Biomaterial Database

[Scanning electron microscopic study of inner ear barotrauma: in the guinea pig under hypobaric pressure]. 1996

T Tanabe, and M Kozuka, and S Fukuta, and N Yanagita

Department of Otorhinolaryngology, Nagoya University School of Medicine.

In order to investigate the mechanism of inner ear barotrauma, guinea pigs, with bilateral eustachian tube occlusion, were subjected to decompression and compression between 760 and 460 mmHg in a hypobaric pressure chamber. We divided the guinea pigs into two groups, A and B. Group A showed normal eustachian tubes, and group B showed bilaterally occluded eustachian tubes. Group B animals were divided into three types according to the rates of compression and decompression. After pressure loading, morphological changes in the hair cells of the organ of Corti were studied by means of scanning electron microscopy. There was no damage to hair cells in the setting of normal eustachian tube function, as in group A. On the other hand, mild to severe hair cell damage was observed with rapid decompression in group B. This observation suggests that relative positive pressure in the middle ear cavity is an important factor in inner ear barotrauma. The mechanism of hair cell damage due to inner ear barotrauma is presumed to be distortion of the organ of Corti caused by a difference in pressure between perilymph and endolymph resulting in injury to the stereocilica.

UI	MeSH Term	Description	Entries
D007758	Ear, Inner	The essential part of the hearing organ consists of two labyrinthine compartments: the bony labyrinthine and the membranous labyrinth. The bony labyrinth is a complex of three interconnecting cavities or spaces (COCHLEA; VESTIBULAR LABYRINTH; and SEMICIRCULAR CANALS) in the TEMPORAL BONE. Within the bony labyrinth lies the membranous labyrinth which is a complex of sacs and tubules (COCHLEAR DUCT; SACCULE AND UTRICLE; and SEMICIRCULAR DUCTS) forming a continuous space enclosed by EPITHELIUM and connective tissue. These spaces are filled with LABYRINTHINE FLUIDS of various compositions.	Labyrinth,Bony Labyrinth,Ear, Internal,Inner Ear,Membranous Labyrinth,Bony Labyrinths,Ears, Inner,Ears, Internal,Inner Ears,Internal Ear,Internal Ears,Labyrinth, Bony,Labyrinth, Membranous,Labyrinths,Labyrinths, Bony,Labyrinths, Membranous,Membranous Labyrinths
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001469	Barotrauma	Injury following pressure changes; includes injury to the eustachian tube, ear drum, lung and stomach.	Barotraumas