1
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Sundaram MV, Pujol N. The Caenorhabditis elegans cuticle and precuticle: a model for studying dynamic apical extracellular matrices in vivo. Genetics 2024; 227:iyae072. [PMID: 38995735 PMCID: PMC11304992 DOI: 10.1093/genetics/iyae072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/25/2024] [Indexed: 07/14/2024] Open
Abstract
Apical extracellular matrices (aECMs) coat the exposed surfaces of animal bodies to shape tissues, influence social interactions, and protect against pathogens and other environmental challenges. In the nematode Caenorhabditis elegans, collagenous cuticle and zona pellucida protein-rich precuticle aECMs alternately coat external epithelia across the molt cycle and play many important roles in the worm's development, behavior, and physiology. Both these types of aECMs contain many matrix proteins related to those in vertebrates, as well as some that are nematode-specific. Extensive differences observed among tissues and life stages demonstrate that aECMs are a major feature of epithelial cell identity. In addition to forming discrete layers, some cuticle components assemble into complex substructures such as ridges, furrows, and nanoscale pillars. The epidermis and cuticle are mechanically linked, allowing the epidermis to sense cuticle damage and induce protective innate immune and stress responses. The C. elegans model, with its optical transparency, facilitates the study of aECM cell biology and structure/function relationships and all the myriad ways by which aECM can influence an organism.
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Affiliation(s)
- Meera V Sundaram
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Nathalie Pujol
- Aix Marseille University, INSERM, CNRS, CIML, Turing Centre for Living Systems, 13009 Marseille, France
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2
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Das A, Franco JA, Mulcahy B, Wang L, Chapman D, Jaisinghani C, Pruitt BL, Zhen M, Goodman MB. C. elegans touch receptor neurons direct mechanosensory complex organization via repurposing conserved basal lamina proteins. Curr Biol 2024; 34:3133-3151.e10. [PMID: 38964319 PMCID: PMC11283674 DOI: 10.1016/j.cub.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 05/13/2024] [Accepted: 06/06/2024] [Indexed: 07/06/2024]
Abstract
The sense of touch is conferred by the conjoint function of somatosensory neurons and skin cells. These cells meet across a gap filled by a basal lamina, an ancient structure found in metazoans. Using Caenorhabditis elegans, we investigate the composition and ultrastructure of the extracellular matrix at the epidermis and touch receptor neuron (TRN) interface. We show that membrane-matrix complexes containing laminin, nidogen, and the MEC-4 mechano-electrical transduction channel reside at this interface and are central to proper touch sensation. Interestingly, the dimensions and spacing of these complexes correspond with the discontinuous beam-like extracellular matrix structures observed in serial-section transmission electron micrographs. These complexes fail to coalesce in touch-insensitive extracellular matrix mutants and in dissociated neurons. Loss of nidogen reduces the density of mechanoreceptor complexes and the amplitude of the touch-evoked currents they carry. Thus, neuron-epithelium cell interfaces are instrumental in mechanosensory complex assembly and function. Unlike the basal lamina ensheathing the pharynx and body wall muscle, nidogen recruitment to the puncta along TRNs is not dependent upon laminin binding. MEC-4, but not laminin or nidogen, is destabilized by point mutations in the C-terminal Kunitz domain of the extracellular matrix component, MEC-1. These findings imply that somatosensory neurons secrete proteins that actively repurpose the basal lamina to generate special-purpose mechanosensory complexes responsible for vibrotactile sensing.
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Affiliation(s)
- Alakananda Das
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA
| | - Joy A Franco
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Ben Mulcahy
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Lingxin Wang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA
| | - Dail Chapman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA
| | - Chandni Jaisinghani
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA
| | - Beth L Pruitt
- Departments of Mechanical Engineering and Molecular, Cellular, & Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Miriam B Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA.
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3
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Essmann CL, Elmi M, Rekatsinas C, Chrysochoidis N, Shaw M, Pawar V, Srinivasan MA, Vavourakis V. The influence of internal pressure and neuromuscular agents on C. elegans biomechanics: an empirical and multi-compartmental in silico modelling study. Front Bioeng Biotechnol 2024; 12:1335788. [PMID: 38558792 PMCID: PMC10978802 DOI: 10.3389/fbioe.2024.1335788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 02/20/2024] [Indexed: 04/04/2024] Open
Abstract
The function of a specific tissue and its biomechanics are interdependent, with pathologies or ageing often being intertwined with structural decline. The biomechanics of Caenorhabditis elegans, a model organism widely used in pharmacological and ageing research, has been established as biomarker for healthy ageing. However, the properties of the constituent tissues, and their contribution to the overall mechanical characteristics of the organism, remain relatively unknown. In this study we investigated the biomechanics of healthy C. elegans cuticle, muscle tissue, and pseudocoelom using a combination of indentation experiments and in silico modelling. We performed stiffness measurements using an atomic force microscope. To approximate the nematode's cylindrical body we used a novel three-compartment nonlinear finite element model, enabling us to analyse of how changes in the elasticity of individual compartments affect the bulk stiffness. We then fine-tuned the parameters of the model to match the simulation force-indentation output to the experimental data. To test the finite element model, we modified distinct compartments experimentally. Our in silico results, in agreement with previous studies, suggest that hyperosmotic shock reduces stiffness by decreasing the internal pressure. Unexpectedly, treatment with the neuromuscular agent aldicarb, traditionally associated with muscle contraction, reduced stiffness by decreasing the internal pressure. Furthermore, our finite element model can offer insights into how drugs, mutations, or processes such as ageing target individual tissues.
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Affiliation(s)
- Clara L. Essmann
- Department of Bioinformatics and Molecular Genetics, University of Freiburg, Freiburg, Baden-Wuerttemberg, Germany
- Department of Computer Science, University College London, London, United Kingdom
| | - Muna Elmi
- Department of Computer Science, University College London, London, United Kingdom
| | | | - Nikolaos Chrysochoidis
- Department of Mechanical Engineering and Aeronautics, University of Patras, Patras, Greece
| | - Michael Shaw
- Department of Computer Science, University College London, London, United Kingdom
- National Physical Laboratory, Teddington, United Kingdom
| | - Vijay Pawar
- Department of Computer Science, University College London, London, United Kingdom
| | | | - Vasileios Vavourakis
- Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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4
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Bennett-Kennett R, Pace J, Lynch B, Domanov Y, Luengo GS, Potter A, Dauskardt RH. Sensory neuron activation from topical treatments modulates the sensorial perception of human skin. PNAS NEXUS 2023; 2:pgad292. [PMID: 37771342 PMCID: PMC10531117 DOI: 10.1093/pnasnexus/pgad292] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 08/22/2023] [Indexed: 09/30/2023]
Abstract
Neural signaling of skin sensory perception from topical treatments is often reported in subjective terms such as a sensation of skin "tightness" after using a cleanser or "softness" after applying a moisturizer. However, the mechanism whereby cutaneous mechanoreceptors and corresponding sensory neurons are activated giving rise to these perceptions has not been established. Here, we provide a quantitative approach that couples in vitro biomechanical testing and detailed computational neural stimulation modeling along with a comprehensive in vivo self-assessment survey to demonstrate how cutaneous biomechanical changes in response to treatments are involved in the sensorial perception of the human skin. Strong correlations are identified between reported perception up to 12 hours post treatment and changes in the computed neural stimulation from mechanoreceptors residing deep under the skin surface. The study reveals a quantitative framework for understanding the biomechanical neural activation mechanism and the subjective perception by individuals.
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Affiliation(s)
- Ross Bennett-Kennett
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Joseph Pace
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Barbara Lynch
- L’Oréal Research and Innovation, Aulnay-sous-Bois 93601, France
| | - Yegor Domanov
- L’Oréal Research and Innovation, Aulnay-sous-Bois 93601, France
| | | | - Anne Potter
- L’Oréal Research and Innovation, Aulnay-sous-Bois 93601, France
| | - Reinhold H Dauskardt
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
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5
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Goodman MB, Haswell ES, Vásquez V. Mechanosensitive membrane proteins: Usual and unusual suspects in mediating mechanotransduction. J Gen Physiol 2023; 155:e202213248. [PMID: 36696153 PMCID: PMC9930137 DOI: 10.1085/jgp.202213248] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
This Viewpoint, which accompanies a Special Issue focusing on membrane mechanosensors, discusses unifying and unique features of both established and emerging mechanosensitive (MS) membrane proteins, their distribution across protein families and phyla, and current and future challenges in the study of these important proteins and their partners. MS membrane proteins are essential for tissue development, cellular motion, osmotic homeostasis, and sensing external and self-generated mechanical cues like those responsible for touch and proprioception. Though researchers' attention and this Viewpoint focus on a few famous ion channels that are considered the usual suspects as MS mechanosensors, we also discuss some of the more unusual suspects, such as G-protein coupled receptors. As the field continues to grow, so too will the list of proteins suspected to function as mechanosensors and the diversity of known MS membrane proteins.
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Affiliation(s)
- Miriam B. Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Elizabeth S. Haswell
- Department of Biology, Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Valeria Vásquez
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
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6
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Mechanosensitive body–brain interactions in Caenorhabditis elegans. Curr Opin Neurobiol 2022; 75:102574. [DOI: 10.1016/j.conb.2022.102574] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 03/30/2022] [Accepted: 05/06/2022] [Indexed: 12/13/2022]
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7
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Goodman MB, Savage-Dunn C. Reciprocal interactions between transforming growth factor beta signaling and collagens: Insights from Caenorhabditis elegans. Dev Dyn 2022; 251:47-60. [PMID: 34537996 PMCID: PMC8982858 DOI: 10.1002/dvdy.423] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 01/03/2023] Open
Abstract
Studies in genetically tractable organisms such as the nematode Caenorhabditis elegans have led to pioneering insights into conserved developmental regulatory mechanisms. For example, Smad signal transducers for the transforming growth factor beta (TGF-β) superfamily were first identified in C. elegans and in the fruit fly Drosophila. Recent studies of TGF-β signaling and the extracellular matrix (ECM) in C. elegans have forged unexpected links between signaling and the ECM, yielding novel insights into the reciprocal interactions that occur across tissues and spatial scales, and potentially providing new opportunities for the study of biomechanical regulation of gene expression.
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Affiliation(s)
- Miriam B. Goodman
- Department of Molecular and Cellular Physiology, Stanford University, CA 94304
| | - Cathy Savage-Dunn
- Department of Biology, Queens College at the City University of New York, 11367,Correspondence to: >
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8
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Iskander A, Bilgi C, Naftalovich R, Hacihaliloglu I, Berkman T, Naftalovich D, Pahlevan N. The Rheology of the Carotid Sinus: A Path Toward Bioinspired Intervention. Front Bioeng Biotechnol 2021; 9:678048. [PMID: 34178967 PMCID: PMC8222608 DOI: 10.3389/fbioe.2021.678048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/05/2021] [Indexed: 11/30/2022] Open
Abstract
The association between blood viscosity and pathological conditions involving a number of organ systems is well known. However, how the body measures and maintains appropriate blood viscosity is not well-described. The literature endorsing the function of the carotid sinus as a site of baroreception can be traced back to some of the earliest descriptions of digital pressure on the neck producing a drop in blood delivery to the brain. For the last 30 years, improved computational fluid dynamic (CFD) simulations of blood flow within the carotid sinus have demonstrated a more nuanced understanding of the changes in the region as it relates to changes in conventional metrics of cardiovascular function, including blood pressure. We suggest that the unique flow patterns within the carotid sinus may make it an ideal site to transduce flow data that can, in turn, enable real-time measurement of blood viscosity. The recent characterization of the PIEZO receptor family in the sinus vessel wall may provide a biological basis for this characterization. When coupled with other biomarkers of cardiovascular performance and descriptions of the blood rheology unique to the sinus region, this represents a novel venue for bioinspired design that may enable end-users to manipulate and optimize blood flow.
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Affiliation(s)
- Andrew Iskander
- Department of Anesthesiology, Westchester Medical Center, New York Medical College, Valhalla, NY, United States
| | - Coskun Bilgi
- Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA, United States
| | - Rotem Naftalovich
- Department of Anesthesiology, New Jersey Medical School, University Hospital, Rutgers University, Newark, NJ, United States.,Medical Corps of the U.S. Army, U.S. Army Medical Department, Fort Sam Houston, San Antonio, TX, United States
| | - Ilker Hacihaliloglu
- Department of Biomedical Engineering, Rutgers School of Engineering, Rutgers University, Piscataway, NJ, United States
| | - Tolga Berkman
- Department of Anesthesiology, New Jersey Medical School, University Hospital, Rutgers University, Newark, NJ, United States
| | - Daniel Naftalovich
- Department of Computational and Mathematical Sciences, California Institute of Technology, Pasadena, CA, United States.,Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Niema Pahlevan
- Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA, United States.,Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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9
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Läubli NF, Burri JT, Marquard J, Vogler H, Mosca G, Vertti-Quintero N, Shamsudhin N, deMello A, Grossniklaus U, Ahmed D, Nelson BJ. 3D mechanical characterization of single cells and small organisms using acoustic manipulation and force microscopy. Nat Commun 2021; 12:2583. [PMID: 33972516 PMCID: PMC8110787 DOI: 10.1038/s41467-021-22718-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Quantitative micromechanical characterization of single cells and multicellular tissues or organisms is of fundamental importance to the study of cellular growth, morphogenesis, and cell-cell interactions. However, due to limited manipulation capabilities at the microscale, systems used for mechanical characterizations struggle to provide complete three-dimensional coverage of individual specimens. Here, we combine an acoustically driven manipulation device with a micro-force sensor to freely rotate biological samples and quantify mechanical properties at multiple regions of interest within a specimen. The versatility of this tool is demonstrated through the analysis of single Lilium longiflorum pollen grains, in combination with numerical simulations, and individual Caenorhabditis elegans nematodes. It reveals local variations in apparent stiffness for single specimens, providing previously inaccessible information and datasets on mechanical properties that serve as the basis for biophysical modelling and allow deeper insights into the biomechanics of these living systems.
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Affiliation(s)
- Nino F Läubli
- Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland
| | - Jan T Burri
- Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland
| | | | - Hannes Vogler
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Gabriella Mosca
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Nadia Vertti-Quintero
- Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, Zürich, Switzerland
| | | | - Andrew deMello
- Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, Zürich, Switzerland
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland
| | - Daniel Ahmed
- Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland.
- Acoustic Robotics Systems Lab, ETH Zurich, Rüschlikon, Switzerland.
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10
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Abstract
Mechanosensing is a key feature through which organisms can receive inputs from the environment and convert them into specific functional and behavioral outputs. Mechanosensation occurs in many cells and tissues, regulating a plethora of molecular processes based on the distribution of forces and stresses both at the cell membrane and at the intracellular organelles levels, through complex interactions between cells’ microstructures, cytoskeleton, and extracellular matrix. Although several primary and secondary mechanisms have been shown to contribute to mechanosensation, a fundamental pathway in simple organisms and mammals involves the presence of specialized sensory neurons and the presence of different types of mechanosensitive ion channels on the neuronal cell membrane. In this contribution, we present a review of the main ion channels which have been proven to be significantly involved in mechanotransduction in neurons. Further, we discuss recent studies focused on the biological mechanisms and modeling of mechanosensitive ion channels’ gating, and on mechanotransduction modeling at different scales and levels of details.
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11
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Nekimken AL, Pruitt BL, Goodman MB. Touch-induced mechanical strain in somatosensory neurons is independent of extracellular matrix mutations in Caenorhabditis elegans. Mol Biol Cell 2020; 31:1735-1743. [PMID: 32579427 PMCID: PMC7521855 DOI: 10.1091/mbc.e20-01-0049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cutaneous mechanosensory neurons are activated by mechanical loads applied to the skin, and these stimuli are proposed to generate mechanical strain within sensory neurons. Using a microfluidic device to deliver controlled stimuli to intact animals and large, immobile, and fluorescent protein-tagged mitochondria as fiducial markers in the touch receptor neurons (TRNs), we visualized and measured touch-induced mechanical strain in Caenorhabditis elegans worms. At steady state, touch stimuli sufficient to activate TRNs induce an average strain of 3.1% at the center of the actuator and this strain decays to near zero at the edges of the actuator. We also measured strain in animals carrying mutations affecting links between the extracellular matrix (ECM) and the TRNs but could not detect any differences in touch-induced mechanical strain between wild-type and mutant animals. Collectively, these results demonstrate that touching the skin induces local mechanical strain in intact animals and suggest that a fully intact ECM is not essential for transmitting mechanical strain from the skin to cutaneous mechanosensory neurons.
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Affiliation(s)
- Adam L Nekimken
- Departments of Mechanical Engineering, Stanford University, Stanford, CA 94305.,Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305
| | - Beth L Pruitt
- Departments of Mechanical Engineering, Stanford University, Stanford, CA 94305.,Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305.,Mechanical Engineering and Biomolecular Science and Engineering, University of California, Santa Barbara, CA 93106
| | - Miriam B Goodman
- Departments of Mechanical Engineering, Stanford University, Stanford, CA 94305.,Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305
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12
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Perks KM, Pierce JT. A quantal code for touch intensity in C. elegans. J Gen Physiol 2019; 151:1343-1346. [PMID: 31653657 PMCID: PMC6888754 DOI: 10.1085/jgp.201912477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Perks and Pierce consider a new study in worms showing that touch intensity is encoded by the quantal activity of mechanoreceptors.
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Affiliation(s)
- Katherine M Perks
- Center for Learning and Memory, Waggoner Center for Alcohol and Addiction Research, Department of Neuroscience, The University of Texas at Austin, Austin, TX
| | - Jonathan T Pierce
- Center for Learning and Memory, Waggoner Center for Alcohol and Addiction Research, Department of Neuroscience, The University of Texas at Austin, Austin, TX
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13
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Katta S, Sanzeni A, Das A, Vergassola M, Goodman MB. Progressive recruitment of distal MEC-4 channels determines touch response strength in C. elegans. J Gen Physiol 2019; 151:1213-1230. [PMID: 31533952 PMCID: PMC6785734 DOI: 10.1085/jgp.201912374] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 08/23/2019] [Indexed: 12/14/2022] Open
Abstract
Touch deforms, or strains, the skin beyond the immediate point of contact. The spatiotemporal nature of the touch-induced strain fields depend on the mechanical properties of the skin and the tissues below. Somatosensory neurons that sense touch branch out within the skin and rely on a set of mechano-electrical transduction channels distributed within their dendrites to detect mechanical stimuli. Here, we sought to understand how tissue mechanics shape touch-induced mechanical strain across the skin over time and how individual channels located in different regions of the strain field contribute to the overall touch response. We leveraged Caenorhabditis elegans' touch receptor neurons as a simple model amenable to in vivo whole-cell patch-clamp recording and an integrated experimental-computational approach to dissect the mechanisms underlying the spatial and temporal dynamics we observed. Consistent with the idea that strain is produced at a distance, we show that delivering strong stimuli outside the anatomical extent of the neuron is sufficient to evoke MRCs. The amplitude and kinetics of the MRCs depended on both stimulus displacement and speed. Finally, we found that the main factor responsible for touch sensitivity is the recruitment of progressively more distant channels by stronger stimuli, rather than modulation of channel open probability. This principle may generalize to somatosensory neurons with more complex morphologies.
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Affiliation(s)
- Samata Katta
- Neuroscience Program, Stanford University, Stanford, CA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA
| | - Alessandro Sanzeni
- National Institute of Mental Health Intramural Program, National Institutes of Health, Bethesda, MD
| | - Alakananda Das
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA
| | - Massimo Vergassola
- Department of Physics, University of California, San Diego, La Jolla, CA
| | - Miriam B Goodman
- Neuroscience Program, Stanford University, Stanford, CA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA
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