1
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Hrncirik F, Roberts I, Sevgili I, Swords C, Bance M. Models of Cochlea Used in Cochlear Implant Research: A Review. Ann Biomed Eng 2023; 51:1390-1407. [PMID: 37087541 PMCID: PMC10264527 DOI: 10.1007/s10439-023-03192-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 03/20/2023] [Indexed: 04/24/2023]
Abstract
As the first clinically translated machine-neural interface, cochlear implants (CI) have demonstrated much success in providing hearing to those with severe to profound hearing loss. Despite their clinical effectiveness, key drawbacks such as hearing damage, partly from insertion forces that arise during implantation, and current spread, which limits focussing ability, prevent wider CI eligibility. In this review, we provide an overview of the anatomical and physical properties of the cochlea as a resource to aid the development of accurate models to improve future CI treatments. We highlight the advancements in the development of various physical, animal, tissue engineering, and computational models of the cochlea and the need for such models, challenges in their use, and a perspective on their future directions.
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Affiliation(s)
- Filip Hrncirik
- Cambridge Hearing Group, Cambridge, UK.
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK.
| | - Iwan Roberts
- Cambridge Hearing Group, Cambridge, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Ilkem Sevgili
- Cambridge Hearing Group, Cambridge, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Chloe Swords
- Cambridge Hearing Group, Cambridge, UK
- Department of Physiology, Development and Neurosciences, University of Cambridge, Cambridge, CB2 3DY, UK
| | - Manohar Bance
- Cambridge Hearing Group, Cambridge, UK
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0QQ, UK
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2
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Yu Y, Shi K, Nielson C, Graham EM, Price MS, Haller TJ, Carraro M, Firpo MA, Park AH, Harrison RV. Hearing loss caused by CMV infection is correlated with reduced endocochlear potentials caused by strial damage in murine models. Hear Res 2022; 417:108454. [DOI: 10.1016/j.heares.2022.108454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 12/22/2021] [Accepted: 01/26/2022] [Indexed: 11/04/2022]
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3
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Yu W, Zong S, Du P, Zhou P, Li H, Wang E, Xiao H. Role of the Stria Vascularis in the Pathogenesis of Sensorineural Hearing Loss: A Narrative Review. Front Neurosci 2021; 15:774585. [PMID: 34867173 PMCID: PMC8640081 DOI: 10.3389/fnins.2021.774585] [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: 09/13/2021] [Accepted: 10/28/2021] [Indexed: 12/20/2022] Open
Abstract
Sensorineural hearing loss is a common sensory impairment in humans caused by abnormalities in the inner ear. The stria vascularis is regarded as a major cochlear structure that can independently degenerate and influence the degree of hearing loss. This review summarizes the current literature on the role of the stria vascularis in the pathogenesis of sensorineural hearing loss resulting from different etiologies, focusing on both molecular events and signaling pathways, and further attempts to explore the underlying mechanisms at the cellular and molecular biological levels. In addition, the deficiencies and limitations of this field are discussed. With the rapid progress in scientific technology, new opportunities are arising to fully understand the role of the stria vascularis in the pathogenesis of sensorineural hearing loss, which, in the future, will hopefully lead to the prevention, early diagnosis, and improved treatment of sensorineural hearing loss.
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Affiliation(s)
- Wenting Yu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shimin Zong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Peiyu Du
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Peng Zhou
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hejie Li
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Enhao Wang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hongjun Xiao
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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4
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Wälchli T, Bisschop J, Miettinen A, Ulmann-Schuler A, Hintermüller C, Meyer EP, Krucker T, Wälchli R, Monnier PP, Carmeliet P, Vogel J, Stampanoni M. Hierarchical imaging and computational analysis of three-dimensional vascular network architecture in the entire postnatal and adult mouse brain. Nat Protoc 2021; 16:4564-4610. [PMID: 34480130 DOI: 10.1038/s41596-021-00587-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 06/08/2021] [Indexed: 02/08/2023]
Abstract
The formation of new blood vessels and the establishment of vascular networks are crucial during brain development, in the adult healthy brain, as well as in various diseases of the central nervous system. Here, we describe a step-by-step protocol for our recently developed method that enables hierarchical imaging and computational analysis of vascular networks in postnatal and adult mouse brains. The different stages of the procedure include resin-based vascular corrosion casting, scanning electron microscopy, synchrotron radiation and desktop microcomputed tomography imaging, and computational network analysis. Combining these methods enables detailed visualization and quantification of the 3D brain vasculature. Network features such as vascular volume fraction, branch point density, vessel diameter, length, tortuosity and directionality as well as extravascular distance can be obtained at any developmental stage from the early postnatal to the adult brain. This approach can be used to provide a detailed morphological atlas of the entire mouse brain vasculature at both the postnatal and the adult stage of development. Our protocol allows the characterization of brain vascular networks separately for capillaries and noncapillaries. The entire protocol, from mouse perfusion to vessel network analysis, takes ~10 d.
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Affiliation(s)
- Thomas Wälchli
- Group of CNS Angiogenesis and Neurovascular Link, Neuroscience Center Zurich, and Division of Neurosurgery, University and University Hospital Zurich, Zurich, Switzerland. .,Division of Neurosurgery, University Hospital Zurich, Zurich, Switzerland. .,Group Brain Vasculature and Perivascular Niche, Division of Experimental and Translational Neuroscience, Krembil Brain Institute, Krembil Research Institute, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada. .,Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.
| | - Jeroen Bisschop
- Group of CNS Angiogenesis and Neurovascular Link, Neuroscience Center Zurich, and Division of Neurosurgery, University and University Hospital Zurich, Zurich, Switzerland.,Division of Neurosurgery, University Hospital Zurich, Zurich, Switzerland.,Group Brain Vasculature and Perivascular Niche, Division of Experimental and Translational Neuroscience, Krembil Brain Institute, Krembil Research Institute, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Arttu Miettinen
- Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland.,Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.,Department of Physics, University of Jyväskylä, Jyväskylä, Finland
| | | | | | - Eric P Meyer
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Thomas Krucker
- Novartis Institutes for BioMedical Research Inc, Emeryville, CA, USA
| | - Regula Wälchli
- Department of Dermatology, Pediatric Skin Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Philippe P Monnier
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Krembil Research Institute, Vision Division, Krembil Discovery Tower, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, KU Leuven, Leuven, Belgium.,Laboratory of Angiogenesis and Vascular Metabolism, VIB Center for Cancer Biology, VIB, Leuven, Belgium
| | - Johannes Vogel
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Marco Stampanoni
- Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland.,Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
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5
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Yee KT, Neupane B, Bai F, Vetter DE. Zika virus infection causes widespread damage to the inner ear. Hear Res 2020; 395:108000. [PMID: 32623238 DOI: 10.1016/j.heares.2020.108000] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/07/2020] [Accepted: 05/20/2020] [Indexed: 12/20/2022]
Abstract
Zika virus (ZIKV) has been recently recognized as a causative agent of newborn microcephaly, as well as other neurological consequences. A less well recognized comorbidity of prenatal ZIKV infection is hearing loss, but cases of hearing impairment following adult ZIKV infection have also been recognized. Diminished hearing following prenatal ZIKV infection in a mouse model has been reported, but no cellular consequences were observed. We examined the effects of ZIKV infection on inner ear cellular integrity and expression levels of various proteins important for cochlear function in type I interferon receptor null (Ifnar1-/-) mice following infection at 5-6 weeks of age. We show that ZIKV antigens are present in cells within the cochlear epithelium, lateral wall, spiral limbus and spiral ganglion. Here we show that ZIKV infection alters cochlear expression of genes that signal cell damage (S100B), transport fluids (AQP1), are gaseous transmitters (eNOs) and modulate immune response (F4/80). Morphological analyses shows that not only are cochlear structures compromised by ZIKV infection, but damage also occurs in vestibular end organs. ZIKV produces a graded distribution of cellular damage in the cochlea, with greatest damage in the apex similar to that reported for cytomegalovirus (CMV) infection. The graded distribution of damage may indicate a differential susceptibility to ZIKV along the cochlear tonotopic axis. Collectively, these data are the first to show the molecular and morphological damage to the inner ear induced by ZIKV infection in adults and suggests multiple mechanisms contributing to the hearing loss reported in the human population.
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Affiliation(s)
- Kathleen T Yee
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, 39202, USA
| | - Biswas Neupane
- Department of Cell and Molecular Biology, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Fengwei Bai
- Department of Cell and Molecular Biology, University of Southern Mississippi, Hattiesburg, MS, 39406, USA.
| | - Douglas E Vetter
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, 39202, USA.
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6
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Hazen M, Cushing SL. Implications of Concurrent Vestibular Dysfunction in Pediatric Hearing Loss. CURRENT OTORHINOLARYNGOLOGY REPORTS 2020. [DOI: 10.1007/s40136-020-00298-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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7
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Furness DN. Forgotten Fibrocytes: A Neglected, Supporting Cell Type of the Cochlea With the Potential to be an Alternative Therapeutic Target in Hearing Loss. Front Cell Neurosci 2019; 13:532. [PMID: 31866825 PMCID: PMC6908467 DOI: 10.3389/fncel.2019.00532] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/15/2019] [Indexed: 12/31/2022] Open
Abstract
Cochlear fibrocytes are a homeostatic supporting cell type embedded in the vascularized extracellular matrix of the spiral ligament, within the lateral wall. Here, they participate in the connective tissue syncytium that enables potassium recirculation into the scala media to take place and ensures development of the endolymphatic potential that helps drive current into hair cells during acoustic stimulation. They have also been implicated in inflammatory responses in the cochlea. Some fibrocytes interact closely with the capillaries of the vasculature in a way which suggests potential involvement, together with the stria vascularis, also in the blood-labyrinth barrier. Several lines of evidence suggests that pathology of the fibrocytes, along with other degenerative changes in this region, contribute to metabolic hearing loss (MHL) during aging that is becoming recognized as distinct from, and potentially a precursor for, sensorineural hearing loss (SNHL). This pathology may underlie a significant proportion of cases of presbycusis. Some evidence points also to an association between fibrocyte degeneration and Ménière’s disease (MD). Fibrocytes are mesenchymal; this characteristic, and their location, make them amenable to potential cell therapy in the form of cell replacement or genetic modification to arrest the process of degeneration that leads to MHL. This review explores the properties and roles of this neglected cell type and suggests potential therapeutic approaches, such as cell transplantation or genetic engineering of fibrocytes, which could be used to prevent this form of presbycusis or provide a therapeutic avenue for MD.
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Affiliation(s)
- David N Furness
- School of Life Sciences, Keele University, Keele, United Kingdom
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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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9
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Poorna Pillutla SV, Kaur C, Roy TS, Jacob TG. Estimation of Volume of Stria Vascularis and the Length of Its Capillaries in the Human Cochlea. J Microsc Ultrastruct 2019; 7:117-123. [PMID: 31548922 PMCID: PMC6753699 DOI: 10.4103/jmau.jmau_12_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background: The stria vascularis (SV) is a vascularized epithelium that secretes endolymph and is located on the lateral wall of the membranous cochlea. The capillaries of SV directly influence the composition of the endolymph and hence the generation of impulses by the hair-cells that are auditory receptors and thus affect hearing. Therefore, the real morphology of the SV would be very important for understanding the hearing system. There are few reliable reports of the morphology of the human SV. Aims and Objectives: In this research, we have estimated the volume of the SV and total length of strial capillaries in the apical, middle and basal turns of the human cochlea by updated stereological techniques. Methods: The point-counting Cavalieri's method and hemispherical volume probes were applied on stained, 40 μm-thick serial sections of five celloidin-embedded, decalcified cochleae. Results: The mean age of persons at the time of death was 51 ± 15.25 years, the mean volume of the SV was 0.56 ± 0.054 mm3 and the mean length of the SV capillaries was 289.08 ± 72.96 mm. We also estimated the same parameters with different stereological parameters, probes and in differently stained sections and checked the relationship and limits of agreement between different methods by paired t-test and Bland-Altman plot. We found agreement in our results. Conclusion: We provide reliable baseline data on the real morphology of the human SV.
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Affiliation(s)
| | - Charanjeet Kaur
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| | - Tara Sankar Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
| | - Tony George Jacob
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India
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Abstract
Sensorineural hearing loss (SNHL) in children occurs in 1 to 3% of live births and acquired hearing loss can additionally occur. This sensory deficit has far reaching consequences that have been shown to extend beyond speech and language development. Thankfully there are many therapeutic options that exist for these children with the aim of decreasing the morbidity of their hearing impairment. Of late, focus has shifted beyond speech and language outcomes to the overall performance of children with SNHL in real-world environments. To account for their residual deficits in such environments, clinicians must understand the extent of their sensory impairments. SNHL commonly coexists with other sensory deficits such as vestibular loss. Vestibular impairment is exceedingly common in children with SNHL with nearly half of children exhibiting vestibular end-organ dysfunction. These deficits naturally lead to impairments in balance and delay in motor milestones. However, this additional sensory deficit likely leads to further impairment in the performance of these children. This article focuses on the following: 1. Defining the coexistence of vestibular impairment in children with SNHL and cochlear implants. 2. Describing screening methods aimed at identifying vestibular dysfunction in children with SNHL. 3. Understanding the functional implications of this dual-sensory impairment. 4. Exploring possible rehabilitative strategies to minimize the impact of vestibular impairment in children with SNHL.
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Affiliation(s)
- Sharon L Cushing
- Department of Otolaryngology, Head and Neck Surgery, Hospital for Sick Children, Toronto, Ontario, Canada.,Cochlear Implant Program, Hospital for Sick Children, Toronto, Ontario, Canada.,Archie's Cochlear Implant Laboratory, Hospital for Sick Children, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Blake C Papsin
- Department of Otolaryngology, Head and Neck Surgery, Hospital for Sick Children, Toronto, Ontario, Canada.,Archie's Cochlear Implant Laboratory, Hospital for Sick Children, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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11
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Fitzakerley JL, Trachte GJ. Genetics of guanylyl cyclase pathways in the cochlea and their influence on hearing. Physiol Genomics 2018; 50:780-806. [PMID: 29958079 DOI: 10.1152/physiolgenomics.00056.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Although hearing loss is the most common sensory deficit in Western societies, there are no successful pharmacological treatments for this disorder. Recent experiments have demonstrated that manipulation of intracellular cyclic guanosine monophosphate (cGMP) concentrations can have both beneficial and harmful effects on hearing. In this review, we will examine the role of cGMP as a key second messenger involved in many aspects of cochlear function and discuss the known functions of downstream effectors of cGMP in sound processing. The nitric oxide-stimulated soluble guanylyl cyclase system (sGC) and the two natriuretic peptide-stimulated particulate GCs (pGCs) will be more extensively covered because they have been studied most thoroughly. The cochlear GC systems are attractive targets for medical interventions that improve hearing while simultaneously representing an under investigated source of sensorineural hearing loss.
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Affiliation(s)
- Janet L Fitzakerley
- Department of Biomedical Sciences, University of Minnesota Medical School , Duluth, Minnesota
| | - George J Trachte
- Department of Biomedical Sciences, University of Minnesota Medical School , Duluth, Minnesota
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12
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Evaluation and management of cytomegalovirus-associated congenital hearing loss. Curr Opin Otolaryngol Head Neck Surg 2018; 25:390-395. [PMID: 28857892 DOI: 10.1097/moo.0000000000000401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The current article reviews the current literature related to congenital cytomegalovirus (CMV)-related hearing loss. The discussion will focus on the epidemiology, pathogenesis, and clinical presentation of human CMV infection as it pertains to hearing loss. Current methods of CMV diagnosis with a focus on the evolving trend toward broader neonatal screening protocols will also be explored. Discussion of medical, surgical, and audiologic management of the condition will also be addressed. RECENT FINDINGS Much of the current research on this topic is focused on improving detection of CMV through screening programs. Some advances in understanding cochlear pathogenesis have also been made. SUMMARY Congenital CMV infection remains an important cause of hearing loss in infants and children. Early detection of CMV infection can broaden treatment options and allow for improved hearing and language outcome for patients with CMV-associated sensorineural hearing loss.
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13
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Bertlich M, Ihler F, Weiss BG, Freytag S, Strupp M, Jakob M, Canis M. Role of capillary pericytes and precapillary arterioles in the vascular mechanism of betahistine in a guinea pig inner ear model. Life Sci 2017; 187:17-21. [DOI: 10.1016/j.lfs.2017.08.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/03/2017] [Accepted: 08/14/2017] [Indexed: 10/19/2022]
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14
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Carraro M, Almishaal A, Hillas E, Firpo M, Park A, Harrison RV. Cytomegalovirus (CMV) Infection Causes Degeneration of Cochlear Vasculature and Hearing Loss in a Mouse Model. J Assoc Res Otolaryngol 2016; 18:263-273. [PMID: 27995350 DOI: 10.1007/s10162-016-0606-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 11/24/2016] [Indexed: 12/20/2022] Open
Abstract
Cytomegalovirus (CMV) infection is one of the most common causes of congenital hearing loss in children. We have used a murine model of CMV infection to reveal functional and structural cochlear pathogenesis. The cerebral cortex of Balb/c mice (Mus musculus) was inoculated with 2000 pfu (plaque forming units) of murine CMV on postnatal day 3. At 6 weeks of age, cochlear function was monitored using auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) measures. Histological assessment of cochlear vasculature using a corrosion cast technique was made at 8 weeks. Vascular casts of mCMV-damaged cochleas, and those of untreated control animals, were examined using scanning electron microscopy. We find very large variations in the degree of vascular damage in animals given identical viral injections (2000 pfu). The primary lesion caused by CMV infection is to the stria vascularis and to the adjacent spiral limbus capillary network. Capillary beds of the spiral ligament are generally less affected. The initial vascular damage is found in the mid-apical turn and appears to progress to more basal cochlear regions. After viral migration to the inner ear, the stria vascularis is the primary affected structure. We suggest that initial auditory threshold losses may relate to the poor development or maintenance of the endocochlear potential caused by strial dysfunction. Our increased understanding of the pathogenesis of CMV-related hearing loss is important for defining methods for early detection and treatment.
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Affiliation(s)
- Mattia Carraro
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Auditory Science Laboratory, Neuroscience and Mental Health Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Ali Almishaal
- Department of Communication Sciences and Disorders, University of Utah, Salt Lake City, UT, USA
| | - Elaine Hillas
- Department of Surgery, University of Utah, Salt Lake City, UT, USA
| | - Matthew Firpo
- Department of Surgery, University of Utah, Salt Lake City, UT, USA
| | - Albert Park
- Department of Surgery, University of Utah, Salt Lake City, UT, USA
- Department of Otolaryngology, University of Utah, Salt Lake City, UT, USA
| | - Robert V Harrison
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
- Auditory Science Laboratory, Neuroscience and Mental Health Program, The Hospital for Sick Children, Toronto, ON, Canada.
- Department of Otolaryngology, Head and Neck Surgery, University of Toronto, Toronto, ON, Canada.
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