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Longridge NS, Mallinson AI. A New Perspective to Interpret How the Vestibular Efferent System Correlates the Complexity of Routine Balance Maintenance with Management of Emergency Fall Prevention Strategies. Audiol Res 2024; 14:518-544. [PMID: 38920965 PMCID: PMC11200673 DOI: 10.3390/audiolres14030044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/13/2024] [Accepted: 06/13/2024] [Indexed: 06/27/2024] Open
Abstract
Bipedalism is unique among mammals. Until modern times, a fall and resulting leg fracture could be fatal. Balance maintenance after a destabilizing event requires instantaneous decision making. The vestibular system plays an essential role in this process, initiating an emergency response. The afferent otolithic neural response is the first directionally oriented information to reach the cortex, and it can then be used to initiate an appropriate protective response. Some vestibular efferent axons feed directly into type I vestibular hair cells. This allows for rapid vestibular feedback via the striated organelle (STO), which has been largely ignored in most texts. We propose that this structure is essential in emergency fall prevention, and also that the system of sensory detection and resultant motor response works by having efferent movement information simultaneously transmitted to the maculae with the movement commands. This results in the otolithic membrane positioning itself precisely for the planned movement, and any error is due to an unexpected external cause. Error is fed back via the vestibular afferent system. The efferent system causes macular otolithic membrane movement through the STO, which occurs simultaneously with the initiating motor command. As a result, no vestibular afferent activity occurs unless an error must be dealt with.
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Affiliation(s)
| | - Arthur I. Mallinson
- Division of Otolaryngology, Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
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You D, Guo J, Zhang Y, Guo L, Lu X, Huang X, Sun S, Li H. The heterogeneity of mammalian utricular cells over the course of development. Clin Transl Med 2022; 12:e1052. [PMID: 36178017 PMCID: PMC9523683 DOI: 10.1002/ctm2.1052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 08/19/2022] [Accepted: 08/25/2022] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND The inner ear organ is a delicate tissue consisting of hair cells (HCs) and supporting cells (SCs).The mammalian inner ear HCs are terminally differentiated cells that cannot spontaneously regenerate in adults. Epithelial non-hair cells (ENHCs) in the utricle include HC progenitors and SCs, and the progenitors share similar characteristics with SCs in the neonatal inner ear. METHODS We applied single-cell sequencing to whole mouse utricles from the neonatal period to adulthood, including samples from postnatal day (P)2, P7 and P30 mice. Furthermore, using transgenic mice and immunostaining, we traced the source of new HC generation. RESULTS We identified several sensory epithelial cell clusters and further found that new HCs arose mainly through differentiation from Sox9+ progenitor cells and that only a few cells were produced by mitotic proliferation in both neonatal and adult mouse utricles. In addition, we identified the proliferative cells using the marker UbcH10 and demonstrated that in adulthood the mitotically generated HCs were primarily found in the extrastriola. Moreover, we observed that not only Type II, but also Type I HCs could be regenerated by either mitotic cell proliferation or progenitor cell differentiation. CONCLUSIONS Overall, our findings expand our understanding of ENHC cell fate and the characteristics of the vestibular organs in mammals over the course of development.
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Affiliation(s)
- Dan You
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina,Department of Otorhinolaryngology‐Head and Neck SurgeryZhongshan HospitalFudan UniversityShanghaiChina
| | - Jin Guo
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Yunzhong Zhang
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Luo Guo
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Xiaoling Lu
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Xinsheng Huang
- Department of Otorhinolaryngology‐Head and Neck SurgeryZhongshan HospitalFudan UniversityShanghaiChina
| | - Shan Sun
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina
| | - Huawei Li
- ENT Institute and Otorhinolaryngology Department of Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceFudan UniversityShanghaiChina,Institutes of Biomedical SciencesFudan UniversityShanghaiChina,NHC Key Laboratory of Hearing Medicine, Fudan UniversityShanghaiChina,The Institutes of Brain Science and the Collaborative Innovation Center for Brain ScienceFudan UniversityShanghaiChina
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Mukhopadhyay M, Pangrsic T. Synaptic transmission at the vestibular hair cells of amniotes. Mol Cell Neurosci 2022; 121:103749. [PMID: 35667549 DOI: 10.1016/j.mcn.2022.103749] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 05/09/2022] [Accepted: 06/01/2022] [Indexed: 11/19/2022] Open
Abstract
A harmonized interplay between the central nervous system and the five peripheral end organs is how the vestibular system helps organisms feel a sense of balance and motion in three-dimensional space. The receptor cells of this system, much like their cochlear equivalents, are the specialized hair cells. However, research over the years has shown that the vestibular endorgans and hair cells evolved very differently from their cochlear counterparts. The structurally unique calyceal synapse, which appeared much later in the evolutionary time scale, and continues to intrigue researchers, is now known to support several forms of synaptic neurotransmission. The conventional quantal transmission is believed to employ the ribbon structures, which carry several tethered vesicles filled with neurotransmitters. However, the field of vestibular hair cell synaptic molecular anatomy is still at a nascent stage and needs further work. In this review, we will touch upon the basic structure and function of the peripheral vestibular system, with the focus on the various modes of neurotransmission at the type I vestibular hair cells. We will also shed light on the current knowledge about the molecular anatomy of the vestibular hair cell synapses and vestibular synaptopathy.
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Affiliation(s)
- Mohona Mukhopadhyay
- Experimental Otology Group, InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, and Institute for Auditory Neuroscience, 37075 Göttingen, Germany
| | - Tina Pangrsic
- Experimental Otology Group, InnerEarLab, Department of Otolaryngology, University Medical Center Göttingen, and Institute for Auditory Neuroscience, 37075 Göttingen, Germany; Auditory Neuroscience Group, Max Planck Institute for Multidisciplinary Sciences, 37075 Göttingen, Germany; Collaborative Research Center 889, University of Göttingen, Göttingen, Germany; Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany.
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Farkhatdinov I, Michalska H, Berthoz A, Hayward V. Gravito-inertial ambiguity resolved through head stabilization. Proc Math Phys Eng Sci 2019; 475:20180010. [PMID: 31007539 PMCID: PMC6451982 DOI: 10.1098/rspa.2018.0010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 02/25/2019] [Indexed: 11/12/2022] Open
Abstract
It has been frequently observed that humans and animals spontaneously stabilize their heads with respect to the gravitational vertical during body movements even in the absence of vision. The interpretations of this intriguing behaviour have so far not included the need, for survival, to robustly estimate verticality. Here we use a mechanistic model of the head/otolith organ to analyse the possibility for this system to render verticality 'observable', a fundamental prerequisite to the determination of the angular position and acceleration of the head from idiothetic, inertial measurements. The intrinsically nonlinear head-vestibular dynamics is shown to generally lack observability unless the head is stabilized in orientation by feedback. Thus, our study supports the hypothesis that a central function of the physiologically costly head stabilization strategy is to enable an organism to estimate the gravitational vertical and head acceleration during locomotion. Moreover, our result exhibits a rare peculiarity of certain nonlinear systems to fortuitously alter their observability properties when feedback is applied.
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Affiliation(s)
- Ildar Farkhatdinov
- School of Electronic Engineering and Computer Science, Queen Mary University of London, Mile End, London, UK
- Department of Bioengineering, Imperial College of Science, Technology and Medicine, South Kensington, London, UK
| | - Hannah Michalska
- Department of Electrical and Computer Engineering, McGill University, Montréal, Quebec, Canada
| | - Alain Berthoz
- Centre Interdisciplinaire de Biologie (CIRB), Collége de France, 11 Place Marcelin Berthelot, Paris 75005, France
| | - Vincent Hayward
- Sorbonne Universités, Institut des Systèmes Intelligents et de Robotique (ISIR), Paris F-75005, France
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Farkhatdinov I, Michalska H, Berthoz A, Hayward V. Review of Anthropomorphic Head Stabilisation and Verticality Estimation in Robots. SPRINGER TRACTS IN ADVANCED ROBOTICS 2019. [DOI: 10.1007/978-3-319-93870-7_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Pastras CJ, Curthoys IS, Brown DJ. In vivo recording of the vestibular microphonic in mammals. Hear Res 2017; 354:38-47. [PMID: 28850921 DOI: 10.1016/j.heares.2017.07.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/15/2017] [Accepted: 07/25/2017] [Indexed: 01/11/2023]
Abstract
BACKGROUND The Vestibular Microphonic (VM) has only featured in a handful of publications, mostly involving non-mammalian and ex vivo models. The VM is the extracellular analogue of the vestibular hair cell receptor current, and offers a tool to monitor vestibular hair cell activity in vivo. OBJECTIVE To characterise features of the VM measured in vivo in guinea pigs, using a relatively simple experimental setup. METHODS The VM, evoked by bone-conducted vibration (BCV), was recorded from the basal surface of either the utricular or saccular macula after surgical removal of the cochlea, in 27 guinea pigs. RESULTS The VM remained after vestibular nerve blockade, but was abolished following end-organ destruction or death. The VM reversed polarity as the recording electrode tracked across the utricular or saccular macula surface, or through the utricular macula. The VM could be evoked by BCV stimuli of frequencies between 100 Hz and 5 kHz, and was largest to vibrations between 600 Hz and 800 Hz. Experimental manipulations demonstrated a reduction in the VM amplitude with maculae displacement, or rupture of the utricular membrane. CONCLUSIONS Results mirror those obtained in previous ex vivo studies, and further demonstrate that vestibular hair cells are sensitive to vibrations of several kilohertz. Changes in the VM with maculae displacement or rupture suggest utricular hydrops may alter vestibular hair cell sensitivity due to either mechanical or ionic changes.
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Affiliation(s)
- C J Pastras
- The Meniere's Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, 2050, Australia
| | - I S Curthoys
- Vestibular Research Laboratory, The University of Sydney, School of Psychology, Sydney, NSW, 2050, Australia
| | - D J Brown
- The Meniere's Laboratory, Sydney Medical School, The University of Sydney, Sydney, NSW, 2050, Australia.
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Marianelli P, Berthoz A, Bennequin D. Crista egregia: a geometrical model of the crista ampullaris, a sensory surface that detects head rotations. BIOLOGICAL CYBERNETICS 2015; 109:5-32. [PMID: 25128319 DOI: 10.1007/s00422-014-0623-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 07/10/2014] [Indexed: 06/03/2023]
Abstract
The crista ampullaris is the epithelium at the end of the semicircular canals in the inner ear of vertebrates, which contains the sensory cells involved in the transduction of the rotational head movements into neuronal activity. The crista surface has the form of a saddle, or a pair of saddles separated by a crux, depending on the species and the canal considered. In birds, it was described as a catenoid by Landolt et al. (J Comp Neurol 159(2):257-287, doi: 10.1002/cne.901590207 , 1972). In the present work, we establish that this particular form results from principles of invariance maximization and energy minimization. The formulation of the invariance principle was inspired by Takumida (Biol Sci Space 15(4):356-358, 2001). More precisely, we suppose that in functional conditions, the equations of linear elasticity are valid, and we assume that in a certain domain of the cupula, in proximity of the crista surface, (1) the stress tensor of the deformed cupula is invariant under the gradient of the pressure, (2) the dissipation of energy is minimum. Then, we deduce that in this domain the crista surface is a minimal surface and that it must be either a planar, or helicoidal Scherk surface, or a piece of catenoid, which is the unique minimal surface of revolution. If we add the hypothesis that the direction of invariance of the stress tensor is unique and that a bilateral symmetry of the crista exists, only the catenoid subsists. This finding has important consequences for further functional modeling of the role of the vestibular system in head motion detection and spatial orientation.
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Affiliation(s)
- Prisca Marianelli
- Translational Neural Engineering LabS, The Biorobotics Institute, Scuola Superiore Sant'Anna, Pontedera, PI, Italy,
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Huwe JA, Logan GJ, Williams B, Rowe MH, Peterson EH. Utricular afferents: morphology of peripheral terminals. J Neurophysiol 2015; 113:2420-33. [PMID: 25632074 DOI: 10.1152/jn.00481.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 01/23/2015] [Indexed: 11/22/2022] Open
Abstract
The utricle provides critical information about spatiotemporal properties of head movement. It comprises multiple subdivisions whose functional roles are poorly understood. We previously identified four subdivisions in turtle utricle, based on hair bundle structure and mechanics, otoconial membrane structure and hair bundle coupling, and immunoreactivity to calcium-binding proteins. Here we ask whether these macular subdivisions are innervated by distinctive populations of afferents to help us understand the role each subdivision plays in signaling head movements. We quantified the morphology of 173 afferents and identified six afferent classes, which differ in structure and macular locus. Calyceal and dimorphic afferents innervate one striolar band. Bouton afferents innervate a second striolar band; they have elongated terminals and the thickest processes and axons of all bouton units. Bouton afferents in lateral (LES) and medial (MES) extrastriolae have small-diameter axons but differ in collecting area, bouton number, and hair cell contacts (LES >> MES). A fourth, distinctive population of bouton afferents supplies the juxtastriola. These results, combined with our earlier findings on utricular hair cells and the otoconial membrane, suggest the hypotheses that MES and calyceal afferents encode head movement direction with high spatial resolution and that MES afferents are well suited to signal three-dimensional head orientation and striolar afferents to signal head movement onset.
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Affiliation(s)
- J A Huwe
- Department of Biological Sciences and Neuroscience Program, Ohio University, Athens, Ohio
| | - G J Logan
- Department of Biological Sciences and Neuroscience Program, Ohio University, Athens, Ohio
| | - B Williams
- Department of Biological Sciences and Neuroscience Program, Ohio University, Athens, Ohio
| | - M H Rowe
- Department of Biological Sciences and Neuroscience Program, Ohio University, Athens, Ohio
| | - E H Peterson
- Department of Biological Sciences and Neuroscience Program, Ohio University, Athens, Ohio
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