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Yang CC, Yap PT, Wu Y, Zidan N, Fefer G, Nelson NC, Gruen ME, Olby NJ. Voxelwise analysis of the central hearing pathway in senior dogs reveals changes associated with fractional lifespan. Sci Rep 2024; 14:18121. [PMID: 39103441 PMCID: PMC11300839 DOI: 10.1038/s41598-024-68828-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 07/29/2024] [Indexed: 08/07/2024] Open
Abstract
Presbycusis, or age-related hearing loss, affects both elderly humans and dogs, significantly impairing their social interactions and cognition. In humans, presbycusis involves changes in peripheral and central auditory systems, with central changes potentially occurring independently. While peripheral presbycusis in dogs is well-documented, research on central changes remains limited. Diffusion tensor imaging (DTI) is a useful tool for detecting and quantifying cerebral white matter abnormalities. This study used DTI to explore the central auditory pathway of senior dogs, aiming to enhance our understanding of canine presbycusis. Dogs beyond 75% of their expected lifespan were recruited and screened with brainstem auditory evoked response testing to select dogs without severe peripheral hearing loss. Sixteen dogs meeting the criteria were scanned using a 3 T magnetic resonance scanner. Tract-based spatial statistics was used to analyze the central auditory pathways. A significant negative correlation between fractional lifespan and fractional anisotropy was found in the acoustic radiation, suggesting age-related white matter changes in the central auditory system. These changes, observed in dogs without severe peripheral hearing loss, may contribute to central presbycusis development.
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Affiliation(s)
- Chin-Chieh Yang
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Pew-Thian Yap
- Department of Radiology and Biomedical Research Imaging Center (BRIC), University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ye Wu
- School of Computer Science and Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, China
| | - Natalia Zidan
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Gilad Fefer
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Nathan C Nelson
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Margaret E Gruen
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA
| | - Natasha J Olby
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA.
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2
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Stanger A, Buhmann G, Dörfelt S, Zablotski Y, Fischer A. Rapid hearing threshold assessment with modified auditory brainstem response protocols in dogs. Front Vet Sci 2024; 11:1358410. [PMID: 38511189 PMCID: PMC10951061 DOI: 10.3389/fvets.2024.1358410] [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: 12/19/2023] [Accepted: 02/26/2024] [Indexed: 03/22/2024] Open
Abstract
Introduction Auditory brainstem response (ABR) is the gold standard for hearing testing in dogs. ABR is commonly used in puppies to diagnose congenital sensorineural deafness. Long test times limit the use for a more comprehensive hearing screening in veterinary practice. This study aimed to establish a super-fast hearing screening protocol in dogs. Methods Hearing thresholds were routinely measured with a mobile device designed for newborn hearing screening in 90 dogs. We introduced modifications of the ABR protocol, e. g., a binaural test mode, higher stimulus rates, a broadband chirp stimulus, and an algorithm for automatic peak V detection in a stepwise fashion. Hearing thresholds were then measured with fast protocols utilizing either 30 Hz click or 90 Hz broadband chirp stimuli with 80, 60, 40, 30, 20, 10, 0 and -10 dBnHL stimulation intensities. Interrater reliability, agreement between click and chirp hearing thresholds and correlations with clinical characteristics of the dogs were assessed. Results Using all innovations, the test time for hearing threshold assessment in both ears was reduced to 1.11 min (mean). The chirp stimulus accentuated both, peak V and the subsequent trough, which are essential features for judgement of the hearing threshold, but preceding peaks were less conspicuous. Interrater reliability and agreement between click and chirp hearing threshold was excellent. Dogs >10 years of age and dogs with abnormal hearing score or otitis score had significantly higher hearing thresholds than younger dogs (p ≤ 0.001) or dogs without abnormalities (p < 0.001). Conclusion The results demonstrate that modifications in ABR protocols speed-up test times significantly while the quality of the recordings for hearing threshold assessment is maintained. Modified ABR protocols enable super-fast hearing threshold assessment in veterinary practice.
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Affiliation(s)
| | | | | | | | - Andrea Fischer
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, Munich, Germany
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3
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Montel C, Arribarat G, Cartiaux B, Gaide N, Mogicato G. Tomodensitometric and histological age-related changes in the normal feline middle and inner ear. Anat Histol Embryol 2023; 52:798-804. [PMID: 37334847 DOI: 10.1111/ahe.12939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 06/08/2023] [Indexed: 06/21/2023]
Abstract
Deafness in cats may be due to acquired causes such as aging. Similar age-related morphological changes in the cochlea have been noted in several animal species. However, little is known about the effects of age on the morphology of the middle and inner ear in cats. The aim of the present study was to compare these structures in middle-aged and geriatric cats using computed tomography and histological morphometric analysis. Data were obtained from 28 cats, aged 3-18 years, with no hearing or neurological disorders. Computed tomography showed an increase in tympanic bulla (middle ear) volume with aging. Histological morphometric analysis revealed thickening of the basilar membrane and atrophy of the stria vascularis (inner ear) in older cats, similar to what has been observed in older humans and dogs. Nevertheless, histological procedures could be improved to provide more data for comparison with different forms of presbycusis in humans.
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Affiliation(s)
- Charles Montel
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, INSERM, UPS, ENVT, Toulouse, France
| | - Germain Arribarat
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, INSERM, UPS, Toulouse, France
| | - Benjamin Cartiaux
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, INSERM, UPS, ENVT, Toulouse, France
| | | | - Giovanni Mogicato
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, INSERM, UPS, ENVT, Toulouse, France
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Sound Localization Ability in Dogs. Vet Sci 2022; 9:vetsci9110619. [DOI: 10.3390/vetsci9110619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
The minimum audible angle (MAA), defined as the smallest detectable difference between the azimuths of two identical sources of sound, is a standard measure of spatial auditory acuity in animals. Few studies have explored the MAA of dogs, using methods that do not allow potential improvement throughout the assessment, and with a very small number of dog(s) assessed. To overcome these limits, we adopted a staircase method on 10 dogs, using a two-forced choice procedure with two sound sources, testing angles of separation from 60° to 1°. The staircase method permits the level of difficulty for each dog to be continuously adapted and allows for the observation of improvement over time. The dogs’ average MAA was 7.6°, although with a large interindividual variability, ranging from 1.3° to 13.2°. A global improvement was observed across the procedure, substantiated by a gradual lowering of the MAA and of choice latency across sessions. The results indicate that the staircase method is feasible and reliable in the assessment of auditory spatial localization in dogs, highlighting the importance of using an appropriate method in a sensory discrimination task, so as to allow improvement over time. The results also reveal that the MAA of dogs is more variable than previously reported, potentially reaching values lower than 2°. Although no clear patterns of association emerged between MAA and dogs’ characteristics such as ear shape, head shape or age, the results suggest the value of conducting larger-scale studies to determine whether these or other factors influence sound localization abilities in dogs.
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Fefer G, Khan MZ, Panek WK, Case B, Gruen ME, Olby NJ. Relationship between hearing, cognitive function, and quality of life in aging companion dogs. J Vet Intern Med 2022; 36:1708-1718. [PMID: 35932193 PMCID: PMC9511086 DOI: 10.1111/jvim.16510] [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: 12/28/2021] [Accepted: 07/19/2022] [Indexed: 12/02/2022] Open
Abstract
Background Elderly people with presbycusis are at higher risk for dementia and depression than the general population. There is no information regarding consequences of presbycusis in dogs. Objective Evaluate the relationship between cognitive function, quality of life, and hearing loss in aging companion dogs. Animals Thirty‐nine elderly companion dogs. Methods Prospective study. Hearing was evaluated using brainstem auditory evoked response (BAER) testing. Dogs were grouped by hearing ability. Owners completed the canine dementia scale (CADES) and canine owner‐reported quality of life (CORQ) questionnaire. Cognitive testing was performed, and cognitive testing outcomes, CADES and CORQ scores and age were compared between hearing groups. Results Nineteen dogs could hear at 50 dB, 12 at 70 dB, and 8 at 90 dB with mean ages (months) of 141 ± 14, 160 ± 16, and 172 ± 15 for each group respectively (P = .0002). Vitality and companionship CORQ scores were significantly lower as hearing deteriorated (6.6‐5.4, 50‐90 dB group, P = .03 and 6.9‐6.2, 50‐90 dB group, P = .02, respectively). Cognitive classification by CADES was abnormal in all 90 dB group dogs and normal in 3/12 70 dB group and 11/19 50 dB group dogs (P = .0004). Performance on inhibitory control, detour and sustained gaze tasks decreased significantly with hearing loss (P = .001, P = .008, P = .002, respectively). In multivariate analysis, higher CADES score was associated with worse hearing (P = .01). Conclusions and Clinical Importance Presbycusis negatively alters owner‐pet interactions and is associated with poor executive performance and owner‐assessed dementia severity.
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Affiliation(s)
- Gilad Fefer
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Michael Z Khan
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Wojciech K Panek
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.,Department of Surgical and Radiological Sciences, University of California, Davis, California, USA
| | - Beth Case
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Margaret E Gruen
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Natasha J Olby
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
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6
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Neubert A, Tannert S, Pirk G. [Hearing loss following the use of topical otitis therapeutics in dogs]. TIERARZTLICHE PRAXIS. AUSGABE K, KLEINTIERE/HEIMTIERE 2022; 50:269-278. [PMID: 36067769 DOI: 10.1055/a-1907-4387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
OBJECTIVE Hearing loss occurring in temporal association with the topical application of otic medications is regularly reported to the Federal Office of Consumer Protection and Food Safety (Bundesamt für Verbraucherschutz und Lebensmittelsicherheit - BVL) in the form of adverse event (AE) reports. Although deafness or impaired hearing are listed as possible adverse reactions in the Summary of Product Characteristics of the otic medications approved in Germany little information about the underlying causes is available to date. MATERIAL AND METHODS A search for cases reporting impaired hearing following the use of otic medication was conducted in the national AE database. Subsequently, descriptive analysis was performed. Due to their small number, cases involving cats were excluded. Possible risk factors and causes of hearing loss were considered against the background of current literature. RESULTS While dogs of all age groups were affected, the majority of reports referred to dogs older than 10 years of age. Besides crossbreds, dogs of the breeds West Highland White Terrier, Dalmatian, Miniature Poodle and French Bulldog were most frequently involved. The analysis of the available data does not point to specific products or active substances that could be associated with a more frequent occurrence of hearing loss. CONCLUSION AND CLINICAL RELEVANCE In addition to possible ototoxicity of a product, other causes of hearing loss should be considered. These include the underlying otitis itself, age-related hearing loss, previously undetected unilateral congenital deafness, or conductive deafness due to obstruction of the ear canal. Treatment options include discontinuation of potentially ototoxic substances or treatment of conductive deafness, e. g. by removal of drug residues and exudate or treatment of otitis media. In the case of hearing loss subsequent to the use of otic medication, the BVL should be notified of this event in as much detail as possible in order to further improve the data situation concerning this topic.
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Affiliation(s)
- Ann Neubert
- Bundesamt für Verbraucherschutz und Lebensmittelsicherheit
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7
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Voelker J, Voelker C, Engert J, Goemann N, Hagen R, Rak K. Spontaneous Calcium Oscillations through Differentiation: A Calcium Imaging Analysis of Rat Cochlear Nucleus Neural Stem Cells. Cells 2021; 10:2802. [PMID: 34685782 PMCID: PMC8534573 DOI: 10.3390/cells10102802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/14/2021] [Accepted: 10/14/2021] [Indexed: 11/28/2022] Open
Abstract
Causal therapies for the auditory-pathway and inner-ear diseases are still not yet available for clinical application. Regenerative medicine approaches are discussed and examined as possible therapy options. Neural stem cells could play a role in the regeneration of the auditory pathway. In recent years, neural stem and progenitor cells have been identified in the cochlear nucleus, the second nucleus of the auditory pathway. The current investigation aimed to analyze cell maturation concerning cellular calcium activity. Cochlear nuclei from PND9 CD rats were microscopically dissected and propagated as neurospheres in free-floating cultures in stem-cell medium (Neurobasal, B27, GlutaMAX, EGF, bFGF). After 30 days, the dissociation and plating of these cells took place under withdrawal of the growth factors and the addition of retinoic acid, which induces neural cell differentiation. Calcium imaging analysis with BAPTA-1/Oregon Green was carried out at different times during the differentiation phase. In addition, the influence of different voltage-dependent calcium channels was analyzed through the targeted application of inhibitors of the L-, N-, R- and T-type calcium channels. For this purpose, comparative examinations were performed on CN NSCs, and primary CN neurons. As the cells differentiated, a significant increase in spontaneous neuronal calcium activity was demonstrated. In the differentiation stage, specific frequencies of the spontaneous calcium oscillations were measured in different regions of the individual cells. Initially, the highest frequency of spontaneous calcium oscillations was ascertainable in the maturing somata. Over time, these were overtaken by calcium oscillations in the axons and dendrites. Additionally, in the area of the growth cones, an increasing activity was determined. By inhibiting voltage-dependent calcium channels, their expression and function in the differentiation process were confirmed. A comparable pattern of maturation of these channels was found in CN NSCs and primary CN neurons. The present results show that neural stem cells of the rat cochlear nucleus differentiated not only morphologically but also functionally. Spontaneous calcium activities are of great relevance in terms of neurogenesis and integration into existing neuronal structures. These functional aspects of neurogenesis within the auditory pathway could serve as future targets for the exogenous control of neuronal regeneration.
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Affiliation(s)
- Johannes Voelker
- Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, Department of Oto-Rhino-Laryngology, University of Wuerzburg Josef-Schneider-Strasse 11, D-97080 Wuerzburg, Germany; (C.V.); (J.E.); (N.G.); (R.H.); (K.R.)
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8
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Bassani S, Beelen E, Rossel M, Voisin N, Morgan A, Arribat Y, Chatron N, Chrast J, Cocca M, Delprat B, Faletra F, Giannuzzi G, Guex N, Machavoine R, Pradervand S, Smits JJ, van de Kamp JM, Ziegler A, Amati F, Marlin S, Kremer H, Locher H, Maurice T, Gasparini P, Girotto G, Reymond A. Variants in USP48 encoding ubiquitin hydrolase are associated with autosomal dominant non-syndromic hereditary hearing loss. Hum Mol Genet 2021; 30:1785-1796. [PMID: 34059922 DOI: 10.1093/hmg/ddab145] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/25/2021] [Accepted: 05/25/2021] [Indexed: 02/07/2023] Open
Abstract
Non-Syndromic Hereditary Hearing Loss (NSHHL) is a genetically heterogeneous sensory disorder with about 120 genes already associated. Through exome sequencing and data aggregation, we identified a family with six affected individuals and one unrelated NSHHL patient with predicted-to-be deleterious missense variants in USP48. We also uncovered an eighth patient presenting unilateral cochlear nerve aplasia and a de novo splice variant in the same gene. USP48 encodes a ubiquitin carboxyl-terminal hydrolase under evolutionary constraint. Pathogenicity of the variants is supported by in vitro assays that showed that the mutated proteins are unable to hydrolyze tetra-ubiquitin. Correspondingly, three-dimensional representation of the protein containing the familial missense variant affects a loop that controls binding to ubiquitin. Consistent with a contribution of USP48 to auditory function, immunohistology showed that the encoded protein is expressed in the developing human inner ear, specifically in the spiral ganglion neurons, outer sulcus, interdental cells of the spiral limbus, stria vascularis, Reissner's membrane, and in the transient Kolliker's organ that is essential for auditory development. Engineered zebrafish knocked-down for usp48, the USP48 ortholog, presented with a delayed development of primary motor neurons, less developed statoacoustic neurons innervating the ears, decreased swimming velocity and circling swimming behavior indicative of vestibular dysfunction and hearing impairment. Corroboratingly, acoustic startle response assays revealed a significant decrease of auditory response of zebrafish lacking usp48 at 600 Hz and 800 Hz wavelengths. In conclusion, we describe a novel autosomal dominant NSHHL gene through a multipronged approach combining exome sequencing, animal modeling, immunohistology and molecular assays.
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Affiliation(s)
- Sissy Bassani
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.,Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy
| | - Edward Beelen
- Department of Otorhinolaryngology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Norine Voisin
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Anna Morgan
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy.,Institute for Maternal and Child Health, IRCCS, Burlo Garofolo, Trieste, Italy
| | - Yoan Arribat
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Nicolas Chatron
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.,Service de Génétique, Hospices Civils de Lyon, Lyon, France
| | - Jacqueline Chrast
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Massimiliano Cocca
- Institute for Maternal and Child Health, IRCCS, Burlo Garofolo, Trieste, Italy
| | | | - Flavio Faletra
- Institute for Maternal and Child Health, IRCCS, Burlo Garofolo, Trieste, Italy
| | - Giuliana Giannuzzi
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Nicolas Guex
- Bioinformatics Competence Center, University of Lausanne, Lausanne, Switzerland
| | - Roxane Machavoine
- Centre de référence Surdités Génétiques, Hôpital Necker, Institut Imagine, Paris, France
| | - Sylvain Pradervand
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Jeroen J Smits
- Department of Otorhinolaryngology and Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jiddeke M van de Kamp
- Department of Clinical Genetics, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Alban Ziegler
- Centre de référence Surdités Génétiques, Hôpital Necker, Institut Imagine, Paris, France
| | - Francesca Amati
- Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Sandrine Marlin
- Centre de référence Surdités Génétiques, Hôpital Necker, Institut Imagine, Paris, France
| | - Hannie Kremer
- Department of Otorhinolaryngology and Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Heiko Locher
- Department of Otorhinolaryngology, Leiden University Medical Center, Leiden, The Netherlands
| | - Tangui Maurice
- MMDN, Univ Montpellier, EPHE, INSERM, Montpellier, France
| | - Paolo Gasparini
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy.,Institute for Maternal and Child Health, IRCCS, Burlo Garofolo, Trieste, Italy
| | - Giorgia Girotto
- Department of Medicine, Surgery and Health Sciences, University of Trieste, Trieste, Italy.,Institute for Maternal and Child Health, IRCCS, Burlo Garofolo, Trieste, Italy
| | - Alexandre Reymond
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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9
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Bognár Z, Piotti P, Szabó D, Le Nézet L, Kubinyi E. A novel behavioural approach to assess responsiveness to auditory and visual stimuli before cognitive testing in family dogs. Appl Anim Behav Sci 2020. [DOI: 10.1016/j.applanim.2020.105016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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10
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Kaur C, Saini S, Pal I, Kumar P, Chandra Sati H, Jacob TG, Bhardwaj DN, Roy TS. Age-related changes in the number of cresyl-violet-stained, parvalbumin and NMDAR 2B expressing neurons in the human spiral ganglion. Hear Res 2020; 388:107883. [PMID: 31981822 DOI: 10.1016/j.heares.2020.107883] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/12/2019] [Accepted: 12/31/2019] [Indexed: 01/11/2023]
Abstract
Animal-studies associate age-related hearing loss (presbycusis) with decreasing number of spiral ganglion neurons (SGNs) in Rosenthal's canal (RC) of cochlea. The excitatory neurotransmitter for SGNs is glutamate (through its receptor NMDAR 2B), which can be neurotoxic through Ca2+ overload. Neurotoxicity is balanced by calcium-binding proteins (CBPs) like Parvalbumin (PV), which is the predominant CBP of the SGNs. To estimate the volume of the RC and total number of SGNs that are immunoreactive to PV and NMDAR 2B, we used unbiased stereology in 35 human cochleae derived from cadavers of persons from 2nd to 8th decade of life (subsequently statistically divided into two groups) and compared them to the total number of cresyl violet (CV) stained SGNs. We also estimated the volume of individual neurons and their nuclei. Regression analysis was made on estimated parameters against age. Hierarchical-cluster analysis was done on the neuronal against neuronal nuclear volumes.The average volume of the RC did not change with increasing age (p = 0.4115). The total number of SGNs (CV-stained and those separately expressing PV and NMDAR 2B) significantly decreased with age (p < 0.001). We identified three distinct populations of neurons on the basis of their volumes among SGNs. Thus, there is significant age-related decline in the total number of SGNs, which starts early in life. It may be due to ambient noise and inadequate neutralisation of excitotoxicity.
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Affiliation(s)
- Charanjeet Kaur
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Shubhi Saini
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Indra Pal
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Punit Kumar
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Hem Chandra Sati
- Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Tony George Jacob
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Daya Nand Bhardwaj
- Department of Forensic Medicine and Toxicology, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Tara Sankar Roy
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi, 110029, India.
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Abstract
Practical relevance: Auditory function is a sense that is central to life for cats - being important in situational awareness of potential predators, pursuit of prey, and for communication with conspecifics, humans and other species. Deafness in cats is most frequently the result of a genetic disorder, strongly associated with white fur and blue eyes, but may also result from acquired causes such as advancing age, ototoxic drugs, infection, environmental noise and physical trauma. Deafness can be sensorineural, where there is loss of cochlear hair cells, or conductive, where sound is muffled on its way to the inner ear. Clinical challenges: Establishing whether a cat is deaf can be difficult as behavioral testing of hearing is subjective and does not reliably detect unilateral deafness. Brainstem auditory evoked response testing is an objective measure but is limited in its availability. Currently, sensorineural deafness is irreversible because no treatments are available to restore lost hair cells. Conductive hearing loss can usually be treated, although full hearing recovery following otitis media may take weeks as the body clears the middle ear of debris. Evidence base: The author draws on the published literature and his extensive research on clinical aspects and molecular genetics of deafness, principally in companion animals, to review types and forms of deafness in cats. He also discusses current diagnostic approaches and provides brief advice for managing cats with hearing loss.
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Affiliation(s)
- George M Strain
- Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
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12
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Strain GM, McGee KA. Distortion product otoacoustic emissions in young adult and geriatric cats. Vet J 2017; 221:34-37. [PMID: 28283078 DOI: 10.1016/j.tvjl.2017.01.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 01/25/2017] [Accepted: 01/30/2017] [Indexed: 12/25/2022]
Abstract
Recordings of distortion product otoacoustic emissions (DPOAEs) were taken from 15 geriatric cats (mean age ± standard deviation, SD, 13.6 ± 2.7 years; range 10.2-19.4 years) and 12 young adult control cats (mean ± SD 4.6 ± 0.5 years; range 3.4-5 years) to identify frequency-specific age-related changes in cochlear responses. Recordings were performed for primary frequencies from 2 to 12 kHz in 2 kHz increments. Cats were considered to be geriatric > 11.9 ± 1.9 years of age. Brainstem auditory evoked response (BAER) recordings were also made for subjective comparison with DPOAE responses. No differences in DPOAE response amplitudes were observed at any tested frequency in geriatric cats compared to control cats, reflecting an apparent absence of loss of cochlear outer hair cells along the length of the cochlea. No linear regression relationships were found for DPOAE response amplitude versus age in geriatric cats, despite the progressive nature of age-related hearing loss in other species. The absence of reductions in response at any of the tested frequencies in cats within the age span where cats are considered to be geriatric indicates that age-related hearing loss, if it does develop in cats, begins later in the life span of cats than in dogs or human beings.
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Affiliation(s)
- George M Strain
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
| | - Kain A McGee
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
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13
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Distortion product otoacoustic emissions in geriatric dogs. Vet J 2016; 216:101-6. [DOI: 10.1016/j.tvjl.2016.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 05/30/2016] [Accepted: 07/17/2016] [Indexed: 01/22/2023]
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Bellows J, Colitz CMH, Daristotle L, Ingram DK, Lepine A, Marks SL, Sanderson SL, Tomlinson J, Zhang J. Common physical and functional changes associated with aging in dogs. J Am Vet Med Assoc 2016; 246:67-75. [PMID: 25517328 DOI: 10.2460/javma.246.1.67] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Jan Bellows
- Pets Dental, 17100 Royal Palm Blvd, Weston, FL 33326
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Palumbo MIP, Resende LADL, Pantoja JCDF, Mayhew IG, Borges AS. Brainstem auditory-evoked potential in Boxer dogs. PESQUISA VETERINARIA BRASILEIRA 2014. [DOI: 10.1590/s0100-736x2014001000014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Brainstem auditory-evoked potential (BAEP) has been widely used for different purposes in veterinary practice and is commonly used to identify inherited deafness and presbycusis. In this study, 43 Boxer dogs were evaluated using the BAEP. Deafness was diagnosed in 3 dogs (2 bilateral and 1 unilateral) allowing the remaining 40 Boxers to be included for normative data analysis including an evaluation on the influence of age on the BAEP. The animals were divided into 2 groups of 20 Boxers each based on age. The mean age was 4.54 years (range, 1-8) in group I, and 9.83 years (range, 8.5-12) in group II. The mean latency for I, III, and V waves were 1.14 (±0.07), 2.64 (±0.11), and 3.48 (±0.10) ms in group I, and 1.20 (±0.12), 2.73 (±0.15), and 3.58 (±0.22) ms in group II, respectively. The mean inter-peak latencies for the I-III, III-V and I-V intervals were 1.50 (±0.15), 0.84 (±0.15), and 2.34 (±0.11) ms in group I, and 1.53 (±0.16), 0.85 (±0.15), and 2.38 (±0.19) ms in group II, respectively. Latencies of waves I and III were significant different between group I and II. For the I-III, III-V and I-V intervals, no significant differences were observed between the 2 groups. As far as we know, this is the first normative study of BAEP obtained from Boxer dogs.
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Gröschel M, Hubert N, Müller S, Ernst A, Basta D. Age-dependent changes of calcium related activity in the central auditory pathway. Exp Gerontol 2014; 58:235-43. [DOI: 10.1016/j.exger.2014.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 07/31/2014] [Accepted: 08/28/2014] [Indexed: 10/24/2022]
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Age-related hearing loss in Mn-SOD heterozygous knockout mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:325702. [PMID: 23936608 PMCID: PMC3710654 DOI: 10.1155/2013/325702] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Accepted: 06/02/2013] [Indexed: 01/07/2023]
Abstract
Age-related hearing loss (AHL) reduces the quality of life for many elderly individuals. Manganese superoxide dismutase (Mn-SOD), one of the antioxidant enzymes acting within the mitochondria, plays a crucial role in scavenging reactive oxygen species (ROS). To determine whether reduction in Mn-SOD accelerates AHL, we evaluated auditory function in Mn-SOD heterozygous knockout (HET) mice and their littermate wild-type (WT) C57BL/6 mice by means of auditory brainstem response (ABR). Mean ABR thresholds were significantly increased at 16 months when compared to those at 4 months in both WT and HET mice, but they did not significantly differ between them at either age. The extent of hair cell loss, spiral ganglion cell density, and thickness of the stria vascularis also did not differ between WT and HET mice at either age. At 16 months, immunoreactivity of 8-hydroxydeoxyguanosine was significantly greater in the SGC and SV in HET mice compared to WT mice, but that of 4-hydroxynonenal did not differ between them. These findings suggest that, although decrease of Mn-SOD by half may increase oxidative stress in the cochlea to some extent, it may not be sufficient to accelerate age-related cochlear damage under physiological aging process.
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Palumbo M, Resende L, Borges A. Estudo normativo e avaliação da influência da idade no potencial evocado auditivo em cães sem raça definida. ARQ BRAS MED VET ZOO 2013. [DOI: 10.1590/s0102-09352013000300002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
O objetivo deste trabalho foi realizar estudo normativo dos potenciais evocados auditivos obtidos de 34 cães sem raça definida e avaliar a influência da idade nos resultados obtidos. Os animais foram divididos em dois grupos de diferentes faixas etárias e o potencial evocado auditivo foi realizado com um estímulo de 85dB. O grupo 1 incluiu 16 cães com idades entre um e oito anos e o grupo 2, 18 animais com idades acima de oito anos. O comprimento e o diâmetro da cabeça foram mensurados e não houve diferença estatística entre os dois grupos. No grupo 1, as médias das latências das ondas I, III e V foram: 1,13; 2,64 e 3,45ms; e dos intervalos I-III, III-V e I-V foram 1,51; 0,81 e 2,32ms, respectivamente. No grupo 2, as médias das latências das ondas I, III e V foram 1,15; 2,62 e 3,55ms; e dos intervalos I-III, III-V e I-V foram 1,47; 0,93 e 2,40ms, respectivamente. As latências observadas neste estudo foram semelhantes a estudos prévios realizados por outros autores. Nos grupos etários analisados e nas condições preestabelecidas deste estudo, a idade influenciou a latência da onda V e, consequentemente, modificou os intervalos III-V e I-V, portanto deve-se considerar essa variante na interpretação dos resultados do BAEP em cães.
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Yokoyama JS, Lam ET, Ruhe AL, Erdman CA, Robertson KR, Webb AA, Williams DC, Chang ML, Hytönen MK, Lohi H, Hamilton SP, Neff MW. Variation in genes related to cochlear biology is strongly associated with adult-onset deafness in border collies. PLoS Genet 2012; 8:e1002898. [PMID: 23028339 PMCID: PMC3441646 DOI: 10.1371/journal.pgen.1002898] [Citation(s) in RCA: 17] [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: 02/27/2012] [Accepted: 06/29/2012] [Indexed: 01/22/2023] Open
Abstract
Domestic dogs can suffer from hearing losses that can have profound impacts on working ability and quality of life. We have identified a type of adult-onset hearing loss in Border Collies that appears to have a genetic cause, with an earlier age of onset (3–5 years) than typically expected for aging dogs (8–10 years). Studying this complex trait within pure breeds of dog may greatly increase our ability to identify genomic regions associated with risk of hearing impairment in dogs and in humans. We performed a genome-wide association study (GWAS) to detect loci underlying adult-onset deafness in a sample of 20 affected and 28 control Border Collies. We identified a region on canine chromosome 6 that demonstrates extended support for association surrounding SNP Chr6.25819273 (p-value = 1.09×10−13). To further localize disease-associated variants, targeted next-generation sequencing (NGS) of one affected and two unaffected dogs was performed. Through additional validation based on targeted genotyping of additional cases (n = 23 total) and controls (n = 101 total) and an independent replication cohort of 16 cases and 265 controls, we identified variants in USP31 that were strongly associated with adult-onset deafness in Border Collies, suggesting the involvement of the NF-κB pathway. We found additional support for involvement of RBBP6, which is critical for cochlear development. These findings highlight the utility of GWAS–guided fine-mapping of genetic loci using targeted NGS to study hereditary disorders of the domestic dog that may be analogous to human disorders. The domestic dog offers a unique opportunity to study complex disorders similar to those seen in humans, but within the context of the much simpler genetic backgrounds of pure breeds, which represent closed populations. We performed a whole-genome search for genetic risk factors of adult-onset deafness in the Border Collie, a breed of herding dog that relies on acute hearing to perceive and respond to commands while working. Adult-onset deafness in Border Collies typically begins in early adulthood and is similar to age-related hearing loss in humans. This earlier onset has particular impact on the utility of working Border Collies and the livelihoods of their owners, and it appears to have a genetic cause. We identified three genetic variants that were strongly associated with adult-onset deafness in a sample of 405 Border Collies. These variants are located in two genes that have previously been linked to deafness, one involved in ear development and another that appears to mitigate tissue damage in the ear. These results provide new insight regarding genetic risk factors for age-related hearing loss in both dogs and humans.
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Affiliation(s)
- Jennifer S. Yokoyama
- Department of Psychiatry and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Ernest T. Lam
- Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Alison L. Ruhe
- Neurogenomics Division, The Translational Genomics Research Institute, Phoenix, Arizona, United States of America
- Veterinary Genetics Laboratory, University of California Davis, Davis, California, United States of America
| | - Carolyn A. Erdman
- Department of Psychiatry and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Kathryn R. Robertson
- Veterinary Genetics Laboratory, University of California Davis, Davis, California, United States of America
| | - Aubrey A. Webb
- CullenWebb Animal Neurology and Ophthalmology Centre, Riverview, New Brunswick, Canada
- Department of Clinical Neuroscience, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - D. Colette Williams
- School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - Melanie L. Chang
- Department of Anthropology, University of Oregon, Eugene, Oregon, United States of America
| | - Marjo K. Hytönen
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Medicine, University of Helsinki and Folkhälsan Research Center, Helsinki, Finland
| | - Hannes Lohi
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Medicine, University of Helsinki and Folkhälsan Research Center, Helsinki, Finland
| | - Steven P. Hamilton
- Department of Psychiatry and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Mark W. Neff
- Neurogenomics Division, The Translational Genomics Research Institute, Phoenix, Arizona, United States of America
- The Van Andel Research Institute, Grand Rapids, Michigan, United States of America
- * E-mail:
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Harcourt-Brown TR, Parker JE, Granger N, Jeffery ND. Effect of middle ear effusion on the brain-stem auditory evoked response of Cavalier King Charles Spaniels. Vet J 2010; 188:341-5. [PMID: 21194995 DOI: 10.1016/j.tvjl.2010.05.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2009] [Revised: 05/04/2010] [Accepted: 05/15/2010] [Indexed: 10/18/2022]
Abstract
Brain-stem auditory evoked responses (BAER) were assessed in 23 Cavalier King Charles Spaniels with and without middle ear effusion at sound intensities ranging from 10 to 100 dB nHL. Significant differences were found between the median BAER threshold for ears where effusions were present (60 dB nHL), compared to those without (30 dB nHL) (P=0.001). The slopes of latency-intensity functions from both groups did not differ, but the y-axis intercept when the x value was zero was greater in dogs with effusions (P=0.009), consistent with conductive hearing loss. Analysis of latency-intensity functions suggested the degree of hearing loss due to middle ear effusion was 21 dB (95% confidence between 10 and 33 dB). Waves I-V inter-wave latency at 90 dB nHL was not significantly different between the two groups. These findings demonstrate that middle ear effusion is associated with a conductive hearing loss of 10-33 dB in affected dogs despite the fact that all animals studied were considered to have normal hearing by their owners.
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Bao J, Ohlemiller KK. Age-related loss of spiral ganglion neurons. Hear Res 2010; 264:93-7. [PMID: 19854255 PMCID: PMC2868093 DOI: 10.1016/j.heares.2009.10.009] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 10/14/2009] [Accepted: 10/16/2009] [Indexed: 01/12/2023]
Abstract
Spiral ganglion neurons (SGNs) are the relay station for auditory information between hair cells and central nervous system. Age-related decline of auditory function due to SGN loss can not be ameliorated by hearing aids or cochlear implants. Recent findings clearly indicate that survival of SGNs during aging depends on genetic and environmental interactions, which can be demonstrated at the systemic, tissue, cellular, and molecular levels. At the systemic level, both insulin/insulin-like growth factor-1 and lipophilic/steroid hormone pathways influence SGN survival during aging. At the level of organ of the Corti, it is difficult to determine whether age-related SGN loss is primary or secondary degeneration. However, a late stage of SGN degeneration may be independent of age-related loss of hair cells. At the cellular and molecular level, several pathways, particularly free radical and calcium signaling pathways, can influence age-related SGN loss, and further studies should determine how these pathways contribute to SGN loss, such as whether they directly or indirectly act on SGNs. With the advancement of recent genetic and pharmacologic tools, we should not only understand how SGNs die during aging, but also find ways to delay this loss.
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Affiliation(s)
- Jianxin Bao
- Fay and Carl Simmons Center for the Biology of Hearing and Deafness, Department of Otolaryngology, Washington University Medical School, 660 S. Euclid, St. Louis, MO 63110, USA.
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Ter Haar G, de Groot JCMJ, Venker-van Haagen AJ, van Sluijs FJ, Smoorenburg GF. Effects of aging on inner ear morphology in dogs in relation to brainstem responses to toneburst auditory stimuli. J Vet Intern Med 2009; 23:536-43. [PMID: 19645839 DOI: 10.1111/j.1939-1676.2009.0290.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Age-related hearing loss (ARHL) is the most common form of hearing loss in humans and is increasingly recognized in dogs. HYPOTHESIS Cochlear lesions in dogs with ARHL are similar to those in humans and the severity of the histological changes is reflected in tone audiograms. ANIMALS Ten geriatric dogs (mean age: 12.7 years) and three 9-month-old dogs serving as controls for histological analysis. METHODS Observational study. Auditory thresholds were determined by recording brainstem responses (BERA) to toneburst auditory stimuli (1, 2, 4, 8, 12, 16, 24, and 32 kHz). After euthanasia and perfusion fixation, the temporal bones were harvested and processed for histological examination of the cochleas. The numbers of outer hair cells (OHCs) and inner hair cells (IHCs) were counted and the spiral ganglion cell (SGC) packing density and stria vascularis cross-sectional area (SVCA) were determined. RESULTS A combination of cochlear lesions was found in all geriatric dogs. There were significant reductions (P .001) in OHC (42%, 95% confidence interval [CI]; 24-64%) and IHC counts (21%, 95% CI; 62-90%) and SGC packing densities (323, 95% CI; 216-290) in the basal turn, SVCA was smaller in all turns. The greatest reduction in auditory sensitivity was at 8-32 kHz. CONCLUSIONS AND CLINICAL IMPORTANCE ARHL in this specific population of geriatric dogs was comparable histologically to the mixed type of ARHL in humans. The predominance of histological changes in the basal cochlear turn was consistent with the large threshold shifts observed in the middle- to high-frequency region.
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Affiliation(s)
- G Ter Haar
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, University Medical Center, Utrecht, The Netherlands.
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Jin DX, Lin Z, Lei D, Bao J. The role of glucocorticoids for spiral ganglion neuron survival. Brain Res 2009; 1277:3-11. [PMID: 19233145 PMCID: PMC2700197 DOI: 10.1016/j.brainres.2009.02.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Revised: 02/09/2009] [Accepted: 02/11/2009] [Indexed: 12/20/2022]
Abstract
Glucocorticoids, which are steroidal stress hormones, have a broad array of biological functions. Synthetic glucocorticoids are frequently used therapeutically for many pathologic conditions, including diseases of the inner ear; however, their exact functions in the cochlea are not completely understood. Recent work has clearly demonstrated the presence of glucocorticoid signaling pathways in the cochlea and elucidated their protective roles against noise-induced hearing loss. Furthermore, indirect evidence suggests the involvement of glucocorticoids in age-related loss of spiral ganglion neurons and extensive studies in the central nervous system demonstrate profound effects of glucocorticoids on neuronal functions. With the advancement of recent pharmacologic and genetic tools, the role of these pathways in the survival of spiral ganglion neurons after noise exposure and during aging should be revealed.
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Affiliation(s)
- David Xu Jin
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110
| | - Zhaoyu Lin
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110
| | - Debin Lei
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110
| | - Jianxin Bao
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, 63110
- Center for Aging, Washington University School of Medicine, St. Louis, Missouri, 63110
- The Division of Biology & Biomedical Science and Neuroscience Program, Washington University School of Medicine, St. Louis, Missouri, 63110
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Ter Haar G, Venker-van Haagen AJ, van den Brom WE, van Sluijs FJ, Smoorenburg GF. Effects of aging on brainstem responses to toneburst auditory stimuli: a cross-sectional and longitudinal study in dogs. J Vet Intern Med 2008; 22:937-45. [PMID: 18564227 DOI: 10.1111/j.1939-1676.2008.0126.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND It is assumed that the hearing of dogs becomes impaired with advancing age, but little is known about the prevalence and electrophysiologic characteristics of presbycusis in this species. HYPOTHESIS As in humans, hearing in dogs becomes impaired with aging across the entire frequency range, but primarily in the high-frequency area. This change can be assessed quantitatively by brainstem-evoked response audiometry (BERA). ANIMALS Three groups of 10 mixed-breed dogs with similar body weights but different mean ages were used. At the start of the study, the mean age was 1.9 years (range, 0.9-3.4) in group I, 5.7 years (3.5-7) in group II, and 12.7 years (11-14) in group III. METHODS In a cross-sectional study, the BERA audiograms obtained with toneburst stimuli were compared among the 3 groups. In a longitudinal study, changes in auditory thresholds of group II dogs were followed for 7 years. RESULTS Thresholds were significantly higher in group III than in groups I and II at all frequencies tested, and higher in group II than in group I at 4 kHz. The audiograms in group II indicated a progressive increase in thresholds associated with aging starting around 8-10 years of age and most pronounced in the middle- to high-frequency region (8-32 kHz). CONCLUSIONS AND CLINICAL IMPORTANCE Age-related hearing loss in these dogs started around 8-10 years of age and encompassed the entire frequency range, but started and progressed most rapidly in the middle- to high-frequency area. Its progression can be followed by BERA with frequency-specific stimulation.
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Affiliation(s)
- G Ter Haar
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
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26
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Le T, Keithley EM. Effects of antioxidants on the aging inner ear. Hear Res 2007; 226:194-202. [PMID: 16843623 DOI: 10.1016/j.heares.2006.04.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Revised: 04/26/2006] [Accepted: 04/28/2006] [Indexed: 10/24/2022]
Abstract
Age-related cochlear structural changes include the degeneration of sensory, neural cells and the stria vascularis. The hypothesis that cellular degeneration results from exposure to oxidative products of respiration was tested by supplementing aged dogs with a diet high in antioxidants and mitochondrial metabolites and by genetically modifying the expression level of the antioxidant, manganese superoxide dismutase (SOD2) in mice. Aged dogs received either a high antioxidant diet or a normal, control diet for the last 3 years of their life. Cellular measures were compared among the two aged groups (10-15 years) and young dogs. Both aged groups had cellular degeneration relative to young dogs, but the animals fed the antioxidant diet showed less degeneration at the base and apex than the control-diet group. Transgenic mice, heterozygous null for SOD2, produce only half as much enzyme as a normal mouse. These mice showed no increase in the amount of hearing loss relative to the background strain. A diet containing antioxidants reduced the magnitude of cochlear degeneration. Genetic reduction of one antioxidant, however, did not increase the magnitude of hearing loss in aging mice. A reduction in one enzyme seems to be compensated while the addition of a complex of factors is effective.
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Affiliation(s)
- Tima Le
- University of California, San Diego, Head and Neck Surgery-Otolaryngology, 9500 Gilman Dr., La Jolla, CA 92093-0666, USA
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Ohlemiller KK. Contributions of mouse models to understanding of age- and noise-related hearing loss. Brain Res 2006; 1091:89-102. [PMID: 16631134 DOI: 10.1016/j.brainres.2006.03.017] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Revised: 03/06/2006] [Accepted: 03/08/2006] [Indexed: 12/21/2022]
Abstract
Once an oddity, mice have become the most widely used hearing research model. Their value for research in noise-induced hearing loss (NIHL) stems from their high vulnerability to noise and reduced variance of results, made possible by genetic standardization. To research in age-related hearing loss (ARHL), they offer economies of small size and a short lifespan, both of which reduce housing costs. Inbred mouse strains show a wide range of noise sensitivities and rates of hearing loss with age. These can be studied using classical genetic analysis, as well as hypothesis-driven experiments utilizing genetic engineering. Through such investigations, presently 3 loci have been identified to date that contribute to NIHL, 10 that promote ARHL, and at least 6 loci that promote both. The types of genes involved implicate homeostatic and protective mechanisms as key to the appearance of either type of pathology and support a causal link between injury and some apparent ARHL. While the majority of mouse ARHL models examined most closely resemble sensory ARHL, recent work has identified mice possessing the essential characteristics of neural and strial ARHL. Using these models, it should be possible to identify genes and alleles that promote the major forms of ARHL and their combinations.
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Affiliation(s)
- Kevin K Ohlemiller
- Department of Otolaryngology, Washington University, 660 S. Euclid, St. Louis, MO 63110, USA.
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Abstract
Diseases of the ear often cause signs of neurologic dysfunction because of damage of peripheral nervous system structures associated with the middle and inner ear. Vestibular dysfunction, facial paralysis, Horner's syndrome, and hearing deficits are the most common neurologic deficits that accompany middle and inner ear disease. Differentiating these signs from disease of the central nervous system is crucial for an accurate diagnosis and prognosis but can be difficult. Understanding the normal anatomy of the ear and its association with the brain is crucial to interpretation of the neurologic examination. This article reviews neurologic dysfunction commonly associated with diseases of the ear and differentiating these signs from central disease.
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Affiliation(s)
- Laurie B Cook
- Animal Neurological Clinic, 352 Warren Avenue, Portland, ME 04103, USA.
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Bhatt KA, Liberman MC, Nadol JB. Morphometric analysis of age-related changes in the human basilar membrane. Ann Otol Rhinol Laryngol 2001; 110:1147-53. [PMID: 11768706 DOI: 10.1177/000348940111001212] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The histopathologic correlates of presbycusis suggest several categories, including degeneration of sensory cells, neurons, or the stria vascularis. Lack of clear-cut histopathologic changes in some cases has suggested an "indeterminate category"; however, several studies have suggested that a disorder of the basilar membrane (BM) may underlie indeterminate presbycusis. The objective of the present study was to quantify age-related changes in the human BM and correlate them with audiometric patterns. Under high-resolution light microscopy, BM thickness was calculated, and the number of tympanic mesothelial cells (TMCs) lining the BM was counted, at 4 cochlear locations in 92 temporal bones. The control group (n = 80) included subjects from 10 decades of age with normal hearing and/or histopathologic findings. The indeterminate group (n = 12) consisted of elderly patients (ages 64 to 91 years) with hearing loss and no apparent histopathologic changes. Age-related BM thickening was seen in both groups, but only in the most basal cochlear region. The BM thickness in the indeterminate group was not significantly different from that of age-matched controls. Counts of TMCs showed age-related decreases in all cochlear regions in both groups; however, TMC counts in the indeterminate group were not different from those of age-matched controls. The results suggest that BM histopathology is not a common cause of presbycusis. Although age-related BM thickening, seen in both groups, could contribute to hearing loss, the extreme basal region, to which the thickening was confined, is not tested in routine audiometry.
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Affiliation(s)
- K A Bhatt
- Department of Otology and Laryngology, Harvard Medical School, and Massachusetts Eye and Ear Infirmary, Boston 02114, USA
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Idrizbegovic E, Viberg A, Bogdanovic N, Canlon B. Peripheral cell loss related to calcium binding protein immunocytochemistry in the dorsal cochlear nucleus in CBA/CaJ mice during aging. Audiol Neurootol 2001; 6:132-9. [PMID: 11474139 DOI: 10.1159/000046820] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The influence of cochlear hair cell and spiral ganglia neuron loss on calcium binding protein immunoreactivity (calretinin, parvalbumin and calbindin) in the dorsal and posteroventral cochlear nuclei (DCN and PVCN) in CBA/CaJ (CBA) mice during aging (1-39 months) was determined. Since calcium binding proteins have buffering properties against calcium overload, they may have a protective role during aging. It is shown that the percentage of calretinin- and parvalbumin-immunopositive neurons in the DCN showed a statistically significant positive correlation with inner hair cell loss, outer hair cell loss, and spiral ganglion cell loss. A correlation was also found between aging and the auditory periphery, and calcium binding proteins in the DCN. These findings imply that the pathophysiological state of the auditory periphery may influence the neuronal homeostasis in the dorsal cochlear nucleus.
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Affiliation(s)
- E Idrizbegovic
- Department of Audiology, Huddinge University Hospital, Karolinska Institutet, Huddinge, Sweden.
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Coppens AG, Kiss R, Heizmann CW, Schäfer BW, Poncelet L. Immunolocalization of the calcium binding S100A1, S100A5 and S100A6 proteins in the dog cochlea during postnatal development. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2001; 126:191-9. [PMID: 11248353 DOI: 10.1016/s0165-3806(00)00153-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The immunolocalization of three members of the S100 calcium-binding protein family was investigated in the dog cochlea during normal postnatal development. Sections of decalcified and paraffin-embedded cochleae from 16 beagle puppies aged from birth to 3 months were treated with polyclonal antisera raised against the human recombinant S100A1, S100A5, and S100A6 proteins. At birth, in the dog cochlea, S100A1 was expressed in the immature Deiter's cells, and slightly in the pillar cells. From the second week, S100A1 was detected in the supporting structures of the organ of Corti, i.e. the Deiter's, the pillar, the border, and the Hensen's cells, and in the reticular membrane. From birth onwards, S100A5 remained a neuronal-specific protein, only located in a subpopulation of neurons in the spiral ganglion. S100A6 was not expressed at birth. From the second week of life, the Schwann cells and nerve sheaths in the modiolus, in the spiral ganglion, and running in the direction of the organ of Corti exhibited S100A6-labeling. From the 12th postnatal day, some scattered intermediate cells started to express S100A6 protein in the stria vascularis. The number of labeled intermediate cells increased during the third week. At adult stage, the intermediate cells were S100A6-stained with cytoplasmic labeling throughout the stria vascularis from the base to the apex of the cochlea. None of the other cochlear structures expressed the S100 proteins under study during the postnatal development of the dog cochlea. The S100A1, S100A5, S100A6 immunostaining was limited to specific cell types in dog cochlea. These S100 proteins were useful markers in the study of supporting cells, neurons, nerve fibers sheaths and stria vascularis (S100A6) during the normal postnatal development of the dog cochlea.
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Affiliation(s)
- A G Coppens
- Laboratory of Anatomy and Embryology, Veterinary Anatomy, Faculty of Medicine, Free University of Brussels, 808 Lennik Street, B-1070 Brussels, Belgium.
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Coppens AG, Résibois A, Poncelet L. Immunolocalization of calbindin D28k and calretinin in the dog cochlea during postnatal development. Hear Res 2000; 145:101-10. [PMID: 10867282 DOI: 10.1016/s0378-5955(00)00077-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The calbindin (CB) and the calretinin (CR) immunoreactivities were studied in the dog cochlea during its postnatal maturation from birth to the 33rd postnatal day. At birth, CB was expressed in the Kölliker's organ, in the immature inner (IHC) and outer hair cells (OHC), in neurons of the spiral ganglion, and in nerve fibers running in the basilar membrane of the apical turn. During the cochlear maturation, non-sensorineuronal structures, such as the Kölliker's organ, the rods of Corti, and the inner sulcus cells, displayed a transient CB-staining. In the adult-like dog cochlea, CB was found in the cytoplasm, the cuticular plate, and the stereocilia of the IHC and OHC. All the neurons of the spiral ganglion and some nerves fibers in the modulius were CB-positive. At birth, CR exhibited a neuronal distribution: about 75% of the spiral ganglion neurons, some nerve fibers in the modulius and nerve fibers running in the basilar membrane were CR-labeled. During the postnatal maturation, a CR-immunostaining appeared around the IHC body and CR was expressed transiently in the OHC. In the adult-like dog cochlea, a CR-positive network surrounded the unlabeled IHC. The neuronal CR-labeling remained unchanged from birth.
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Affiliation(s)
- A G Coppens
- Laboratoire d'Anatomie vétérinaire, CP 619 Université Libre de Bruxelles, Faculté de médecine, Brussels, Belgium.
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Abstract
CBA mice do not exhibit age-related loss of auditory sensitivity or cochlear pathology until relatively late in life. Therefore, this strain is believed to be an excellent animal model for the examination of the effects of age on the cochlea. To evaluate the effects of age on outer hair cell function, 2f1-f2 distortion product otoacoustic emissions (DPOAEs) were measured for f2 between 8 and 16 kHz in CBA/J mice between 1 and 25 months of age. CBA mice exhibited mild age-related changes in DPOAE level and detection threshold at 17 months of age, and changes of 20-40 dB by 25 months of age. The DPOAE level decreased and detection threshold increased with age in a frequency-dependent manner, starting at high frequencies and eventually extending to low frequencies. The range of frequencies in which notches were observed in the DPOAE input/output (I/O) functions extended toward lower frequencies by 17 months of age. Notches were absent in the I/O functions of 25-month-old mice. The present results for a frequency range of 8-16 kHz suggest that age has modest effects on outer hair cell function in CBA mice.
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Affiliation(s)
- K Parham
- Department of Surgery, University of Connecticut Health Center, Farmington 06030-1110, USA.
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