{"title":"Structure and scaling of the middle ear in domestic dog breeds","authors":"Matthew J. Mason, Madaleine A. Lewis","doi":"10.1111/joa.14049","DOIUrl":null,"url":null,"abstract":"<p>Although domestic dogs vary considerably in both body size and skull morphology, behavioural audiograms have previously been found to be similar in breeds as distinct as a Chihuahua and a St Bernard. In this study, we created micro-CT reconstructions of the middle ears and bony labyrinths from the skulls of 17 dog breeds, including both Chihuahua and St Bernard, plus a mongrel and a wolf. From these reconstructions, we measured middle ear cavity and ossicular volumes, eardrum and stapes footplate areas and bony labyrinth volumes. All of these ear structures scaled with skull size with negative allometry and generally correlated better with condylobasal length than with maximum or interaural skull widths. Larger dogs have larger ear structures in absolute terms: the volume of the St Bernard's middle ear cavity was 14 times that of the Chihuahua. The middle and inner ears are otherwise very similar in morphology, the ossicular structure being particularly well-conserved across breeds. The expectation that larger ear structures in larger dogs would translate into hearing ranges shifted towards lower frequencies is not consistent with the existing audiogram data. Assuming that the audiograms accurately reflect the hearing of the breeds in question, oversimplifications in existing models of middle ear function or limitations imposed by other parts of the auditory system may be responsible for this paradox.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/joa.14049","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Anatomy","FirstCategoryId":"3","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/joa.14049","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ANATOMY & MORPHOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Although domestic dogs vary considerably in both body size and skull morphology, behavioural audiograms have previously been found to be similar in breeds as distinct as a Chihuahua and a St Bernard. In this study, we created micro-CT reconstructions of the middle ears and bony labyrinths from the skulls of 17 dog breeds, including both Chihuahua and St Bernard, plus a mongrel and a wolf. From these reconstructions, we measured middle ear cavity and ossicular volumes, eardrum and stapes footplate areas and bony labyrinth volumes. All of these ear structures scaled with skull size with negative allometry and generally correlated better with condylobasal length than with maximum or interaural skull widths. Larger dogs have larger ear structures in absolute terms: the volume of the St Bernard's middle ear cavity was 14 times that of the Chihuahua. The middle and inner ears are otherwise very similar in morphology, the ossicular structure being particularly well-conserved across breeds. The expectation that larger ear structures in larger dogs would translate into hearing ranges shifted towards lower frequencies is not consistent with the existing audiogram data. Assuming that the audiograms accurately reflect the hearing of the breeds in question, oversimplifications in existing models of middle ear function or limitations imposed by other parts of the auditory system may be responsible for this paradox.
期刊介绍:
Journal of Anatomy is an international peer-reviewed journal sponsored by the Anatomical Society. The journal publishes original papers, invited review articles and book reviews. Its main focus is to understand anatomy through an analysis of structure, function, development and evolution. Priority will be given to studies of that clearly articulate their relevance to the anatomical community. Focal areas include: experimental studies, contributions based on molecular and cell biology and on the application of modern imaging techniques and papers with novel methods or synthetic perspective on an anatomical system.
Studies that are essentially descriptive anatomy are appropriate only if they communicate clearly a broader functional or evolutionary significance. You must clearly state the broader implications of your work in the abstract.
We particularly welcome submissions in the following areas:
Cell biology and tissue architecture
Comparative functional morphology
Developmental biology
Evolutionary developmental biology
Evolutionary morphology
Functional human anatomy
Integrative vertebrate paleontology
Methodological innovations in anatomical research
Musculoskeletal system
Neuroanatomy and neurodegeneration
Significant advances in anatomical education.