Ultrastructural Analysis of Odontocete Cochlea
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Reticular Lamina and Basilar Membrane Vibrations in Living Mouse Cochleae
Reticular lamina and basilar membrane vibrations in living mouse cochleae Tianying Rena,1, Wenxuan Hea, and David Kempb aOregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, Portland, OR 97239; and bUniversity College London Ear Institute, University College London, London WC1E 6BT, United Kingdom Edited by Mario A. Ruggero, Northwestern University, Evanston, IL, and accepted by Editorial Board Member Peter L. Strick July 1, 2016 (received for review May 9, 2016) It is commonly believed that the exceptional sensitivity of mamma- (Fig. 1 A and B and Materials and Methods). The results from this lian hearing depends on outer hair cells which generate forces for study do not demonstrate the commonly expected cochlear local amplifying sound-induced basilar membrane vibrations, yet how feedback but instead indicate a global hydromechanical mecha- cellular forces amplify vibrations is poorly understood. In this study, nism for outer hair cells to enhance hearing sensitivity. by measuring subnanometer vibrations directly from the reticular lamina at the apical ends of outer hair cells and from the basilar Results membrane using a custom-built heterodyne low-coherence interfer- Vibrations of the Reticular Lamina and Basilar Membrane in Sensitive ometer, we demonstrate in living mouse cochleae that the sound- Cochleae. Vibrations of the reticular lamina and basilar membrane induced reticular lamina vibration is substantially larger than the measured from a sensitive cochlea are presented in Fig. 1 C–J. basilar membrane vibration not only at the best frequency but Below 50 dB sound pressure level (SPL) (0 dB SPL = 20 μPa), the surprisingly also at low frequencies. -
Vocabulario De Morfoloxía, Anatomía E Citoloxía Veterinaria
Vocabulario de Morfoloxía, anatomía e citoloxía veterinaria (galego-español-inglés) Servizo de Normalización Lingüística Universidade de Santiago de Compostela COLECCIÓN VOCABULARIOS TEMÁTICOS N.º 4 SERVIZO DE NORMALIZACIÓN LINGÜÍSTICA Vocabulario de Morfoloxía, anatomía e citoloxía veterinaria (galego-español-inglés) 2008 UNIVERSIDADE DE SANTIAGO DE COMPOSTELA VOCABULARIO de morfoloxía, anatomía e citoloxía veterinaria : (galego-español- inglés) / coordinador Xusto A. Rodríguez Río, Servizo de Normalización Lingüística ; autores Matilde Lombardero Fernández ... [et al.]. – Santiago de Compostela : Universidade de Santiago de Compostela, Servizo de Publicacións e Intercambio Científico, 2008. – 369 p. ; 21 cm. – (Vocabularios temáticos ; 4). - D.L. C 2458-2008. – ISBN 978-84-9887-018-3 1.Medicina �������������������������������������������������������������������������veterinaria-Diccionarios�������������������������������������������������. 2.Galego (Lingua)-Glosarios, vocabularios, etc. políglotas. I.Lombardero Fernández, Matilde. II.Rodríguez Rio, Xusto A. coord. III. Universidade de Santiago de Compostela. Servizo de Normalización Lingüística, coord. IV.Universidade de Santiago de Compostela. Servizo de Publicacións e Intercambio Científico, ed. V.Serie. 591.4(038)=699=60=20 Coordinador Xusto A. Rodríguez Río (Área de Terminoloxía. Servizo de Normalización Lingüística. Universidade de Santiago de Compostela) Autoras/res Matilde Lombardero Fernández (doutora en Veterinaria e profesora do Departamento de Anatomía e Produción Animal. -
Investigations of Auditory Filters Based Excitation Patterns for Assessment of Noise Induced Hearing Loss
Investigations of Auditory Filters Based Excitation Patterns for Assessment of Noise Induced Hearing Loss Wisam Subhi Al-Dayyeni, Pengfei Sun, Jun Qin Department of Electrical and Computer Engineering, Southern Illinois University, Carbondale, IL, USA Abstract: Noise induced hearing loss (NIHL) as one of major avoidable occupational related health issues has been studied for decades. To assess NIHL, the excitation pattern (EP) has been considered as one of mechanisms to estimate movements of basilar membrane (BM) in cochlea. In this study, two auditory filters, dual resonance nonlinear (DRNL) filter and rounded- exponential (ROEX) filter, have been applied to create two EPs, referring as the velocity EP and the loudness EP, respectively. Two noise hazard metrics are also proposed based on the developed EPs to evaluate hazardous levels caused by different types of noise. Moreover, Gaussian noise and pure-tone noise have been simulated to evaluate performances of the developed EPs and noise metrics. The results show that both developed EPs can reflect the responses of BM to different types of noise. For Gaussian noise, there is a frequency shift between the velocity EP and the loudness EP. For pure-tone noise, both EPs can reflect the frequencies of input noise accurately. The results suggest that both EPs can be potentially used for assessment of NIHL. Key words: Noise induced hearing loss; excitation pattern; basilar membrane motion; auditory filter; noise assessment metrics. 1. Introduction Noise-induced hearing loss (NIHL) remains as one of the most common health related problems nowadays as stated by the World Health Organization (WHO). One of the main causes of the permanent hearing loss is the exposure to excessive noise [1-3]. -
Vibration Hotspots Reveal Longitudinal Funneling of Sound-Evoked Motion in the Mammalian Cochlea
ARTICLE DOI: 10.1038/s41467-018-05483-z OPEN Vibration hotspots reveal longitudinal funneling of sound-evoked motion in the mammalian cochlea Nigel P. Cooper 1, Anna Vavakou1 & Marcel van der Heijden 1 The micromechanical mechanisms that underpin tuning and dynamic range compression in the mammalian inner ear are fundamental to hearing, but poorly understood. Here, we present new, high-resolution optical measurements that directly map sound-evoked vibra- 1234567890():,; tions on to anatomical structures in the intact, living gerbil cochlea. The largest vibrations occur in a tightly delineated hotspot centering near the interface between the Deiters’ and outer hair cells. Hotspot vibrations are less sharply tuned, but more nonlinear, than basilar membrane vibrations, and behave non-monotonically (exhibiting hyper-compression) near their characteristic frequency. Amplitude and phase differences between hotspot and basilar membrane responses depend on both frequency and measurement angle, and indicate that hotspot vibrations involve longitudinal motion. We hypothesize that structural coupling between the Deiters’ and outer hair cells funnels sound-evoked motion into the hotspot region, under the control of the outer hair cells, to optimize cochlear tuning and compression. 1 Department of Neuroscience, Erasmus MC, Room Ee 1285, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. Correspondence and requests for materials should be addressed to M.v.d.H. (email: [email protected]) NATURE COMMUNICATIONS | (2018) 9:3054 | DOI: 10.1038/s41467-018-05483-z -
Reduced Connexin26 in the Mature Cochlea Increases Susceptibility to Noise-Induced Hearing Loss in Mice
International Journal of Molecular Sciences Article Reduced Connexin26 in the Mature Cochlea Increases Susceptibility to Noise-Induced Hearing Loss in Mice Xing-Xing Zhou 1,†, Sen Chen 1,†, Le Xie 1, Yu-Zi Ji 1, Xia Wu 1, Wen-Wen Wang 1, Qi Yang 1, Jin-Tao Yu 1, Yu Sun 1,*, Xi Lin 2 and Wei-Jia Kong 1,3,* 1 Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Jiefang Avenue 1277, Wuhan 430022, China; [email protected] (X.-X.Z.); [email protected] (S.C.); [email protected] (L.X.); [email protected] (Y.-Z.J.); [email protected] (X.W.); [email protected] (W.-W.W.); [email protected] (Q.Y.); [email protected] (J.-T.Y.) 2 Department of Otolaryngology Head and Neck Surgery, Emory University School of Medicine, 615 Michael Street, Whitehead Bldg Rm#543, Atlanta, GA 30322, USA; [email protected] 3 Institute of Otorhinolaryngology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China * Correspondence: [email protected]; (Y.S.); [email protected] (W.-J.K.); Tel.: +86-27-8535-1632 (Y.S.); +86-27-8535-1706 (W.-J.K.); Fax: +86-27-8577-6343 (Y.S. & W.-J.K.) † These authors contributed equally to this work. Academic Editor: Nicholas Delihas Received: 20 January 2016; Accepted: 22 February 2016; Published: 26 February 2016 Abstract: Connexin26 (Cx26, encoded by GJB2) mutations are the most common cause of non-syndromic deafness. GJB2 is thought to be involved in noise-induced hearing loss (NIHL). However, the role of Cx26 in NIHL is still obscure. -
ANATOMY of EAR Basic Ear Anatomy
ANATOMY OF EAR Basic Ear Anatomy • Expected outcomes • To understand the hearing mechanism • To be able to identify the structures of the ear Development of Ear 1. Pinna develops from 1st & 2nd Branchial arch (Hillocks of His). Starts at 6 Weeks & is complete by 20 weeks. 2. E.A.M. develops from dorsal end of 1st branchial arch starting at 6-8 weeks and is complete by 28 weeks. 3. Middle Ear development —Malleus & Incus develop between 6-8 weeks from 1st & 2nd branchial arch. Branchial arches & Development of Ear Dev. contd---- • T.M at 28 weeks from all 3 germinal layers . • Foot plate of stapes develops from otic capsule b/w 6- 8 weeks. • Inner ear develops from otic capsule starting at 5 weeks & is complete by 25 weeks. • Development of external/middle/inner ear is independent of each other. Development of ear External Ear • It consists of - Pinna and External auditory meatus. Pinna • It is made up of fibro elastic cartilage covered by skin and connected to the surrounding parts by ligaments and muscles. • Various landmarks on the pinna are helix, antihelix, lobule, tragus, concha, scaphoid fossa and triangular fossa • Pinna has two surfaces i.e. medial or cranial surface and a lateral surface . • Cymba concha lies between crus helix and crus antihelix. It is an important landmark for mastoid antrum. Anatomy of external ear • Landmarks of pinna Anatomy of external ear • Bat-Ear is the most common congenital anomaly of pinna in which antihelix has not developed and excessive conchal cartilage is present. • Corrections of Pinna defects are done at 6 years of age. -
The Notch Ligand Jagged1 Is Required for the Formation, Maintenance, And
bioRxiv preprint doi: https://doi.org/10.1101/2020.05.04.076448; this version posted May 5, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. 1 Title: The Notch Ligand Jagged1 is Required for the Formation, Maintenance, and 2 Survival of Hensen Cells in the Mouse Cochlea. 3 4 Elena Chrysostomou1, *, Luyi Zhou2, *, Yuanzhao L. Darcy2, Kaley A. Graves2, Angelika 5 Doetzlhofer1, $, and Brandon C. Cox2,3, $ 6 7 1. The Solomon H. Snyder Department of Neuroscience and Center for Sensory 8 Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21205 9 2. Departments of Pharmacology and 3. Otolaryngology, Southern Illinois University 10 School of Medicine, Springfield, Illinois, 62702 11 * Denotes co-first authors, $ denotes co-corresponding authors 12 13 Corresponding authors email addresses: 14 Angelika Doetzlhofer: [email protected] 15 Brandon C. Cox: [email protected] 16 17 18 19 20 21 bioRxiv preprint doi: https://doi.org/10.1101/2020.05.04.076448; this version posted May 5, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. 22 ABSTRACT 23 During cochlear development, the Notch ligand JAGGED 1 (JAG1) plays an important 24 role in the specification of the prosensory region, which gives rise to sound-sensing hair 25 cells and neighboring supporting cells (SCs). -
Renewed Proliferation in Adult Mouse Cochlea and Regeneration of Hair Cells
ARTICLE https://doi.org/10.1038/s41467-019-13157-7 OPEN Renewed proliferation in adult mouse cochlea and regeneration of hair cells Yilai Shu1,2,3,4,10, Wenyan Li1,2,3,4,10, Mingqian Huang1,2,10, Yi-Zhou Quan1,2,10, Deborah Scheffer1,2,5, Chunjie Tian1,2, Yong Tao1,2, Xuezhong Liu6, Konrad Hochedlinger 7,8,9, Artur A. Indzhykulian1,2, Zhengmin Wang3,4, Huawei Li3,4 & Zheng-Yi Chen 1,2* The adult mammalian inner ear lacks the capacity to divide or regenerate. Damage to inner 1234567890():,; ear generally leads to permanent hearing loss in humans. Here, we present that repro- gramming of the adult inner ear induces renewed proliferation and regeneration of inner ear cell types. Co-activation of cell cycle activator Myc and inner ear progenitor gene Notch1 induces robust proliferation of diverse adult cochlear sensory epithelial cell types. Transient MYC and NOTCH activities enable adult supporting cells to respond to transcription factor Atoh1 and efficiently transdifferentiate into hair cell-like cells. Furthermore, we uncover that mTOR pathway participates in MYC/NOTCH-mediated proliferation and regeneration. These regenerated hair cell-like cells take up the styryl dye FM1-43 and are likely to form con- nections with adult spiral ganglion neurons, supporting that Myc and Notch1 co-activation is sufficient to reprogram fully mature supporting cells to proliferate and regenerate hair cell- like cells in adult mammalian auditory organs. 1 Department of Otolaryngology-Head and Neck Surgery, Graduate Program in Speech and Hearing Bioscience and Techology and Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA. -
Ultrastructural Analysis and ABR Alterations in the Cochlear Hair-Cells Following Aminoglycosides Administration in Guinea Pig
Global Journal of Otolaryngology ISSN 2474-7556 Research Article Glob J Otolaryngol Volume 15 Issue 4 - May 2018 Copyright © All rights are reserved by Mohammed A Akeel DOI: 10.19080/GJO.2018.15.555916 Ultrastructural Analysis and ABR Alterations in the Cochlear Hair-cells Following Aminoglycosides Administration in Guinea Pig Mohammed A Akeel* Department of Anatomy, Faculty of Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia Submission: April 18, 2018; Published: May 08, 2018 *Corresponding author: Mohammed A Akeel, Faculty of Medicine, Jazan University, P.O.Box 114, Jazan, Kingdom of Saudi Arabia. Tel: ; Email: Abstract Aims: since their introduction in the 1940. The aim of the present work was to characterize ultrastructural alterations of the sensory hair-cell following different aminoglycosides Aminoglycosides administration, (AG) antibiotics intratympanic were the first VS ototoxic intraperitoneal agents to and highlight to correlate the problem them with of drug-induced auditory brainstem hearing responses and vestibular (ABR). loss, Methods: streptomycin, gentamycin, or netilmicin; respectively, via the peritoneal route. The next four groups received similar treatment via trans- tympanic route. A Thetotal treatment of 48 adult was guinea administered pigs were dividedfor seven into consecutive 8 groups; sixdays. animals On day in 10,each ABR group. was The utilized first fourfor hearing groups receivedevaluation saline and (control),scanning electron microscopy (SEM) examination of the sensory organs was used for morphological study. Results: Streptomycin produced the most severe morphological changes and a higher elevation of ABR thresholds, followed, in order, by gentamycin and netilmicin. Netilmicin ototoxicity observed in both systemic and transtympanic routes was low because of lesser penetration into the inner ear or/ and lower intrinsic toxicity. -
The Tectorial Membrane of the Rat'
The Tectorial Membrane of the Rat’ MURIEL D. ROSS Department of Anatomy, The University of Michigan, Ann Arbor, Michigan 48104 ABSTRACT Histochemical, x-ray analytical and scanning and transmission electron microscopical procedures have been utilized to determine the chemical nature, physical appearance and attachments of the tectorial membrane in nor- mal rats and to correlate these results with biochemical data on protein-carbo- hydrate complexes. Additionally, pertinent histochemical and ultrastructural findings in chemically sympathectomized rats are considered. The results indi- cate that the tectorial membrane is a viscous, complex, colloid of glycoprotein( s) possessing some oriented molecules and an ionic composition different from either endolymph or perilymph. It is attached to the reticular laminar surface of the organ of Corti and to the tips of the outer hair cells; it is attached to and encloses the hairs of the inner hair cells. A fluid compartment may exist within the limbs of the “W’formed by the hairs on each outer hair cell surface. Present biochemical concepts of viscous glycoproteins suggest that they are polyelectro- lytes interacting physically to form complex networks. They possess character- istics making them important in fluid and ion transport. Furthermore, the macro- molecular configuration assumed by such polyelectrolytes is unstable and subject to change from stress or shifts in pH or ions. Thus, the attachments of the tec- torial membrane to the hair cells may play an important role in the transduction process at the molecular level. The present investigation is an out- of the tectorial membrane remain matters growth of a prior study of the effects of of dispute. -
Current Practices in the Assessment of Recreational Noise-Induced Hearing Loss: a Review
Current Practices in the Assessment of Make Listening Safe WHO Recreational Noise- induced Hearing Loss: a review This document presents a review of current practices in the assessment of hearing loss caused by exposure to loud sounds in recreational settings. The review will be used to February 2017 stimulate discussion and consider the points raised in the accompanying discussion paper regarding the need for a universal research protocol. This review has been undertaken by Dr. Kamakshi Gopal, in collaboration with the World Health Organization. Current Practices in the Assessment of Recreational Noise-induced Hearing Loss: a review Authored by: Dr Kamakshi Gopal Professor of Audiology University of Northern Texas United States with inputs from …… any other name to be added?? Reviewed by: Dr Peter Thorne Professor of Audiology University of Auckland New Zealand Dr Shelly Chadha Technical Officer, Prevention of deafness and hearing loss World Health Organization Geneva, Switzerland 1 Table of Contents Purpose ……………………………………………………………………………. 3 Methods …………………………………………………………………………... 3 Executive Summary ………………………………………………………….. 4 Concerts/Discotheques/Bars ……………………………………………. 6 Personal Audio Systems (PAS) Studies ………………………………. 22 Sporting Events (Arenas) ………………………………………………….. 40 References ……………………………………………………………………….. 42 2 PURPOSE OF THE REPORT Hearing loss, temporary or permanent, from exposure to recreational noise is a worsening public health problem, particularly in children, adolescents, and young adults. This is attributable to the fact that young people utilize their leisure and relaxation time in activities that expose them to high levels of music or noise at concerts, bars, sports arenas and clubs, or listen to unsafe levels of music on their personal audio systems. Despite this emerging widespread trend, there are currently no universal standards set to limit exposure to recreational noise. -
Anatomic Moment
Anatomic Moment Hearing, I: The Cochlea David L. Daniels, Joel D. Swartz, H. Ric Harnsberger, John L. Ulmer, Katherine A. Shaffer, and Leighton Mark The purpose of the ear is to transform me- cochlear recess, which lies on the medial wall of chanical energy (sound) into electric energy. the vestibule (Fig 3). As these sound waves The external ear collects and directs the sound. enter the perilymph of the scala vestibuli, they The middle ear converts the sound to fluid mo- are transmitted through the vestibular mem- tion. The inner ear, specifically the cochlea, brane into the endolymph of the cochlear duct, transforms fluid motion into electric energy. causing displacement of the basilar membrane, The cochlea is a coiled structure consisting of which stimulates the hair cell receptors of the two and three quarter turns (Figs 1 and 2). If it organ of Corti (Figs 4–7) (4, 5). It is the move- were elongated, the cochlea would be approxi- ment of hair cells that generates the electric mately 30 mm in length. The fluid-filled spaces potentials that are converted into action poten- of the cochlea are comprised of three parallel tials in the auditory nerve fibers. The basilar canals: an outer scala vestibuli (ascending spi- membrane varies in width and tension from ral), an inner scala tympani (descending spi- base to apex. As a result, different portions of ral), and the central cochlear duct (scala media) the membrane respond to different auditory fre- (1–7). The scala vestibuli and scala tympani quencies (2, 5). These perilymphatic waves are contain perilymph, a substance similar in com- transmitted via the apex of the cochlea (helico- position to cerebrospinal fluid.