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Gautam M, Yamada A, Yamada AI, Wu Q, Kridsada K, Ling J, Yu H, Dong P, Ma M, Gu J, Luo W. Distinct local and global functions of mouse Aβ low-threshold mechanoreceptors in mechanical nociception. Nat Commun 2024; 15:2911. [PMID: 38575590 PMCID: PMC10995180 DOI: 10.1038/s41467-024-47245-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 03/13/2024] [Indexed: 04/06/2024] Open
Abstract
The roles of Aβ low-threshold mechanoreceptors (LTMRs) in transmitting mechanical hyperalgesia and in alleviating chronic pain have been of great interest but remain contentious. Here we utilized intersectional genetic tools, optogenetics, and high-speed imaging to specifically examine functions of SplitCre labeled mouse Aβ-LTMRs in this regard. Genetic ablation of SplitCre-Aβ-LTMRs increased mechanical nociception but not thermosensation in both acute and chronic inflammatory pain conditions, indicating a modality-specific role in gating mechanical nociception. Local optogenetic activation of SplitCre-Aβ-LTMRs triggered nociception after tissue inflammation, whereas their broad activation at the dorsal column still alleviated mechanical hypersensitivity of chronic inflammation. Taking all data into consideration, we propose a model, in which Aβ-LTMRs play distinctive local and global roles in transmitting or alleviating mechanical hyperalgesia of chronic pain, respectively. Our model suggests a strategy of global activation plus local inhibition of Aβ-LTMRs for treating mechanical hyperalgesia.
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Affiliation(s)
- Mayank Gautam
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Akihiro Yamada
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Ayaka I Yamada
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Qinxue Wu
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kim Kridsada
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jennifer Ling
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Huasheng Yu
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Peter Dong
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Minghong Ma
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jianguo Gu
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| | - Wenqin Luo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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2
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Chakrabarti S, Klich JD, Khallaf MA, Hulme AJ, Sánchez-Carranza O, Baran ZM, Rossi A, Huang ATL, Pohl T, Fleischer R, Fürst C, Hammes A, Bégay V, Hörnberg H, Finol-Urdaneta RK, Poole K, Dottori M, Lewin GR. Touch sensation requires the mechanically gated ion channel ELKIN1. Science 2024; 383:992-998. [PMID: 38422143 DOI: 10.1126/science.adl0495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/26/2024] [Indexed: 03/02/2024]
Abstract
Touch perception is enabled by mechanically activated ion channels, the opening of which excites cutaneous sensory endings to initiate sensation. In this study, we identify ELKIN1 as an ion channel likely gated by mechanical force, necessary for normal touch sensitivity in mice. Touch insensitivity in Elkin1-/- mice was caused by a loss of mechanically activated currents (MA currents) in around half of all sensory neurons activated by light touch (low-threshold mechanoreceptors). Reintroduction of Elkin1 into sensory neurons from Elkin1-/- mice restored MA currents. Additionally, small interfering RNA-mediated knockdown of ELKIN1 from induced human sensory neurons substantially reduced indentation-induced MA currents, supporting a conserved role for ELKIN1 in human touch. Our data identify ELKIN1 as a core component of touch transduction in mice and potentially in humans.
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Affiliation(s)
- Sampurna Chakrabarti
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Jasmin D Klich
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Mohammed A Khallaf
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
- Department of Zoology and Entomology, Faculty of Science, Assiut University, Assiut 71516, Egypt
| | - Amy J Hulme
- School of Medical, Indigenous and Health Sciences, Molecular Horizons, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Oscar Sánchez-Carranza
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Zuzanna M Baran
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
- Molecular and Cellular Basis of Behavior, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Alice Rossi
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Angela Tzu-Lun Huang
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Tobias Pohl
- Molecular and Cellular Basis of Behavior, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Raluca Fleischer
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Carina Fürst
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
- Molecular Pathways in Cortical Development, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Annette Hammes
- Molecular Pathways in Cortical Development, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Valérie Bégay
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
| | - Hanna Hörnberg
- Molecular and Cellular Basis of Behavior, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
- NeuroCure Cluster of Excellence, Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Rocio K Finol-Urdaneta
- School of Medical, Indigenous and Health Sciences, Molecular Horizons, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Kate Poole
- School of Biomedical Sciences, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW 2052, Australia
| | - Mirella Dottori
- School of Medical, Indigenous and Health Sciences, Molecular Horizons, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation Laboratory, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin-Buch, Germany
- Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
- German Center for Mental Health (DZPG), partner site Berlin, 10117 Berlin, Germany
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3
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Acar B, Unal M, May H, Ozturk S, Tanrıover G, Sındel M. Distribution of nerve endings in human thumb interphalangeal joint. J Anat 2024; 244:468-475. [PMID: 37946592 PMCID: PMC10862168 DOI: 10.1111/joa.13970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/18/2023] [Accepted: 10/18/2023] [Indexed: 11/12/2023] Open
Abstract
This study aims to quantitatively analyze the distribution of encapsulated nerve endings in the human thumb interphalangeal (IP) joint capsule. There are three types of nerve endings. Type-I nerve endings (Ruffini-like ending) sense pressure changes, Type II (Pacini-like ending) nerve endings contribute to the kinesthetic sense, and Type III (Golgi-like ending) nerve ending provides proprioceptive information. We dissected five right thumbs IP joints from freshly frozen cadavers (5 men). The mean age of the cadavers at the time of death was 63.4 years (55-73). Sections were stained with the hematoxylin-eosin and antiprotein gene product 9.5 (PGP9.5) to identify encapsulated nerve endings. Transverse sections were cut and divided into volar, dorsal, and then into two equal parts, proximal and distal. The density of encapsulated nerve endings compared to volar versus dorsal and proximal versus distal regions was examined. This study showed that type 1 nerve endings were more common in the distal parts of the IP joint (p < 0.05). Also, type 3 nerve endings were observed in the thumb IP joint. There was no difference between regions in type II and type III nerve endings. The current study demonstrates that the distribution of encapsulated nerve endings in the IP joint is different from the PIP and DIP joints. Moreover, further studies are required to understand the thumb's physiology.
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Affiliation(s)
- Baver Acar
- Medical Faculty, Antalya Training and Research Hospital, Department of Orthopedics and Traumatology, University of Health Sciences, Antalya, Turkey
| | - Melih Unal
- Medical Faculty, Antalya Training and Research Hospital, Department of Orthopedics and Traumatology, University of Health Sciences, Antalya, Turkey
| | - Hasan May
- Medical Faculty, Antalya Training and Research Hospital, Department of Orthopedics and Traumatology, University of Health Sciences, Antalya, Turkey
| | - Serra Ozturk
- Department of Anatomy, Faculty of Medicine, School of Medicine, Akdeniz University, Antalya, Turkey
| | - Gamze Tanrıover
- Department of Histology and Embryology, Faculty of Medicine, School of Medicine, Akdeniz University, Antalya, Turkey
| | - Muzaffer Sındel
- Department of Anatomy, Faculty of Medicine, School of Medicine, Akdeniz University, Antalya, Turkey
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Ojeda-Alonso J, Calvo-Enrique L, Paricio-Montesinos R, Kumar R, Zhang MD, Poulet JFA, Ernfors P, Lewin GR. Sensory Schwann cells set perceptual thresholds for touch and selectively regulate mechanical nociception. Nat Commun 2024; 15:898. [PMID: 38320986 PMCID: PMC10847425 DOI: 10.1038/s41467-024-44845-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/08/2024] [Indexed: 02/08/2024] Open
Abstract
Previous work identified nociceptive Schwann cells that can initiate pain. Consistent with the existence of inherently mechanosensitive sensory Schwann cells, we found that in mice, the mechanosensory function of almost all nociceptors, including those signaling fast pain, were dependent on sensory Schwann cells. In polymodal nociceptors, sensory Schwann cells signal mechanical, but not cold or heat pain. Terminal Schwann cells also surround mechanoreceptor nerve-endings within the Meissner's corpuscle and in hair follicle lanceolate endings that both signal vibrotactile touch. Within Meissner´s corpuscles, two molecularly and functionally distinct sensory Schwann cells positive for Sox10 and Sox2 differentially modulate rapidly adapting mechanoreceptor function. Using optogenetics we show that Meissner's corpuscle Schwann cells are necessary for the perception of low threshold vibrotactile stimuli. These results show that sensory Schwann cells within diverse glio-neural mechanosensory end-organs are sensors for mechanical pain as well as necessary for touch perception.
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Affiliation(s)
- Julia Ojeda-Alonso
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Laura Calvo-Enrique
- Department of Medical Biochemistry and Biophysics, Division of Molecular Neurobiology, Karolinska Institutet, Stockholm, Sweden
- Departamento de Biología Celular y Patología, Instituto de Neurociencias de Castilla y León, University of Salamanca, Salamanca, Spain
| | - Ricardo Paricio-Montesinos
- Neural Circuits and Behavior, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), Venusberg-Campus 1/99, 53127, Bonn, Germany
| | - Rakesh Kumar
- Department of Medical Biochemistry and Biophysics, Division of Molecular Neurobiology, Karolinska Institutet, Stockholm, Sweden
- Pain Center, Department of Anesthesiology Washington University School of Medicine, CB 8108, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Ming-Dong Zhang
- Department of Medical Biochemistry and Biophysics, Division of Molecular Neurobiology, Karolinska Institutet, Stockholm, Sweden
| | - James F A Poulet
- Neural Circuits and Behavior, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Patrik Ernfors
- Department of Medical Biochemistry and Biophysics, Division of Molecular Neurobiology, Karolinska Institutet, Stockholm, Sweden.
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany.
- Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
- German Center for Mental Health (DZPG), partner site Berlin, Berlin, Germany.
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Bhat GM, Bashir S, Jan SS, Banoo S, Khan JA. Bovine Meissner-like corpuscle and evolutionary ecology of mammalian somatosensory acuity. Anat Histol Embryol 2024; 53:e12969. [PMID: 37724616 DOI: 10.1111/ahe.12969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/30/2023] [Accepted: 09/05/2023] [Indexed: 09/21/2023]
Abstract
The mammalian snout has Meissner's corpuscles (MCs), which transmit epicritic sensations as the animal explores its surroundings. To comprehend the somatosensory acuity in mammals, we examined the structural organization and density of bovine Meissner-like corpuscles (BMLCs) at various ages and compared the changes with other mammalian MCs. The skin from the snout of cows or oxen (2-11 years old) was obtained and processed through routine histological technique. Five-μm thick sections were prepared, silver stained according to the Bielschowsky technique as modified by Winkelman and Schmidt (Mayo Clinic Proceedings, 1957, 217), and observed under a compound light microscope quantitatively and qualitatively. The glabrous skin of the cow snout consisted of two types of BMLCs: One was a cylindrical or elongated structure found in the dermal papillae. The other type was spherical and developed in the superficial layers of the epidermis. BMLCs consisted of both coarse and fine nerve fibres. In the young, the corpuscle comprised thin nerve fibres with indistinct cell outlines. In adults, nerve fibres in the corpuscles were closely packed, and networks, varicosities and end bulbs were well developed. With advancing age, the MCs attenuated into a disorganized mass of nerve fibres. The bovine snout is a highly evolved somatosensory organ due to its rich nerve supply and functionally resembles the anthropoid fingertip. Somatosensory acuity will be lower in the glabrous bovine skin than in primate glabrous skin of the fingertip, as the nerve terminals within the BMLCs are less elaborate in content and structural complexity.
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Affiliation(s)
- Ghulam M Bhat
- Department of Anatomy, Government Medical College Srinagar, Srinagar, Jammu and Kashmir, India
| | - Samina Bashir
- Department of Anatomy, Government Medical College Srinagar, Srinagar, Jammu and Kashmir, India
| | - Shah S Jan
- Department of Anatomy, Government Medical College Srinagar, Srinagar, Jammu and Kashmir, India
| | - Shamima Banoo
- Department of Anatomy, Government Medical College Srinagar, Srinagar, Jammu and Kashmir, India
| | - Javeed A Khan
- Department of Anatomy, Government Medical College Srinagar, Srinagar, Jammu and Kashmir, India
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6
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Webb JF. Structural and functional evolution of the mechanosensory lateral line system of fishesa). J Acoust Soc Am 2023; 154:3526-3542. [PMID: 38171014 PMCID: PMC10908562 DOI: 10.1121/10.0022565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 01/05/2024]
Abstract
The mechanosensory lateral line system is the flow sensing system present in all 34 000+ species of fishes. Its neuromast receptor organs, located on the skin or in bony canals on the head and tubed scales on the trunk, respond to the near field component of acoustic stimuli as well as short range, low frequency (0-200 Hz) water flows of biotic and abiotic origin. Here, I discuss the genesis of my research career and its focus on the structural and functional evolution of the lateral line system among a wide taxonomic range of fishes including those from different aquatic habitats (tropical lakes to coral reefs and the deep sea). I discuss the importance of investigating structure before function, using investigations in my laboratory that had unexpected outcomes, as well as the role of serendipity in the evolution of a career and in the nature of scientific discovery.
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Affiliation(s)
- Jacqueline F Webb
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island 02881, USA
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Abstract
Proprioception, the sense of body position in space, has a critical role in the control of posture and movement. Aside from skin and joint receptors, the main sources of proprioceptive information in tetrapods are mechanoreceptive end organs in skeletal muscle: muscle spindles (MSs) and Golgi tendon organs (GTOs). The sensory neurons that innervate these receptors are divided into subtypes that detect discrete aspects of sensory information from muscles with different biomechanical functions. Despite the importance of proprioceptive neurons in motor control, the developmental mechanisms that control the acquisition of their distinct functional properties and positional identity are not yet clear. In this review, we discuss recent findings on the development of mouse proprioceptor subtypes and challenges in defining them at the molecular and functional level.
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Affiliation(s)
- Joriene C de Nooij
- Department of Neurology, Division of Translational Neurobiology, Vagelos College of Physicians and Surgeons, 650 West 168th Street, New York, NY 10032, USA; Columbia University Motor Neuron Center, Columbia University Medical Center, 630 West 168th Street, New York, NY 10032, USA.
| | - Niccolò Zampieri
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
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8
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Cataldo A, Frier W, Haggard P. Quantifying spatial acuity of frequency resolved midair ultrasound vibrotactile stimuli. Sci Rep 2023; 13:21149. [PMID: 38036579 PMCID: PMC10689848 DOI: 10.1038/s41598-023-48037-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 11/21/2023] [Indexed: 12/02/2023] Open
Abstract
Spatial acuity is a fundamental property of any sensory system. In the case of the somatosensory system, the two-point discrimination (2PD) test has long been used to investigate tactile spatial resolution. However, the somatosensory system comprises three main mechanoreceptive channels: the slowly adapting channel (SA) responds to steady pressure, the rapidly adapting channel (RA) responds to low-frequency vibration, and the Pacinian channel (PC) responds to high-frequency vibration. The use of mechanical stimuli in the classical 2PD test means that previous studies on tactile acuity have primarily focussed on the pressure-sensitive channel alone, while neglecting other submodalities. Here, we used a novel ultrasound stimulation to systematically investigate the spatial resolution of the two main vibrotactile channels. Contrary to the textbook view of poor spatial resolution for PC-like stimuli, across four experiments we found that high-frequency vibration produced surprisingly good spatial acuity. This effect remained after controlling for interchannel differences in stimulus detectability and perceived intensity. Laser doppler vibrometry experiments confirmed that the acuity of the PC channel was not simply an artifact of the skin's resonance to high-frequency mechanical stimulation. Thus, PC receptors may transmit substantial spatial information, despite their sparse distribution, deep location, and large receptive fields.
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Affiliation(s)
- Antonio Cataldo
- Institute of Cognitive Neuroscience, University College London, Alexandra House, 17 Queen Square, London, WCIN 3AZ, UK.
| | | | - Patrick Haggard
- Institute of Cognitive Neuroscience, University College London, Alexandra House, 17 Queen Square, London, WCIN 3AZ, UK
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Sanfeliu-Cerdán N, Català-Castro F, Mateos B, Garcia-Cabau C, Ribera M, Ruider I, Porta-de-la-Riva M, Canals-Calderón A, Wieser S, Salvatella X, Krieg M. A MEC-2/stomatin condensate liquid-to-solid phase transition controls neuronal mechanotransduction during touch sensing. Nat Cell Biol 2023; 25:1590-1599. [PMID: 37857834 PMCID: PMC10635833 DOI: 10.1038/s41556-023-01247-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 09/01/2023] [Indexed: 10/21/2023]
Abstract
A growing body of work suggests that the material properties of biomolecular condensates ensuing from liquid-liquid phase separation change with time. How this aging process is controlled and whether the condensates with distinct material properties can have different biological functions is currently unknown. Using Caenorhabditis elegans as a model, we show that MEC-2/stomatin undergoes a rigidity phase transition from fluid-like to solid-like condensates that facilitate transport and mechanotransduction, respectively. This switch is triggered by the interaction between the SH3 domain of UNC-89 (titin/obscurin) and MEC-2. We suggest that this rigidity phase transition has a physiological role in frequency-dependent force transmission in mechanosensitive neurons during body wall touch. Our data demonstrate a function for the liquid and solid phases of MEC-2/stomatin condensates in facilitating transport or mechanotransduction, and a previously unidentified role for titin homologues in neurons.
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Affiliation(s)
- Neus Sanfeliu-Cerdán
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Frederic Català-Castro
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Borja Mateos
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Carla Garcia-Cabau
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Maria Ribera
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Iris Ruider
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Montserrat Porta-de-la-Riva
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Adrià Canals-Calderón
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Stefan Wieser
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Xavier Salvatella
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain.
- ICREA, Barcelona, Spain.
| | - Michael Krieg
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain.
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10
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de Nooij JC. Engineering mechanoreceptor feature selectivity. Neuron 2023; 111:3137-3139. [PMID: 37857088 DOI: 10.1016/j.neuron.2023.09.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 09/26/2023] [Accepted: 09/26/2023] [Indexed: 10/21/2023]
Abstract
Touch and proprioception rely on the discriminative abilities of distinct classes of mechanosensory neurons. In this issue of Neuron, two studies1,2 provide evidence that biomechanical mechanisms and ultrastructural cellular specializations are key contributors in defining mechanoreceptor stimulus threshold and selectivity.
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Affiliation(s)
- Joriene C de Nooij
- Department of Neurology and Columbia University Motor Neuron Center, Columbia University Irving Medical Center, New York, NY, USA.
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11
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Handler A, Zhang Q, Pang S, Nguyen TM, Iskols M, Nolan-Tamariz M, Cattel S, Plumb R, Sanchez B, Ashjian K, Shotland A, Brown B, Kabeer M, Turecek J, DeLisle MM, Rankin G, Xiang W, Pavarino EC, Africawala N, Santiago C, Lee WCA, Xu CS, Ginty DD. Three-dimensional reconstructions of mechanosensory end organs suggest a unifying mechanism underlying dynamic, light touch. Neuron 2023; 111:3211-3229.e9. [PMID: 37725982 PMCID: PMC10773061 DOI: 10.1016/j.neuron.2023.08.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/31/2023] [Accepted: 08/22/2023] [Indexed: 09/21/2023]
Abstract
Across mammalian skin, structurally complex and diverse mechanosensory end organs respond to mechanical stimuli and enable our perception of dynamic, light touch. How forces act on morphologically dissimilar mechanosensory end organs of the skin to gate the requisite mechanotransduction channel Piezo2 and excite mechanosensory neurons is not understood. Here, we report high-resolution reconstructions of the hair follicle lanceolate complex, Meissner corpuscle, and Pacinian corpuscle and the subcellular distribution of Piezo2 within them. Across all three end organs, Piezo2 is restricted to the sensory axon membrane, including axon protrusions that extend from the axon body. These protrusions, which are numerous and elaborate extensively within the end organs, tether the axon to resident non-neuronal cells via adherens junctions. These findings support a unified model for dynamic touch in which mechanical stimuli stretch hundreds to thousands of axon protrusions across an end organ, opening proximal, axonal Piezo2 channels and exciting the neuron.
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Affiliation(s)
- Annie Handler
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Qiyu Zhang
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Song Pang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Tri M Nguyen
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Michael Iskols
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Michael Nolan-Tamariz
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Stuart Cattel
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Rebecca Plumb
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Brianna Sanchez
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Karyl Ashjian
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Aria Shotland
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Bartianna Brown
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Madiha Kabeer
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Josef Turecek
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Michelle M DeLisle
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Genelle Rankin
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Wangchu Xiang
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Elisa C Pavarino
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Nusrat Africawala
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Celine Santiago
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Wei-Chung Allen Lee
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - C Shan Xu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - David D Ginty
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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12
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Piccini I, Chéret J, Tsutsumi M, Sakaguchi S, Ponce L, Almeida L, Funk W, Kückelhaus M, Kajiya K, Paus R, Bertolini M. Preliminary evidence that Merkel cells exert chemosensory functions in human epidermis. Exp Dermatol 2023; 32:1848-1855. [PMID: 37587642 DOI: 10.1111/exd.14907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/30/2023] [Accepted: 07/31/2023] [Indexed: 08/18/2023]
Abstract
The mechanotransduction of light-touch sensory stimuli is considered to be the main physiological function of epidermal Merkel cells (MCs). Recently, however, MCs have been demonstrated to be also thermo-sensitive, suggesting that their role in skin physiologically extends well beyond mechanosensation. Here, we demonstrate that in healthy human skin epidermal MCs express functional olfactory receptors, namely OR2AT4, just like neighbouring keratinocytes. Selective stimulation of OR2AT4 by topical application of the synthetic odorant, Sandalore®, significantly increased Piccolo protein expression in MCs, as assessed by quantitative immunohistomorphometry, indicating increased vesicle trafficking and recycling, and significantly reduced nerve growth factor (NGF) immunoreactivity within MCs, possibly indicating increased neurotrophin release upon OR2AT4 activation. Live-cell imaging showed that Sandalore® rapidly induces a loss of FFN206-dependent fluorescence in MCs, suggesting OR2AT4-dependent MC depolarization and subsequent vesicle secretion. Yet, in contrast to keratinocytes, OR2AT4 stimulation by Sandalore® altered neither the number nor the proliferation status of MCs. These preliminary ex vivo findings demonstrate that epidermal MCs also exert OR-dependent chemosensory functions in human skin, and invite one to explore whether these newly identified properties are dysregulated in selected skin disorders, for example, in pruritic dermatoses, and if these novel MC functions can be therapeutically targeted to maintain/promote skin health.
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Affiliation(s)
- Ilaria Piccini
- Monasterium Laboratory, Skin and Hair Research Solutions GmbH, Münster, Germany
| | - Jeremy Chéret
- Monasterium Laboratory, Skin and Hair Research Solutions GmbH, Münster, Germany
- Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Moe Tsutsumi
- MIRAI Technology Institute, Shiseido Co., Ltd., Yokohama, Japan
| | - Saito Sakaguchi
- MIRAI Technology Institute, Shiseido Co., Ltd., Yokohama, Japan
| | - Leslie Ponce
- Monasterium Laboratory, Skin and Hair Research Solutions GmbH, Münster, Germany
| | - Luis Almeida
- Monasterium Laboratory, Skin and Hair Research Solutions GmbH, Münster, Germany
| | - Wolfgang Funk
- Clinic for Plastic, Aesthetic and Reconstructive Surgery, Munich, Germany
| | | | - Kentaro Kajiya
- MIRAI Technology Institute, Shiseido Co., Ltd., Yokohama, Japan
| | - Ralf Paus
- Monasterium Laboratory, Skin and Hair Research Solutions GmbH, Münster, Germany
- Dr. Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
- CUTANEON - Skin & Hair Innovations, Hamburg, Germany
| | - Marta Bertolini
- Monasterium Laboratory, Skin and Hair Research Solutions GmbH, Münster, Germany
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13
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Weda J, van Erp J, Mader A. The Effect of Actuation Speed on the Perception Threshold of a Squeezing Soft Actuator. IEEE Trans Haptics 2023; 16:574-579. [PMID: 37155386 DOI: 10.1109/toh.2023.3273774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The actuation speed of a pressure stimulus may influence its perception threshold. This is relevant for the design of haptic actuators and haptic interaction. We ran a study using a motorized ribbon to apply pressure stimuli (squeezes) to the arm at three different actuation speeds and used the PSI method to find the perception threshold for 21 participants. We found a significant effect of actuation speed on the perception threshold. Namely, a lower speed seems to increase the thresholds of normal force, pressure and indentation. This could be due to multiple factors like temporal summation, stimulating a larger population of mechanoreceptors for faster stimuli, and different responses of SA and RA receptors to stimuli of varying speeds. Our results show that actuation speed is an important parameter for the design of new haptic actuators and the design of haptic interaction for pressure.
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14
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Lam RM, von Buchholtz LJ, Falgairolle M, Osborne J, Frangos E, Servin-Vences MR, Nagel M, Nguyen MQ, Jayabalan M, Saade D, Patapoutian A, Bönnemann CG, Ryba NJP, Chesler AT. PIEZO2 and perineal mechanosensation are essential for sexual function. Science 2023; 381:906-910. [PMID: 37616369 DOI: 10.1126/science.adg0144] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 07/13/2023] [Indexed: 08/26/2023]
Abstract
Despite the potential importance of genital mechanosensation for sexual reproduction, little is known about how perineal touch influences mating. We explored how mechanosensation affords exquisite awareness of the genitals and controls reproduction in mice and humans. Using genetic strategies and in vivo functional imaging, we demonstrated that the mechanosensitive ion channel PIEZO2 (piezo-type mechanosensitive ion channel component 2) is necessary for behavioral sensitivity to perineal touch. PIEZO2 function is needed for triggering a touch-evoked erection reflex and successful mating in both male and female mice. Humans with complete loss of PIEZO2 function have genital hyposensitivity and experience no direct pleasure from gentle touch or vibration. Together, our results help explain how perineal mechanoreceptors detect the gentlest of stimuli and trigger physiologically important sexual responses, thus providing a platform for exploring the sensory basis of sexual pleasure and its relationship to affective touch.
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Affiliation(s)
- Ruby M Lam
- National Center for Complementary and Integrative Health (NCCIH), Bethesda, MD 20892, USA
- Brown-National Institutes of Health Graduate Partnerships Program, Brown University, Providence, RI 02912, USA
| | | | - Melanie Falgairolle
- National Center for Complementary and Integrative Health (NCCIH), Bethesda, MD 20892, USA
| | - Jennifer Osborne
- National Center for Complementary and Integrative Health (NCCIH), Bethesda, MD 20892, USA
| | - Eleni Frangos
- National Center for Complementary and Integrative Health (NCCIH), Bethesda, MD 20892, USA
| | - M Rocio Servin-Vences
- Howard Hughes Medical Institute, Department of Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Maximilian Nagel
- National Center for Complementary and Integrative Health (NCCIH), Bethesda, MD 20892, USA
| | - Minh Q Nguyen
- National Institute of Dental and Craniofacial Research, Bethesda, MD 20892, USA
| | - Monessha Jayabalan
- National Center for Complementary and Integrative Health (NCCIH), Bethesda, MD 20892, USA
| | - Dimah Saade
- National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Ardem Patapoutian
- Howard Hughes Medical Institute, Department of Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Carsten G Bönnemann
- National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Nicholas J P Ryba
- National Institute of Dental and Craniofacial Research, Bethesda, MD 20892, USA
| | - Alexander T Chesler
- National Center for Complementary and Integrative Health (NCCIH), Bethesda, MD 20892, USA
- National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
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15
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Wolfson RL, Abdelaziz A, Rankin G, Kushner S, Qi L, Mazor O, Choi S, Sharma N, Ginty DD. DRG afferents that mediate physiologic and pathologic mechanosensation from the distal colon. Cell 2023; 186:3368-3385.e18. [PMID: 37541195 PMCID: PMC10440726 DOI: 10.1016/j.cell.2023.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 04/23/2023] [Accepted: 07/06/2023] [Indexed: 08/06/2023]
Abstract
The properties of dorsal root ganglia (DRG) neurons that innervate the distal colon are poorly defined, hindering our understanding of their roles in normal physiology and gastrointestinal (GI) disease. Here, we report genetically defined subsets of colon-innervating DRG neurons with diverse morphologic and physiologic properties. Four colon-innervating DRG neuron populations are mechanosensitive and exhibit distinct force thresholds to colon distension. The highest threshold population, selectively labeled using Bmpr1b genetic tools, is necessary and sufficient for behavioral responses to high colon distension, which is partly mediated by the mechanosensory ion channel Piezo2. This Aδ-HTMR population mediates behavioral over-reactivity to colon distension caused by inflammation in a model of inflammatory bowel disease. Thus, like cutaneous DRG mechanoreceptor populations, colon-innervating mechanoreceptors exhibit distinct anatomical and physiological properties and tile force threshold space, and genetically defined colon-innervating HTMRs mediate pathophysiological responses to colon distension, revealing a target population for therapeutic intervention.
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Affiliation(s)
- Rachel L Wolfson
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Division of Gastroenterology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Amira Abdelaziz
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Genelle Rankin
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Sarah Kushner
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Lijun Qi
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Ofer Mazor
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Seungwon Choi
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
| | - Nikhil Sharma
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Department of Systems Biology, Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY 10032, USA
| | - David D Ginty
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA; Howard Hughes Medical Institute, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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16
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Laginestra FG, Favaretto T, Giuriato G, Martignon C, Barbi C, Pedrinolla A, Cavicchia A, Venturelli M. Concurrent metaboreflex activation increases chronotropic and ventilatory responses to passive leg movement without sex-related differences. Eur J Appl Physiol 2023; 123:1751-1762. [PMID: 37014452 PMCID: PMC10363078 DOI: 10.1007/s00421-023-05186-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023]
Abstract
Previous studies in animal models showed that exercise-induced metabolites accumulation may sensitize the mechanoreflex-induced response. The aim of this study was to assess whether the magnitude of the central hemodynamic and ventilatory adjustments evoked by isolated stimulation of the mechanoreceptors in humans are influenced by the prior accumulation of metabolic byproducts in the muscle. 10 males and 10 females performed two exercise bouts consisting of 5-min of intermittent isometric knee-extensions performed 10% above the previously determined critical force. Post-exercise, the subjects recovered for 5 min either with a suprasystolic circulatory occlusion applied to the exercised quadriceps (PECO) or under freely-perfused conditions (CON). Afterwards, 1-min of continuous passive leg movement was performed. Central hemodynamics, pulmonary data, and electromyography from exercising/passively-moved leg were recorded throughout the trial. Root mean square of successive differences (RMSSD, index of vagal tone) was also calculated. Δpeak responses of heart rate (ΔHR) and ventilation ([Formula: see text]) to passive leg movement were higher in PECO compared to CON (ΔHR: 6 ± 5 vs 2 ± 4 bpm, p = 0.01; 3.9 ± 3.4 vs 1.9 ± 1.7 L min-1, p = 0.02). Δpeak of mean arterial pressure (ΔMAP) was significantly different between conditions (5 ± 3 vs - 3 ± 3 mmHg, p < 0.01). Changes in RMSSD with passive leg movement were different between PECO and CON (p < 0.01), with a decrease only in the former (39 ± 18 to 32 ± 15 ms, p = 0.04). No difference was found in all the other measured variables between conditions (p > 0.05). These findings suggest that mechanoreflex-mediated increases in HR and [Formula: see text] are sensitized by metabolites accumulation. These responses were not influenced by biological sex.
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Affiliation(s)
- Fabio Giuseppe Laginestra
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy.
- Department of Internal Medicine, University of Utah, 500 Foothill Drive, Salt Lake City, UT, 84148, USA.
| | - Thomas Favaretto
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Gaia Giuriato
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Camilla Martignon
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Chiara Barbi
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Anna Pedrinolla
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Alessandro Cavicchia
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
- Respiratory Rehabilitation of the Institute of Lumezzane, Istituti Clinici Scientifici Maugeri IRCCS, Lumezzane, Italy
| | - Massimo Venturelli
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
- Department of Internal Medicine, University of Utah, 500 Foothill Drive, Salt Lake City, UT, 84148, USA
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17
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Lowenstein ED, Ruffault PL, Misios A, Osman KL, Li H, Greenberg RS, Thompson R, Song K, Dietrich S, Li X, Vladimirov N, Woehler A, Brunet JF, Zampieri N, Kühn R, Liberles SD, Jia S, Lewin GR, Rajewsky N, Lever TE, Birchmeier C. Prox2 and Runx3 vagal sensory neurons regulate esophageal motility. Neuron 2023; 111:2184-2200.e7. [PMID: 37192624 DOI: 10.1016/j.neuron.2023.04.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 10/31/2022] [Accepted: 04/24/2023] [Indexed: 05/18/2023]
Abstract
Vagal sensory neurons monitor mechanical and chemical stimuli in the gastrointestinal tract. Major efforts are underway to assign physiological functions to the many distinct subtypes of vagal sensory neurons. Here, we use genetically guided anatomical tracing, optogenetics, and electrophysiology to identify and characterize vagal sensory neuron subtypes expressing Prox2 and Runx3 in mice. We show that three of these neuronal subtypes innervate the esophagus and stomach in regionalized patterns, where they form intraganglionic laminar endings. Electrophysiological analysis revealed that they are low-threshold mechanoreceptors but possess different adaptation properties. Lastly, genetic ablation of Prox2 and Runx3 neurons demonstrated their essential roles for esophageal peristalsis in freely behaving mice. Our work defines the identity and function of the vagal neurons that provide mechanosensory feedback from the esophagus to the brain and could lead to better understanding and treatment of esophageal motility disorders.
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Affiliation(s)
- Elijah D Lowenstein
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany; NeuroCure Cluster of Excellence, CharitéUniversitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Pierre-Louis Ruffault
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Aristotelis Misios
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany; NeuroCure Cluster of Excellence, CharitéUniversitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Kate L Osman
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Huimin Li
- The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Rachel S Greenberg
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Rebecca Thompson
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Kun Song
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Stephan Dietrich
- Development and Function of Neural Circuits, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Xun Li
- Immune Regulation and Cancer, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Nikita Vladimirov
- Systems Biology Imaging, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Andrew Woehler
- Systems Biology Imaging, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Jean-François Brunet
- Institut de Biologie de l'ENS (IBENS), Inserm, CNRS, École normale supérieure, PSL Research University, Paris, France
| | - Niccolò Zampieri
- Development and Function of Neural Circuits, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Ralf Kühn
- Genome Engineering & Disease Models, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Stephen D Liberles
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Shiqi Jia
- The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Nikolaus Rajewsky
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Teresa E Lever
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Carmen Birchmeier
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany; NeuroCure Cluster of Excellence, CharitéUniversitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
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18
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Loutit AJ, Wheat HE, Khamis H, Vickery RM, Macefield VG, Birznieks I. How Tactile Afferents in the Human Fingerpad Encode Tangential Torques Associated with Manipulation: Are Monkeys Better than Us? J Neurosci 2023; 43:4033-4046. [PMID: 37142429 PMCID: PMC10254986 DOI: 10.1523/jneurosci.1305-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 04/14/2023] [Accepted: 04/17/2023] [Indexed: 05/06/2023] Open
Abstract
Dexterous object manipulation depends critically on information about forces normal and tangential to the fingerpads, and also on torque associated with object orientation at grip surfaces. We investigated how torque information is encoded by human tactile afferents in the fingerpads and compared them to 97 afferents recorded in monkeys (n = 3; 2 females) in our previous study. Human data included slowly-adapting Type-II (SA-II) afferents, which are absent in the glabrous skin of monkeys. Torques of different magnitudes (3.5-7.5 mNm) were applied in clockwise and anticlockwise directions to a standard central site on the fingerpads of 34 human subjects (19 females). Torques were superimposed on a 2, 3, or 4 N background normal force. Unitary recordings were made from fast-adapting Type-I (FA-I, n = 39), and slowly-adapting Type-I (SA-I, n = 31) and Type-II (SA-II, n = 13) afferents supplying the fingerpads via microelectrodes inserted into the median nerve. All three afferent types encoded torque magnitude and direction, with torque sensitivity being higher with smaller normal forces. SA-I afferent responses to static torque were inferior to dynamic stimuli in humans, while in monkeys the opposite was true. In humans this might be compensated by the addition of sustained SA-II afferent input, and their capacity to increase or decrease firing rates with direction of rotation. We conclude that the discrimination capacity of individual afferents of each type was inferior in humans than monkeys which could be because of differences in fingertip tissue compliance and skin friction.SIGNIFICANCE STATEMENT We investigated how individual human tactile nerve fibers encode rotational forces (torques) and compared them to their monkey counterparts. Human hands, but not monkey hands, are innervated by a tactile neuron type (SA-II afferents) specialized to encode directional skin strain yet, so far, torque encoding has only been studied in monkeys. We find that human SA-I afferents were generally less sensitive and less able to discriminate torque magnitude and direction than their monkey counterparts, especially during the static phase of torque loading. However, this shortfall in humans could be compensated by SA-II afferent input. This indicates that variation in afferent types might complement each other signaling different stimulus features possibly providing computational advantage to discriminate stimuli.
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Affiliation(s)
- Alastair J Loutit
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Biomedical Sciences, UNSW Sydney, Sydney, New South Wales 2031, Australia
| | - Heather E Wheat
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Heba Khamis
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- Graduate School of Biomedical Engineering, UNSW Sydney, Sydney, New South Wales 2031, Australia
| | - Richard M Vickery
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Biomedical Sciences, UNSW Sydney, Sydney, New South Wales 2031, Australia
- Bionics and Bio-robotics, Tyree Foundation Institute of Health Engineering, UNSW Sydney, Sydney, New South Wales 2031, Australia
| | - Vaughan G Macefield
- Baker Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria 3052, Australia
- Department of Neuroscience, Monash University, Melbourne, Victoria 3052, Australia
| | - Ingvars Birznieks
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Biomedical Sciences, UNSW Sydney, Sydney, New South Wales 2031, Australia
- Bionics and Bio-robotics, Tyree Foundation Institute of Health Engineering, UNSW Sydney, Sydney, New South Wales 2031, Australia
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19
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Pomaville MB, Wright KM. Follicle-innervating Aδ-low threshold mechanoreceptive neurons form receptive fields through homotypic competition. Neural Dev 2023; 18:2. [PMID: 37106422 PMCID: PMC10134579 DOI: 10.1186/s13064-023-00170-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 04/20/2023] [Indexed: 04/29/2023] Open
Abstract
The mammalian somatosensory system is comprised of multiple neuronal populations that form specialized, highly organized sensory endings in the skin. The organization of somatosensory endings is essential to their functions, yet the mechanisms which regulate this organization remain unclear. Using a combination of genetic and molecular labeling approaches, we examined the development of mouse hair follicle-innervating low-threshold mechanoreceptors (LTMRs) and explored competition for innervation targets as a mechanism involved in the patterning of their receptive fields. We show that follicle innervating neurons are present in the skin at birth and that LTMR receptive fields gradually add follicle-innervating endings during the first two postnatal weeks. Using a constitutive Bax knockout to increase the number of neurons in adult animals, we show that two LTMR subtypes have differential responses to an increase in neuronal population size: Aδ-LTMR neurons shrink their receptive fields to accommodate the increased number of neurons innervating the skin, while C-LTMR neurons do not. Our findings suggest that competition for hair follicles to innervate plays a role in the patterning and organization of follicle-innervating LTMR neurons.
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Affiliation(s)
- Matthew B Pomaville
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239, USA
- Department of Cell, Developmental, and Cancer Biology, Cell and Developmental Biology Graduate Program, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Kevin M Wright
- Vollum Institute, Oregon Health and Science University, Portland, OR, 97239, USA.
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20
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Abstract
Muscle spindles, one of the two main classes of proprioceptors together with Golgi tendon organs, are sensory structures that keep the central nervous system updated about the position and movement of body parts. Although they were discovered more than 150 years ago, their function during movement is not yet fully understood. Here, we summarize the morphology and known functions of muscle spindles, with a particular focus on locomotion. Although certain properties such as the sensitivity to dynamic and static muscle stretch are long known, recent advances in molecular biology have allowed the characterization of the molecular mechanisms for signal transduction in muscle spindles. Building upon classic literature showing that a lack of sensory feedback is deleterious to locomotion, we bring to the discussion more recent findings that support a pivotal role of muscle spindles in maintaining murine and human locomotor robustness, defined as the ability to cope with perturbations. Yet, more research is needed to expand the existing mechanistic understanding of how muscle spindles contribute to the production of robust, functional locomotion in real world settings. Future investigations should focus on combining different animal models to identify, in health and disease, those peripheral, spinal and brain proprioceptive structures involved in the fine tuning of motor control when locomotion happens in challenging conditions.
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Affiliation(s)
- Alessandro Santuz
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Life Sciences Research Institute, Dalhousie University, Halifax, NS, Canada
| | - Turgay Akay
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Life Sciences Research Institute, Dalhousie University, Halifax, NS, Canada
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21
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Meklef RA, Siemers F, Rein S. Development of a 3D-immunofluorescence analysis for sensory nerve endings in human ligaments. J Neurosci Methods 2022; 382:109724. [PMID: 36207004 DOI: 10.1016/j.jneumeth.2022.109724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 09/29/2022] [Accepted: 10/01/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND The analysis of ligamentous mechanoreceptors is difficult due to a high amount of unclassifiable mechanoreceptors, which result from incomplete visualization through limited microscopic techniques. NEW METHOD The method was developed using dorsal intercarpal ligaments and dorsal regions of the scapholunate interosseous ligament from human cadaver wrists. Consecutive 70 µm thick cryosections were stained with immunofluorescence markers for protein S100B, neurotrophin receptor p75 (p75), protein gene product 9.5 (PGP 9.5) and 4',6-diamidino-2-phenylindole (DAPI). 3D images of sensory nerve endings were obtained using a confocal laser scanning microscope. Experimental point spread functions (PSF) were used to deconvolve images. Sensory nerve endings were localised in each section plane and classified according to Freeman and Wyke. Finally, confocal data was visualized as 3D-images. RESULTS The method produced excellent image quality, revealing detailed three-dimensional structures. The created 3D-model of sensory nerve endings could be analyzed in all three dimensions, augmenting visualization of the form and immunoreactive pattern of sensory nerve endings. Deconvolution with experimentally measured PSFs aided in enhancing image quality. COMPARISON WITH EXISTING METHODS Using a triple immunofluorescent staining method allows to visualize the structure of sensory nerve endings more precisely than techniques with serial analysis of different monostaining of neural markers. Imaging in three dimensions enhances morphologic details, which are limited in 2D-microscopy. CONCLUSION 3D-triple immunofluorescence produces high quality visualization of mechanoreceptors, thereby improving their analysis. As an elaborate technique, it is ideal for defined research questions concerning the microstructure of sensory nerve endings.
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Affiliation(s)
- Rami Al Meklef
- Department of Plastic and Hand Surgery, Burn Unit, Klinikum Sankt Georg, Delitzscher Straße 141, 04129 Leipzig, Germany; Martin-Luther-University Halle-Wittenberg, Germany
| | - Frank Siemers
- Martin-Luther-University Halle-Wittenberg, Germany; Department of Plastic and Hand Surgery with Burn Unit, Trauma Center Bergmannstrost, 06112 Halle, Germany
| | - Susanne Rein
- Department of Plastic and Hand Surgery, Burn Unit, Klinikum Sankt Georg, Delitzscher Straße 141, 04129 Leipzig, Germany; Martin-Luther-University Halle-Wittenberg, Germany.
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22
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Abstract
The muscle spindle (MS) provides essential sensory information for motor control and proprioception. The Group Ia and II MS afferents are low threshold slowly-adapting mechanoreceptors and report both static muscle length and dynamic muscle movement information. The exact molecular mechanism by which MS afferents transduce muscle movement into action potentials is incompletely understood. This short review will discuss recent evidence suggesting that PIEZO2 is an essential mechanically sensitive ion channel in MS afferents and that vesicle-released glutamate contributes to maintaining afferent excitability during the static phase of stretch. Other mechanically gated ion channels, voltage-gated sodium channels, other ion channels, regulatory proteins, and interactions with the intrafusal fibers are also important for MS afferent mechanosensation. Future studies are needed to fully understand mechanosensation in the MS and whether different complements of molecular mediators contribute to the different response properties of Group Ia and II afferents.
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23
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Wei Y, McGlone FP, Marshall AG, Makdani A, Zou Z, Ren L, Wei G. From skin mechanics to tactile neural coding: Predicting afferent neural dynamics during active touch and perception. IEEE Trans Biomed Eng 2022; 69:3748-3759. [PMID: 35604990 DOI: 10.1109/tbme.2022.3177006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
First order cutaneous neurons allow object recognition, texture discrimination, and sensorimotor feedback. Their function is well-investigated under passive stimulation while their role during active touch or sensorimotor control is understudied. To understand how human perception and sensorimotor controlling strategy depend on cutaneous neural signals under active tactile exploration, the finite element (FE) hand and Izhikevich neural dynamic model were combined to predict the cutaneous neural dynamics and the resulting perception during a discrimination test. Using in-vivo microneurography generated single afferent recordings, 75% of the data was applied for the model optimization and another 25% was used for validation. By using this integrated numerical model, the predicted tactile neural signals of the single afferent fibers agreed well with the microneurography test results, achieving the out-of-sample values of 0.94 and 0.82 for slowly adapting type I (SAI) and fast adapting type I unit (FAI) respectively. Similar discriminating capability with the human subject was achieved based on this computational model. Comparable performance with the published numerical model on predicting the cutaneous neural response under passive stimuli was also presented, ensuring the potential applicability of this multi-level numerical model in studying the human tactile sensing mechanisms during active touch. The predicted population-level 1st order afferent neural signals under active touch suggest that different coding strategies might be applied to the afferent neural signals elicited from different cutaneous neurons simultaneously.
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24
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Abstract
The primary function of the gut is to procure nutrients. Synchronized mechanical activities underlie nearly all its endeavours. Coordination of mechanical activities depends on sensing of the mechanical forces, in a process called mechanosensation. The gut has a range of mechanosensory cells. They function either as specialized mechanoreceptors, which convert mechanical stimuli into coordinated physiological responses at the organ level, or as non-specialized mechanosensory cells that adjust their function based on the mechanical state of their environment. All major cell types in the gastrointestinal tract contain subpopulations that act as specialized mechanoreceptors: epithelia, smooth muscle, neurons, immune cells, and others. These cells are tuned to the physical properties of the surrounding tissue, so they can discriminate mechanical stimuli from the baseline mechanical state. The importance of gastrointestinal mechanosensation has long been recognized, but the latest discoveries of molecular identities of mechanosensors and technical advances that resolve the relevant circuitry have poised the field to make important intellectual leaps. This Review describes the mechanical factors relevant for normal function, as well as the molecules, cells and circuits involved in gastrointestinal mechanosensing. It concludes by outlining important unanswered questions in gastrointestinal mechanosensing.
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Affiliation(s)
- Arnaldo Mercado-Perez
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, MN, USA
- Medical Scientist Training Program (MSTP), Mayo Clinic, Rochester, MN, USA
| | - Arthur Beyder
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, MN, USA.
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
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25
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Nakamura N, Ikeda N, Heng P, Muraoka I. Muscle stiffening is associated with muscle mechanoreflex-mediated cardioacceleration. Eur J Appl Physiol 2022; 122:781-790. [PMID: 35024946 DOI: 10.1007/s00421-022-04885-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 01/05/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE Although the muscle mechanoreflex is an important mediator to cardiovascular regulation during exercise, its modulation factors remain relatively unknown. Therefore, the purpose of this study was to investigate the effect of muscle stiffness on the muscle mechanoreflex. METHODS Participants were divided based on their median muscle stiffness (2.00 Nm/mm) into a low group (n = 15) and a high group (n = 15), and the muscle mechanoreflex was compared between the groups. After a 15-min rest in the supine position, heart rate (HR), blood pressure (BP), stroke volume (SV), and cardiac output (CO) were measured at rest for 3 min and during static passive dorsiflexion (SPD) at 20° for 1 min. Following a 15-min re-rest, muscle stiffness and passive resistive torque were evaluated in the distal end of the muscle belly of the medial gastrocnemius. RESULTS Peak relative changes in HR (low group: 6 ± 4% and high group: 12 ± 4%) and CO (low group: 8 ± 10% and high group: 13 ± 9%) were greater in the high group than in the low group (both, P < 0.05). A significant positive correlation was found between resistive torque during SPD and muscle stiffness and peak relative changes in HR (r = 0.51 and 0.61, both P < 0.05). However, there was no correlation between muscle elongation during SPD and peak relative changes in HR (r = - 0.23, P = 0.20). CONCLUSION These findings suggest that muscle stiffness may be modulatory factor of muscle mechanoreflex.
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Affiliation(s)
- Nobuhiro Nakamura
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan.
| | - Naoki Ikeda
- Institute of General Education, Ritsumeikan University, Kyoto, Kyoto, Japan
| | - Peng Heng
- Graduate School of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan
| | - Isao Muraoka
- Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan
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26
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Ng KKW, Tee X, Vickery RM, Birznieks I. The Relationship Between Tactile Intensity Perception and Afferent Spike Count is Moderated by a Function of Frequency. IEEE Trans Haptics 2022; 15:14-19. [PMID: 34990370 DOI: 10.1109/toh.2022.3140877] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
It has been suggested that tactile intensity perception can be explained by a linear function of spike rate weighted by afferent type. Other than relying on mathematical models, verifying this experimentally is difficult due to the frequency tuning of different afferent types and changes in population recruitment patterns with vibrotactile frequency. To overcome these complexities, we used pulsatile mechanical stimuli which activate the same afferent population regardless of the repetition rate (frequency), generating one action potential per pulse. We used trains of different frequencies (20-200 Hz) to investigate perceived intensity. Subjects' magnitude ratings increased with pulse rate up to ∼100 Hz and plateaued beyond this frequency. This was true regardless of pulse amplitude, from small pulses that exclusively activated Pacinian (PC) afferents, to pulses large enough to activate other afferents including slowly adapting. Electrical stimulation, which activates afferents indiscriminately, plateaued at a similar frequency, although not in all subjects. As the plateauing did not depend on indentation magnitude and hence on afferent weights, we propose that the contribution of spike count to intensity perception is weighted by a function of frequency. This may explain why fine textures evoking high frequency vibrations of a small magnitude do not feel disproportionally intense.
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27
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Suresh AK, Greenspon CM, He Q, Rosenow JM, Miller LE, Bensmaia SJ. Sensory computations in the cuneate nucleus of macaques. Proc Natl Acad Sci U S A 2021; 118:e2115772118. [PMID: 34853173 PMCID: PMC8670430 DOI: 10.1073/pnas.2115772118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 10/25/2021] [Indexed: 12/15/2022] Open
Abstract
Tactile nerve fibers fall into a few classes that can be readily distinguished based on their spatiotemporal response properties. Because nerve fibers reflect local skin deformations, they individually carry ambiguous signals about object features. In contrast, cortical neurons exhibit heterogeneous response properties that reflect computations applied to convergent input from multiple classes of afferents, which confer to them a selectivity for behaviorally relevant features of objects. The conventional view is that these complex response properties arise within the cortex itself, implying that sensory signals are not processed to any significant extent in the two intervening structures-the cuneate nucleus (CN) and the thalamus. To test this hypothesis, we recorded the responses evoked in the CN to a battery of stimuli that have been extensively used to characterize tactile coding in both the periphery and cortex, including skin indentations, vibrations, random dot patterns, and scanned edges. We found that CN responses are more similar to their cortical counterparts than they are to their inputs: CN neurons receive input from multiple classes of nerve fibers, they have spatially complex receptive fields, and they exhibit selectivity for object features. Contrary to consensus, then, the CN plays a key role in processing tactile information.
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Affiliation(s)
- Aneesha K Suresh
- Committee on Computational Neuroscience, University of Chicago, Chicago, IL 60637
| | - Charles M Greenspon
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637
| | - Qinpu He
- Committee on Computational Neuroscience, University of Chicago, Chicago, IL 60637
| | - Joshua M Rosenow
- Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Lee E Miller
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL 60208
- Shirley Ryan AbilityLab, Chicago, IL 60611
| | - Sliman J Bensmaia
- Committee on Computational Neuroscience, University of Chicago, Chicago, IL 60637;
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637
- Grossman Institute for Neuroscience, Quantitative Biology, and Human Behavior, University of Chicago, Chicago, IL 60637
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28
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Abstract
Joint torque feedback is a new and promising means of kinesthetic feedback imposed by a wearable device. The torque feedback provides the wearer temporal and spatial information during a motion task. Nevertheless, little research has been conducted on quantifying the psychophysical parameters of how well humans can perceive external torques under various joint conditions. This study aims to investigate the just noticeable difference (JND) perceptual ability of the elbow joint to joint torques. The paper focuses on the ability of two primary joint proprioceptors, the Golgi-tendon organ (GTO) and muscle spindle (MS), to detect elbow torques, since touch and pressure sensors were masked. We studied 14 subjects while the arm was isometrically contracted (static condition) and was moving at a constant speed (dynamic condition). In total there were 10 joint conditions investigated, which varied the direction of the arm's movement and the preload direction as well as torque direction. The JND torques under static conditions ranged from 0.097 Nm with no preload to 0.197 Nm with a preload of 1.28 Nm. The maximum dynamic JND torques were 0.799 Nm and 0.428 Nm, when the arm was flexing and extending at 213 degrees per second, respectively.
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Affiliation(s)
- Hubert Kim
- Mechanical Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Alan T Asbeck
- Mechanical Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
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29
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Yang T, Yuan Z, Liu C, Liu T, Zhang W. A neural circuit integrates pharyngeal sensation to control feeding. Cell Rep 2021; 37:109983. [PMID: 34758309 DOI: 10.1016/j.celrep.2021.109983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 08/20/2021] [Accepted: 10/20/2021] [Indexed: 11/18/2022] Open
Abstract
Swallowing is an essential step of eating and drinking. However, how the quality of a food bolus is sensed by pharyngeal neurons is largely unknown. Here we find that mechanical receptors along the Drosophila pharynx are required for control of meal size, especially for food of high viscosity. The mechanical force exerted by the bolus passing across the pharynx is detected by neurons expressing the mechanotransduction channel NOMPC (no mechanoreceptor potential C) and is relayed, together with gustatory information, to IN1 neurons in the subesophageal zone (SEZ) of the brain. IN1 (ingestion neurons) neurons act directly upstream of a group of peptidergic neurons that encode satiety. Prolonged activation of IN1 neurons suppresses feeding. IN1 neurons receive inhibition from DSOG1 (descending subesophageal neurons) neurons, a group of GABAergic neurons that non-selectively suppress feeding. Our results reveal the function of pharyngeal mechanoreceptors and their downstream neural circuits in the control of food ingestion.
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Affiliation(s)
- Tingting Yang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Zixuan Yuan
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Chenxi Liu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Ting Liu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Wei Zhang
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
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30
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Sherf N, Shamir M. STDP and the distribution of preferred phases in the whisker system. PLoS Comput Biol 2021; 17:e1009353. [PMID: 34534208 PMCID: PMC8480728 DOI: 10.1371/journal.pcbi.1009353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 09/29/2021] [Accepted: 08/17/2021] [Indexed: 11/19/2022] Open
Abstract
Rats and mice use their whiskers to probe the environment. By rhythmically swiping their whiskers back and forth they can detect the existence of an object, locate it, and identify its texture. Localization can be accomplished by inferring the whisker’s position. Rhythmic neurons that track the phase of the whisking cycle encode information about the azimuthal location of the whisker. These neurons are characterized by preferred phases of firing that are narrowly distributed. Consequently, pooling the rhythmic signal from several upstream neurons is expected to result in a much narrower distribution of preferred phases in the downstream population, which however has not been observed empirically. Here, we show how spike timing dependent plasticity (STDP) can provide a solution to this conundrum. We investigated the effect of STDP on the utility of a neural population to transmit rhythmic information downstream using the framework of a modeling study. We found that under a wide range of parameters, STDP facilitated the transfer of rhythmic information despite the fact that all the synaptic weights remained dynamic. As a result, the preferred phase of the downstream neuron was not fixed, but rather drifted in time at a drift velocity that depended on the preferred phase, thus inducing a distribution of preferred phases. We further analyzed how the STDP rule governs the distribution of preferred phases in the downstream population. This link between the STDP rule and the distribution of preferred phases constitutes a natural test for our theory. The distribution of preferred phases of whisking neurons in the somatosensory system of rats and mice presents a conundrum: a simple pooling model predicts a distribution that is an order of magnitude narrower than what is observed empirically. Here, we suggest that this non-trivial distribution may result from activity-dependent plasticity in the form of spike timing dependent plasticity (STDP). We show that under STDP, the synaptic weights do not converge to a fixed value, but rather remain dynamic. As a result, the preferred phases of the whisking neurons vary in time, hence inducing a non-trivial distribution of preferred phases, which is governed by the STDP rule. Our results imply that the considerable synaptic volatility which has long been viewed as a difficulty that needs to be overcome, may actually be an underlying principle of the organization of the central nervous system.
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Affiliation(s)
- Nimrod Sherf
- Physics Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- * E-mail:
| | - Maoz Shamir
- Physics Department, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Department of Physiology and Cell Biology Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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31
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Abstract
Our sense of touch emerges from an array of mechanosensory structures residing within the fabric of our skin. These tactile end organ structures convert innocuous forces acting on the skin into electrical signals that propagate to the CNS via the axons of low-threshold mechanoreceptors (LTMRs). Our rich capacity for tactile discrimination arises from the dissimilar intrinsic properties of the LTMR subtypes that innervate different regions of the skin and the structurally distinct end organ complexes with which they associate. These end organ structures comprise a range of non-neuronal cell types, which may themselves actively contribute to the transformation of tactile forces into neural impulses within the LTMR afferents. Although the mechanism and the site of transduction across end organs remain unclear, PIEZO2 has emerged as the principal mechanosensitive channel involved in light touch of the skin. Here we review the physiological properties of LTMR subtypes and discuss how features of their cutaneous end organ complexes shape subtype-specific tuning.
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Affiliation(s)
- Annie Handler
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
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32
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Weber AI, Daniel TL, Brunton BW. Wing structure and neural encoding jointly determine sensing strategies in insect flight. PLoS Comput Biol 2021; 17:e1009195. [PMID: 34379622 PMCID: PMC8382179 DOI: 10.1371/journal.pcbi.1009195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 08/23/2021] [Accepted: 06/18/2021] [Indexed: 11/21/2022] Open
Abstract
Animals rely on sensory feedback to generate accurate, reliable movements. In many flying insects, strain-sensitive neurons on the wings provide rapid feedback that is critical for stable flight control. While the impacts of wing structure on aerodynamic performance have been widely studied, the impacts of wing structure on sensing are largely unexplored. In this paper, we show how the structural properties of the wing and encoding by mechanosensory neurons interact to jointly determine optimal sensing strategies and performance. Specifically, we examine how neural sensors can be placed effectively on a flapping wing to detect body rotation about different axes, using a computational wing model with varying flexural stiffness. A small set of mechanosensors, conveying strain information at key locations with a single action potential per wingbeat, enable accurate detection of body rotation. Optimal sensor locations are concentrated at either the wing base or the wing tip, and they transition sharply as a function of both wing stiffness and neural threshold. Moreover, the sensing strategy and performance is robust to both external disturbances and sensor loss. Typically, only five sensors are needed to achieve near-peak accuracy, with a single sensor often providing accuracy well above chance. Our results show that small-amplitude, dynamic signals can be extracted efficiently with spatially and temporally sparse sensors in the context of flight. The demonstrated interaction of wing structure and neural encoding properties points to the importance of understanding each in the context of their joint evolution. In addition to generating forces for flight, insect wings also serve an important role as sensory structures, providing rapid feedback about wing bending that is used to stabilize flight. While much is known about how wing structure affects aerodynamic performance, the effects of wing structure on sensing remain unexplored. Using a computational model of a flapping wing, we examine how sensing strategies depend on wing stiffness and sensor properties. We show that body rotations can be accurately detected with a small number of sensors on the wing across a wide range of conditions. Optimal sensor locations are clustered at either the wing base or wing tip, depending on a combination of wing stiffness and sensor properties. Moreover, sensing performance is robust to multiple kinds of perturbations. Our work provides a basis for understanding how wing structure impacts incoming sensory information during flight.
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Affiliation(s)
- Alison I. Weber
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| | - Thomas L. Daniel
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Bingni W. Brunton
- Department of Biology, University of Washington, Seattle, Washington, United States of America
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33
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Revilla-i-Domingo R, Rajan VBV, Waldherr M, Prohaczka G, Musset H, Orel L, Gerrard E, Smolka M, Stockinger A, Farlik M, Lucas RJ, Raible F, Tessmar-Raible K. Characterization of cephalic and non-cephalic sensory cell types provides insight into joint photo- and mechanoreceptor evolution. eLife 2021; 10:e66144. [PMID: 34350831 PMCID: PMC8367381 DOI: 10.7554/elife.66144] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 08/04/2021] [Indexed: 12/11/2022] Open
Abstract
Rhabdomeric opsins (r-opsins) are light sensors in cephalic eye photoreceptors, but also function in additional sensory organs. This has prompted questions on the evolutionary relationship of these cell types, and if ancient r-opsins were non-photosensory. A molecular profiling approach in the marine bristleworm Platynereis dumerilii revealed shared and distinct features of cephalic and non-cephalic r-opsin1-expressing cells. Non-cephalic cells possess a full set of phototransduction components, but also a mechanosensory signature. Prompted by the latter, we investigated Platynereis putative mechanotransducer and found that nompc and pkd2.1 co-expressed with r-opsin1 in TRE cells by HCR RNA-FISH. To further assess the role of r-Opsin1 in these cells, we studied its signaling properties and unraveled that r-Opsin1 is a Gαq-coupled blue light receptor. Profiling of cells from r-opsin1 mutants versus wild-types, and a comparison under different light conditions reveals that in the non-cephalic cells light - mediated by r-Opsin1 - adjusts the expression level of a calcium transporter relevant for auditory mechanosensation in vertebrates. We establish a deep-learning-based quantitative behavioral analysis for animal trunk movements and identify a light- and r-Opsin-1-dependent fine-tuning of the worm's undulatory movements in headless trunks, which are known to require mechanosensory feedback. Our results provide new data on peripheral cell types of likely light sensory/mechanosensory nature. These results point towards a concept in which such a multisensory cell type evolved to allow for fine-tuning of mechanosensation by light. This implies that light-independent mechanosensory roles of r-opsins may have evolved secondarily.
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Affiliation(s)
- Roger Revilla-i-Domingo
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna BioCenterViennaAustria
| | - Vinoth Babu Veedin Rajan
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Monika Waldherr
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Günther Prohaczka
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Hugo Musset
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Lukas Orel
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
| | - Elliot Gerrard
- Division of Neuroscience & Experimental Psychology, University of ManchesterManchesterUnited Kingdom
| | - Moritz Smolka
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Center for Integrative Bioinformatics Vienna, Max Perutz Labs, University of Vienna and Medical University of ViennaViennaAustria
| | - Alexander Stockinger
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna BioCenterViennaAustria
| | - Matthias Farlik
- CeMM Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
- Department of Dermatology, Medical University of ViennaViennaAustria
| | - Robert J Lucas
- Division of Neuroscience & Experimental Psychology, University of ManchesterManchesterUnited Kingdom
| | - Florian Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform "Single-Cell Regulation of Stem Cells", University of Vienna, Vienna BioCenterViennaAustria
| | - Kristin Tessmar-Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenterViennaAustria
- Research Platform “Rhythms of Life”, University of Vienna, Vienna BioCenterViennaAustria
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Luo Y, Bresee CS, Rudnicki JW, Hartmann MJZ. Constraints on the deformation of the vibrissa within the follicle. PLoS Comput Biol 2021; 17:e1007887. [PMID: 33793548 PMCID: PMC8016108 DOI: 10.1371/journal.pcbi.1007887] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 12/10/2020] [Indexed: 11/26/2022] Open
Abstract
Nearly all mammals have a vibrissal system specialized for tactile sensation, composed of whiskers growing from sensor-rich follicles in the skin. When a whisker deflects against an object, it deforms within the follicle and exerts forces on the mechanoreceptors inside. In addition, during active whisking behavior, muscle contractions around the follicle and increases in blood pressure in the ring sinus will affect the whisker deformation profile. To date, however, it is not yet possible to experimentally measure how the whisker deforms in an intact follicle or its effects on different groups of mechanoreceptors. The present study develops a novel model to predict vibrissal deformation within the follicle sinus complex. The model is based on experimental results from a previous ex vivo study on whisker deformation within the follicle, and on a new histological analysis of follicle tissue. It is then used to simulate whisker deformation within the follicle during passive touch and active whisking. Results suggest that the most likely whisker deformation profile is “S-shaped,” crossing the midline of the follicle right below the ring sinus. Simulations of active whisking indicate that an increase in overall muscle stiffness, an increase in the ratio between deep and superficial intrinsic muscle stiffness, and an increase in sinus blood pressure will all enhance tactile sensitivity. Finally, we discuss how the deformation profiles might map to the responses of primary afferents of each mechanoreceptor type. The mechanical model presented in this study is an important first step in simulating mechanical interactions within whisker follicles. Many mammals rely on whiskers as a mode of tactile sensation, especially when exploring in darkness. Active, rhythmic protraction and retraction of the whiskers, commonly referred to as “whisking,” is observed among many whisker specialist animals. During whisker-based sensing, forces and moments generated by external stimuli are transmitted to the base of the whisker shaft inside the follicle. Within the follicle, the interaction between the whisker’s deformation and the surrounding tissue determines how different groups of mechanoreceptors will deform, thereby transducing the mechanical signals into electrical signals. However, it is not yet possible to experimentally measure this interaction in vivo. We therefore created a mechanical model of the follicle sinus complex to simulate whisker deformation within the follicle resulting from external whisker deflection. Our results provide the first estimate of whisker shape as it deforms in the follicle, during both passive touch and active whisking. In turn, these shape estimates allow us to predict how the whisker will deform against different types of mechanoreceptors at different locations within the follicle. In addition, we find that both intrinsic muscle contraction and an increase in blood pressure will improve the tactile sensitivity of the whisker system.
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Affiliation(s)
- Yifu Luo
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois, United States of America
| | - Chris S. Bresee
- Interdepartmental Neuroscience Program, Northwestern University, Evanston, Illinois, United States of America
| | - John W. Rudnicki
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois, United States of America
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois, United States of America
| | - Mitra J. Z. Hartmann
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois, United States of America
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States of America
- * E-mail:
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Abstract
Spiders show a broad range of motions in addition to walking and running with their eight coordinated legs taking them towards their resources and away from danger. The usefulness of all these motions depends on the ability to control and adjust them to changing environmental conditions. A remarkable wealth of sensory receptors guarantees the necessary guidance. Many facets of such guidance have emerged from neuroethological research on the wandering spider Cupiennius salei and its allies, although sensori-motor control was not the main focus of this work. The present review may serve as a springboard for future studies aiming towards a more complete understanding of the spider's control of its different types of motion. Among the topics shortly addressed are the involvement of lyriform slit sensilla in path integration, muscle reflexes in the walking legs, the monitoring of joint movement, the neuromuscular control of body raising, the generation of vibratory courtship signals, the sensory guidance of the jump to flying prey and the triggering of spiderling dispersal behavior. Finally, the interaction of sensors on different legs in oriented turning behavior and that of the sensory systems for substrate vibration and medium flow are addressed.
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Affiliation(s)
- Friedrich G Barth
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Althanstr.14, 1090, Vienna, Austria.
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Parvizi-Fard A, Amiri M, Kumar D, Iskarous MM, Thakor NV. A functional spiking neuronal network for tactile sensing pathway to process edge orientation. Sci Rep 2021; 11:1320. [PMID: 33446742 PMCID: PMC7809061 DOI: 10.1038/s41598-020-80132-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 12/17/2020] [Indexed: 01/24/2023] Open
Abstract
To obtain deeper insights into the tactile processing pathway from a population-level point of view, we have modeled three stages of the tactile pathway from the periphery to the cortex in response to indentation and scanned edge stimuli at different orientations. Three stages in the tactile pathway are, (1) the first-order neurons which innervate the cutaneous mechanoreceptors, (2) the cuneate nucleus in the midbrain and (3) the cortical neurons of the somatosensory area. In the proposed network, the first layer mimics the spiking patterns generated by the primary afferents. These afferents have complex skin receptive fields. In the second layer, the role of lateral inhibition on projection neurons in the cuneate nucleus is investigated. The third layer acts as a biomimetic decoder consisting of pyramidal and cortical interneurons that correspond to heterogeneous receptive fields with excitatory and inhibitory sub-regions on the skin. In this way, the activity of pyramidal neurons is tuned to the specific edge orientations. By modifying afferent receptive field size, it is observed that the larger receptive fields convey more information about edge orientation in the first spikes of cortical neurons when edge orientation stimuli move across the patch of skin. In addition, the proposed spiking neural model can detect edge orientation at any location on the simulated mechanoreceptor grid with high accuracy. The results of this research advance our knowledge about tactile information processing and can be employed in prosthetic and bio-robotic applications.
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Affiliation(s)
- Adel Parvizi-Fard
- Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mahmood Amiri
- Medical Technology Research Center, Institute of Health Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran.
| | - Deepesh Kumar
- SINAPSE Laboratory, National University of Singapore, Singapore, Singapore
| | - Mark M Iskarous
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Nitish V Thakor
- SINAPSE Laboratory, National University of Singapore, Singapore, Singapore.
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
- Department of Biomedical Engineering, National University of Singapore, Singapore, Singapore.
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Pacheco DA, Thiberge SY, Pnevmatikakis E, Murthy M. Auditory activity is diverse and widespread throughout the central brain of Drosophila. Nat Neurosci 2021; 24:93-104. [PMID: 33230320 PMCID: PMC7783861 DOI: 10.1038/s41593-020-00743-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 10/19/2020] [Indexed: 11/09/2022]
Abstract
Sensory pathways are typically studied by starting at receptor neurons and following postsynaptic neurons into the brain. However, this leads to a bias in analyses of activity toward the earliest layers of processing. Here, we present new methods for volumetric neural imaging with precise across-brain registration to characterize auditory activity throughout the entire central brain of Drosophila and make comparisons across trials, individuals and sexes. We discover that auditory activity is present in most central brain regions and in neurons responsive to other modalities. Auditory responses are temporally diverse, but the majority of activity is tuned to courtship song features. Auditory responses are stereotyped across trials and animals in early mechanosensory regions, becoming more variable at higher layers of the putative pathway, and this variability is largely independent of ongoing movements. This study highlights the power of using an unbiased, brain-wide approach for mapping the functional organization of sensory activity.
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Affiliation(s)
- Diego A Pacheco
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Stephan Y Thiberge
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
- Bezos Center for Neural Circuit Dynamics, Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Eftychios Pnevmatikakis
- Center for Computational Mathematics, Flatiron Institute, Simons Foundation, New York, NY, USA
| | - Mala Murthy
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.
- Bezos Center for Neural Circuit Dynamics, Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA.
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Iosip AL, Böhm J, Scherzer S, Al-Rasheid KAS, Dreyer I, Schultz J, Becker D, Kreuzer I, Hedrich R. The Venus flytrap trigger hair-specific potassium channel KDM1 can reestablish the K+ gradient required for hapto-electric signaling. PLoS Biol 2020; 18:e3000964. [PMID: 33296375 PMCID: PMC7725304 DOI: 10.1371/journal.pbio.3000964] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/05/2020] [Indexed: 12/18/2022] Open
Abstract
The carnivorous plant Dionaea muscipula harbors multicellular trigger hairs designed to sense mechanical stimuli upon contact with animal prey. At the base of the trigger hair, mechanosensation is transduced into an all-or-nothing action potential (AP) that spreads all over the trap, ultimately leading to trap closure and prey capture. To reveal the molecular basis for the unique functional repertoire of this mechanoresponsive plant structure, we determined the transcriptome of D. muscipula’s trigger hair. Among the genes that were found to be highly specific to the trigger hair, the Shaker-type channel KDM1 was electrophysiologically characterized as a hyperpolarization- and acid-activated K+-selective channel, thus allowing the reuptake of K+ ions into the trigger hair’s sensory cells during the hyperpolarization phase of the AP. During trap development, the increased electrical excitability of the trigger hair is associated with the transcriptional induction of KDM1. Conversely, when KDM1 is blocked by Cs+ in adult traps, the initiation of APs in response to trigger hair deflection is reduced, and trap closure is suppressed. KDM1 thus plays a dominant role in K+ homeostasis in the context of AP and turgor formation underlying the mechanosensation of trigger hair cells and thus D. muscipula’s hapto-electric signaling. Transcriptomic and electrophysiological studies of the carnivorous Venus flytrap reveal that potassium uptake via a trigger hair-specific potassium channel builds the basis for mechanosensation of likely prey and generation of an action potential that triggers closure of the trap.
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Affiliation(s)
- Anda L. Iosip
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
- Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
| | - Jennifer Böhm
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Sönke Scherzer
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | | | - Ingo Dreyer
- Center of Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, Talca, Chile
| | - Jörg Schultz
- Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
| | - Dirk Becker
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Ines Kreuzer
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
- * E-mail: (IK); (RH)
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
- * E-mail: (IK); (RH)
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Hampel S, Eichler K, Yamada D, Bock DD, Kamikouchi A, Seeds AM. Distinct subpopulations of mechanosensory chordotonal organ neurons elicit grooming of the fruit fly antennae. eLife 2020; 9:e59976. [PMID: 33103999 PMCID: PMC7652415 DOI: 10.7554/elife.59976] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/25/2020] [Indexed: 11/13/2022] Open
Abstract
Diverse mechanosensory neurons detect different mechanical forces that can impact animal behavior. Yet our understanding of the anatomical and physiological diversity of these neurons and the behaviors that they influence is limited. We previously discovered that grooming of the Drosophila melanogaster antennae is elicited by an antennal mechanosensory chordotonal organ, the Johnston's organ (JO) (Hampel et al., 2015). Here, we describe anatomically and physiologically distinct JO mechanosensory neuron subpopulations that each elicit antennal grooming. We show that the subpopulations project to different, discrete zones in the brain and differ in their responses to mechanical stimulation of the antennae. Although activation of each subpopulation elicits antennal grooming, distinct subpopulations also elicit the additional behaviors of wing flapping or backward locomotion. Our results provide a comprehensive description of the diversity of mechanosensory neurons in the JO, and reveal that distinct JO subpopulations can elicit both common and distinct behavioral responses.
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Affiliation(s)
- Stefanie Hampel
- Institute of Neurobiology, University of Puerto Rico Medical Sciences CampusSan JuanPuerto Rico
| | - Katharina Eichler
- Institute of Neurobiology, University of Puerto Rico Medical Sciences CampusSan JuanPuerto Rico
| | - Daichi Yamada
- Division of Biological Science, Graduate School of Science, Nagoya UniversityNagoyaJapan
| | - Davi D Bock
- Department of Neurological Sciences, Larner College of Medicine, University of VermontBurlingtonUnited States
| | - Azusa Kamikouchi
- Division of Biological Science, Graduate School of Science, Nagoya UniversityNagoyaJapan
| | - Andrew M Seeds
- Institute of Neurobiology, University of Puerto Rico Medical Sciences CampusSan JuanPuerto Rico
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Dannhäuser S, Lux TJ, Hu C, Selcho M, Chen JTC, Ehmann N, Sachidanandan D, Stopp S, Pauls D, Pawlak M, Langenhan T, Soba P, Rittner HL, Kittel RJ. Antinociceptive modulation by the adhesion GPCR CIRL promotes mechanosensory signal discrimination. eLife 2020; 9:e56738. [PMID: 32996461 PMCID: PMC7546736 DOI: 10.7554/elife.56738] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022] Open
Abstract
Adhesion-type GPCRs (aGPCRs) participate in a vast range of physiological processes. Their frequent association with mechanosensitive functions suggests that processing of mechanical stimuli may be a common feature of this receptor family. Previously, we reported that the Drosophila aGPCR CIRL sensitizes sensory responses to gentle touch and sound by amplifying signal transduction in low-threshold mechanoreceptors (Scholz et al., 2017). Here, we show that Cirl is also expressed in high-threshold mechanical nociceptors where it adjusts nocifensive behaviour under physiological and pathological conditions. Optogenetic in vivo experiments indicate that CIRL lowers cAMP levels in both mechanosensory submodalities. However, contrasting its role in touch-sensitive neurons, CIRL dampens the response of nociceptors to mechanical stimulation. Consistent with this finding, rat nociceptors display decreased Cirl1 expression during allodynia. Thus, cAMP-downregulation by CIRL exerts opposing effects on low-threshold mechanosensors and high-threshold nociceptors. This intriguing bipolar action facilitates the separation of mechanosensory signals carrying different physiological information.
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Affiliation(s)
- Sven Dannhäuser
- Department of Animal Physiology, Institute of Biology, Leipzig UniversityLeipzigGermany
- Carl-Ludwig-Institute for Physiology, Leipzig UniversityLeipzigGermany
| | - Thomas J Lux
- Center for Interdisciplinary Pain Medicine, Department of Anaesthesiology, University Hospital WürzburgWürzburgGermany
| | - Chun Hu
- Neuronal Patterning and Connectivity, Center for Molecular Neurobiology, University Medical Center Hamburg-EppendorfHamburgGermany
| | - Mareike Selcho
- Department of Animal Physiology, Institute of Biology, Leipzig UniversityLeipzigGermany
- Carl-Ludwig-Institute for Physiology, Leipzig UniversityLeipzigGermany
| | - Jeremy T-C Chen
- Center for Interdisciplinary Pain Medicine, Department of Anaesthesiology, University Hospital WürzburgWürzburgGermany
| | - Nadine Ehmann
- Department of Animal Physiology, Institute of Biology, Leipzig UniversityLeipzigGermany
- Carl-Ludwig-Institute for Physiology, Leipzig UniversityLeipzigGermany
| | - Divya Sachidanandan
- Department of Animal Physiology, Institute of Biology, Leipzig UniversityLeipzigGermany
- Carl-Ludwig-Institute for Physiology, Leipzig UniversityLeipzigGermany
| | - Sarah Stopp
- Department of Animal Physiology, Institute of Biology, Leipzig UniversityLeipzigGermany
- Carl-Ludwig-Institute for Physiology, Leipzig UniversityLeipzigGermany
| | - Dennis Pauls
- Department of Animal Physiology, Institute of Biology, Leipzig UniversityLeipzigGermany
- Carl-Ludwig-Institute for Physiology, Leipzig UniversityLeipzigGermany
| | - Matthias Pawlak
- Department of Neurophysiology, Institute of Physiology, University of WürzburgWürzburgGermany
| | - Tobias Langenhan
- Rudolf Schönheimer Institute of Biochemistry, Division of General Biochemistry, Medical Faculty, Leipzig UniversityLeipzigGermany
| | - Peter Soba
- Neuronal Patterning and Connectivity, Center for Molecular Neurobiology, University Medical Center Hamburg-EppendorfHamburgGermany
| | - Heike L Rittner
- Center for Interdisciplinary Pain Medicine, Department of Anaesthesiology, University Hospital WürzburgWürzburgGermany
| | - Robert J Kittel
- Department of Animal Physiology, Institute of Biology, Leipzig UniversityLeipzigGermany
- Carl-Ludwig-Institute for Physiology, Leipzig UniversityLeipzigGermany
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Okubo TS, Patella P, D'Alessandro I, Wilson RI. A Neural Network for Wind-Guided Compass Navigation. Neuron 2020; 107:924-940.e18. [PMID: 32681825 PMCID: PMC7507644 DOI: 10.1016/j.neuron.2020.06.022] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 05/13/2020] [Accepted: 06/22/2020] [Indexed: 11/27/2022]
Abstract
Spatial maps in the brain are most accurate when they are linked to external sensory cues. Here, we show that the compass in the Drosophila brain is linked to the direction of the wind. Shifting the wind rightward rotates the compass as if the fly were turning leftward, and vice versa. We describe the mechanisms of several computations that integrate wind information into the compass. First, an intensity-invariant representation of wind direction is computed by comparing left-right mechanosensory signals. Then, signals are reformatted to reduce the coding biases inherent in peripheral mechanics, and wind cues are brought into the same circular coordinate system that represents visual cues and self-motion signals. Because the compass incorporates both mechanosensory and visual cues, it should enable navigation under conditions where no single cue is consistently reliable. These results show how local sensory signals can be transformed into a global, multimodal, abstract representation of space.
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Affiliation(s)
- Tatsuo S Okubo
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Paola Patella
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | | | - Rachel I Wilson
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
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Acton D, Ren X, Di Costanzo S, Dalet A, Bourane S, Bertocchi I, Eva C, Goulding M. Spinal Neuropeptide Y1 Receptor-Expressing Neurons Form an Essential Excitatory Pathway for Mechanical Itch. Cell Rep 2020; 28:625-639.e6. [PMID: 31315043 PMCID: PMC6709688 DOI: 10.1016/j.celrep.2019.06.033] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 05/20/2019] [Accepted: 06/06/2019] [Indexed: 01/08/2023] Open
Abstract
Acute itch can be generated by either chemical or mechanical stimuli,
which activate separate pathways in the periphery and spinal cord. While
substantial progress has been made in mapping the transmission pathway for
chemical itch, the central pathway for mechanical itch remains obscure. Using
complementary genetic and pharmacological manipulations, we show that excitatory
neurons marked by the expression of the neuropeptide Y1 receptor
(Y1Cre neurons) form an essential pathway in the dorsal spinal
cord for the transmission of mechanical but not chemical itch. Ablating or
silencing the Y1Cre neurons abrogates mechanical itch, while
chemogenetic activation induces scratching. Moreover, using Y1
conditional knockout mice, we demonstrate that endogenous neuropeptide Y (NPY)
acts via dorsal horn Y1-expressing neurons to suppress light punctate touch and
mechanical itch stimuli. NPY-Y1 signaling thus regulates the transmission of
innocuous tactile information by establishing biologically relevant thresholds
for touch discrimination and mechanical itch reflexes. Acton et al. identify the excitatory neurons in the dorsal spinal cord
that drive mechanical itch. These cells mediate responses to light punctate
touch and are inhibited by neuropeptide Y (NPY)::Cre interneurons. Light touch
sensitivity and mechanical itch responses are gated by NPY signaling mediated by
Y1-expressing neurons in the dorsal horn.
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Affiliation(s)
- David Acton
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Xiangyu Ren
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Biology Graduate Program, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Stefania Di Costanzo
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Biology Graduate Program, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Antoine Dalet
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Steeve Bourane
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Ilaria Bertocchi
- Department of Neuroscience, University of Torino, Neuroscience Institute of the Cavalieri-Ottolenghi Foundation, Regione Gonzole 1, 10043 Orbassano, Italy
| | - Carola Eva
- Department of Neuroscience, University of Torino, Neuroscience Institute of the Cavalieri-Ottolenghi Foundation, Regione Gonzole 1, 10043 Orbassano, Italy
| | - Martyn Goulding
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Tan H, Tao Q, Pande I, Majumdar S, Liu F, Zhou Y, Persson POÅ, Rosen J, van Dijken S. Tactile sensory coding and learning with bio-inspired optoelectronic spiking afferent nerves. Nat Commun 2020; 11:1369. [PMID: 32170075 PMCID: PMC7070032 DOI: 10.1038/s41467-020-15105-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/11/2020] [Indexed: 01/28/2023] Open
Abstract
The integration and cooperation of mechanoreceptors, neurons and synapses in somatosensory systems enable humans to efficiently sense and process tactile information. Inspired by biological somatosensory systems, we report an optoelectronic spiking afferent nerve with neural coding, perceptual learning and memorizing capabilities to mimic tactile sensing and processing. Our system senses pressure by MXene-based sensors, converts pressure information to light pulses by coupling light-emitting diodes to analog-to-digital circuits, then integrates light pulses using a synaptic photomemristor. With neural coding, our spiking nerve is capable of not only detecting simultaneous pressure inputs, but also recognizing Morse code, braille, and object movement. Furthermore, with dimensionality-reduced feature extraction and learning, our system can recognize and memorize handwritten alphabets and words, providing a promising approach towards e-skin, neurorobotics and human-machine interaction technologies.
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Affiliation(s)
- Hongwei Tan
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076, Aalto, Finland.
| | - Quanzheng Tao
- Thin Film Physics, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Linköping, Sweden
| | - Ishan Pande
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076, Aalto, Finland
| | - Sayani Majumdar
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076, Aalto, Finland
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Fu Liu
- Department of Electronics and Nanoengineering, Aalto University, P.O. Box 15500, FI-00076, Aalto, Finland
| | - Yifan Zhou
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076, Aalto, Finland
| | - Per O Å Persson
- Thin Film Physics, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Linköping, Sweden
| | - Johanna Rosen
- Thin Film Physics, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Linköping, Sweden
| | - Sebastiaan van Dijken
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076, Aalto, Finland.
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Furuta T, Bush NE, Yang AET, Ebara S, Miyazaki N, Murata K, Hirai D, Shibata KI, Hartmann MJZ. The Cellular and Mechanical Basis for Response Characteristics of Identified Primary Afferents in the Rat Vibrissal System. Curr Biol 2020; 30:815-826.e5. [PMID: 32004452 PMCID: PMC10623402 DOI: 10.1016/j.cub.2019.12.068] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 07/09/2019] [Accepted: 12/20/2019] [Indexed: 01/06/2023]
Abstract
Compared to our understanding of the response properties of receptors in the auditory and visual systems, we have only a limited understanding of the mechanoreceptor responses that underlie tactile sensation. Here, we exploit the stereotyped morphology of the rat vibrissal (whisker) array to investigate coding and transduction properties of identified primary tactile afferents. We performed in vivo intra-axonal recording and labeling experiments to quantify response characteristics of four different types of identified mechanoreceptors in the vibrissal follicle: ring-sinus Merkel; lanceolate; clublike; and rete-ridge collar Merkel. Of these types, only ring-sinus Merkel endings exhibited slowly adapting properties. A weak inverse relationship between response magnitude and onset response latency was found across all types. All afferents exhibited strong "angular tuning," i.e., their response magnitude and latency depended on the whisker's deflection angle. Although previous studies suggested that this tuning should be aligned with the angular location of the mechanoreceptor in the follicle, such alignment was observed only for Merkel afferents; angular tuning of the other afferent types showed no clear alignment with mechanoreceptor location. Biomechanical modeling suggested that this tuning difference might be explained by mechanoreceptors' differential sensitivity to the force directed along the whisker length. Electron microscopic investigations of Merkel endings and lanceolate endings at the level of the ring sinus revealed unique anatomical features that may promote these differential sensitivities. The present study systematically integrates biomechanical principles with the anatomical and morphological characterization of primary afferent endings to describe the physical and cellular processing that shapes the neural representation of touch.
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Affiliation(s)
- Takahiro Furuta
- Department of Oral Anatomy and Neurobiology, Graduate School of Dentistry, Osaka University, 1-8 Yamada-Oka, Suita, Osaka 565-0871, Japan; Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Nicholas E Bush
- Interdepartmental Neuroscience Program, Northwestern University, Evanston, IL 60208, USA
| | - Anne En-Tzu Yang
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Satomi Ebara
- Department of Anatomy, Meiji University of Integrative Medicine, Kyoto 629-0392, Japan
| | - Naoyuki Miyazaki
- National Institute for Physiological Sciences, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Kazuyoshi Murata
- National Institute for Physiological Sciences, 38 Nishigonaka Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Daichi Hirai
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Ken-Ichi Shibata
- Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Mitra J Z Hartmann
- Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA; Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
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Urrutia A, García-Angulo VA, Fuentes A, Caneo M, Legüe M, Urquiza S, Delgado SE, Ugalde J, Burdisso P, Calixto A. Bacterially produced metabolites protect C. elegans neurons from degeneration. PLoS Biol 2020; 18:e3000638. [PMID: 32208418 PMCID: PMC7092960 DOI: 10.1371/journal.pbio.3000638] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 02/18/2020] [Indexed: 12/20/2022] Open
Abstract
Caenorhabditis elegans and its cognate bacterial diet comprise a reliable, widespread model to study diet and microbiota effects on host physiology. Nonetheless, how diet influences the rate at which neurons die remains largely unknown. A number of models have been used in C. elegans as surrogates for neurodegeneration. One of these is a C. elegans strain expressing a neurotoxic allele of the mechanosensory abnormality protein 4 (MEC-4d) degenerin/epithelial Na+ (DEG/ENaC) channel, which causes the progressive degeneration of the touch receptor neurons (TRNs). Using this model, our study evaluated the effect of various dietary bacteria on neurodegeneration dynamics. Although degeneration of TRNs was steady and completed at adulthood in the strain routinely used for C. elegans maintenance (Escherichia coli OP50), it was significantly reduced in environmental and other laboratory bacterial strains. Strikingly, neuroprotection reached more than 40% in the E. coli HT115 strain. HT115 protection was long lasting well into old age of animals and was not restricted to the TRNs. Small amounts of HT115 on OP50 bacteria as well as UV-killed HT115 were still sufficient to produce neuroprotection. Early growth of worms in HT115 protected neurons from degeneration during later growth in OP50. HT115 diet promoted the nuclear translocation of DAF-16 (ortholog of the FOXO family of transcription factors), a phenomenon previously reported to underlie neuroprotection caused by down-regulation of the insulin receptor in this system. Moreover, a daf-16 loss-of-function mutation abolishes HT115-driven neuroprotection. Comparative genomics, transcriptomics, and metabolomics approaches pinpointed the neurotransmitter γ-aminobutyric acid (GABA) and lactate as metabolites differentially produced between E. coli HT115 and OP50. HT115 mutant lacking glutamate decarboxylase enzyme genes (gad), which catalyze the conversion of GABA from glutamate, lost the ability to produce GABA and also to stop neurodegeneration. Moreover, in situ GABA supplementation or heterologous expression of glutamate decarboxylase in E. coli OP50 conferred neuroprotective activity to this strain. Specific C. elegans GABA transporters and receptors were required for full HT115-mediated neuroprotection. Additionally, lactate supplementation also increased anterior ventral microtubule (AVM) neuron survival in OP50. Together, these results demonstrate that bacterially produced GABA and other metabolites exert an effect of neuroprotection in the host, highlighting the role of neuroactive compounds of the diet in nervous system homeostasis.
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Affiliation(s)
- Arles Urrutia
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Víctor A. García-Angulo
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile, Chile
| | - Andrés Fuentes
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Mauricio Caneo
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Marcela Legüe
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Sebastián Urquiza
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Scarlett E. Delgado
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Juan Ugalde
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
| | - Paula Burdisso
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Plataforma Argentina de Biología Estructural y Metabolómica (PLABEM), Rosario, Santa Fe, Argentina
| | - Andrea Calixto
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
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Hu C, Kanellopoulos AK, Richter M, Petersen M, Konietzny A, Tenedini FM, Hoyer N, Cheng L, Poon CLC, Harvey KF, Windhorst S, Parrish JZ, Mikhaylova M, Bagni C, Calderon de Anda F, Soba P. Conserved Tao Kinase Activity Regulates Dendritic Arborization, Cytoskeletal Dynamics, and Sensory Function in Drosophila. J Neurosci 2020; 40:1819-1833. [PMID: 31964717 PMCID: PMC7046460 DOI: 10.1523/jneurosci.1846-19.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 01/13/2020] [Accepted: 01/16/2020] [Indexed: 12/11/2022] Open
Abstract
Dendritic arborization is highly regulated and requires tight control of dendritic growth, branching, cytoskeletal dynamics, and ion channel expression to ensure proper function. Abnormal dendritic development can result in altered network connectivity, which has been linked to neurodevelopmental disorders, including autism spectrum disorders (ASDs). How neuronal growth control programs tune dendritic arborization to ensure function is still not fully understood. Using Drosophila dendritic arborization (da) neurons as a model, we identified the conserved Ste20-like kinase Tao as a negative regulator of dendritic arborization. We show that Tao kinase activity regulates cytoskeletal dynamics and sensory channel localization required for proper sensory function in both male and female flies. We further provide evidence for functional conservation of Tao kinase, showing that its ASD-linked human ortholog, Tao kinase 2 (Taok2), could replace Drosophila Tao and rescue dendritic branching, dynamic microtubule alterations, and behavioral defects. However, several ASD-linked Taok2 variants displayed impaired rescue activity, suggesting that Tao/Taok2 mutations can disrupt sensory neuron development and function. Consistently, we show that Tao kinase activity is required in developing and as well as adult stages for maintaining normal dendritic arborization and sensory function to regulate escape and social behavior. Our data suggest an important role for Tao kinase signaling in cytoskeletal organization to maintain proper dendritic arborization and sensory function, providing a strong link between developmental sensory aberrations and behavioral abnormalities relevant for Taok2-dependent ASDs.SIGNIFICANCE STATEMENT Autism spectrum disorders (ASDs) are linked to abnormal dendritic arbors. However, the mechanisms of how dendritic arbors develop to promote functional and proper behavior are unclear. We identified Drosophila Tao kinase, the ortholog of the ASD risk gene Taok2, as a regulator of dendritic arborization in sensory neurons. We show that Tao kinase regulates cytoskeletal dynamics, controls sensory ion channel localization, and is required to maintain somatosensory function in vivo Interestingly, ASD-linked human Taok2 mutations rendered it nonfunctional, whereas its WT form could restore neuronal morphology and function in Drosophila lacking endogenous Tao. Our findings provide evidence for a conserved role of Tao kinase in dendritic development and function of sensory neurons, suggesting that aberrant sensory function might be a common feature of ASDs.
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Affiliation(s)
- Chun Hu
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | | | - Melanie Richter
- Neuronal Development Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Meike Petersen
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Anja Konietzny
- Neuronal Protein Transport Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Federico M Tenedini
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Nina Hoyer
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Lin Cheng
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Carole L C Poon
- Peter MacCallum Cancer Centre, Melbourne, 3000 Victoria, Australia
| | - Kieran F Harvey
- Peter MacCallum Cancer Centre, Melbourne, 3000 Victoria, Australia
- Department of Anatomy and Developmental Biology, and Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Sabine Windhorst
- Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, 98195 Washington, and
| | - Marina Mikhaylova
- Neuronal Protein Transport Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, 1005 Lausanne, Switzerland
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Froylan Calderon de Anda
- Neuronal Development Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Peter Soba
- Neuronal Patterning and Connectivity Laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany,
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47
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Abstract
Mechanosensation is central to a wide range of functions, including tactile and pain perception, hearing, proprioception, and control of blood pressure, but identifying the molecules underlying mechanotransduction has proved challenging. In Caenorhabditis elegans, the avoidance response to gentle body touch is mediated by six touch receptor neurons (TRNs), and is dependent on MEC-4, a DEG/ENaC channel. We show that hemichannels containing the innexin protein UNC-7 are also essential for gentle touch in the TRNs, as well as harsh touch in both the TRNs and the PVD nociceptors. UNC-7 and MEC-4 do not colocalize, suggesting that their roles in mechanosensory transduction are independent. Heterologous expression of unc-7 in touch-insensitive chemosensory neurons confers ectopic touch sensitivity, indicating a specific role for UNC-7 hemichannels in mechanosensation. The unc-7 touch defect can be rescued by the homologous mouse gene Panx1 gene, thus, innexin/pannexin proteins may play broadly conserved roles in neuronal mechanotransduction.
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Affiliation(s)
- Denise S Walker
- MRC Laboratory of Molecular Biology, Cambridge Biomedical CampusCambridgeUnited Kingdom
| | - William R Schafer
- MRC Laboratory of Molecular Biology, Cambridge Biomedical CampusCambridgeUnited Kingdom
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48
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Blagburn JM. A new method of recording from the giant fiber of Drosophila melanogaster shows that the strength of its auditory inputs remains constant with age. PLoS One 2020; 15:e0224057. [PMID: 31910219 PMCID: PMC6946141 DOI: 10.1371/journal.pone.0224057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 12/13/2019] [Indexed: 11/19/2022] Open
Abstract
There have been relatively few studies of how central synapses age in adult Drosophila melanogaster. In this study we investigate the aging of the synaptic inputs to the Giant Fiber (GF) from auditory Johnston's Organ neurons (JONs). In previously published experiments an indirect assay of this synaptic connection was used; here we describe a new, more direct assay, which allows reliable detection of the GF action potential in the neck connective, and long term recording of its responses to sound. Genetic poisoning using diphtheria toxin expressed in the GF with R68A06-GAL4 was used to confirm that this signal indeed arose from the GF and not from other descending neurons. As before, the sound-evoked action potentials (SEPs) in the antennal nerve were recorded via an electrode inserted at the base of the antenna. It was noted that an action potential in the GF elicited an antennal twitch, which in turn evoked a mechanosensory response from the JONs in the absence of sound. We then used these extracellular recording techniques in males and female of different ages to quantify the response of the JONs to a brief sound impulse, and also to measure the strength of the connection between the JONs and the GF. At no age was there any significant difference between males and females, for any of the parameters measured. The sensitivity of the JONs to a sound impulse approximately doubled between 1 d and 10 d after eclosion, which corresponds to the period when most mating is taking place. Subsequently JON sensitivity decreased with age, being approximately half as sensitive at 20 d and one-third as sensitive at 50 d, as compared to 10 d. However, the strength of the connection between the auditory input and the GF itself remained unchanged with age, although it did show some variability that could mask any small changes.
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Affiliation(s)
- Jonathan M. Blagburn
- Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, PR, United States of America
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49
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Abstract
C-tactile afferents form a distinct channel that encodes pleasant tactile stimulation. Prevailing views indicate they project, as with other unmyelinated afferents, in lamina I-spinothalamic pathways. However, we found that spinothalamic ablation in humans, whilst profoundly impairing pain, temperature and itch, had no effect on pleasant touch perception. Only discriminative touch deficits were seen. These findings preclude privileged C-tactile-lamina I-spinothalamic projections and imply integrated hedonic and discriminative spinal processing from the body.
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Affiliation(s)
- Andrew G Marshall
- Institute of Aging and Chronic DiseaseUniversity of LiverpoolLiverpoolUnited Kingdom
- School of Natural Sciences and PsychologyLiverpool John Moores UniversityLiverpoolUnited Kingdom
- Department of Pain MedicineWalton Centre NHS Foundation TrustLiverpoolUnited Kingdom
| | - Manohar L Sharma
- Department of Pain MedicineWalton Centre NHS Foundation TrustLiverpoolUnited Kingdom
| | - Kate Marley
- Specialist Palliative Care TeamUniversity Hospital AintreeLiverpoolUnited Kingdom
| | - Hakan Olausson
- Specialist Palliative Care TeamUniversity Hospital AintreeLiverpoolUnited Kingdom
- Center for Social and Affective NeuroscienceLinköping UniversityLinköpingSweden
- Department of Clinical NeurophysiologyLinköping University HospitalLinköpingSweden
| | - Francis P McGlone
- School of Natural Sciences and PsychologyLiverpool John Moores UniversityLiverpoolUnited Kingdom
- Institute of Psychology, Health and SocietyUniversity of LiverpoolLiverpoolUnited Kingdom
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50
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Koll R, Martorell Ribera J, Brunner RM, Rebl A, Goldammer T. Gene Profiling in the Adipose Fin of Salmonid Fishes Supports its Function as a Flow Sensor. Genes (Basel) 2019; 11:genes11010021. [PMID: 31878086 PMCID: PMC7016824 DOI: 10.3390/genes11010021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/13/2019] [Accepted: 12/17/2019] [Indexed: 11/16/2022] Open
Abstract
In stock enhancement and sea-ranching procedures, the adipose fin of hundreds of millions of salmonids is removed for marking purposes annually. However, recent studies proved the significance of the adipose fin as a flow sensor and attraction feature. In the present study, we profiled the specific expression of 20 neuron- and glial cell-marker genes in the adipose fin and seven other tissues (including dorsal and pectoral fin, brain, skin, muscle, head kidney, and liver) of the salmonid species rainbow trout Oncorhynchus mykiss and maraena whitefish Coregonus maraena. Moreover, we measured the transcript abundance of genes coding for 15 mechanoreceptive channel proteins from a variety of mechanoreceptors known in vertebrates. The overall expression patterns indicate the presence of the entire repertoire of neurons, glial cells and receptor proteins on the RNA level. This quantification suggests that the adipose fin contains considerable amounts of small nerve fibers with unmyelinated or slightly myelinated axons and most likely mechanoreceptive potential. The findings are consistent for both rainbow trout and maraena whitefish and support a previous hypothesis about the innervation and potential flow sensory function of the adipose fin. Moreover, our data suggest that the resection of the adipose fin has a stronger impact on the welfare of salmonid fish than previously assumed.
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Affiliation(s)
- Raphael Koll
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
| | - Joan Martorell Ribera
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
| | - Ronald M. Brunner
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
| | - Alexander Rebl
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
| | - Tom Goldammer
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
- Professorship for Molecular Biology and Fish Genetics, Faculty of Agriculture and Environmental Sciences, University of Rostock, 18055 Rostock, Germany
- Correspondence: ; Tel.: +49-38208-68-708
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