Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tectorial Membrane”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed1994

A characteristics protein highly expressed in guinea pig inner ear, defined by monoclonal antibody WH-1.

A new monoclonal antibody (termed WH-1; isotype IgG2b) was established using a homogenate of dissected guinea pig cochleas (N = 60) as immunogen. Western blotting and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) identified the WH-1 antigen as a protein or glycoprotein with M(r) approximately 40 kDa. Immunoperoxidase treatment of histologic cryosections of guinea pig cochlea, followed by light microscopic examination, revealed strong positive staining at three sites: (i) parts of Hensen's stripe, marginal band, covering net, and Kimura's membrane (within the tectorial membrane [TM]); (ii) Deiters' cells, pillar cells, Hensen's cells, and stereocilia of outer hair cells (within the organ of Corti); (iii) interdental cells, inner and outer sulcus cells, Reissner's membrane, and surface membrane of stria vascularis epithelium. Similar staining patterns were observed for cryosections of rat and mouse cochleas. Only a trace quantity of cross-reacting protein was detectable in brainstem. The protein was not detectable in tongue extract by Western blotting. However, sections of brainstem and tongue did show positive immunohistological staining with WH-1. Localization of WH-1 antigen was further examined by electron microscopy. WH-1 positivity on outer hair cell stereocilia, certain sites on the TM, interdental cell surface, Reissner's membrane epithelia, and inner and outer sulcus cells was confirmed. WH-1 antigen was not detected on inner hair cell stereocilia by light or electron microscopy. The localization of WH-1 antigen on outer hair cell stereocilia and TM suggests that it may play some role in adhesion between these structures.

Animals↗
PubMedDate not supplied

Doppler optical coherence microscopy for studies of cochlear mechanics.

The possibility of measuring subnanometer motions with micron scale spatial resolution in the intact mammalian cochlea using Doppler optical coherence microscopy (DOCM) is demonstrated. A novel DOCM system is described that uses two acousto-optic modulators to generate a stable 500-kHz heterodyne frequency. Images and motion measurements are obtained using phase-resolved analysis of the interference signal. The DOCM system permits imaging with micron-scale resolution and 85-dB sensitivity and motion measurements with 100-kHz bandwidth, directional discrimination, and 30-pm/Hz(0.5) noise floor. Images and motion measurements are presented that demonstrate the ability to resolve motions of structures of interest in a mammalian cochlea in vitro including the basilar membrane, reticular lamina, tectorial membrane, and outer hair cells.

Animals↗
PubMed2006

Comment on "The cochlear amplifier as a standing wave: 'squirting' waves between rows of outer hair cells?" J. Acoust.Soc. Am. 116, 1016-1024.

Bell and Fletcher [J. Acoust. Soc. Am. 116, 1016-1024 (2004)] proposed that one of the functions of activity of the outer hair cells (OHCs) might be a fluid-pumping action generating lateral fluid flow in the gap between the reticular membrane and the tectorial membrane and they supplied mathematical and descriptive justification for their theory which drew heavily upon the postulation (Gold, 1948) of the need for an active mechanism in the mammalian cochlea. In the 1970s there had been considerable speculation about how the inner hair cell (IHC) stereocilia are stimulated, whether they are stimulated in proportion to basilar membrane displacement or velocity or both, and whether the velocity dependence is due to subtectorial fluid flow. In 1977 experiments were conducted to investigate the possibility of subtectorial fluid flows using a dye as tracer. The work was not reported because it had been conducted at a time when visual observation of cochlear function had fallen out of favor in comparison with the more sensitive techniques thought necessary to observe submicroscopic phenomena, and secondly because it yielded a negative result. The essential details of those experiments are reported here to note for the record the extent to which this elaborate idea has already been tested.

Action Potentials↗
PubMed1989

[Potentiation of inner ear damage following electron beam irradiation with CDDP administration].

The study was designed to examine the combined ototoxic effect of CDDP (Cisplatin, Cis-diammine dichloroplatinum) and electron beam irradiation, using guinea pigs. One group received physiological saline solution of 4 ml/kg/day, and another group received CDDP of 2 mg/kg/day for five days. And following the injection of saline or CDDP, the electron beam of 14Gy/day was applied to the both groups to the right ear for five days. Animals were sacrificed after 21 days, and temporal bones of these animals were removed for the inner ear histopathology. Temporal bones were classified into four groups (control, electron beam irradiation, CDDP administration, and combined administration group), and the inner ears were observed by the surface preparation technique with a phase contrast microscope, and by scanning and transmission electron microscopy, and by temporal bone study of serial sectioned slides. The main pathologic findings of the inner ear are as follows: Electron beam irradiation group showed no hair cell damage. CDDP group induced slight damage to the outer hair cells. Combined administration group (CDDP + electron beam irradiation) showed severe outer hair cell damage. Stria vascularis was degenerated moderately in the combined administration group and slightly in some animals of electron beam irradiation group. And Reissner's membrane and Hensen's cells, were damaged in the basal turn of cochlea of the combined administration group. All other cochlear structures (spiral ganglion, spiral lamina, basilar membrane, spiral prominence, tectorial membrane, blood vessels of the cochlea) and vestibular organs were lack of significant changes in all groups by a light microscopic observation. This study was clarified that combined administration of CDDP and electron beam irradiation showed severe ototoxic potentiation. Therefore, it is important that we must pay attention to the inner ear damage caused by combined therapy of CDDP and electron beam irradiation involving inner ear for the head and neck tumor.

Animals↗
PubMed1997

A model of cochlear micromechanics.

A cochlear model is presented which has two degrees of freedom, the motion of the basilar membrane and that of the tectorial membrane (TM), in every cross section of the organ of Corti. It assumes that the reticular lamina is virtually rigid, so that the apical portion of the outer hair cells is firmly anchored to it, and also that the TM is directly driven by the BM through the marginal net of the TM, which anchor to the phalanges of the outermost row of Deiters' cells or Hensen's cells, or both. It is shown that the model can produce more than 40 dB of cochlear gain in the frequency-domain simulation and 30 dB in time-domain simulation. Transiently evoked otoacoustic emissions and cochlear microphonics are simulated in the time domain.

Acoustic Stimulation↗
PubMedDate not supplied

Cochlear changes after herpes simplex virus infection.

After direct inoculation of herpes simplex virus (HSV) into the scala tympani of the guinea pig, the tectorial membrane showed various morphological changes: atrophy, roll-up and dot formation. Immunofluorescent and electronmicroscopic studies revealed that the changes were due to HSV infection. The findings were compared with those observed in the temporal bones of a 77-year-old patient who suffered from sudden deafness. The tectorial membranes of both temporal bones showed various changes identical with those observed in experimental viral labyrinthitis. This supports the view that sudden deafness in this particular patient was of viral origin. In the animal experiment, HSV antigen could be detected from the cochlea of the non-inoculated side, which was morphologically normal. Further study is required to reactivate HSV in the cochlea with latent infection. This animal can probably be used as an animal model for sudden deafness.

Aged↗
PubMed2004

Col11a1 and Col11a2 mRNA expression in the developing mouse cochlea: implications for the correlation of hearing loss phenotype with mutant type XI collagen genotype.

OBJECTIVE: Mutations in the fibrillar collagen genes COL11A1 and COL11A2 can cause sensorineural hearing loss associated with Stickler syndrome. There is a correlation of hearing loss severity, onset, progression and affected frequencies with the underlying mutated collagen gene. We sought to determine whether differences in spatial or temporal expression of these genes underlie this correlation, and to identify the cochlear cell populations expressing these genes and the structures likely to be affected by mutations. MATERIALS AND METHODS: We used in situ hybridization analysis of C57BL/6J mouse temporal bones. RESULTS: Similar, diffuse expression of Col11a1 and Col11a2 mRNA was first observed in the cochlear duct at embryonic Day 15.5, with increasingly focal hybridization being noted at postnatal Days 1 and 5 in the greater epithelial ridge and lateral wall of the cochlea. The greater epithelial ridge appeared to be the main, if not only, source of mRNA encoding Col11a1 and Col11a2 in the tectorial membrane. At postnatal Day 13, Col11a1 and Col11a2 expression became more focal and co-localized in the inner sulcus, Claudius' cells and cells of Boettcher. CONCLUSIONS: We did not observe spatial or temporal differences in mRNA expression that could account for the auditory phenotype genotype correlation. The expression patterns suggest essential roles for Col11a1 and Col11a2 in the basilar or tectorial membranes.

Animals↗
PubMed1997

Immunoreactivity for taurine in the cochlea: its abundance in supporting cells.

Taurine is the second most abundant free amino acid in the brain where its osmoregulatory function is well established. Taurine-deprived kittens show retinal pathology leading to blindness. In the inner ear, taurine has been reported to be the most abundant free amino acid although its role in inner ear function is not known. Immunohistochemistry was employed here to investigate the localisation of taurine in normal cochleae of the guinea pig compared with two different conditions: experimentally induced endolymphatic hydrops and after oral administration of glycerol. In normal cochleae, by light microscopy, taurine-like immunoreaction was never observed in the sensory outer hair cells and appeared absent from the inner hair cells. In contrast taurine-like immunolabeling was found to be present in all supporting tissue with the striking exception of the tectorial membrane and the outer pillar cell which had no or little taurine immunoreactivity respectively. In early experimental endolymphatic hydrops, the distribution of taurine-like immunoreactivity appeared similar to that observed for normal cochleae. In long-term hydrops, degenerated outer hair cells were replaced by the swelling of the phalangeal process of the Deiters' cells which became highly immunoreactive to taurine. After glycerol administration, the tectorial membrane became more tightly bound to the apical surface of the sensory hair cells and distinctly immunoreactive to taurine. The localisation of taurine in the organ of Corti shown here is consistent with taurine being involved in the maintenance of osmotic equilibrium in the normal and perhaps also in the restructuration of the pathological organ of Corti.

Administration, Oral↗
PubMed1997

Antibodies to the sulphated, high molecular mass mouse tectorin stain hair bundles and the olfactory mucus layer.

Polyclonal antibodies were raised in chickens to the glycosylated forms of the high (H), medium (M) and low (L) molecular mass (MM) mouse tectorins. In the mouse cochlea, all three antibodies stained the tectorial membrane. Antibodies raised to HMM tectorin also stained the hair bundles of both inner and outer hair cells. A number of other mouse tissues were screened with the anti-tectorin antibodies to look for similar or antigenically related molecules. Staining was not observed in any other tissue type with the antibodies directed against the MMM and LMM tectorins. In the nose, the anti-HMM tectorin antibodies stained Bowman's glands and the mucus layer overlying the olfactory epithelium. The surface of the adjacent respiratory epithelium was not stained by these antibodies. HMM tectorin can be specifically radiolabelled by injecting neonatal mice with 35SO4 and undergoes a shift in electrophoretic mobility following treatment with keratanase, an endo-beta-galactosidase from Pseudomonas. However, when centrifuged on shallow CsCl gradients HMM tectorin has a buoyant density similar to that of glycoproteins and does not behave as a typical cartilage type proteoglycan. HMM tectorin does not react with mab 5D4, a monoclonal antibody that recognises keratan sulphate glycosaminoglycan from corneal and skeletal muscle proteoglycan. Unlike antibodies to HMM tectorin, mab 5D4 selectively stains the upper surface of the tectorial membrane, Hensen's stripe and the mucus layer overlying the respiratory epithelium. These studies indicate that the MMM and LMM tectorins may be unique to the cochlea, and that HMM may be a "light' keratan sulphate proteoglycan that is antigenically related to either the mucins or a more specific component of the olfactory mucus layer.

Animals↗
PubMed1991

Pilocarpine elicits the interdental cell secretory activity of the inner ear.

Subcutaneous injection of pilocarpine in guinea pigs resulted in the following ultrastructural changes: 1) the apical cavities of the interdental cells were filled with a substance indistinguishable from the overlying amorphous layer of the TM; 2) a great number of spherical structures appeared over the limbal portion of the tectorial membrane. In TEM photomicrographs these structures displayed the same appearance as the amorphous layer of the TM and were usually continuous to it; 3) the number of holes that decorate the upper surface of the limbal portion of the TM was dramatically increased and it was found that they connect the endolymphatic space to the apical cavities of the interdental cells; 4) there was an increase in the number of the small extracellular vesicles found in the clear spaces of the tectorial membrane. These facts suggest that pilocarpine stimulates the secretion of the interdental cells, confirming the existence of the secretory processes previously described (Prieto et al., 1990). These findings can be related to the turnover of the TM in the adult animal and, perhaps, to the secretion of some organic compound to the endolymph. We postulate that the actions of pilocarpine on the interdental cells are most probably mediated by the activation of muscarinic acetylcholine receptors in these cells.

Animals↗
PubMed1980

A freeze-fracture study of intercellular junctions between various kinds of epithelial cells surrounding common endolymphatic space in the hearing organ of the chick.

Intercellular junctions between various epithelial cells in the hearing organ (basilar papilla) of the chick were studied with the freeze-fracture technique. The effects of hypertonic solutions on the intercellular junctions were also examined. The basilar papilla of the chick is primarily composed of hair cells and supporting cells in the neuroepithelium, specialized columnar cells (TMC) which attach to the tectorial membrane, and light cells (LC) and dark cells (DC) in the tegmentum vasculosum. All of these epithelial cells surround a common endolymphatic space. The tight junctions between hair and supporting cells, and those between adjacent supporting cells in the neuroepithelium are 0.1--0.3 micrometer in depth and display the usual network of branching and anastomosing strands of shared intramembrane proteins. The tight junctions in the tegmentum vasculosum have the same structure as in the neuroepithelium. In contrast, the tight junctions between the TMCs are extremely well developed. They are 1--2 micrometer in depth. In freeze-fracture replicas, they appear as a fingerprint pattern of unbranched parallel particulate strands, running both parallel and perpendicular to the cell surface. After exposure to hypertonic solutions, all the epithelial cells are shrunken and intercellular spaces are expanded; all tight junctions, however, are intact. Thus, tight junctions in the basilar papillae are resistant to dissociation by hypertonic solutions. The usual zonulae occuludentes in the neuroepithelium and tegmentum vasculosum are thought to prevent diffusion of endolymph through the intercellular spaces of epithelial cells. However, the tight junctions on the TMCs may function not only as a diffusion barrier, but also provide structural support to the cells anchoring the tectorial membrane which receives mechanical forces induced by the vibration of the basilar membrane. Extensive gap junctions are found between all the supporting cells (supporting cells in the neuroepithelium, TMCs, and LCs in the tegmentum vasculosum) surrounding the endolymphatic space.

Animals↗
PubMed1979

Ultrastructure of the turkey's basilar papilla and the damping elements in the scala media.

The ultrastructure of the turkey's inner ear was investigated by use of scanning and transmission electron microscopes. It was shown that hair cells of the basilar papilla are separated from each other by microvilli of the supporting cells. Organized compartments in the lower surface of the tectorial membrane of the turkey are arranged in polarized fashion as are the hair bundles. Kinocilia were not identified in the hair bundles examined in this study. Well-organized filamentous elements were observed in the cutucular plates. The continuation of these filamentous elements into the stereocilia indicates that the theory of adjustable resistor in generating cochlear potential may be closely associated with these elements. Membrane bound homogeneous material was found in the scala media between the tegmentum vasculosum and the tectorial membrane. The presence of this homogeneous damping material is believed to be essential in offsetting the sensitivity and enhancing the time resolution ability of the relatively short avian cochlea.

Animals↗
PubMed1976

Endolymphatic hydrops: mechanical causes of hearing loss.

An explanation for the mechanical origin of the hearing loss in endolymphatic hydrops is presented that is based on studies in mechanical cochlear models. An elastic bias of the basilar membrane and/or a mass loading of the cochlear duct account for the low-frequency hearing loss, diplacusis, and even-harmonic distortion. In addition, the static shearing displacement between the tectorial membrane and the organ of Corti, caused by the displacement of the basilar membrane, may partially decouple the hair cells from the tectorial membrane, an event that would explain the tinnitus, recruitment, and perhaps even the disportional loss of speech intelligibility associated with endolymphatic hydrops.

Basilar Membrane↗
PubMed1994

Ultrastructural findings in the cochlea of AIDS cases.

Neurotologic manifestations associated with the human immunodeficiency virus (HIV-1) are poorly understood. Eight temporal bones of acquired immunodeficiency syndrome (AIDS) cases were dissected and investigated ultrastructurally to determine if pathogens and pathologic changes were present within the cochlea. Extracellular viral-like particles with morphologic characteristics of HIV-1 were identified on the tectorial membrane in three cases. Numerous viral-like particles with cores appeared trapped within lacunae along the tectorial membrane in one specimen. Intracellular viral-like particles, appearing essentially similar to identified HIV-1 particles of infected lymphocyte cultures, were found within the cytoplasm of connective tissue cells. These same cells had gradients of enlarged viral envelopes forming cisterns that contained cores and varying amounts of cistern particulate. Some sectioned profiles of enlarged cytoplasmic cisterns revealed the attachment and inward protrusion of the core from the cistern wall. Other ultrastructural findings included cytoplasmic globular-dense particulate bodies, aggregates of smaller viral-like particles, and mitochondrial changes. This demonstration of prominent viral-like particles and cochlear pathology may help to explain the neurotologic manifestations associated with HIV-1 infection.

Adult↗
PubMedDate not supplied

Electron probe determination of relative ion distribution in the inner ear.

The relative amounts of potassium and chlorine present in various parts of the inner ear were studied by using an energy dispersive X-ray spectrometer in conjunction with a scanning electron microscope. Whereas the amount of chlorine was high in all compartments investigated, potassium was high in endolymphatic spaces and low in perilymphatic spaces. High contents of potassium and chlorine were also found in the tectorial membrane, in the inner sulcus and in the cupula of the semicircular canal. It is concluded that the tectorial membrane and the cupula do not present a barrier to ions and that therefore the sensory hairs in the inner ear are exposed to the ionic environment provided by the endolymph.

Animals↗
PubMed1987

Scanning electron microscopic observations of the canine inner ear.

The sensory epithelia of the inner ear of the dog have been investigated using scanning electron microscopy (SEM). The surface appearance of the cristae ampullares of the semicircular canals and of the macula utriculi are very similar to other mammalian species. The crista ampullaris of the anterior vertical semicircular canal is divided by a non-sensory septum cruciatum, found in cats and rats but not, for example, in man. The vestibular sensory cells possess two distinct types of stereocilia, one is thick and rigid appearing, the other is thin and limp. Neither type of stereocilium is restricted to a particular hair cell type. From SEM views of the undersurface of the tectorial membrane of the cochlea we show evidence that some inner hair cell stereocilia may be attached to the tectorial membrane. This observation is made only in middle to upper cochlear regions (those subserving transduction of low frequencies of sound).

Animals↗
PubMed1990

Micro-architectures of the osseous spiral laminae and spiral limbus in the mouse cochlea: a scanning electron microscopic study on the morphological basis of the auditory mechanics.

The auditory mechanics in the cochlea are closely related to the structural variations along the cochlear duct. In this study, the auditory teeth of the spiral limbus and the primary and secondary osseous spiral laminae in the mouse were examined along the entire course of the cochlear spiral by scanning electron microscopy (SEM) after removing the cochlear duct epithelium or the organic material with chemical maceration methods. The cochlear canal consisted of a hook and a spiral of one and half turns and the three-dimensional images and surface structures of the connective tissue forming the spiral limbus including the auditory teeth and the osseous spiral laminae are well demonstrated; the widths of the primary and secondary laminae, the spiral fissure between the two laminae, the tympanic lip, and the vestibular lip with the auditory teeth were measured, and the population density of the auditory teeth were determined in the hook and every half turn. The findings suggest that, in the cochlea the width of the basilar membrane increases in the hook and is almost constant in the spiral portion, the amount of fibers in the basilar membrane linearly decreases from the base to the apex, the displacement mode of the pillar cells during basilar membrane vibrations differs between the apical region lacking the bony edge of the tympanic lip and the other regions with bony edge, the connective tissue fibers from the auditory teeth are inserted to the bone surface of the primary lamina to support the teeth, the teeth on the marginal side of the vestibular lip maintain the stability of the tectorial membrane which is vibrating together with the basilar membrane in response to high frequency sounds on the basal side of the cochlear duct and low frequencies on the apical side, and the interdental cells on the Reissner membrane side maintain the size of the tectorial membrane which shows a linear increase in size from the base to the apex of the cochlear duct.

Animals↗
PubMed2005

Ultrastructure of the normal human organ of corti. new anatomical findings in surgical specimens.

CONCLUSION: A thorough scanning electron microscopy (SEM) investigation of immediately fixed human adult cochleae obtained during surgery for petro-clival meningiomas conveyed new information about morphology. OBJECTIVE: To investigate the ultrastructure of human adult cochleae using SEM. MATERIAL AND METHODS: Two human cochleae were decalcified, fixed with glutaraldehyde and osmium and prepared for SEM. RESULTS: The excellently preserved morphology showed the pathways of nerve fibres through the organ of Corti. Undulating lateral cell membranes of Hensen and Claudius cells created an enlarged surface that may be important for homoeostasis. The distal attachment of the tectorial membrane to the reticular lamina was present in the shape of a marginal net, which was extended through marginal pillars. Stereocilia imprints extended as far as the distal end of the marginal pillars. The presence of an irregularly distributed fourth row of outer hair cells attached to the marginal pillars raises questions about differences in the excitation of the last row of outer hair cells as a result of differences in the composition of the tectorial membrane.

Cochlea↗