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Wu JP, Yang X, Wang Y, Swift B, Adamson R, Zheng Y, Zhang R, Zhong W, Chen F. High Resolution and Labeling Free Studying the 3D Microstructure of the Pars Tensa-Annulus Unit of Mice. Front Cell Dev Biol 2021; 9:720383. [PMID: 34692679 PMCID: PMC8532514 DOI: 10.3389/fcell.2021.720383] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/13/2021] [Indexed: 11/21/2022] Open
Abstract
Hearing loss is a serious illness affecting people’s normal life enormously. The acoustic properties of a tympanic membrane play an important role in hearing, and highly depend on its geometry, composition, microstructure and connection to the surrounding annulus. While the conical geometry of the tympanic membrane is critical to the sound propagation in the auditory system, it presents significant challenges to the study of the 3D microstructure of the tympanic membrane using traditional 2D imaging techniques. To date, most of our knowledge about the 3D microstructure and composition of tympanic membranes is built from 2D microscopic studies, which precludes an accurate understanding of the 3D microstructure, acoustic behaviors and biology of the tissue. Although the tympanic membrane has been reported to contain elastic fibers, the morphological characteristic of the elastic fibers and the spatial arrangement of the elastic fibers with the predominant collagen fibers have not been shown in images. We have developed a 3D imaging technique for the three-dimensional examination of the microstructure of the full thickness of the tympanic membranes in mice without requiring tissue dehydration and stain. We have also used this imaging technique to study the 3D arrangement of the collagen and elastic fibrillar network with the capillaries and cells in the pars tensa-annulus unit at a status close to the native. The most striking findings in the study are the discovery of the 3D form of the elastic and collagen network, and the close spatial relationships between the elastic fibers and the elongated fibroblasts in the tympanic membranes. The 3D imaging technique has enabled to show the 3D waveform contour of the collagen and elastic scaffold in the conical tympanic membrane. Given the close relationship among the acoustic properties, composition, 3D microstructure and geometry of tympanic membranes, the findings may advance the understanding of the structure—acoustic functionality of the tympanic membrane. The knowledge will also be very helpful in the development of advanced cellular therapeutic technologies and 3D printing techniques to restore damaged tympanic membranes to a status close to the native.
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Affiliation(s)
- Jian-Ping Wu
- Academy of Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China.,Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Xiaojie Yang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Yilin Wang
- Core Research Facilities, Southern University of Science and Technology, Shenzhen, China
| | - Ben Swift
- College of Computing, Australian National University, Canberra, ACT, Australia
| | - Robert Adamson
- School of Biomedical Engineering, Electrical and Computer Engineering, Dalhousie University, Halifax, NS, Canada
| | - Yongchang Zheng
- Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Rongli Zhang
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Science, School of Medicine, South China University of Technology, Guangzhou, China
| | - Wen Zhong
- School of Mechanical Engineering and Automation, Xihua University, Chengdu, China
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China.,Department of Biology, Brain Research Centre, Southern University of Science and Technology, Shenzhen, China
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Kim YY, Chao JR, Kim C, Kang TC, Park HS, Chang J, Suh JG, Lee JH. Applicability of vital staining and tissue clearing to vascular anatomy and melanocytes' evaluation of temporal bone in six laboratory species. Anat Histol Embryol 2019; 48:296-305. [PMID: 30916435 DOI: 10.1111/ahe.12440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/11/2019] [Accepted: 02/26/2019] [Indexed: 12/14/2022]
Abstract
The purpose of the present study was to define the applicability of tissue clearing to the field of otology. We combined tissue clearing with vital staining perfusion via a pumping system to examine the vascular anatomy of temporal bones in laboratory animals. We used six different types of species including Korean wild mouse, mouse, Mongolian gerbil, hamsters and Guinea pigs. A mixture of Alcian blue reagent and 4% paraformaldehyde was circulated throughout the entire circulatory system of the animal via a perfusion pump system. Transparency images were obtained from the temporal bones according to the protocol of the SunHyun 3D Imaging Kit. In examining the inner surface of the tympanic membrane, flaccid part (pars flaccida) was positioned along the entire marginal area in Guinea pig. In the Guinea pig, unlike the other species, the cortical bone of the mastoid (bullae) was easily removed using cold instruments, allowing a direct approach to the enclosed structures. The distribution and pattern of cochlea melanocytes were compared among the species. "Mobius strip"-like accumulated melanocytes in vestibules were shown in both the Korean wild mouse and mouse. The collateral blood supply to the cochlea in six different species was checked in various pattern. Combining dye infusion with tissue-clearing techniques, we documented the middle ear and transparent inner ear structures in six different species. The information and associated images will help other researchers to develop hypotheses and design experimental investigations.
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Affiliation(s)
- Yoo Yeon Kim
- Department of Medical Genetics, College of Medicine, Hallym University, Chuncheon, Korea
| | - Janet Ren Chao
- Division of Otolaryngology, Department of Surgery, Yale School of Medicine, New Haven, Connecticut
| | - Chulho Kim
- Department of Neurology, Chuncheon Sacred Heart Hospital, Hallym University, Chuncheon, Korea
| | - Tae-Cheon Kang
- Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chuncheon, Korea
| | - Hae Sang Park
- Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Korea.,Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Korea
| | - Jiwon Chang
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Korea
| | - Jun-Gyo Suh
- Department of Medical Genetics, College of Medicine, Hallym University, Chuncheon, Korea
| | - Jun Ho Lee
- Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Korea.,Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Hallym University, Chuncheon, Korea
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Liu J, Agrawal SK, Ladak HM, Wan W. Fiber Arrangement in the Rat Tympanic Membrane. Anat Rec (Hoboken) 2016; 299:1531-1539. [PMID: 27532441 DOI: 10.1002/ar.23461] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/15/2016] [Accepted: 06/20/2016] [Indexed: 11/07/2022]
Abstract
The fiber arrangement in the pars tensa of the rat tympanic membrane (TM) was observed using a high resolution scanning electron microscope. The entire pars tensa is composed of fibrils with diameter of approximately 25 nm. These fibrils can be grouped into radial, circular, parabolic, and oblique fibers as reported in other mammals. The radial fibrils interweave into a planar form rather than into discrete cylindrical fibers. Before attaching to the manubrium and tympanic ring, the radial fibrils bend and cross neighboring fibrils to form a random fibril network, and change their direction from perpendicular to somewhat parallel to the manubrium and tympanic ring. The circular fibrils form cylindrical fibers near the peripheral part of the TM while closer to the manubrium, they form planar bundles. The observed fiber morphology and arrangement may provide helpful information in improving numerical models for the TM's acoustical response and designing a fibrous graft for the repair of TM perforations. Anat Rec, 299:1531-1539, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Jian Liu
- Department of Chemical and Biochemical Engineering, Western University, London, Ontario, Canada
| | - Sumit K Agrawal
- Department of Medical Biophysics, Western University, London, Ontario, Canada
- Department of Electrical and Computer Engineering, Western University, London, Ontario, Canada
- Department of Otolaryngology - Head and Neck Surgery, London Health Sciences Centre, London, Ontario, Canada
| | - Hanif M Ladak
- Department of Medical Biophysics, Western University, London, Ontario, Canada.
- Department of Electrical and Computer Engineering, Western University, London, Ontario, Canada.
- Department of Otolaryngology - Head and Neck Surgery, London Health Sciences Centre, London, Ontario, Canada.
- Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada.
| | - Wankei Wan
- Department of Chemical and Biochemical Engineering, Western University, London, Ontario, Canada.
- Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada.
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Tympanic membrane boundary deformations derived from static displacements observed with computerized tomography in human and gerbil. J Assoc Res Otolaryngol 2009; 11:1-17. [PMID: 19834763 DOI: 10.1007/s10162-009-0192-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Accepted: 09/24/2009] [Indexed: 10/20/2022] Open
Abstract
The middle ear is too complex a system for its function to be fully understood with simple descriptive models. Realistic mathematical models must be used in which structural elements are represented by geometrically correct three-dimensional (3D) models with correct physical parameters and boundary conditions. In the past, the choice of boundary conditions could not be based on experimental evidence as no clear-cut data were available. We have, therefore, studied the deformation of the tympanic membrane (TM) at its boundaries using X-ray microscopic computed tomography in human and gerbil while static pressure was applied to the ear canal. The 3D models of the TM and its bony attachments were carefully made and used to measure the deformation of the TM with focus on the periphery and the manubrium attachment. For the pars flaccida of the gerbil, the boundary condition can, for the most part, be described as simply supported. For the human pars flaccida, the situation is more complicated: superiorly, the membrane contacts the underlying bone more and more when pushed further inward, and it gradually detaches from the wall when sucked outward. In gerbil, the attachment of the TM to the manubrium can be described as simply supported. In human, the manubrium is attached underneath the TM via the plica mallearis and the contact of the TM with the bone is indirect. For both human and gerbil, a simple boundary condition for the peripheral edge of the pars tensa is not appropriate due to the intricate structure at the edge: the TM thickens rapidly before continuing into the annulus fibrosis which finally makes contact with the bone.
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Knutsson J, Bagger-Sjöbäck D, von Unge M. Distribution of Different Collagen Types in the Rat's Tympanic Membrane and Its Suspending Structures. Otol Neurotol 2007; 28:486-91. [PMID: 17529850 DOI: 10.1097/01.mao.0000265202.85119.1c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND The objective of the study was to investigate the histological distribution of collagens in the healthy rat's tympanic membrane. METHODS Immunohistochemical analysis of collagen type I, II, III, and IV in the tympanic membranes in healthy adult female Sprague-Dawley rats. The staining was semiquantified using light microscopy in a blinded fashion, not knowing what type of collagen the slide had been stained for. RESULTS The pars tensa of the tympanic membrane was mainly stained for collagen type II and IV. The fibrous annulus could on immunohistochemistry be subdivided into an inner and an outer portion. The inner portion of the fibrous annulus was mainly stained for collagen type II, whereas the outer portion was most strongly stained for collagen type III and collagen type IV. The test-retest reliability of the semiquantative method was 81%. CONCLUSION Collagen type II and IV are the major collagen constituents of the pars tensa of the tympanic membrane. The outer portion of the fibrous annulus has collagen type III and IV as its major constituents, whereas the inner portion is made up of collagen type II.
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Affiliation(s)
- Johan Knutsson
- Center for Hearing and Communication Research, Karolinska Institute, Stockholm, Sweden.
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