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Gradwell MA, Ozeri-Engelhard N, Eisdorfer JT, Laflamme OD, Gonzalez M, Upadhyay A, Medlock L, Shrier T, Patel KR, Aoki A, Gandhi M, Abbas-Zadeh G, Oputa O, Thackray JK, Ricci M, George A, Yusuf N, Keating J, Imtiaz Z, Alomary SA, Bohic M, Haas M, Hernandez Y, Prescott SA, Akay T, Abraira VE. Multimodal sensory control of motor performance by glycinergic interneurons of the mouse spinal cord deep dorsal horn. Neuron 2024; 112:1302-1327.e13. [PMID: 38452762 DOI: 10.1016/j.neuron.2024.01.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 10/31/2023] [Accepted: 01/26/2024] [Indexed: 03/09/2024]
Abstract
Sensory feedback is integral for contextually appropriate motor output, yet the neural circuits responsible remain elusive. Here, we pinpoint the medial deep dorsal horn of the mouse spinal cord as a convergence point for proprioceptive and cutaneous input. Within this region, we identify a population of tonically active glycinergic inhibitory neurons expressing parvalbumin. Using anatomy and electrophysiology, we demonstrate that deep dorsal horn parvalbumin-expressing interneuron (dPV) activity is shaped by convergent proprioceptive, cutaneous, and descending input. Selectively targeting spinal dPVs, we reveal their widespread ipsilateral inhibition onto pre-motor and motor networks and demonstrate their role in gating sensory-evoked muscle activity using electromyography (EMG) recordings. dPV ablation altered limb kinematics and step-cycle timing during treadmill locomotion and reduced the transitions between sub-movements during spontaneous behavior. These findings reveal a circuit basis by which sensory convergence onto dorsal horn inhibitory neurons modulates motor output to facilitate smooth movement and context-appropriate transitions.
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Affiliation(s)
- Mark A Gradwell
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Nofar Ozeri-Engelhard
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Neuroscience PhD program, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Jaclyn T Eisdorfer
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Olivier D Laflamme
- Dalhousie PhD program, Dalhousie University, Halifax, NS, Canada; Department of Medical Neuroscience, Atlantic Mobility Action Project, Brain Repair Center, Dalhousie University, Halifax, NS, Canada
| | - Melissa Gonzalez
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Department of Biomedical Engineering, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Aman Upadhyay
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Neuroscience PhD program, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Laura Medlock
- Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, ON, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Tara Shrier
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Komal R Patel
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Adin Aoki
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Melissa Gandhi
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Gloria Abbas-Zadeh
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Olisemaka Oputa
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Joshua K Thackray
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Human Genetics Institute of New Jersey, Rutgers University, The State University of New Jersey, Piscataway, NJ, USA; Tourette International Collaborative Genetics Study (TIC Genetics)
| | - Matthew Ricci
- School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Arlene George
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Nusrath Yusuf
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; Neuroscience PhD program, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Jessica Keating
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Zarghona Imtiaz
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Simona A Alomary
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Manon Bohic
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Michael Haas
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Yurdiana Hernandez
- W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA
| | - Steven A Prescott
- Neurosciences & Mental Health, The Hospital for Sick Children, Toronto, ON, Canada; Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Turgay Akay
- Department of Medical Neuroscience, Atlantic Mobility Action Project, Brain Repair Center, Dalhousie University, Halifax, NS, Canada
| | - Victoria E Abraira
- Cell Biology and Neuroscience Department, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA; W.M. Keck Center for Collaborative Neuroscience, Rutgers University, The State University of New Jersey, New Brunswick, NJ, USA.
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Laflamme OD, Markin SN, Deska-Gauthier D, Banks R, Zhang Y, Danner SM, Akay T. Distinct roles of spinal commissural interneurons in transmission of contralateral sensory information. Curr Biol 2023; 33:3452-3464.e4. [PMID: 37531957 PMCID: PMC10528931 DOI: 10.1016/j.cub.2023.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/29/2023] [Accepted: 07/10/2023] [Indexed: 08/04/2023]
Abstract
Crossed reflexes are mediated by commissural pathways transmitting sensory information to the contralateral side of the body, but the underlying network is not fully understood. Commissural pathways coordinating the activities of spinal locomotor circuits during locomotion have been characterized in mice, but their relationship to crossed reflexes is unknown. We show the involvement of two genetically distinct groups of commissural interneurons (CINs) described in mice, V0 and V3 CINs, in the crossed reflex pathways. Our data suggest that the exclusively excitatory V3 CINs are directly involved in the excitatory crossed reflexes and show that they are essential for the inhibitory crossed reflexes. In contrast, the V0 CINs, a population that includes excitatory and inhibitory CINs, are not directly involved in excitatory or inhibitory crossed reflexes but downregulate the inhibitory crossed reflexes. Our data provide insights into the spinal circuitry underlying crossed reflexes in mice, describing the roles of V0 and V3 CINs in crossed reflexes.
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Affiliation(s)
- Olivier D Laflamme
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Dalhousie University, Halifax, NS B3T 0A6, Canada
| | - Sergey N Markin
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA 19129, USA
| | - Dylan Deska-Gauthier
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Dalhousie University, Halifax, NS B3T 0A6, Canada
| | - Rachel Banks
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Dalhousie University, Halifax, NS B3T 0A6, Canada
| | - Ying Zhang
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Dalhousie University, Halifax, NS B3T 0A6, Canada
| | - Simon M Danner
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA 19129, USA
| | - Turgay Akay
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Dalhousie University, Halifax, NS B3T 0A6, Canada.
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3
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Whittier TT, Patrick CM, Fling BW. Somatosensory Information in Skilled Motor Performance: A Narrative Review. J Mot Behav 2023; 55:453-474. [PMID: 37245865 DOI: 10.1080/00222895.2023.2213198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 04/26/2023] [Accepted: 05/05/2023] [Indexed: 05/30/2023]
Abstract
Historically, research aimed at improving motor performance has largely focused on the neural processes involved in motor execution due to their role in muscle activation. However, accompanying somatosensory and proprioceptive sensory information is also vitally involved in performing motor skills. Here we review research from interdisciplinary fields to provide a description for how somatosensation informs the successful performance of motor skills as well as emphasize the need for careful selection of study methods to isolate the neural processes involved in somatosensory perception. We also discuss upcoming strategies of intervention that have been used to improve performance via somatosensory targets. We believe that a greater appreciation for somatosensation's role in motor learning and control will enable researchers and practitioners to develop and apply methods for the enhancement of human performance that will benefit clinical, healthy, and elite populations alike.
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Affiliation(s)
- Tyler T Whittier
- Sensorimotor Neuroimaging Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Christopher M Patrick
- Sensorimotor Neuroimaging Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
- Molecular, Cellular and Integrative Neurosciences Program, Colorado State University, Fort Collins, CO, USA
| | - Brett W Fling
- Sensorimotor Neuroimaging Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
- Molecular, Cellular and Integrative Neurosciences Program, Colorado State University, Fort Collins, CO, USA
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4
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McCallum GA, Shiralkar J, Suciu D, Covarrubias G, Yu JS, Karathanasis E, Durand DM. Chronic neural activity recorded within breast tumors. Sci Rep 2020; 10:14824. [PMID: 32908180 PMCID: PMC7481786 DOI: 10.1038/s41598-020-71670-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/10/2020] [Indexed: 12/19/2022] Open
Abstract
Nerve fibers are known to reside within malignant tumors and the greater the neuronal density the worse prognosis for the patient. Recent discoveries using tumor bearing animal models have eluded to the autonomic nervous system having a direct effect on tumor growth and metastasis. We report the first direct and chronic in vivo measurements of neural activity within tumors. Using a triple-negative mammary cancer mouse model and chronic neural interface techniques, we have recorded neural activity directly within the tumor mass while the tumor grows and metastasizes. The results indicate that there is a strong connection between the autonomic nervous system and the tumor and could help uncover the mechanisms of tumor growth and metastasis.
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Affiliation(s)
- Grant A McCallum
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.
| | - Jay Shiralkar
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Diana Suciu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Gil Covarrubias
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA
| | - Jennifer S Yu
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA.,Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA.,Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Efstathios Karathanasis
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA
| | - Dominique M Durand
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.
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5
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Christensen NR, De Luca M, Lever MB, Richner M, Hansen AB, Noes-Holt G, Jensen KL, Rathje M, Jensen DB, Erlendsson S, Bartling CR, Ammendrup-Johnsen I, Pedersen SE, Schönauer M, Nissen KB, Midtgaard SR, Teilum K, Arleth L, Sørensen AT, Bach A, Strømgaard K, Meehan CF, Vaegter CB, Gether U, Madsen KL. A high-affinity, bivalent PDZ domain inhibitor complexes PICK1 to alleviate neuropathic pain. EMBO Mol Med 2020; 12:e11248. [PMID: 32352640 PMCID: PMC7278562 DOI: 10.15252/emmm.201911248] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 04/01/2020] [Accepted: 04/07/2020] [Indexed: 12/13/2022] Open
Abstract
Maladaptive plasticity involving increased expression of AMPA-type glutamate receptors is involved in several pathologies, including neuropathic pain, but direct inhibition of AMPARs is associated with side effects. As an alternative, we developed a cell-permeable, high-affinity (~2 nM) peptide inhibitor, Tat-P4 -(C5)2 , of the PDZ domain protein PICK1 to interfere with increased AMPAR expression. The affinity is obtained partly from the Tat peptide and partly from the bivalency of the PDZ motif, engaging PDZ domains from two separate PICK1 dimers to form a tetrameric complex. Bivalent Tat-P4 -(C5)2 disrupts PICK1 interaction with membrane proteins on supported cell membrane sheets and reduce the interaction of AMPARs with PICK1 and AMPA-receptor surface expression in vivo. Moreover, Tat-P4 -(C5)2 administration reduces spinal cord transmission and alleviates mechanical hyperalgesia in the spared nerve injury model of neuropathic pain. Taken together, our data reveal Tat-P4 -(C5)2 as a novel promising lead for neuropathic pain treatment and expand the therapeutic potential of bivalent inhibitors to non-tandem protein-protein interaction domains.
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Affiliation(s)
- Nikolaj R Christensen
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, Faculty of Health and Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Marta De Luca
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael B Lever
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette Richner
- Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic-EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Astrid B Hansen
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gith Noes-Holt
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kathrine L Jensen
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette Rathje
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dennis Bo Jensen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Simon Erlendsson
- Structural biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Christian Ro Bartling
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, Faculty of Health and Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Ina Ammendrup-Johnsen
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sofie E Pedersen
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michèle Schönauer
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, Faculty of Health and Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Klaus B Nissen
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, Faculty of Health and Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Søren R Midtgaard
- Structural Biophysics, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Kaare Teilum
- Structural biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Lise Arleth
- Structural Biophysics, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Andreas T Sørensen
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anders Bach
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, Faculty of Health and Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Kristian Strømgaard
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, Faculty of Health and Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Claire F Meehan
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Christian B Vaegter
- Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic-EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Ulrik Gether
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kenneth L Madsen
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Morikawa Y, Yamagiwa S, Sawahata H, Numano R, Koida K, Kawano T. Donut-Shaped Stretchable Kirigami: Enabling Electronics to Integrate with the Deformable Muscle. Adv Healthc Mater 2019; 8:e1900939. [PMID: 31697038 DOI: 10.1002/adhm.201900939] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/05/2019] [Indexed: 11/07/2022]
Abstract
Electronic devices used to record biological signals are important in neuroscience, brain-machine interfaces, and medical applications. Placing electronic devices below the skin surface and recording the muscle offers accurate and robust electromyography (EMG) recordings. The device stretchability and flexibility must be similar to the tissues to achieve an intimate integration of the electronic device with the biological tissues. However, conventional elastomer-based EMG electrodes have a Young's modulus that is ≈20 times higher than that of muscle. In addition, these stretchable devices also have an issue of displacement on the tissue surface, thereby causing some challenges during accurate and robust EMG signal recordings. In general, devices with kirigami design solve the issue of the high Young's modulus of conventional EMG devices. In this study, donut-shaped kirigami bioprobes are proposed to reduce the device displacement on the muscle surface. The fabricated devices are tested on an expanding balloon and they show no significant device (microelectrode) displacement. As the package, the fabricated device is embedded in a dissolvable material-based scaffold for easy-to-use stretchable kirigami device in an animal experiment. Finally, the EMG signal recording capability and stability using the fabricated kirigami device is confirmed in in vivo experiments without significant device displacements.
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Affiliation(s)
- Yusuke Morikawa
- Department of Electrical and Electronic Information EngineeringToyohashi University of Technology 1‐1 Hibarigaoka Tempaku‐cho Toyohashi Aichi 441‐8580 Japan
| | - Shota Yamagiwa
- Department of Electrical and Electronic Information EngineeringToyohashi University of Technology 1‐1 Hibarigaoka Tempaku‐cho Toyohashi Aichi 441‐8580 Japan
| | - Hirohito Sawahata
- National Institute of Technology Ibaraki College, 866 Nakane Hitachinaka Ibaraki 312‐8508 Japan
| | - Rika Numano
- Electronics‐Interdisciplinary Research Institute (EIIRIS)Toyohashi University of Technology 1‐1 Hibarigaoka Tempaku‐cho Toyohashi Aichi 441‐8580 Japan
- Department of Applied Chemistry and Life ScienceToyohashi University of Technology 1‐1 Hibarigaoka Tempaku‐cho Toyohashi 441‐8580 Japan
| | - Kowa Koida
- Electronics‐Interdisciplinary Research Institute (EIIRIS)Toyohashi University of Technology 1‐1 Hibarigaoka Tempaku‐cho Toyohashi Aichi 441‐8580 Japan
- Department of Computer Science and EngineeringToyohashi University of Technology 1‐1 Hibarigaoka Tempaku‐cho Toyohashi 441‐8580 Japan
| | - Takeshi Kawano
- Department of Electrical and Electronic Information EngineeringToyohashi University of Technology 1‐1 Hibarigaoka Tempaku‐cho Toyohashi Aichi 441‐8580 Japan
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7
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Characterisation of One Class of Group III Sensory Neurons Innervating Abdominal Muscles of the Mouse. Neuroscience 2019; 421:162-175. [PMID: 31682818 DOI: 10.1016/j.neuroscience.2019.09.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 09/11/2019] [Accepted: 09/12/2019] [Indexed: 11/24/2022]
Abstract
Group III/IV striated muscle afferents are small diameter sensory neurons that play important roles in reflexes and sensation. To date, the morphological features of physiologically characterised group III/IV muscular afferents have not been identified. Here, the electrophysiological and morphological characteristics of sensory neurons innervating striated muscles of the mouse abdominal wall were investigated, ex vivo. Extracellular recordings were made from subcostal nerve trunks innervating the muscles. A distinctive class of mechanosensitive afferents was identified by a combination of physiological features including sensitivity to local compression, saturating response to graded stretch and, in most cases, absence of spontaneous firing. Studies were restricted to these distinctive units. These units had conduction velocities averaging 14 ± 4 m/s (range: 8-20 m/s, n = 7); within the range of group III fibres in mice. Von Frey hairs were used to map receptive fields, which covered an area of 0.36 ± 0.18 mm2 (n = 7). In 7 preparations, biotinamide filling of recorded nerve trunks revealed a single axon in the marked receptive field, with distinctive axonal branching and terminations meandering through the connective tissue sandwiched between two closely associated muscle layers. These axons were not immunoreactive for CGRP (n = 7) and were not activated by application of capsaicin (1 µM, n = 14). All of these afferents were strongly activated by a "metabolite mix" containing lactate, adenosine triphosphate and reduced pH. Responses to mechanical stimuli and to metabolites were additive. We have characterised a distinctive class of mechano- and chemo-sensitive group III afferent endings associated with connective tissue close to muscle fibres.
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8
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Michoud F, Sottas L, Browne LE, Asboth L, Latremoliere A, Sakuma M, Courtine G, Woolf CJ, Lacour SP. Optical cuff for optogenetic control of the peripheral nervous system. J Neural Eng 2019; 15:015002. [PMID: 28978778 DOI: 10.1088/1741-2552/aa9126] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Nerves in the peripheral nervous system (PNS) contain axons with specific motor, somatosensory and autonomic functions. Optogenetics offers an efficient approach to selectively activate axons within the nerve. However, the heterogeneous nature of nerves and their tortuous route through the body create a challenging environment to reliably implant a light delivery interface. APPROACH Here, we propose an optical peripheral nerve interface-an optocuff-, so that optogenetic modulation of peripheral nerves become possible in freely behaving mice. MAIN RESULTS Using this optocuff, we demonstrate orderly recruitment of motor units with epineural optical stimulation of genetically targeted sciatic nerve axons, both in anaesthetized and in awake, freely behaving animals. Behavioural experiments and histology show the optocuff does not damage the nerve thus is suitable for long-term experiments. SIGNIFICANCE These results suggest that the soft optocuff might be a straightforward and efficient tool to support more extensive study of the PNS using optogenetics.
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Affiliation(s)
- Frédéric Michoud
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronics Interface, Institute of Microengineering, Institute of Bioengineering, Centre for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland. Department of Neurobiology, Harvard Medical School, Boston, MA 02115, United States of America. FM Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, United States of America
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9
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Paquette JP, Yoo PB. Recruitment of unmyelinated C-fibers mediates the bladder-inhibitory effects of tibial nerve stimulation in a continuous-fill anesthetized rat model. Am J Physiol Renal Physiol 2019; 317:F163-F171. [PMID: 31141398 DOI: 10.1152/ajprenal.00502.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Although percutaneous tibial nerve stimulation is considered a clinically effective therapy for treating overactive bladder, the mechanism by which overactive bladder symptoms are suppressed remains unclear. The goal of the present study was to better understand the role of specific neural inputs (i.e., fiber types) on the bladder-inhibitory effects of tibial nerve stimulation (TNS). In 24 urethane-anesthetized rats, a continuous suprapubic saline infusion model was used to achieve repeated filling and emptying of the bladder. A total of 4 TNS trials (pulse frequency: 5 Hz) were applied in randomized order, where each trial used different amplitude settings: 1) no stimulation (control), 2) Aβ-fiber activation, 3) Aδ-fiber activation, and 4) C-fiber activation. Each stimulation trial was 30 min in duration, with an intertrial washout period of 60-90 min. Our findings showed that TNS evoked statistically significant changes in bladder function (e.g., bladder capacity, residual volume, voiding efficiency, and basal pressure) only at stimulation amplitudes that electrically recruited unmyelinated C-fibers. In a subset of experiments, TNS also resulted in transient episodes of overflow incontinence. It is noted that changes in bladder function occurred only during the poststimulation period. The bladder-inhibitory effects of TNS in a continuous bladder filling model suggests that electrical recruitment of unmyelinated C-fibers has important functional significance. The implications of these findings in percutaneous tibial nerve stimulation therapy should be further investigated.
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Affiliation(s)
- Jason P Paquette
- Institute of Biomaterials and Biomedical Engineering, University of Toronto , Toronto, Ontario , Canada
| | - Paul B Yoo
- Institute of Biomaterials and Biomedical Engineering, University of Toronto , Toronto, Ontario , Canada.,Department of Electrical and Computer Engineering, University of Toronto , Toronto, Ontario , Canada
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10
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Laflamme OD, Akay T. Excitatory and inhibitory crossed reflex pathways in mice. J Neurophysiol 2018; 120:2897-2907. [PMID: 30303749 DOI: 10.1152/jn.00450.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Sensory information from one leg has been known to elicit reflex responses in the contralateral leg, known as "crossed reflexes," and these have been investigated extensively in cats and humans. Furthermore, experiments with mice have shown commissural pathways in detail by using in vitro and in vivo physiological approaches combined with genetics. However, the relationship between these commissural pathways discovered in mice and crossed reflex pathways described in cats and humans is not known. In this study, we analyzed the crossed reflex in mice by using in vivo electromyographic recording techniques combined with peripheral nerve stimulation protocols to provide a detailed description of the crossed reflex pathways. We show that excitatory crossed reflexes are mediated by both proprioceptive and cutaneous afferent activation. In addition, we provide evidence for a short-latency inhibitory crossed reflex pathway likely mediated by cutaneous feedback. Furthermore, the short-latency crossed inhibition is downregulated in the knee extensor muscle and the ankle flexor muscle during locomotion. In conclusion, this article provides an analysis of excitatory and inhibitory crossed reflex pathways during resting and locomoting mice in vivo. The data presented in this article pave the way for future research aimed at understanding crossed reflexes using genetics in mice. NEW & NOTEWORTHY We describe for the first time excitatory and inhibitory crossed reflex pathways in mouse spinal cord in vivo and show that the inhibitory pathways are modulated during walking. This is a first step toward an understanding of crossed reflexes and their function during walking using in vivo recording techniques combined with mouse genetics.
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Affiliation(s)
- Olivier D Laflamme
- Atlantic Mobility Action Project, Brain Repair Center, Department of Medical Neuroscience, Dalhousie University , Halifax, Nova Scotia , Canada
| | - Turgay Akay
- Atlantic Mobility Action Project, Brain Repair Center, Department of Medical Neuroscience, Dalhousie University , Halifax, Nova Scotia , Canada
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11
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Caravaca AS, Tsaava T, Goldman L, Silverman H, Riggott G, Chavan SS, Bouton C, Tracey KJ, Desimone R, Boyden ES, Sohal HS, Olofsson PS. A novel flexible cuff-like microelectrode for dual purpose, acute and chronic electrical interfacing with the mouse cervical vagus nerve. J Neural Eng 2017; 14:066005. [PMID: 28628030 PMCID: PMC6130808 DOI: 10.1088/1741-2552/aa7a42] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Neural reflexes regulate immune responses and homeostasis. Advances in bioelectronic medicine indicate that electrical stimulation of the vagus nerve can be used to treat inflammatory disease, yet the understanding of neural signals that regulate inflammation is incomplete. Current interfaces with the vagus nerve do not permit effective chronic stimulation or recording in mouse models, which is vital to studying the molecular and neurophysiological mechanisms that control inflammation homeostasis in health and disease. We developed an implantable, dual purpose, multi-channel, flexible 'microelectrode' array, for recording and stimulation of the mouse vagus nerve. APPROACH The array was microfabricated on an 8 µm layer of highly biocompatible parylene configured with 16 sites. The microelectrode was evaluated by studying the recording and stimulation performance. Mice were chronically implanted with devices for up to 12 weeks. MAIN RESULTS Using the microelectrode in vivo, high fidelity signals were recorded during physiological challenges (e.g potassium chloride and interleukin-1β), and electrical stimulation of the vagus nerve produced the expected significant reduction of blood levels of tumor necrosis factor (TNF) in endotoxemia. Inflammatory cell infiltration at the microelectrode 12 weeks of implantation was limited according to radial distribution analysis of inflammatory cells. SIGNIFICANCE This novel device provides an important step towards a viable chronic interface for cervical vagus nerve stimulation and recording in mice.
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Affiliation(s)
- A S Caravaca
- Department of Medicine, Solna, Karolinska Institutet, Center for Molecular Medicine, Center for Bioelectronic Medicine, Karolinska University Hospital, Stockholm, Solna, Sweden
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12
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Abstract
BACKGROUND Genetic techniques rendering murine models a popular choice for neuroscience research has led to important insights on neural networks controlling locomotor function. Using genetically altered mouse models for in vivo, electrophysiological studies in the adult state could validate key principles of locomotor network organization that have been described in neonatal, in vitro preparations. NEW METHOD The experimental model presented here describes a decerebrate, in vivo adult mouse preparation in which focal, electrical midbrain stimulation was combined with monitoring lumbar neural activity and motor output after pre-collicular decerebration and neuromuscular blockade. RESULTS Lumbar cord dorsum potentials (in 9/10 animals) and motoneuron output (in 3/5 animals) including fictive locomotion, was achieved by focal midbrain stimulation. The stimulation electrode locations could be reconstructed (in 6/7 animals) thereby allowing anatomical identification of the stimulated supraspinal regions. COMPARISON WITH EXISTING METHODS This preparation allows for concomitant recording or stimulation in the spinal cord and in the mid/hindbrain of adult mice. It differs from other methods used in the past with adult mice as it does not require pharmacological manipulation of neural excitability in order to generate motor output. CONCLUSIONS Midbrain stimulation can consistently be used for inducing lumbar neural activity in adult mice under neuromuscular blockade. This model is suited for examination of brain-spinal connectivity and it may benefit a wide range of fields depending on the features of the genetically modified mouse models used in combination with the presented methods.
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Affiliation(s)
- Katinka Stecina
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, 745 Bannatyne Ave., BMSB-436, Winnipeg, MB, R3E0J9, Canada.
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13
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Dibaj P, Schomburg ED. In vivo recording of nerve conduction velocity of spinal CNS fibers in the mouse. Physiol Res 2017; 66:545-548. [PMID: 28248539 DOI: 10.33549/physiolres.933489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Anesthetic and surgical procedures and an electrophysiological method were developed for recording nerve conduction velocity (NCV) of CNS fibers in the murine spinal cord. Under intravenous anesthesia and artificial ventilation the lumbar spinal cord segments L1 to L4 and dorsal roots L3 to L5 on the left side were exposed by laminectomy. After stimulation of the dorsal root L4, a compound action potential (CAP) was recorded at the ipsilateral left fasciculus gracilis at the spinal cord level L1. The latency from stimulation to the CAP together with the measured distance between the electrodes was used for the determination of the NCV. NCV of the fastest fibers in the fasciculus gracilis was observed to be approximately 28 m/s. Reversible decrease of the NCV was measured, in vivo, under general hypothermia. The technique described serves for in vivo electrophysiological investigations of spinal central fibers in wildtype and mutant mice.
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Affiliation(s)
- P Dibaj
- Max-Planck-Institute for Experimental Medicine, Göttingen, Germany.
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Patzig J, Erwig MS, Tenzer S, Kusch K, Dibaj P, Möbius W, Goebbels S, Schaeren-Wiemers N, Nave KA, Werner HB. Septin/anillin filaments scaffold central nervous system myelin to accelerate nerve conduction. eLife 2016; 5. [PMID: 27504968 PMCID: PMC4978525 DOI: 10.7554/elife.17119] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/13/2016] [Indexed: 12/15/2022] Open
Abstract
Myelination of axons facilitates rapid impulse propagation in the nervous system. The axon/myelin-unit becomes impaired in myelin-related disorders and upon normal aging. However, the molecular cause of many pathological features, including the frequently observed myelin outfoldings, remained unknown. Using label-free quantitative proteomics, we find that the presence of myelin outfoldings correlates with a loss of cytoskeletal septins in myelin. Regulated by phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P2)-levels, myelin septins (SEPT2/SEPT4/SEPT7/SEPT8) and the PI(4,5)P2-adaptor anillin form previously unrecognized filaments that extend longitudinally along myelinated axons. By confocal microscopy and immunogold-electron microscopy, these filaments are localized to the non-compacted adaxonal myelin compartment. Genetic disruption of these filaments in Sept8-mutant mice causes myelin outfoldings as a very specific neuropathology. Septin filaments thus serve an important function in scaffolding the axon/myelin-unit, evidently a late stage of myelin maturation. We propose that pathological or aging-associated diminishment of the septin/anillin-scaffold causes myelin outfoldings that impair the normal nerve conduction velocity. DOI:http://dx.doi.org/10.7554/eLife.17119.001 Normal communication within the brain or between the brain and other parts of the body requires information to flow quickly around the nervous system. This information travels along nerve cells in the form of electrical signals. To speed up the signals, a part of the nerve cell called the axon is frequently wrapped in an electrically insulating sheath made up of a membrane structure called myelin. The myelin sheath becomes impaired as a result of disease or ageing. In order to understand what might produce these changes, Patzig et al. have used biochemical and microscopy techniques to study mice that had similar defects in their myelin sheaths. The study reveals that forming a normal myelin sheath around an axon requires a newly identified ‘scaffold’ made of a group of proteins called the septins. Combining with another protein called anillin, septins assemble into filaments in the myelin sheath. These filaments then knit together into a scaffold that grows lengthways along the myelin-wrapped axon. Without this scaffold, the myelin sheath grew defects known as outfoldings. Axons transmitted electrical signals much more slowly than normal when the septin scaffold was missing from the myelin sheath. Future studies are needed to understand the factors that control how the septin scaffold forms. This could help to reveal ways of reversing the changes that alter the myelin sheath during ageing and disease. DOI:http://dx.doi.org/10.7554/eLife.17119.002
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Affiliation(s)
- Julia Patzig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Michelle S Erwig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Payam Dibaj
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Sandra Goebbels
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | | | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
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Badia J, Raspopovic S, Carpaneto J, Micera S, Navarro X. Spatial and Functional Selectivity of Peripheral Nerve Signal Recording With the Transversal Intrafascicular Multichannel Electrode (TIME). IEEE Trans Neural Syst Rehabil Eng 2015; 24:20-7. [PMID: 26087496 DOI: 10.1109/tnsre.2015.2440768] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The selection of suitable peripheral nerve electrodes for biomedical applications implies a trade-off between invasiveness and selectivity. The optimal design should provide the highest selectivity for targeting a large number of nerve fascicles with the least invasiveness and potential damage to the nerve. The transverse intrafascicular multichannel electrode (TIME), transversally inserted in the peripheral nerve, has been shown to be useful for the selective activation of subsets of axons, both at inter- and intra-fascicular levels, in the small sciatic nerve of the rat. In this study we assessed the capabilities of TIME for the selective recording of neural activity, considering the topographical selectivity and the distinction of neural signals corresponding to different sensory types. Topographical recording selectivity was proved by the differential recording of CNAPs from different subsets of nerve fibers, such as those innervating toes 2 and 4 of the hindpaw of the rat. Neural signals elicited by sensory stimuli applied to the rat paw were successfully recorded. Signal processing allowed distinguishing three different types of sensory stimuli such as tactile, proprioceptive and nociceptive ones with high performance. These findings further support the suitability of TIMEs for neuroprosthetic applications, by exploiting the transversal topographical structure of the peripheral nerves.
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Dibaj P, Schomburg ED, Steffens H. Contractile characteristics of gastrocnemius-soleus muscle in the SOD1G93A ALS mouse model. Neurol Res 2015; 37:693-702. [DOI: 10.1179/1743132815y.0000000039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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Kennedy DS, McNeil CJ, Gandevia SC, Taylor JL. Fatigue-related firing of distal muscle nociceptors reduces voluntary activation of proximal muscles of the same limb. J Appl Physiol (1985) 2013; 116:385-94. [PMID: 24356522 DOI: 10.1152/japplphysiol.01166.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
With fatiguing exercise, firing of group III/IV muscle afferents reduces voluntary activation and force of the exercised muscles. These afferents can also act across agonist/antagonist pairs, reducing voluntary activation and force in nonfatigued muscles. We hypothesized that maintained firing of group III/IV muscle afferents after a fatiguing adductor pollicis (AP) contraction would decrease voluntary activation and force of AP and ipsilateral elbow flexors. In two experiments (n = 10) we examined voluntary activation of AP and elbow flexors by measuring changes in superimposed twitches evoked by ulnar nerve stimulation and transcranial magnetic stimulation of the motor cortex, respectively. Inflation of a sphygmomanometer cuff after a 2-min AP maximal voluntary contraction (MVC) blocked circulation of the hand for 2 min and maintained firing of group III/IV muscle afferents. After a 2-min AP MVC, maximal AP voluntary activation was lower with than without ischemia (56.2 ± 17.7% vs. 76.3 ± 14.6%; mean ± SD; P < 0.05) as was force (40.3 ± 12.8% vs. 57.1 ± 13.8% peak MVC; P < 0.05). Likewise, after a 2-min AP MVC, elbow flexion voluntary activation was lower with than without ischemia (88.3 ± 7.5% vs. 93.6 ± 3.9%; P < 0.05) as was torque (80.2 ± 4.6% vs. 86.6 ± 1.0% peak MVC; P < 0.05). Pain during ischemia was reported as Moderate to Very Strong. Postfatigue firing of group III/IV muscle afferents from the hand decreased voluntary drive and force of AP. Moreover, this effect decreased voluntary drive and torque of proximal unfatigued muscles, the elbow flexors. Fatigue-sensitive group III/IV muscle nociceptors act to limit voluntary drive not only to fatigued muscles but also to unfatigued muscles within the same limb.
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Affiliation(s)
- David S Kennedy
- Neuroscience Research Australia, Randwick, New South Wales, Australia
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18
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Schomburg ED, Kalezic I, Dibaj P, Steffens H. Reflex transmission to lumbar α-motoneurones in the mouse similar and different to those in the cat. Neurosci Res 2013; 76:133-40. [PMID: 23562791 DOI: 10.1016/j.neures.2013.03.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 03/26/2013] [Accepted: 03/26/2013] [Indexed: 11/15/2022]
Abstract
Investigation and interpretation of defective motor circuitries in transgenic mice required further basic results from wild-type mice. Therefore, we investigated the lumbar motor reflex pattern in anaesthetised mice using intracellular motoneuronal recording and monosynaptic reflex testing. Thresholds and latencies in mice were similar to those in cats: thresholds for monosynaptic (group I) EPSPs were slightly above 1T (T=threshold for the lowest threshold fibres), around 1.5T for group II EPSPs and above 10T for group III EPSPs; group I EPSPs were maximal with a stimulus strength around 2T, group II EPSPs were maximal with 5-8T; latencies to the group I incoming volley were below 1ms for monosynaptic group I EPSPs, around 3ms for polysynaptic group II EPSPs and above 4ms for polysynaptic group III EPSPs. In contrast to reflex actions in the cat, monosynaptic gastrocnemius-soleus reflexes were facilitated by conditioning stimulation of the peroneal, sural and tibial nerves, i.e. by a variety of different, probably flexor reflex afferents. This facilitation persisted after high lumbar spinalisation indicating an independency to supraspinal influences. Nociceptive muscle afferents facilitated the peroneal monosynaptic reflex while nociceptive cutaneous afferents from the foot sole inhibited the ipsilateral but facilitated the contralateral peroneal reflex.
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Affiliation(s)
- Eike D Schomburg
- Institute of Physiology, University of Göttingen, Göttingen, Germany.
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