SEARCH · PubMed Health

Results for “Tectorial Membrane”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 109 records · Page 6Linked to original sources

PubMed1987

Stereocilia and tectorial membrane development in the rat cochlea. A SEM study.

Maturation of the rat cochlea, from postnatal days 2 to 60, was studied using scanning electron microscopy (SEM), with emphasis on stereocilia and tectorial membrane (TM). Two days after birth, the organ of Corti was very immature. An adult appearance of its surface was observed by day 16 in the basal turn, and by the end of the 3rd postnatal week in the apex. Stereocilia started their development first on inner hair cells. By contrast, the apical pole of outer hair cells ended its maturation before that of inner hair cells. Top-links were detected very early in inner hair cell stereociliary development (postnatal day 2). Marginal pillars temporarily attached the TM to the organ of Corti; they disappeared first in the apical region. This transient attachment seems to play a role in the coupling of outer hair cells to the TM, as prints of their longest stereocilia appeared at the undersurface of the TM by the same time. Moreover, these prints were more clear and regular at the base than at the apex of the cochlea. Results are discussed in relation to ultrastructural and functional data on rat cochlea maturation.

Animals↗

PubMed1990

Observations of the sensing and the tectorial membrane in bullfrog amphibian papilla: their possible functional roles.

Three dimensional reconstructions of the amphibian papilla were performed with light microscopic observations, mainly for the sensing membrane (SM). In horizontal sections of the papilla, the anteromedial end of the SM, which makes contact with the massive anterior portion of the tectorial membrane (TM), is several times thicker than the posterolateral end close to the column of the innervating nerves. This gradient of thickness is observed in all the sections from the dorsal portion attached to the TM to the ventral floor of the papilla. The SM connects to the TM in a topological manner; the anteromedial portion of the TM relates to the anterior end of the SM and the anterolateral and the middle portions of the TM correspond to the sites shifting posteriorly on the SM. The morphology of the SM and its manner of connection to the TM suggest that the SM plays important roles in the occurrence of frequency selectivity and of tonotopic organization of the amphibian papilla.

Animals↗

PubMed2026

TECTB Variants Reveal Tectorial Membrane Vulnerability in Dominant Non-Syndromic Hearing Loss.

Identifying new genes responsible for non-syndromic hearing loss remains a critical goal as many patients still lack a molecular diagnosis despite comprehensive genetic testing. The tectorial membrane (TM) is a specialized acellular matrix of the inner ear, essential for stimulating mechanosensitive hair cell stereocilia bundles and maintaining frequency tuning and auditory sensitivity. Although mutations in genes encoding several non-collagenous proteins found in the TM (TECTA, CEACAM16, OTOG, OTOGL) have been identified as deafness genes, definitive evidence implicating β-tectorin (TECTB) has been lacking. Here, we present multiple lines of genetic and experimental evidence linking heterozygous missense variants in TECTB (NM_058222.3:c.674G>A, p.Cys225Tyr and NM_058222.3:c.853C>T, p.Arg285Cys), with hearing loss. Each variant affects highly conserved residues within or directly flanking the zona pellucida domain. Using a Tectb-C225Y knock-in mouse model, we show that homozygous animals exhibit severe hearing loss and profound disruption of TM morphology, while heterozygous animals display decreased staining density within the TM and increased susceptibility to noise-induced hearing loss, despite normal auditory thresholds. These findings identify TECTB as a novel human deafness gene, further elucidate its contribution to maintaining TM integrity and resilience against environmentally-related auditory decline.

beta‐tectorin (TECTB)↗

PubMed1987

Development of the tectorial membrane.

During development, the organization of the stereociliary bundles undergoes drastic changes from the microvilli-like nascent stereocilia to the 'W' formation of the step-like arrangement of the adult form. During this period the developing tectorial membrane (TM) establishes prescribed attachments with various substructures of the developing sensory ciliary bundles and supporting cells. The TM detaches from the supporting cells and inner hair cell stereociliary bundles as Kölliker's organ matures. The inter-connecting linkage system develops postnatally, and the 'tip-linkages' are already found in one-week-old mice, suggesting that the critical organization of the micromechanics of the stereocilia matures rapidly during the postnatal period. The TM develops in stages, and its development parallels that of the organ of Corti. The major TM is initially secreted by the greater epithelial ridge cells, and the minor TM is produced by the lesser epithelial ridge cells. The substructures of the TM are formed by the participation of a number of different supporting cells. During the active stage of production of the substructures by the supporting cells, these cells are intensely Alcian blue-PAS stained, indicating that the glycoconjugates are locally produced by these cells.

Animals↗

PubMed1991

Imprints of the tectorial membrane following acoustic overstimulation and kanamycin treatment.

Normal imprints in guinea pigs were examined mainly using a scanning electron microscope (SEM). Morphological changes in imprints after loading of the conditions mentioned below were also investigated. Imprints observed on the normal tectorial membrane were composed of small concavities lined on a W-shaped line and the W-type was of a V-type in proportion to ascend to the upper turn. The imprints occurred at the rate of one for every outer hair cell and in 3-4 lines corresponding to the outer hair cell hairs. With exposure to a high intensity of sound, small concavities of the imprints were deformed and remnant sensory hairs were observed, sporadically. Another line of new imprints was sometimes evident in the lower turn of the cochlea, in addition to the original imprints. In case of inner ear disturbances due to kanamycin (KM) loading, the imprints were little deformed, but the remnant sensory hairs were numerous and their time-course revealed a gradual decrease and the disposal required a longer time than seen in the degenerated cell fractions on the reticular membrane. With exposure to high intensity sound after KM loading, KM-type changes or high intensity sound-type changes were observed and depended on severity of the KM-induced disturbance. The imprints existed for a considerably long time even when the lower region sensory cells degenerated or disappeared in the presence of various conditions.

Animals↗

PubMed1993

Incorporation of D3H glucosamine to the adult and developing cochlear tectorial membrane of normal and hypothyroid rats.

The uptake of D-3H-glucosamine by the developing cochlea of normal and hypothyroid rats was examined using light microscopic radioautography. During postnatal development, normal and hypothyroid rat cochleas exhibited a layer of radiolabelling in the tectorial membrane (TM). This layer first appeared in the TM region which covers the spiral limbus and the Kölliker's organ (KO), then progressively reached the apical part of the TM covering the organ of Corti. Radiolabelling was significantly greater in hypothyroid than in normal cochleas. These findings suggests that the enormous size reached by the TM in the congenital hypothyroidism could be related to an increase of epithelial secretion, at least for carbohydrates. It also suggests that TM, in normal and hypothyroid cochleas, could be formed during development by the addition of successive layers. Older layers could be displaced upwards by the new ones. Cochleas of normal young adult rats, treated with D-3H-glucosamine, showed a very scarce and diffuse radiolabelling. Cochleas of hypothyroid young adult rats exhibited a thickened and distorted TM, which incorporated a significant amount of carbohydrates. These results suggest that TM secretion is highly reduced in young adult normal animals, while in young adult hypothyroid ones it is still active. During cochlear maturation, thyroxine seems to be necessary, not only for the synthesis of normal glycoproteins (as suggested by previous reports), but also for the control of glycoprotein secretion.

Animals↗

PubMedDate not supplied

Tectorial membrane repair in the quail following multiple exposures to intense sound.

Adult quail were exposed one, two or three times to an intense octave band noise. Birds were sacrificed 0 or 14 days after the last exposure and their ears processed for scanning electron microscopy (SEM). SEM observations demonstrated a patch lesion in every ear at 0 and 14 days after exposure. In the single-exposed ear immediately after noise, the lesion lacked any tectorial membrane (TM). At 14 days of recovery, the site of injury was covered by a partially regenerated TM (referred to as the honeycomb). However, the patterns of TM damage and repair varied among the twice- and thrice-exposed papillae. At 0 days after exposure, the multiple-exposed ear displayed a lesion with two segments. In one portion the TM was missing, and in the other portion the TM was present as one or two honeycomb layers. Fourteen days later, a new honeycomb was observed underneath the remaining honeycomb. These results suggest that the quail is able to repeatedly repair its TM following multiple noise exposures.

Animals↗

PubMed1993

Hearing and glycoconjugates: localization of Le(y), Le(x) and sialosyl-Le(x) in guinea pig cochlea, particularly at the tectorial membrane and sensory epithelia of the organ of Corti.

Immunohistological examination of guinea pig cochleas was performed using a panel of 25 monoclonal antibodies directed to various lacto-, ganglio- and globo-series carbohydrate epitopes as well as mucin-type epitopes. Lacto-series structures were found to be localized at specific sites of the tectorial membrane (TM) and Corti's organ, i.e. alpha 1-->3 fucosyl type 2 chain (Le(x)) at Kimura's membrane, marginal band and covering net of TM; alpha 1-->2, alpha 1-->3 difucosyl type 2 chain (Le(y)) at covering net; and sialosyl-Le(x) and sialosyl-i at Kimura's membrane and sensory epithelia, particularly sensory tips of hair cells of Corti's organ. In striking contrast, ganglio-series structures (GM3, GD3, GD2, 9-O-Ac-GD3) were detected at spiral ganglion cells, neuronal fibres and stria vascularis, but were completely absent from Corti's organ and most of the TM. Other epitope structures defined by various antibodies were not detectable at any location. The functional roles of lacto-series carbohydrate epitopes expressed at TM and Corti's organ remain unknown. However, the expression of Le(y) (but not other structures) in association with developmental deficiency of TM induced by 6-N-propyl-2-thiouracil in rats suggests that Le(y) plays some role in normal TM development. The presence of Le(x) at Kimura's membrane and sialosyl-Le(x) at hair cell sensory tips of Corti's organ suggests the intriguing possibility that these fucosylated/sialosylated carbohydrate structures play some role in interactions (either attractive or repulsive) of these inner ear components, which have been implicated in the physiology of hearing, i.e. the conversion of sound waves to nerve impulses.

Animals↗

PubMedDate not supplied

Early aspects of human cochlea development and tectorial membrane histogenesis.

Several human embryos and foetuses cochlea from the first half of pregnancy were studied by light, transmission and scanning electron microscopy. Cochlea development in man is the result of three coexisting processes: First, coiling and maturation of the cartilaginous otic capsule. Second, resorption of the periodic mesenchymal reticulum with the appearance of the labyrinthine fluids. Third, differentiation of the sensory epithelium. Tectorial membrane morphogenesis is closely related to the apocrine secretory activity of the greater and lesser epithelial ridges in the 50 mm c.r.l. specimen. In the 70, 110 and 120 mm c.r.l. specimens the secretory activity rests on the interdental cells of the spiral limbus, the undifferentiated cells of Corti's primordium and in the most external cells of the lesser epithelial ridge.

Cochlea↗

PubMed1999

Ablation of inner hair cells by carboplatin alters cells in the medial K(+) flow route and disrupts tectorial membrane.

The thesis that K(+) effluxing from inner hair cells (IHCs) cycles medially back to endolymph through inner sulcus and interdental cells (IDCs) was tested by comparing control chinchilla cochleas with those in which IHCs were selectively destroyed by carboplatin. By light microscopy inner sulcus cells appeared tall and nearly empty in control ears, but 4 months after the carboplatin treatment many showed vacuolization and shrinkage. Inner pillar cells also consistently developed abnormal vacuoles after carboplatin treatment. Control cochleas exhibited lateral columns and central clusters of IDCs which at their apex possessed expanded presumably hydrated phalanges. Four months after carboplatin, the IDC epithelium enclosed empty looking spaces and the apical phalangeal compartment collapsed into a thin, apparently dehydrated layer. This alteration was accompanied by changes in the tectorial membrane (TM) whereby the membrane's limbal zone thickened progressively to form a tall hollow mound in advanced lesions. The clear spaces in the epithelium and collapse of the phalanges are thought to reflect diminished flow of ions and fluid through IDCs. The accumulation of limbal TM supports the premise that IDCs secrete macromolecules for TM turnover as well as ions and fluid for promoting lateral migration of its precursor constituents. Occurring after ablation of IHCs by carboplatin, the changes in inner pillar, inner sulcus and IDCs and limbal TM can be viewed as a secondary effect of the interrupted ion efflux from IHCs and as further evidence that this effluent follows a medial route.

Animals↗

PubMed2004

Evidence of tectorial membrane radial motion in a propagating mode of a complex cochlear model.

Knowledge of vibratory patterns in the cochlea is crucial to understanding the stimulation of mechanosensory cells. Experiments to determine the motion of the cochlear partition and surrounding fluid are extremely challenging. As a result, the motion data are incomplete and often contradictory. The bending mechanism of hair bundles, thought to be related to the shear motion and endolymphatic flow between the tectorial membrane (TM) and reticular lamina (RL), is controversial. We, therefore, extend the frequency range of our previous hybrid analytical-finite-element approach to model the basal as well as apical regions of the guinea pig cochlea. We solve the fluid-solid interaction eigenvalue problem for the axial wavenumber, fluid pressure, and vibratory relative motions of the cochlear partition as a function of frequency. A simple monophasic vibratory mode of the basilar membrane is found at both ends of the cochlea. However, this simple movement is associated with a complex frequency-dependent relative deformation between the TM and the RL. We provide evidence of a radial component of TM motion that is out of phase with the RL and that facilitates the bending of outer hair cell stereocilia at appropriate frequencies at both the cochlear base and apex.

Cochlea↗

PubMed2000

Structural evidence for ion transport and tectorial membrane maintenance in the gerbil limbus.

Cells medial to the tunnel of Corti were examined to assess fine structural features relevant to their proposed role in cochlear K(+) homeostasis. A dense network of canaliculi referred to as canalicular reticulum (CR) resided in the foot body of inner pillar cells, where it bordered and could resorb ions released from inner radial and spiral nerves. Lateral interdental cells (IDCs) formed columns which connected the inner sulcus epithelium with the base of the tectorial membrane's (TM) middle zone. A spout-like neck in cells at the top of lateral IDC columns housed a dense concentration of CR which resembled that characteristic of ion transporting epithelia and appeared to be located here for transporting ions and fluid toward the TM. Clustered IDCs in the center of the limbus connected underlying limbal stroma with the TM's limbal zone and appeared capable of transporting ions from stroma to TM. Abundant CR in limbal stellate fibrocytes evidenced their capacity to transport ions and fluid, presumably from inner sulcus epithelium toward central IDCs. The most medial IDCs possibly function as the terminus of an ion cycling path from scala vestibuli to endolymph. Light fibrocytes situated between supralimbal fibrocytes and medial IDCs appeared to serve as a link in this pathway. The limbal zone of the TM overlying central IDCs consisted of three distinct regions which offered a structural basis for transformation of an amorphous matrix supplied by central IDCs into the protofibrils of the membrane's middle zone.

Animals↗

PubMed1952