10 cells of two types with overlapping receptive fields. Each mechanoreceptor neuron of the leech varies spike count and response latency to both touch intensity and location, leading to ambiguous responses to different stimuli. Nevertheless, three different stimulus estimation techniques consistently reveal that the neuronal population allows reliable decoding of both stimulus properties. For the two mechanoreceptor types, the transient responses of T (touch) cells and the sustained responses of P (pressure) cells, the relative timing of the first spikes of two mechanoreceptors encodes stimulus location, whereas summed spike counts represent touch intensity. Differences between the cell types become evident in responses to combined stimulus properties. The best estimation performance for stimulus location is obtained from the relative first spike timing of the faster and temporally more precise T cells. Simultaneously, the sustained responses of P cells indicate touch intensity by summed spike counts and stimulus duration by the duration of spike responses. The striking similarities of these results with previous findings on primate mechanosensory afferents suggest multiplexed population coding as a general principle of somatosensation. SIGNIFICANCE STATEMENT Multiplexing, the simultaneous encoding of different stimulus properties by distinct neuronal response features, has recently been suggested as a mechanism used in several sensory systems, including primate somatosensation. While a rigorous experimental verification of the multiplexing hypothesis is difficult to accomplish in a complex vertebrate system, it is feasible for a small population of individually characterized leech neurons. Monitoring the responses of all four mechanoreceptors innervating a patch of skin revealed striking similarities between touch encoding in the primate and the leech: summed spike counts represent stimulus intensity, whereas relative timing of first spikes encodes stimulus location. These findings suggest that multiplexed population coding is a general mechanism of touch encoding common to species as different as man and worm.
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728
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Topically applied mesoridazine exhibits the strongest cutaneous analgesia and minimized skin disruption among tricyclic antidepressants: The skin absorption assessment. Eur J Pharm Biopharm 2016; 105:59-68. [DOI: 10.1016/j.ejpb.2016.05.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 05/29/2016] [Accepted: 05/30/2016] [Indexed: 01/16/2023]
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729
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Osborn L, Nguyen H, Betthauser J, Kaliki R, Thakor N. Biologically inspired multi-layered synthetic skin for tactile feedback in prosthetic limbs. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2016:4622-4625. [PMID: 28269305 PMCID: PMC8092020 DOI: 10.1109/embc.2016.7591757] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The human body offers a template for many state-of-the-art prosthetic devices and sensors. In this work, we present a novel, sensorized synthetic skin that mimics the natural multi-layered nature of mechanoreceptors found in healthy glabrous skin to provide tactile information. The multi-layered sensor is made up of flexible piezoresistive textiles that act as force sensitive resistors (FSRs) to convey tactile information, which are embedded within a silicone rubber to resemble the compliant nature of human skin. The top layer of the synthetic skin is capable of detecting small loads less than 5 N whereas the bottom sensing layer responds reliably to loads over 7 N. Finite element analysis (FEA) of a simplified human fingertip and the synthetic skin was performed. Results suggest similarities in behavior during loading. A natural tactile event is simulated by loading the synthetic skin on a prosthetic limb. Results show the sensors' ability to detect applied loads as well as the ability to simulate neural spiking activity based on the derivative and temporal differences of the sensor response. During the tactile loading, the top sensing layer responded 0.24 s faster than the bottom sensing layer. A synthetic biologically-inspired skin such as this will be useful for enhancing the functionality of prosthetic limbs through tactile feedback.
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730
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Tuthill JC, Wilson RI. Parallel Transformation of Tactile Signals in Central Circuits of Drosophila. Cell 2016; 164:1046-59. [PMID: 26919434 DOI: 10.1016/j.cell.2016.01.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/23/2015] [Accepted: 01/04/2016] [Indexed: 01/30/2023]
Abstract
To distinguish between complex somatosensory stimuli, central circuits must combine signals from multiple peripheral mechanoreceptor types, as well as mechanoreceptors at different sites in the body. Here, we investigate the first stages of somatosensory integration in Drosophila using in vivo recordings from genetically labeled central neurons in combination with mechanical and optogenetic stimulation of specific mechanoreceptor types. We identify three classes of central neurons that process touch: one compares touch signals on different parts of the same limb, one compares touch signals on right and left limbs, and the third compares touch and proprioceptive signals. Each class encodes distinct features of somatosensory stimuli. The axon of an individual touch receptor neuron can diverge to synapse onto all three classes, meaning that these computations occur in parallel, not hierarchically. Representing a stimulus as a set of parallel comparisons is a fast and efficient way to deliver somatosensory signals to motor circuits.
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Affiliation(s)
- John C Tuthill
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Rachel I Wilson
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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731
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Desai VH, Anand S, Tran M, Kanneganti A, Vasudevan S, Seifert JL, Cheng J, Keefer EW, Romero-Ortega MI. Chronic sensory-motor activity in behaving animals using regenerative multi-electrode interfaces. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2014:1973-6. [PMID: 25570368 DOI: 10.1109/embc.2014.6944000] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Regenerative peripheral nerve interfaces have been proposed as viable alternatives for the natural control and feel of robotic prosthetic limbs. We have developed a Regenerative Multi-electrode Interface (REMI) that guides re-growing axons through an electrode array deployed in the lumen of a nerve guide. While acute studies have shown the use of the REMI in the rat sciatic nerve, the quality of chronic signal recording has not been reported. Here we show that implantation of this interface in the sciatic nerve is stable with high quality recordings up to 120 days and failures mainly attributable to abiotic factors related to pedestal detachment and wire breakage. We further tested the interfacing of REMI with fascicles of the sciatic nerve that primarily innervate muscles (tibial) and skin (sural). When implanted into the tibial nerve, bursting activity was observed synchronous to stepping. However, implantation of REMI into the sural nerve failed due to its small size. While fascicles smaller than 300 μm are a challenge for regenerative interfacing, we show that a modified REMI can be used in an insertion mode to record sensory signals from skin. In summary, the REMI represents an effective tool for recording firing patterns of specific axon types during voluntary movement, which may be used to improve the motor control and sensory feedback in closed loop control systems for robotic prosthesis.
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732
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Narayanan P, Sondermann J, Rouwette T, Karaca S, Urlaub H, Mitkovski M, Gomez-Varela D, Schmidt M. Native Piezo2 Interactomics Identifies Pericentrin as a Novel Regulator of Piezo2 in Somatosensory Neurons. J Proteome Res 2016; 15:2676-87. [PMID: 27345391 DOI: 10.1021/acs.jproteome.6b00235] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ability of somatosensory neurons to perceive mechanical stimuli relies on specialized mechanotransducing proteins and their molecular environment. Only recently has the identity of a major transducer of mechanical forces in vertebrates been revealed by the discovery of Piezo2. Further work has established its pivotal role for innocuous touch in mice. Therefore, Piezo2 offers a unique platform for the molecular investigation of somatosensory mechanosensation. We performed a mass spectrometry-based interactomics screen on native Piezo2 in somatosensory neurons of mouse dorsal root ganglia (DRG). Stringent and quantitative data analysis yielded the identity of 36 novel binding partners of Piezo2. The biological significance of this data set is reflected by functional experiments demonstrating a role for Pericentrin in modulating Piezo2 activity and membrane expression in somatosensory neurons. Collectively, our findings provide a framework for understanding Piezo2 physiology and serve as a rich resource for the molecular dissection of mouse somatosensation.
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Affiliation(s)
- Pratibha Narayanan
- Max-Planck Institute of Experimental Medicine , Somatosensory Signaling and Systems Biology Group, D-37075 Goettingen, Germany
| | - Julia Sondermann
- Max-Planck Institute of Experimental Medicine , Somatosensory Signaling and Systems Biology Group, D-37075 Goettingen, Germany
| | - Tom Rouwette
- Max-Planck Institute of Experimental Medicine , Somatosensory Signaling and Systems Biology Group, D-37075 Goettingen, Germany
| | - Samir Karaca
- Max Planck Institute of Biophysical Chemistry , Bioanalytical Mass Spectrometry Group, D-37077 Goettingen, Germany
| | - Henning Urlaub
- Max Planck Institute of Biophysical Chemistry , Bioanalytical Mass Spectrometry Group, D-37077 Goettingen, Germany.,Bioanaytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen , D-37075 Göttingen, Germany
| | - Mišo Mitkovski
- Max-Planck Institute of Experimental Medicine , Light Microscopy Facility, D-37075 Goettingen, Germany
| | - David Gomez-Varela
- Max-Planck Institute of Experimental Medicine , Somatosensory Signaling and Systems Biology Group, D-37075 Goettingen, Germany
| | - Manuela Schmidt
- Max-Planck Institute of Experimental Medicine , Somatosensory Signaling and Systems Biology Group, D-37075 Goettingen, Germany
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733
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Gomez-Ramirez M, Hysaj K, Niebur E. Neural mechanisms of selective attention in the somatosensory system. J Neurophysiol 2016; 116:1218-31. [PMID: 27334956 DOI: 10.1152/jn.00637.2015] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 06/09/2016] [Indexed: 11/22/2022] Open
Abstract
Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates.
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Affiliation(s)
- Manuel Gomez-Ramirez
- Department of Neuroscience, Brown University, Providence, Rhode Island; The Zanvyl Krieger Mind/Brain Institute, The Johns Hopkins University, Baltimore, Maryland; and The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Kristjana Hysaj
- The Zanvyl Krieger Mind/Brain Institute, The Johns Hopkins University, Baltimore, Maryland; and
| | - Ernst Niebur
- The Zanvyl Krieger Mind/Brain Institute, The Johns Hopkins University, Baltimore, Maryland; and The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins School of Medicine, Baltimore, Maryland
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734
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Orefice LL, Zimmerman AL, Chirila AM, Sleboda SJ, Head JP, Ginty DD. Peripheral Mechanosensory Neuron Dysfunction Underlies Tactile and Behavioral Deficits in Mouse Models of ASDs. Cell 2016; 166:299-313. [PMID: 27293187 DOI: 10.1016/j.cell.2016.05.033] [Citation(s) in RCA: 238] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 03/25/2016] [Accepted: 05/06/2016] [Indexed: 10/21/2022]
Abstract
Patients with autism spectrum disorders (ASDs) commonly experience aberrant tactile sensitivity, yet the neural alterations underlying somatosensory dysfunction and the extent to which tactile deficits contribute to ASD characteristics are unknown. We report that mice harboring mutations in Mecp2, Gabrb3, Shank3, and Fmr1 genes associated with ASDs in humans exhibit altered tactile discrimination and hypersensitivity to gentle touch. Deletion of Mecp2 or Gabrb3 in peripheral somatosensory neurons causes mechanosensory dysfunction through loss of GABAA receptor-mediated presynaptic inhibition of inputs to the CNS. Remarkably, tactile defects resulting from Mecp2 or Gabrb3 deletion in somatosensory neurons during development, but not in adulthood, cause social interaction deficits and anxiety-like behavior. Restoring Mecp2 expression exclusively in the somatosensory neurons of Mecp2-null mice rescues tactile sensitivity, anxiety-like behavior, and social interaction deficits, but not lethality, memory, or motor deficits. Thus, mechanosensory processing defects contribute to anxiety-like behavior and social interaction deficits in ASD mouse models. PAPERCLIP.
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Affiliation(s)
- Lauren L Orefice
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Amanda L Zimmerman
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Anda M Chirila
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Steven J Sleboda
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Joshua P Head
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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735
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Vidal GWV, Rynes ML, Kelliher Z, Goodwin SJ. Review of Brain-Machine Interfaces Used in Neural Prosthetics with New Perspective on Somatosensory Feedback through Method of Signal Breakdown. SCIENTIFICA 2016; 2016:8956432. [PMID: 27313959 PMCID: PMC4904116 DOI: 10.1155/2016/8956432] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 03/22/2016] [Accepted: 04/28/2016] [Indexed: 06/06/2023]
Abstract
The brain-machine interface (BMI) used in neural prosthetics involves recording signals from neuron populations, decoding those signals using mathematical modeling algorithms, and translating the intended action into physical limb movement. Recently, somatosensory feedback has become the focus of many research groups given its ability in increased neural control by the patient and to provide a more natural sensation for the prosthetics. This process involves recording data from force sensitive locations on the prosthetics and encoding these signals to be sent to the brain in the form of electrical stimulation. Tactile sensation has been achieved through peripheral nerve stimulation and direct stimulation of the somatosensory cortex using intracortical microstimulation (ICMS). The initial focus of this paper is to review these principles and link them to modern day applications such as restoring limb use to those who lack such control. With regard to how far the research has come, a new perspective for the signal breakdown concludes the paper, offering ideas for more real somatosensory feedback using ICMS to stimulate particular sensations by differentiating touch sensors and filtering data based on unique frequencies.
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Affiliation(s)
| | - Mathew L. Rynes
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Zachary Kelliher
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Shikha Jain Goodwin
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
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736
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Immunostaining for Homer reveals the majority of excitatory synapses in laminae I-III of the mouse spinal dorsal horn. Neuroscience 2016; 329:171-81. [PMID: 27185486 PMCID: PMC4915440 DOI: 10.1016/j.neuroscience.2016.05.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/01/2016] [Accepted: 05/06/2016] [Indexed: 12/25/2022]
Abstract
Identifying glutamatergic synapses is important for tracing synaptic circuits. Most proteins at glutamatergic synapses are masked by tissue fixation. Homer can reveal glutamatergic synapses without the need for antigen retrieval.
The spinal dorsal horn processes somatosensory information before conveying it to the brain. The neuronal organization of the dorsal horn is still poorly understood, although recent studies have defined several distinct populations among the interneurons, which account for most of its constituent neurons. All primary afferents, and the great majority of neurons in laminae I–III are glutamatergic, and a major factor limiting our understanding of the synaptic circuitry has been the difficulty in identifying glutamatergic synapses with light microscopy. Although there are numerous potential targets for antibodies, these are difficult to visualize with immunocytochemistry, because of protein cross-linking following tissue fixation. Although this can be overcome by antigen retrieval methods, these lead to difficulty in detecting other antigens. The aim of this study was to test whether the postsynaptic protein Homer can be used to reveal glutamatergic synapses in the dorsal horn. Immunostaining for Homer gave punctate labeling when viewed by confocal microscopy, and this was restricted to synapses at the ultrastructural level. We found that Homer puncta were colocalized with the AMPA receptor GluR2 subunit, but not with the inhibitory synapse-associated protein gephyrin. We also examined several populations of glutamatergic axons and found that most boutons were in contact with at least one Homer punctum. These results suggest that Homer antibodies can be used to reveal the great majority of glutamatergic synapses without antigen retrieval. This will be of considerable value in tracing synaptic circuits, and also in investigating plasticity of glutamatergic synapses in pain states.
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737
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Seal RP. Do the distinct synaptic properties of VGLUTs shape pain? Neurochem Int 2016; 98:82-8. [PMID: 27180049 DOI: 10.1016/j.neuint.2016.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 04/26/2016] [Accepted: 04/28/2016] [Indexed: 11/25/2022]
Abstract
The somatosensory system transmits touch, temperature, itch and pain. Three vesicular glutamate transporter isoforms mediate the release of glutamate throughout the mammalian nervous system with largely non-overlapping distributions and unique roles at the synapse. This review discusses the contribution of each of these essential transporters to circuits underlying pain and other somatosensory behaviors throughout postnatal development and in the adult. A better understanding of the individual contributions of the VGLUT isoforms could provide new avenues for therapeutic intervention.
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Affiliation(s)
- Rebecca P Seal
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
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738
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Montgomery KL, Iyer SM, Christensen AJ, Deisseroth K, Delp SL. Beyond the brain: Optogenetic control in the spinal cord and peripheral nervous system. Sci Transl Med 2016; 8:337rv5. [DOI: 10.1126/scitranslmed.aad7577] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 04/18/2016] [Indexed: 12/12/2022]
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739
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Genetic Identification of an Expansive Mechanoreceptor Sensitive to Skin Stroking. Cell 2016; 163:1783-1795. [PMID: 26687362 DOI: 10.1016/j.cell.2015.11.060] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 11/12/2015] [Accepted: 11/23/2015] [Indexed: 01/15/2023]
Abstract
Touch perception begins with activation of low-threshold mechanoreceptors (LTMRs) in the periphery. LTMR terminals exhibit tremendous morphological heterogeneity that specifies their mechanical receptivity. In a survey of mammalian skin, we found a preponderance of neurofilament-heavy-chain(+) circumferential endings associated with hair follicles, prompting us to develop a genetic strategy to interrogate these neurons. Targeted in vivo recordings revealed them to be Aβ field-LTMRs, identified 50 years ago but largely elusive thereafter. Remarkably, while Aβ field-LTMRs are highly sensitive to gentle stroking of the skin, they are unresponsive to hair deflection, and they encode skin indentation in the noxious range across large, spotty receptive fields. Individual Aβ field-LTMRs form up to 180 circumferential endings, making them the most anatomically expansive LTMR identified to date. Thus, Aβ field-LTMRs are a major mammalian LTMR subtype that forms circumferential endings in hairy skin, and their sensitivity to gentle skin stroking arises through integration across many low-sensitivity circumferential endings.
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740
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Abstract
Scientists and philosophers have long appreciated that active somatosensation requires the sensory and motor systems to exchange information about body the body's movements as well as touch in order to accurately interpret incoming somatosensory information and plan future movements. However, the circuitry underlying this sensory and motor integration is complicated and is difficult to study without tools to label specific cellular components in the various brain regions involved. Here, I review the general pathways that convey ascending sensory and descending motor information, using the rodent whisker system as a model to take advantage of the cell type specificity possible in this model. I then detail the circuits in motor cortex in which incoming information from somatosensory cortex and thalamus is integrated. I close with a brief description of changes in these circuits during motor learning.
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Affiliation(s)
- Bryan M Hooks
- 1 Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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741
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Olson W, Dong P, Fleming M, Luo W. The specification and wiring of mammalian cutaneous low-threshold mechanoreceptors. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 5:389-404. [PMID: 26992078 DOI: 10.1002/wdev.229] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 01/04/2016] [Accepted: 01/12/2016] [Indexed: 11/08/2022]
Abstract
The mammalian cutaneous low-threshold mechanoreceptors (LTMRs) are a diverse set of primary somatosensory neurons that function to sense external mechanical force. Generally, LTMRs are composed of Aβ-LTMRs, Aδ-LTMRs, and C-LTMRs, which have distinct molecular, physiological, anatomical, and functional features. The specification and wiring of each type of mammalian cutaneous LTMRs is established during development by the interplay of transcription factors with trophic factor signalling. In this review, we summarize the cohort of extrinsic and intrinsic factors generating the complex mammalian cutaneous LTMR circuits that mediate our tactile sensations and behaviors. For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- William Olson
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Peter Dong
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael Fleming
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Wenqin Luo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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742
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Gutierrez-Mecinas M, Furuta T, Watanabe M, Todd AJ. A quantitative study of neurochemically defined excitatory interneuron populations in laminae I-III of the mouse spinal cord. Mol Pain 2016; 12:12/0/1744806916629065. [PMID: 27030714 PMCID: PMC4946630 DOI: 10.1177/1744806916629065] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 12/10/2015] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Excitatory interneurons account for the majority of neurons in laminae I-III, but their functions are poorly understood. Several neurochemical markers are largely restricted to excitatory interneuron populations, but we have limited knowledge about the size of these populations or their overlap. The present study was designed to investigate this issue by quantifying the neuronal populations that express somatostatin (SST), neurokinin B (NKB), neurotensin, gastrin-releasing peptide (GRP) and the γ isoform of protein kinase C (PKCγ), and assessing the extent to which they overlapped. Since it has been reported that calretinin- and SST-expressing cells have different functions, we also looked for co-localisation of calretinin and SST. RESULTS SST, preprotachykinin B (PPTB, the precursor of NKB), neurotensin, PKCγ or calretinin were detected with antibodies, while cells expressing GRP were identified in a mouse line (GRP-EGFP) in which enhanced green fluorescent protein (EGFP) was expressed under control of the GRP promoter. We found that SST-, neurotensin-, PPTB- and PKCγ-expressing cells accounted for 44%, 7%, 12% and 21% of the neurons in laminae I-II, and 16%, 8%, 4% and 14% of those in lamina III, respectively. GRP-EGFP cells made up 11% of the neuronal population in laminae I-II. The neurotensin, PPTB and GRP-EGFP populations showed very limited overlap, and we estimate that between them they account for ~40% of the excitatory interneurons in laminae I-II. SST which is expressed by ~60% of excitatory interneurons in this region, was found in each of these populations, as well as in cells that did not express any of the other peptides. Neurotensin and PPTB were often found in cells with PKCγ, and between them, constituted around 60% of the PKCγ cells. Surprisingly, we found extensive co-localisation of SST and calretinin. CONCLUSIONS These results suggest that cells expressing neurotensin, NKB or GRP form largely non-overlapping sets that are likely to correspond to functional populations. In contrast, SST is widely expressed by excitatory interneurons that are likely to be functionally heterogeneous.
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Affiliation(s)
- Maria Gutierrez-Mecinas
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Takahiro Furuta
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo, Japan
| | - Andrew J Todd
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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743
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Oddo CM, Raspopovic S, Artoni F, Mazzoni A, Spigler G, Petrini F, Giambattistelli F, Vecchio F, Miraglia F, Zollo L, Di Pino G, Camboni D, Carrozza MC, Guglielmelli E, Rossini PM, Faraguna U, Micera S. Intraneural stimulation elicits discrimination of textural features by artificial fingertip in intact and amputee humans. eLife 2016; 5:e09148. [PMID: 26952132 PMCID: PMC4798967 DOI: 10.7554/elife.09148] [Citation(s) in RCA: 179] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 01/28/2016] [Indexed: 01/02/2023] Open
Abstract
Restoration of touch after hand amputation is a desirable feature of ideal prostheses. Here, we show that texture discrimination can be artificially provided in human subjects by implementing a neuromorphic real-time mechano-neuro-transduction (MNT), which emulates to some extent the firing dynamics of SA1 cutaneous afferents. The MNT process was used to modulate the temporal pattern of electrical spikes delivered to the human median nerve via percutaneous microstimulation in four intact subjects and via implanted intrafascicular stimulation in one transradial amputee. Both approaches allowed the subjects to reliably discriminate spatial coarseness of surfaces as confirmed also by a hybrid neural model of the median nerve. Moreover, MNT-evoked EEG activity showed physiologically plausible responses that were superimposable in time and topography to the ones elicited by a natural mechanical tactile stimulation. These findings can open up novel opportunities for sensory restoration in the next generation of neuro-prosthetic hands. DOI:http://dx.doi.org/10.7554/eLife.09148.001 Our hands provide us with a wide variety of information about our surroundings, enabling us to detect pain, temperature and pressure. Our sense of touch also allows us to interact with objects by feeling their texture and solidity. However, completely reproducing a sense of touch in artificial or prosthetic hands has proven challenging. While commercial prostheses can mimic the range of movements of natural limbs, even the latest experimental prostheses have only a limited ability to ‘feel’ the objects being manipulated. Oddo, Raspopovic et al. have now brought this ability a step closer by exploiting an artificial fingertip and appropriate neural interfaces through which different textures can be identified. The initial experiments were performed in four healthy volunteers with intact limbs. Oddo, Raspopovic et al. connected the artificial fingertip to the volunteers via an electrode inserted into a nerve in the arm. When moved over a rough surface, sensors in the fingertip produced patterns of electrical pulses that stimulated the nerve, causing the volunteers to feel like they were touching the surface. The volunteers were even able to tell the difference between the different surface textures the artificial fingertip moved across. The temporary electrodes used in this group of volunteers are unsuitable for use with prosthetic limbs because they can easily be knocked out of position. Therefore, in a further experiment involving a volunteer who had undergone an arm amputation a number of years previously, Oddo, Raspopovic et al. tested an implanted electrode array that could, in principle, remain in place long-term. This volunteer could also identify the different textures the artificial fingertip touched, with a slightly higher degree of accuracy than the previous group of intact volunteers. Further studies are now required to explore the potential of this approach in larger groups of volunteers. DOI:http://dx.doi.org/10.7554/eLife.09148.002
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Affiliation(s)
| | - Stanisa Raspopovic
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy.,Bertarelli Foundation Chair in Translational NeuroEngineering, Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Center for Neuroprosthetics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Fiorenzo Artoni
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy.,Bertarelli Foundation Chair in Translational NeuroEngineering, Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Alberto Mazzoni
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Giacomo Spigler
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Francesco Petrini
- Bertarelli Foundation Chair in Translational NeuroEngineering, Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Center for Neuroprosthetics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Laboratory of Biomedical Robotics & Biomicrosystems, Università Campus Bio-Medico di Roma, Roma, Italy.,Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Roma, Italy
| | | | - Fabrizio Vecchio
- Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Roma, Italy
| | | | - Loredana Zollo
- Laboratory of Biomedical Robotics & Biomicrosystems, Università Campus Bio-Medico di Roma, Roma, Italy
| | - Giovanni Di Pino
- Laboratory of Biomedical Robotics & Biomicrosystems, Università Campus Bio-Medico di Roma, Roma, Italy.,Institute of Neurology, Università Campus Bio-Medico di Roma, Roma, Italy
| | - Domenico Camboni
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Eugenio Guglielmelli
- Laboratory of Biomedical Robotics & Biomicrosystems, Università Campus Bio-Medico di Roma, Roma, Italy
| | - Paolo Maria Rossini
- Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Roma, Italy.,Institute of Neurology, Catholic University of The Sacred Heart, Roma, Italy
| | - Ugo Faraguna
- Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy.,IRCCS Stella Maris Foundation, Pisa, Italy.,Dipartimento di Ricerca Traslazionale e delle Nuove Tecnologie in Medicina e Chirurgia, Università di Pisa, Pisa, Italy
| | - Silvestro Micera
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy.,Center for Neuroprosthetics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Bertarelli Foundation Chair in Translational NeuroEngineering, Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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744
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Misiaszek J, Forero J, Hiob E, Urbanczyk T. Automatic postural responses following rapid displacement of a light touch contact during standing. Neuroscience 2016; 316:1-12. [DOI: 10.1016/j.neuroscience.2015.12.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/14/2015] [Accepted: 12/16/2015] [Indexed: 11/17/2022]
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745
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Abstract
Disorders of the somatosensory system such as neuropathic pain are common in people with chronic neurologic and musculoskeletal diseases, yet these conditions remain an underappreciated morbidity in veterinary patients. This is likely because assessment of neuropathic pain in people relies heavily on self-reporting, something our veterinary patients are not able to do. The development of neuropathic pain is a complex phenomenon, and concepts related to it are frequently not addressed in the standard veterinary medical curriculum such that veterinarians may not recognize this as a potential problem in patients. The goals of this review are to discuss basic concepts in the pathophysiology of neuropathic pain, provide definitions for common clinical terms used in association with the condition, and discuss pharmacological treatment options for dogs with neuropathic pain. The development of neuropathic pain involves key mechanisms such as ectopic afferent nerve activity, peripheral sensitization, central sensitization, impaired inhibitory modulation, and pathologic activation of microglia. Treatments aimed at reducing neuropathic pain are targeted at one or more of these mechanisms. Several drugs are commonly used in the veterinary clinical setting to treat neuropathic pain. These include gabapentin, pregabalin, amantadine, and amitriptyline. Proposed mechanisms of action for each drug, and known pharmacokinetic profiles in dogs are discussed. Strong evidence exists in the human literature for the utility of most of these treatments, but clinical veterinary-specific literature is currently limited. Future studies should focus on objective methods to document neuropathic pain and monitor response to therapy in veterinary patients.
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Affiliation(s)
- Sarah A Moore
- Department of Veterinary Clinical Sciences, The Ohio State University , Columbus, OH , USA
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746
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Taatjes DJ, Roth J. The Histochemistry and Cell Biology omnium-gatherum: the year 2015 in review. Histochem Cell Biol 2016; 145:239-74. [DOI: 10.1007/s00418-016-1417-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2016] [Indexed: 02/07/2023]
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747
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Campagner D, Evans MH, Bale MR, Erskine A, Petersen RS. Prediction of primary somatosensory neuron activity during active tactile exploration. eLife 2016; 5. [PMID: 26880559 PMCID: PMC4764568 DOI: 10.7554/elife.10696] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 01/06/2016] [Indexed: 11/13/2022] Open
Abstract
Primary sensory neurons form the interface between world and brain. Their function is well-understood during passive stimulation but, under natural behaving conditions, sense organs are under active, motor control. In an attempt to predict primary neuron firing under natural conditions of sensorimotor integration, we recorded from primary mechanosensory neurons of awake, head-fixed mice as they explored a pole with their whiskers, and simultaneously measured both whisker motion and forces with high-speed videography. Using Generalised Linear Models, we found that primary neuron responses were poorly predicted by whisker angle, but well-predicted by rotational forces acting on the whisker: both during touch and free-air whisker motion. These results are in apparent contrast to previous studies of passive stimulation, but could be reconciled by differences in the kinematics-force relationship between active and passive conditions. Thus, simple statistical models can predict rich neural activity elicited by natural, exploratory behaviour involving active movement of sense organs.
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Affiliation(s)
- Dario Campagner
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - Mathew Hywel Evans
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - Michael Ross Bale
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.,School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Andrew Erskine
- Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.,Mill Hill Laboratory, The Francis Crick Institute, London, United Kingdom
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748
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Terada SI, Matsubara D, Onodera K, Matsuzaki M, Uemura T, Usui T. Neuronal processing of noxious thermal stimuli mediated by dendritic Ca(2+) influx in Drosophila somatosensory neurons. eLife 2016; 5. [PMID: 26880554 PMCID: PMC4786431 DOI: 10.7554/elife.12959] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 02/13/2016] [Indexed: 01/17/2023] Open
Abstract
Adequate responses to noxious stimuli causing tissue damages are essential for organismal survival. Class IV neurons in Drosophila larvae are polymodal nociceptors responsible for thermal, mechanical, and light sensation. Importantly, activation of Class IV provoked distinct avoidance behaviors, depending on the inputs. We found that noxious thermal stimuli, but not blue light stimulation, caused a unique pattern of Class IV, which were composed of pauses after high-frequency spike trains and a large Ca2+ rise in the dendrite (the Ca2+ transient). Both these responses depended on two TRPA channels and the L-type voltage-gated calcium channel (L-VGCC), showing that the thermosensation provokes Ca2+ influx. The precipitous fluctuation of firing rate in Class IV neurons enhanced the robust heat avoidance. We hypothesize that the Ca2+ influx can be a key signal encoding a specific modality. DOI:http://dx.doi.org/10.7554/eLife.12959.001 Animals often need to get away quickly from dangers in their environment, such as temperatures that are hot enough to damage their tissues. As such, an animal’s brain often encodes automatic ‘avoidance responses’ to signs of danger, which help the animal move away from harm. The nervous system of a fruit fly larva, for example, contains a distinct class of neurons (known as class IV neurons) that respond specifically to high temperatures and ultraviolet or blue light. Both of these stimuli are potentially harmful, but the larvae escape from heat by rolling with a corkscrew-like motion, yet they turn their heads away from a source of ultraviolet or blue light. So, how does the same set of neurons orchestrate these two different types of behavior? To answer this question, Terada, Matsubara, Onodera et al. measured the activity in the class IV neurons in two different ways. First, the levels of calcium ions in the neurons, which play a key role in neurons’ activity, were imaged using a calcium-sensitive biosensor. Second, electrodes were used to directly on the class IV neurons to record changes in their electrical activity. The experiments showed that class IV neurons responded to heat by producing a characteristic burst of electrical activity followed by a pause, and that this pattern of electrical activity was accompanied by a large rise in the calcium signal. In contrast, the same neurons did not show this ‘burst and pause’ pattern of activity when the fruit fly larvae were exposed to ultraviolet/blue light. Instead, these conditions triggered much smaller changes in electrical activity. Further experiments then confirmed that the characteristic ‘burst and pause’ pattern of electrical activity was linked to the rolling motion observed when the larvae try to escape from heat. These findings show how differing patterns of activity in the same neurons can be used to differentiate between different types of stimuli. Further work is now needed to explain how these two different patterns of activity in one set of neurons is translated by the fruit fly’s brain into different patterns of behavior. DOI:http://dx.doi.org/10.7554/eLife.12959.002
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Affiliation(s)
| | | | - Koun Onodera
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Masanori Matsuzaki
- Division of Brain Circuits, National Institute for Basic Biology, Okazaki, Japan
| | - Tadashi Uemura
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Tadao Usui
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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749
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Djouhri L. Electrophysiological evidence for the existence of a rare population of C-fiber low threshold mechanoreceptive (C-LTM) neurons in glabrous skin of the rat hindpaw. Neurosci Lett 2016; 613:25-9. [DOI: 10.1016/j.neulet.2015.12.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 12/17/2015] [Accepted: 12/18/2015] [Indexed: 12/31/2022]
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750
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Djouhri L. Aδ-fiber low threshold mechanoreceptors innervating mammalian hairy skin: A review of their receptive, electrophysiological and cytochemical properties in relation to Aδ-fiber high threshold mechanoreceptors. Neurosci Biobehav Rev 2016; 61:225-38. [DOI: 10.1016/j.neubiorev.2015.12.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 12/10/2015] [Accepted: 12/18/2015] [Indexed: 01/06/2023]
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