The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH.
Sensory cells in the organ of Corti, characterized by their apical stereocilia (hair-like projections). The inner and outer hair cells, as defined by their proximity to the core of spongy bone (the modiolus), change morphologically along the COCHLEA. Towards the cochlear apex, the length of hair cell bodies and their apical STEREOCILIA increase, allowing differential responses to various frequencies of sound.
The spiral EPITHELIUM containing sensory AUDITORY HAIR CELLS and supporting cells in the cochlea. Organ of Corti, situated on the BASILAR MEMBRANE and overlaid by a gelatinous TECTORIAL MEMBRANE, converts sound-induced mechanical waves to neural impulses to the brain.
The sensory ganglion of the COCHLEAR NERVE. The cells of the spiral ganglion send fibers peripherally to the cochlear hair cells and centrally to the COCHLEAR NUCLEI of the BRAIN STEM.
Pathological processes of the snail-like structure (COCHLEA) of the inner ear (LABYRINTH) which can involve its nervous tissue, blood vessels, or fluid (ENDOLYMPH).
Auditory sensory cells of organ of Corti, usually placed in one row medially to the core of spongy bone (the modiolus). Inner hair cells are in fewer numbers than the OUTER AUDITORY HAIR CELLS, and their STEREOCILIA are approximately twice as thick as those of the outer hair cells.
Sensory cells of organ of Corti. In mammals, they are usually arranged in three or four rows, and away from the core of spongy bone (the modiolus), lateral to the INNER AUDITORY HAIR CELLS and other supporting structures. Their cell bodies and STEREOCILIA increase in length from the cochlear base toward the apex and laterally across the rows, allowing differential responses to various frequencies of sound.
A spiral thickening of the fibrous lining of the cochlear wall. Spiral ligament secures the membranous COCHLEAR DUCT to the bony spiral canal of the COCHLEA. Its spiral ligament fibrocytes function in conjunction with the STRIA VASCULARIS to mediate cochlear ion homeostasis.
The ability or act of sensing and transducing ACOUSTIC STIMULATION to the CENTRAL NERVOUS SYSTEM. It is also called audition.
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.
Cells forming a framework supporting the sensory AUDITORY HAIR CELLS in the organ of Corti. Lateral to the medial inner hair cells, there are inner pillar cells, outer pillar cells, Deiters cells, Hensens cells, Claudius cells, Boettchers cells, and others.
Electrical waves in the CEREBRAL CORTEX generated by BRAIN STEM structures in response to auditory click stimuli. These are found to be abnormal in many patients with CEREBELLOPONTINE ANGLE lesions, MULTIPLE SCLEROSIS, or other DEMYELINATING DISEASES.
A layer of stratified EPITHELIUM forming the endolymphatic border of the cochlear duct at the lateral wall of the cochlea. Stria vascularis contains primarily three cell types (marginal, intermediate, and basal), and capillaries. The marginal cells directly facing the ENDOLYMPH are important in producing ion gradients and endochoclear potential.
The cochlear part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The cochlear nerve fibers originate from neurons of the SPIRAL GANGLION and project peripherally to cochlear hair cells and centrally to the cochlear nuclei (COCHLEAR NUCLEUS) of the BRAIN STEM. They mediate the sense of hearing.
Fenestra of the cochlea, an opening in the basal wall between the MIDDLE EAR and the INNER EAR, leading to the cochlea. It is closed by a secondary tympanic membrane.
The electric response of the cochlear hair cells to acoustic stimulation.
A general term for the complete loss of the ability to hear from both ears.
The fluid separating the membranous labyrinth from the osseous labyrinth of the ear. It is entirely separate from the ENDOLYMPH which is contained in the membranous labyrinth. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1396, 642)
The lymph fluid found in the membranous labyrinth of the ear. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
One of the three ossicles of the middle ear. It transmits sound vibrations from the INCUS to the internal ear (Ear, Internal see LABYRINTH).
Self-generated faint acoustic signals from the inner ear (COCHLEA) without external stimulation. These faint signals can be recorded in the EAR CANAL and are indications of active OUTER AUDITORY HAIR CELLS. Spontaneous otoacoustic emissions are found in all classes of land vertebrates.
A membrane, attached to the bony SPIRAL LAMINA, overlying and coupling with the hair cells of the ORGAN OF CORTI in the inner ear. It is a glycoprotein-rich keratin-like layer containing fibrils embedded in a dense amorphous substance.
The lower chamber of the COCHLEA, extending from the round window to the helicotrema (the opening at the apex that connects the PERILYMPH-filled spaces of scala tympani and SCALA VESTIBULI).
A general term for the complete or partial loss of the ability to hear from one or both ears.
Hearing loss due to exposure to explosive loud noise or chronic exposure to sound level greater than 85 dB. The hearing loss is often in the frequency range 4000-6000 hertz.
A spiral tube that is firmly suspended in the bony shell-shaped part of the cochlea. This ENDOLYMPH-filled cochlear duct begins at the vestibule and makes 2.5 turns around a core of spongy bone (the modiolus) thus dividing the PERILYMPH-filled spiral canal into two channels, the SCALA VESTIBULI and the SCALA TYMPANI.
The audibility limit of discriminating sound intensity and pitch.
Either of a pair of compound bones forming the lateral (left and right) surfaces and base of the skull which contains the organs of hearing. It is a large bone formed by the fusion of parts: the squamous (the flattened anterior-superior part), the tympanic (the curved anterior-inferior part), the mastoid (the irregular posterior portion), and the petrous (the part at the base of the skull).
A genus of the family Chinchillidae which consists of three species: C. brevicaudata, C. lanigera, and C. villidera. They are used extensively in biomedical research.
Use of sound to elicit a response in the nervous system.
Hearing loss resulting from damage to the COCHLEA and the sensorineural elements which lie internally beyond the oval and round windows. These elements include the AUDITORY NERVE and its connections in the BRAINSTEM.
A subfamily of the Muridae consisting of several genera including Gerbillus, Rhombomys, Tatera, Meriones, and Psammomys.
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.
Surgical insertion of an electronic hearing device (COCHLEAR IMPLANTS) with electrodes to the COCHLEAR NERVE in the inner ear to create sound sensation in patients with residual nerve fibers.
An oval semitransparent membrane separating the external EAR CANAL from the tympanic cavity (EAR, MIDDLE). It contains three layers: the skin of the external ear canal; the core of radially and circularly arranged collagen fibers; and the MUCOSA of the middle ear.
Any sound which is unwanted or interferes with HEARING other sounds.
The 8th cranial nerve. The vestibulocochlear nerve has a cochlear part (COCHLEAR NERVE) which is concerned with hearing and a vestibular part (VESTIBULAR NERVE) which mediates the sense of balance and head position. The fibers of the cochlear nerve originate from neurons of the SPIRAL GANGLION and project to the cochlear nuclei (COCHLEAR NUCLEUS). The fibers of the vestibular nerve arise from neurons of Scarpa's ganglion and project to the VESTIBULAR NUCLEI.
Electronic hearing devices typically used for patients with normal outer and middle ear function, but defective inner ear function. In the COCHLEA, the hair cells (HAIR CELLS, VESTIBULAR) may be absent or damaged but there are residual nerve fibers. The device electrically stimulates the COCHLEAR NERVE to create sound sensation.
The space and structures directly internal to the TYMPANIC MEMBRANE and external to the inner ear (LABYRINTH). Its major components include the AUDITORY OSSICLES and the EUSTACHIAN TUBE that connects the cavity of middle ear (tympanic cavity) to the upper part of the throat.
The narrow passage way that conducts the sound collected by the EAR AURICLE to the TYMPANIC MEMBRANE.
Gradual bilateral hearing loss associated with aging that is due to progressive degeneration of cochlear structures and central auditory pathways. Hearing loss usually begins with the high frequencies then progresses to sounds of middle and low frequencies.
NEURAL PATHWAYS and connections within the CENTRAL NERVOUS SYSTEM, beginning at the hair cells of the ORGAN OF CORTI, continuing along the eighth cranial nerve, and terminating at the AUDITORY CORTEX.
Fluids found within the osseous labyrinth (PERILYMPH) and the membranous labyrinth (ENDOLYMPH) of the inner ear. (From Gray's Anatomy, 30th American ed, p1328, 1332)
An oval, bony chamber of the inner ear, part of the bony labyrinth. It is continuous with bony COCHLEA anteriorly, and SEMICIRCULAR CANALS posteriorly. The vestibule contains two communicating sacs (utricle and saccule) of the balancing apparatus. The oval window on its lateral wall is occupied by the base of the STAPES of the MIDDLE EAR.
Neurons which send impulses peripherally to activate muscles or secretory cells.
The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.
A type of non-ionizing radiation in which energy is transmitted through solid, liquid, or gas as compression waves. Sound (acoustic or sonic) radiation with frequencies above the audible range is classified as ultrasonic. Sound radiation below the audible range is classified as infrasonic.
An accumulation of ENDOLYMPH in the inner ear (LABYRINTH) leading to buildup of pressure and distortion of intralabyrinthine structures, such as COCHLEA and SEMICIRCULAR CANALS. It is characterized by SENSORINEURAL HEARING LOSS; TINNITUS; and sometimes VERTIGO.
The brain stem nucleus that receives the central input from the cochlear nerve. The cochlear nucleus is located lateral and dorsolateral to the inferior cerebellar peduncles and is functionally divided into dorsal and ventral parts. It is tonotopically organized, performs the first stage of central auditory processing, and projects (directly or indirectly) to higher auditory areas including the superior olivary nuclei, the medial geniculi, the inferior colliculi, and the auditory cortex.
The dense rock-like part of temporal bone that contains the INNER EAR. Petrous bone is located at the base of the skull. Sometimes it is combined with the MASTOID PROCESS and called petromastoid part of temporal bone.
Surgery performed on the external, middle, or internal ear.
A mobile chain of three small bones (INCUS; MALLEUS; STAPES) in the TYMPANIC CAVITY between the TYMPANIC MEMBRANE and the oval window on the wall of INNER EAR. Sound waves are converted to vibration by the tympanic membrane then transmitted via these ear ossicles to the inner ear.
Pathological processes of the inner ear (LABYRINTH) which contains the essential apparatus of hearing (COCHLEA) and balance (SEMICIRCULAR CANALS).
The process by which cells convert mechanical stimuli into a chemical response. It can occur in both cells specialized for sensing mechanical cues such as MECHANORECEPTORS, and in parenchymal cells whose primary function is not mechanosensory.
Nerve structures through which impulses are conducted from a nerve center toward a peripheral site. Such impulses are conducted via efferent neurons (NEURONS, EFFERENT), such as MOTOR NEURONS, autonomic neurons, and hypophyseal neurons.
A continuing periodic change in displacement with respect to a fixed reference. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The branch of physics that deals with sound and sound waves. In medicine it is often applied in procedures in speech and hearing studies. With regard to the environment, it refers to the characteristics of a room, auditorium, theatre, building, etc. that determines the audibility or fidelity of sounds in it. (From Random House Unabridged Dictionary, 2d ed)
Conditions that impair the transmission of auditory impulses and information from the level of the ear to the temporal cortices, including the sensorineural pathways.
Pathological processes of the VESTIBULOCOCHLEAR NERVE, including the branches of COCHLEAR NERVE and VESTIBULAR NERVE. Common examples are VESTIBULAR NEURITIS, cochlear neuritis, and ACOUSTIC NEUROMA. Clinical signs are varying degree of HEARING LOSS; VERTIGO; and TINNITUS.
A disease of the inner ear (LABYRINTH) that is characterized by fluctuating SENSORINEURAL HEARING LOSS; TINNITUS; episodic VERTIGO; and aural fullness. It is the most common form of endolymphatic hydrops.
The hearing and equilibrium system of the body. It consists of three parts: the EXTERNAL EAR, the MIDDLE EAR, and the INNER EAR. Sound waves are transmitted through this organ where vibration is transduced to nerve signals that pass through the ACOUSTIC NERVE to the CENTRAL NERVOUS SYSTEM. The inner ear also contains the vestibular organ that maintains equilibrium by transducing signals to the VESTIBULAR NERVE.
Two membranous sacs within the vestibular labyrinth of the INNER EAR. The saccule communicates with COCHLEAR DUCT through the ductus reuniens, and communicates with utricle through the utriculosaccular duct from which the ENDOLYMPHATIC DUCT arises. The utricle and saccule have sensory areas (acoustic maculae) which are innervated by the VESTIBULAR NERVE.
Refers to animals in the period of time just after birth.
The testing of the acuity of the sense of hearing to determine the thresholds of the lowest intensity levels at which an individual can hear a set of tones. The frequencies between 125 and 8000 Hz are used to test air conduction thresholds and the frequencies between 250 and 4000 Hz are used to test bone conduction thresholds.
Measurement of distances or movements by means of the phenomena caused by the interference of two rays of light (optical interferometry) or of sound (acoustic interferometry).
Measurement of hearing based on the use of pure tones of various frequencies and intensities as auditory stimuli.
The anatomical study of specific regions or parts of organisms, emphasizing the relationship between the various structures (e.g. muscles, nerves, skeletal, cardiovascular, etc.).
Antibiotic complex produced by Streptomyces kanamyceticus from Japanese soil. Comprises 3 components: kanamycin A, the major component, and kanamycins B and C, the minor components.
Part of an ear examination that measures the ability of sound to reach the brain.
The blind pouch at the end of the endolymphatic duct. It is a storage reservoir for excess ENDOLYMPH, formed by the blood vessels in the membranous labyrinth.
The posterior pair of the quadrigeminal bodies which contain centers for auditory function.
A part of the MEDULLA OBLONGATA situated in the olivary body. It is involved with motor control and is a major source of sensory input to the CEREBELLUM.
Mechanosensing organelles of hair cells which respond to fluid motion or fluid pressure changes. They have various functions in many different animals, but are primarily used in hearing.
A nonspecific symptom of hearing disorder characterized by the sensation of buzzing, ringing, clicking, pulsations, and other noises in the ear. Objective tinnitus refers to noises generated from within the ear or adjacent structures that can be heard by other individuals. The term subjective tinnitus is used when the sound is audible only to the affected individual. Tinnitus may occur as a manifestation of COCHLEAR DISEASES; VESTIBULOCOCHLEAR NERVE DISEASES; INTRACRANIAL HYPERTENSION; CRANIOCEREBRAL TRAUMA; and other conditions.

3D MRI of the membranous labyrinth. An age related comparison of MR findings in patients with labyrinthine fibrosis and in persons without inner ear symptoms. (1/1700)

PURPOSE: We compared MRI of the membranous labyrinth in patients with chronic non-neoplastic inner ear disease and MR signs of labyrinthine fibrosis and controls depending on their age, in order to establish whether there were any MR differences regarding patient age groups, control age groups and between the patients and controls themselves. MATERIALS AND METHODS: Clinical ENT examinations as well as a T2* weighted 3D CISS (Constructive Interference in Steady State) sequence with a slice thickness of 0.7 mm were performed. Our collective was subdivided as follows: 0-19 years (10 controls, 3 patients with chronic non-neoplastic inner ear disease), 20-49 years (55 controls, 8 patients), 50 years and older (40 controls, 22 patients). Detectability of labyrinthine structures (e.g. cochlea, vestibule, semicircular canals) and filling defects were evaluated. RESULTS: In the 3 age-groups of the control collective no significant differences were observed in the membranous labyrinth. However differences concerning labyrinthine detectability emerged between controls and patients in both the 20-49 years and 50 years and older age groups. In the patient collective the 3 age groups showed no significant discrepancy in the mean number of lesions. CONCLUSION: Filling defects of the membranous labyrinth on 3D CISS MR images are pathological even in older persons. We would therefore recommend high resolution T2* weighted MRI in the case of suspected labyrinthine fibrosis.  (+info)

Inner ear and kidney anomalies caused by IAP insertion in an intron of the Eya1 gene in a mouse model of BOR syndrome. (2/1700)

A spontaneous mutation causing deafness and circling behavior was discovered in a C3H/HeJ colony of mice at the Jackson Laboratory. Pathological analysis of mutant mice revealed gross morphological abnormalities of the inner ear, and also dysmorphic or missing kidneys. The deafness and abnormal behavior were shown to be inherited as an autosomal recessive trait and mapped to mouse chromosome 1 near the position of the Eya1 gene. The human homolog of this gene, EYA1, has been shown to underly branchio-oto-renal (BOR) syndrome, an autosomal dominant disorder characterized by hearing loss with associated branchial and renal anomalies. Molecular analysis of the Eya1 gene in mutant mice revealed the insertion of an intracisternal A particle (IAP) element in intron 7. The presence of the IAP insertion was associated with reduced expression of the normal Eya1 message and formation of additional aberrant transcripts. The hypomorphic nature of the mutation may explain its recessive inheritance, if protein levels in homozygotes, but not heterozygotes, are below a critical threshold needed for normal developmental function. The new mouse mutation is designated Eya1(bor) to denote its similarity to human BOR syndrome, and will provide a valuable model for studying mutant gene expression and etiology.  (+info)

Synapses involving auditory nerve fibers in primate cochlea. (3/1700)

The anatomical mechanisms for processing auditory signals are extremely complex and incompletely understood, despite major advances already made with the use of electron microscopy. A major enigma, for example, is the presence in the mammalian cochlea of a double hair cell receptor system. A renewed attempt to discover evidence of synaptic coupling between the two systems in the primate cochlea, postulated from physiological studies, has failed. However, in the outer spiral bundle the narrow and rigid clefts seen between pairs of presumptive afferent fibers suggest the possibility of dendro-dendritic interaction confined to the outer hair cell system. The clustering of afferent processes within folds of supporting cells subjacent to outer hair cells is in contrast to the lack of such close associations in the inner hair cell region. The difference reinforces the suggestion of functional interaction of some sort between the outer hair cell afferent nerve processes.  (+info)

Development of acetylcholine-induced responses in neonatal gerbil outer hair cells. (4/1700)

Cochlear outer hair cells (OHCs) are dominantly innervated by efferents, with acetylcholine (ACh) being their principal neurotransmitter. ACh activation of the cholinergic receptors on isolated OHCs induces calcium influx through the ionotropic receptors, followed by a large outward K+ current through nearby Ca2+-activated K+ channels. The outward K+ current hyperpolarizes the cell, resulting in the fast inhibitory effects of efferent action. Although the ACh receptors (AChRs) in adult OHCs have been identified and the ACh-induced current responses have been characterized, it is unclear when the ACh-induced current responses occur during development. In this study we attempt to address this question by determining the time of onset of the ACh-induced currents in neonatal gerbil OHCs, using whole cell patch-clamp techniques. Developing gerbils ranging in age from 4 to 12 days were used in these experiments, because efferent synaptogenesis and functional maturation of OHCs occur after birth. Results show that the first detectable ACh-induced current occurred at 6 days after birth (DAB) in 12% of the basal turn cells with a small outward current. The fraction of responsive cells and the size of outward currents increased as development progressed. By 11 DAB, the fraction of responsive cells and the current size were comparable with those of adult OHCs. The results indicate that the maturation of the ACh-induced response begins around 6 DAB. It appears that the development of ACh-induced responses occur during the same time period when OHCs develop motility but before the onset of auditory function, which is around 12 DAB when cochlear microphonic potentials can first be evoked with acoustic stimulation in gerbils.  (+info)

Comparing in vitro, in situ, and in vivo experimental data in a three-dimensional model of mammalian cochlear mechanics. (5/1700)

Normal mammalian hearing is refined by amplification of the motion of the cochlear partition. This partition, comprising the organ of Corti sandwiched between the basilar and tectorial membranes, contains the outer hair cells that are thought to drive this amplification process. Force generation by outer hair cells has been studied extensively in vitro and in situ, but, to understand cochlear amplification fully, it is necessary to characterize the role played by each of the components of the cochlear partition in vivo. Observations of cochlear partition motion in vivo are severely restricted by its inaccessibility and sensitivity to surgical trauma, so, for the present study, a computer model has been used to simulate the operation of the cochlea under different experimental conditions. In this model, which uniquely retains much of the three-dimensional complexity of the real cochlea, the motions of the basilar and tectorial membranes are fundamentally different during in situ- and in vivo-like conditions. Furthermore, enhanced outer hair cell force generation in vitro leads paradoxically to a decrease in the gain of the cochlear amplifier during sound stimulation to the model in vivo. These results suggest that it is not possible to extrapolate directly from experimental observations made in vitro and in situ to the normal operation of the intact organ in vivo.  (+info)

Gene disruption of p27(Kip1) allows cell proliferation in the postnatal and adult organ of corti. (6/1700)

Hearing loss is most often the result of hair-cell degeneration due to genetic abnormalities or ototoxic and traumatic insults. In the postembryonic and adult mammalian auditory sensory epithelium, the organ of Corti, no hair-cell regeneration has ever been observed. However, nonmammalian hair-cell epithelia are capable of regenerating sensory hair cells as a consequence of nonsensory supporting-cell proliferation. The supporting cells of the organ of Corti are highly specialized, terminally differentiated cell types that apparently are incapable of proliferation. At the molecular level terminally differentiated cells have been shown to express high levels of cell-cycle inhibitors, in particular, cyclin-dependent kinase inhibitors [Parker, S. B., et al. (1995) Science 267, 1024-1027], which are thought to be responsible for preventing these cells from reentering the cell cycle. Here we report that the cyclin-dependent kinase inhibitor p27(Kip1) is selectively expressed in the supporting-cell population of the organ of Corti. Effects of p27(Kip1)-gene disruption include ongoing cell proliferation in postnatal and adult mouse organ of Corti at time points well after mitosis normally has ceased during embryonic development. This suggests that release from p27(Kip1)-induced cell-cycle arrest is sufficient to allow supporting-cell proliferation to occur. This finding may provide an important pathway for inducing hair-cell regeneration in the mammalian hearing organ.  (+info)

A changing pattern of brain-derived neurotrophic factor expression correlates with the rearrangement of fibers during cochlear development of rats and mice. (7/1700)

The reorganization of specific neuronal connections is a typical feature of the developing nervous system. It is assumed that the refinement of connections in sensory systems requires spontaneous activity before the onset of cochlear function and selective sensory experience during the ensuing period. The mechanism of refinement through sensory experience is currently postulated as being based on the selective reinforcement of active projections by neurotrophins. We studied a presumed role of neurotrophins for rearrangement of afferent and efferent fibers before the onset of sensory function in the precisely innervated auditory end organ, the cochlea. We observed a spatiotemporal change in the localization of brain-derived neurotrophic factor (BDNF) protein and mRNA, which correlated with the reorganization of fibers. Thus, BDNF decreased in target hair cells during fiber retraction and was subsequently upregulated in neurons, target hair cells, and adjacent supporting cells concomitant with the formation of new synaptic contacts. Analysis of the innervation pattern in BDNF gene-deleted mice by immunohistochemistry and confocal microscopy revealed a failure in the rearrangement of fibers and a BDNF dependency of distinct neuronal projections that reorganize in control animals. Our data suggest that, before the onset of auditory function, a spatiotemporal change in BDNF expression in sensory, epithelial, and neuronal cells may guide the initial steps of refinement of the innervation pattern.  (+info)

Dose dependent protection by lipoic acid against cisplatin-induced ototoxicity in rats: antioxidant defense system. (8/1700)

This study investigated the alterations that occur in auditory brainstem-evoked responses (ABRs) concurrent with changes in cochlear concentrations of glutathione (GSH), lipid peroxidation, and antioxidant enzyme activity in cisplatin-induced ototoxicity and in dose-dependent otoprotection by an antioxidant lipoate. Male Wistar rats were divided into different groups and were treated as follows, with: (1) vehicle (saline) control; (2) cisplatin (16 mg/kg, i.p.); (3) lipoate (100 mg/kg, i.p.) plus saline; (4) cisplatin plus lipoate (25 mg/kg); (5) cisplatin plus lipoate (50 mg/kg), and (6) cisplatin plus lipoate (100 mg/kg). Post-treatment ABRs were evaluated after three days, the rats were sacrificed, and cochleae were harvested and analyzed. The cisplatin-injected rats showed ABR threshold elevations above the pre-treatment thresholds. Rats treated with lipoate plus cisplatin did not show significant elevation of hearing thresholds. Cisplatin administration resulted in a depletion of cochlear GSH concentration (69% of control), whereas, cisplatin-plus-lipoate treatment increased GSH concentration close to control value. Cisplatin-treated rats showed a decrease in cochlear superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione reductase (GR) activities (57, 78, 59, and 58% of control, respectively), and an increase in malondialdehyde (MDA) concentration (196% of control). Cochlear SOD, CAT, GSH-Px, and GR activities and MDA concentrations were restored in the rats injected with cisplatin plus graded doses of lipoate than those with cisplatin alone. It is concluded that cisplatin-induced ototoxicity is related to impairment of the cochlear antioxidant defense system, and the dose-dependent otoprotection conferred by an antioxidant lipoate against cisplatin ototoxicity is associated with sparing of the cochlear antioxidant defense system.  (+info)

The mammalian cochlea is a complex macroscopic structure due to its helical shape and the microscopic arrangements of the individual layers of cells. To improve the outcomes of hearing restoration in deaf patients, it is important to understand the anatomic structure and composition of the cochlea ex vivo. Hitherto, only one histological technique based on confocal laser scanning microscopy and optical clearing has been developed for in toto optical imaging of the murine cochlea. However, with a growing size of the specimen, e.g., human cochlea, this technique reaches its limitations. Here, we demonstrate scanning laser optical tomography (SLOT) as a valuable imaging technique to visualize the murine cochlea in toto without any physical slicing. This technique can also be applied in larger specimens up to cm3 such as the human cochlea. Furthermore, immunolabeling allows visualization of inner hair cells (otoferlin) or spiral ganglion cells (neurofilament) within the whole cochlea. After image ...
TY - JOUR. T1 - Acoustic trauma in the guinea pig cochlea. T2 - Early changes in ultrastructure and neural threshold. AU - Robertson, Donald. AU - Johnstone, Brian M.. PY - 1980/1/1. Y1 - 1980/1/1. N2 - Scanning microscopy was used to examine guinea pig cochleas for structural damage immediately after exposure to a pure tone ranging from 96 to 129 dB SPL. Functional changes to the cochlear neural sensitivity were assessed using the N1 audiogram. Principal findings were: (1) The order of damge to receptor cells with increasing sound intensity was OHC1, then IHC, then OHC2 and OHC3. (2) The spatial distribution of damage to OHC1 and IHC differed with IHC tending to show damage mainly in the vicinity of the exposure frequency location and OHC1 damage spreading basalward of this point. (3) N1 threshold losses spread progressively to lower frequencies as exposure intensity increased. This was accompanied by an apical spread of damage to the receptor cells.. AB - Scanning microscopy was used to ...
Excessive contact with noise damages the main cochlear structures resulting in hearing impairment. both peptides considerably improved both development of hearing thresholds as well as the degenerative adjustments induced by noise-exposure in lateral wall structure structures. Moreover, remedies ameliorated the inflammatory condition and redox stability. These therapeutic results had been dose-dependent and far better if the TGF-1 inhibitors had been administered ahead of inducing the damage. To conclude, inhibition of TGF-1 activities with antagonistic peptides signifies a new, encouraging therapeutic technique for the avoidance and fix of noise-induced cochlear harm. knock-out mice (Shull et al., 1992; Kulkarni et al., 1993). The function of TGF- family members elements in cochlear pathophysiology isnt fully understood. Latest evaluation of genes highly relevant to hearing and deafness directed to TGF-1 being a nodal molecule in non-syndromic deafness and otic capsule advancement gene systems ...
Nitric oxide (NO) has been implicated as a mediator of vasodilation and neurotransmission in the mammalian cochlea. This is demonstrated by the presence of nitric oxide synthase (NOS) and nitric oxide (NO) in the blood vessels and the organ of Corti in the cochlea. It is not certain if the neurons in the spiral ganglion produce NO since no fluorescent signal could be detected by 4,5-diaminofluorescein diacetate (DAF-2DA), a fluorescent indicator of NO. To determine if NO/peroxynitrite plays any role in neurodestruction observed in ischemic cochlea of the guinea pig, the effects of NO donors, such as S-nitrosocysteine (S-NC) and nitroglycerine (NTG); peroxynitrite generators, such as 3-morpholinosydnonimine (SIN-1); peroxynitrite inhibitors, such as superoxide dismutase plus catalase (SOD/Cat); and NOS inhibitors, such as NG-nitro-L-arginine methyl ether (L-NAME) were tested on normal and ischemic cochleae. The level of NO in the cochlea after 20 to 120 minutes of ischemia was indicated by ...
To determine when the abnormal phenotypes of the hair bundles and the kinocilium were observed in aberrantly attached Nectin-3-/- HCs, we analysed the localisation of γ-tubulin in E16.5 mouse HCs. The maturation of the organ of Corti starts from the basal turn and proceeds to the apical turn of the cochlea; therefore, HCs in the apical turn are less mature than those in the middle turn (Lim and Anniko, 1985). In both the apical and middle turns of the Nectin-3-/- cochlea, HCs were aberrantly attached to each other and the immunofluorescence signals for Nectin-1 and afadin (Mllt4 - Mouse Genome Informatics) were concentrated at the boundary between attached HCs (Fig. 5A,B). In the apical turn of the Nectin-3+/- cochlea, the signal for γ-tubulin was observed in the centre of the apical surface of HCs, whereas it was positioned at the lateral side in the middle turn (Fig. 5C; supplementary material Fig. S4A). In the Nectin-3+/- cochlea, aberrantly attached HCs were fewer than in the Nectin-3-/- ...
TY - JOUR. T1 - Intra-tympanic delivery of short interfering RNA into the adult mouse cochlea. AU - Oishi, Naoki. AU - Chen, Fu Quan. AU - Zheng, Hong Wei. AU - Sha, Su Hua. N1 - Funding Information: The research project described was supported by grant R01 DC009222 from the National Institute on Deafness and Other Communication Disorders, National Institutes of Health . This work was partially conducted in the Walton Research Building in renovated space supported by grant C06 RR014516. Some animals used in this study were housed in MUSC CRI animal facilities supported by grant C06 RR015455 from the Extramural Research Facilities Program of the National Center for Research Resources . We thank Dr. Jochen Schacht for his valuable comments on the manuscript.. PY - 2013/2. Y1 - 2013/2. N2 - Trans-tympanic injection into the middle ear has long been the standard for local delivery of compounds in experimental studies. Here we demonstrate the advantages of the novel method of intra-tympanic injection ...
The distribution of organ of corti protein II (OCP II) was assessed in the developing and mature gerbil cochlea by light and electron microscopic immunohistochemistry. In the mature cochlea, OCP II was expressed in all supporting cells of the organ of Corti, inner and outer sulcus cells and interdental cells. The highest gold particle labeling density was seen overlying intracellular regions devoid of organelles. In the developing inner ear, OCP II was first detected at 2 days after birth with the strongest staining in immature Deiters, inner phalangeal and pillar cells. Immunostaining intensity increased gradually in cells lying laterally and medially to the more centrally located supporting cells and reached adult levels ln all reactive cell types around 18 days after birth. The results demonstrate conclusively that OCP II is a cytosolic protein and fail to support its postulated role as a transcription factor based on its high amino acid sequence homology with p15. The high level of ...
In the chicken basilar papilla it has been reported that overexpression of activated β-catenin induces ectopic HC formation (Stevens et al., 2003) and, more recently, it has been shown that canonical Wnt activation can induce proliferation within dissociated epithelial cells of the avian utricle (Alvarado et al., 2011). The role for this pathway during mammalian cochlear development, however, was unknown. Although multiple transgenic canonical Wnt reporter mice have been generated (listed on the Wnt homepage http://www.stanford.edu/group/nusselab/cgi-bin/wnt/), inconsistencies existed as to the exact spatiotemporal pattern of endogenous Wnt/β-catenin activity (Barolo, 2006). In the inner ear, Qian et al. (Qian et al., 2007) reported no Wnt/β-catenin activity in the otocyst and developing cochlea using the BAT-gal mouse (Maretto et al., 2003), whereas Laine et al. (Laine et al., 2010) identified low-level activity in cochleae of the same BAT-gal strain as well as in the TOP-gal reporter ...
Authors: Suh, Myung Whan , Shin, Dong Hoon , Lee, Ho Sun , Park, Ji Yeong , Kim, Chong Sun , Oh, Seung Ha Article Type: Research Article Abstract: Unlike mammals, avian cochlear hair cells can regenerate after acoustic overstimulation. The WDR1 gene is one of the genes suspected to play an important role in this difference. In an earlier study, we found that the WDR1 gene is over-expressed in the chick cochlea after acoustic overstimulation. The aim of this study was to compare the expression of WDR1 before and after acoustic overstimulation in the chick vestibule. Seven-day-old chicks were divided into three groups: normal …group, damage group, and regeneration group. The damage and regeneration group was exposed to 120 dB SPL white noise for 5-6 hours. The damage group was euthanized shortly after the impulse, but the regeneration group was allowed to recover for 2 days. The utricle, saccule, and the three ampullae of each semicircular canal were dissected and immunohistochemically stained ...
The high degree of bone marrow cell (BMC) plasticity has prompted us to test its restoration possibility in inner ear repair. Our aim was to determine the potential of these cells to transdifferentiate into specialized cochlea cell types after acoustic injury and BMC mobilization. Lethally irradiated mice were transplanted with BMCs from green fluorescent protein (GFP) transgenic mice and subjected to acoustic deafening 3 months later. In a separate experiment, stem cell factor and granulocyte colony-stimulating factor were administered to test the effect of BMC mobilization on bone marrow-derived cell (BMDC) transdifferentiation. All mice showed almost complete chimerism 3 months after bone marrow transplantation. Upon acoustic trauma, robust BMDC migration was observed in the deafened cochlea. GFP+ cell migration was most prominent during the first week after acoustic deafening, and these cells accumulated significantly at the spiral ligament, perilymphatic compartment walls, and limbus ...
By using a device that provides high-resolution images of the inner ear, researchers are learning about the mechanics of hearing. In order to develop therapies for hearing loss, its important to understand the functions of different areas of the cochlea, and until now, that hasnt been very easy.. Because the cochlea is so small and difficult to access, researchers havent been able to study it very easily without causing damage to the ear. But by using this technology (OCT, or optical coherence tomography), researchers at Texas A&M and Stanford have been able to gather information about the way the cochlea converts vibrations into nerve impulses to create sound without having to open the bone around it.. The concept has been proven in mice, and researchers have been able to gather measurements without causing any damage to the mouse cochlea or surrounding tissues. A prototype device has been developed for human use. If researchers can map the human cochlea and determine what happens to the ...
Maturation of neurotransmission in the developing rat cochlea: immunohistochemical evidence from differential expression of synaptophysin and synaptobrevin 2
Cochlea: The cochlea contains the sensory organ of hearing. It bears a striking resemblance to the shell of a snail and in fact takes its name from the Greek word for this object. The cochlea is a spiral tube that is…
By using a device that provides high-resolution images of the inner ear, researchers are learning about the mechanics of hearing. In order to develop therapies for hearing loss, its important to understand the functions of different areas of the cochlea, and until now, that hasnt been very easy.. Because the cochlea is so small and difficult to access, researchers havent been able to study it very easily without causing damage to the ear. But by using this technology (OCT, or optical coherence tomography), researchers at Texas A&M and Stanford have been able to gather information about the way the cochlea converts vibrations into nerve impulses to create sound without having to open the bone around it.. The concept has been proven in mice, and researchers have been able to gather measurements without causing any damage to the mouse cochlea or surrounding tissues. A prototype device has been developed for human use. If researchers can map the human cochlea and determine what happens to the ...
Initial studies on the effects of activation of the IGF signaling pathway focused on promotion of cellular proliferation (Baker et al., 1993; Liu et al., 1993). However, more recent findings have linked IGF signaling with pleiotropic effects including cellular differentiation, axon outgrowth and polarity, cell migration and patterning, and cell survival (Fukudome et al., 2003; Vicario-Abejón et al., 2003; Ye and DErcole, 2006; Scolnick et al., 2008). The results presented here are consistent with a broader role for IGF signaling as many of the changes observed in the inner ears of Igf1r−/− mutants are not consistent with a decrease in proliferation.. A particularly intriguing aspect of the effect of the deletion of Igf1r was the disruption in the transition between uncommitted prosensory cells and differentiating hair cells and supporting cells. Recent work has demonstrated that an important step in cochlear development is the transition of proliferative Sox2-positive prosensory cells to a ...
The risks and efficacy of transplanting two varieties of stem cells into mouse cochlea have been evaluated by Japanese researchers.
The cochlea is a fluid-filled structure in the middle ear. The sound waves are translated to fluid waves in the cochlea that are then sensed by nerves connected to fine hairs that float in the fluid and is then sent on to the brain for interpretation. This is the area that a human cochlear implant stimulates to help correct hearing loss. The feline cochlea has 3 complete turns while the human cochlea only has 2.75 turns. They have 10,000 more auditory nerves than humans. Near the cochlea is another fluid- and carbonate crystal-filled structure called the vestibular apparatus that is in charge of balance.. Cats are exquisitely adept at locating prey. They can distinguish between two different sound sources 8 cm apart (shorter than the length of an iPhone) at 2 yards and 40cm apart (about 1 foot, or a little longer than 3 iPhones) at 20 yards. They can hear a rustling mouse 20-30 yards away. They can hear 10 distinct octaves of notes vs. humans 8.5 octaves. They even hear one octave above their ...
You may find this publication the answer to your problems. Brain Research Protocols Volume 6, Issue 3, February 2001, Pages 159-166 Cryoembedding and sectioning of cochleas for immunocytochemistry and in situ hybridization Donna S. Whitlon, Renee Szakaly, Mary A. Greiner Abstract Current emphasis on biochemical and molecular aspects of cochlear anatomy underscores the necessity for high quality cryostat sections of the inner ear. The large volume of fluid space within the cochlea makes cryoembedding and sectioning of the organ more problematic than that of other, more homogeneous tissues. Our method for cryoembedding of cochleas for immunocytochemistry and in situ hybridization uses slow infiltration with increasing concentrations of sucrose followed by degassed embedding medium before final orientation and freezing. This method permits high quality cryosections to be cut which preserve overall structure and cellular resolution. Author Keywords: Cryosections; Cochlea; Immunocytochemistry; In ...
The cochlea receives its main blood supply from the basilar artery, via the anterior inferior cerebellar artery and the spiral modiolar artery. It is of clinica...
The observed disorganization and expansion of the organ of Corti, in addition to the proliferation following ectopic β-catenin activation, suggested changes in the adhesion complexes within the epithelium. In addition to roles in proliferation and differentiation, β-catenin plays a role in cell adhesion by binding to the cytoplasmic tail of cadherins at the plasma membrane (Ozawa et al., 1989). Similar to β-catenin, E-cadherin is expressed within the cell membranes of the cochlear sensory epithelium (Whitlon, 1993; Leonova and Raphael, 1997; Simonneau et al., 2003). When we overexpressed β-catenin in the cochlea after initiation of tamoxifen at E13.5 in the Sox2-CreER;β-cateninflox(exon3) mouse, elongation of the sensory epithelium proceeded into the apical region (Fig. 8A) as expected, and staining for EdU as well as Ki67, a cell proliferation marker, were observed (Fig. 8B), but E-cadherin expression within the cell membranes was decreased (Fig. 8C,E). The cochlea contained multiple rows ...
Fishpond Australia, Cochlea & Eustachia by Hans Rickheit (By (artist)) Hans RickheitBuy . Books online: Cochlea & Eustachia, 2014, Fishpond.com.au
Our aims are to identify the molecular mechanisms that regulate the expression of Fgf20 during the embryonic development of the cochlea; to determine how FGF20 regulates sensory progenitor cell growth and the differentiation of cochlear outer hair and supporting cells in the organ of Corti; and to identify the specific genes and pathways that act downstream of FGF20 during cochlear development using Next Gen mRNA sequencing. We are testing the hypothesis that FGF signaling can enhance sensory cell regeneration following ototoxic damage.. 2. Regulation of neuronal excitability by intracellular FGFs.. We are studying a unique subfamily of FGFs that act intracellularly (iFGFs) in neurons and cardiomyocytes and that are important for regulating cell excitability through interactions with voltage gated sodium channels. Disruption of FGF14, one of four iFGFs, results in an anatomically normal mouse with severe neurobehavioral phenotypes including ataxia, seizure, paroxysmal dystonia and cognitive ...
Aminoglycoside antibiotics are implicated as culprits of hearing reduction in more than 120,000 individuals annually. Research has shown that this sensory cells, but not supporting cells, of the cochlea are readily damaged and/or lost after use of such antibiotics. High-frequency outer hair cells (OHCs) show a greater sensitivity to antibiotics than high- and low-frequency inner hair cells (IHCs). We hypothesize that variations in mitochondrial metabolism account for differences in susceptibility. Fluorescence lifetime microscopy was utilized to quantify adjustments in NAD(P)H in sensory and helping cells from explanted murine cochleae subjected to mitochondrial uncouplers, inhibitors, and an ototoxic antibiotic, gentamicin (GM). Adjustments in metabolic condition led to a redistribution of NAD(P)H between subcellular fluorescence life time pools. Helping cells acquired a considerably much longer life time than sensory cells. Pretreatment with GM increased NAD(P)H intensity in high-frequency ...
Sounds pass from the outer ear through to the inner ear, which contains the cochlea and auditory nerve. The cochlea is a coiled, spiral tube containing a large number of sensitive hair cells. The auditory nerve transmits sound signals to the brain.. If part of the cochlea is damaged, it will stop sending information to your brain. The brain may then actively seek out signals from parts of the cochlea that still work. These signals might then become over-represented in the brain, which may cause the sounds of tinnitus.. In older people, damage to the cochlea often occurs naturally with age. In younger people, it can be caused by repeated exposure to excessive noise.. ...
Sounds pass from the outer ear through to the inner ear, which contains the cochlea and auditory nerve. The cochlea is a coiled, spiral tube containing a large number of sensitive hair cells. The auditory nerve transmits sound signals to the brain.. If part of the cochlea is damaged, it will stop sending information to your brain. The brain may then actively seek out signals from parts of the cochlea that still work. These signals might then become over-represented in the brain, which may cause the sounds of tinnitus.. In older people, damage to the cochlea often occurs naturally with age. In younger people, it can be caused by repeated exposure to excessive noise.. ...
Eight patients implanted with multiple-channel cochlear prostheses have displayed good discrimination of sound sensations elicited at different sites within the cochlea. All patients rank the sensations from sharp to dull in an order which corresponds with basal to apical position in the cochlea. Detailed psychophysical studies have been carried out on two patients. These showed that discrimination of rate of (pulsatile) stimulation is good for frequencies up to 300 Hz and falls off sharply for frequencies above this. Electrode transitions (changes in position along the cochlea) are well discriminated for fast changes (25 msec), whereas rate transitions are not well discriminated for changes faster than 100 msec. From these results a speech processing strategy was formulated where second formant information is mapped to position in the cochlea and fundamental frequency mapped to rate of stimulation. Vowel and consonant confusion studies show consistent results for all patients using this ...
The avian cochlea has a remarkable ability to regenerate sensory hair cells after injury, and a major goal of our research is to understand the molecular basis of this regenerative process. An ongoing study, conducted in collaboration with the Lovett lab (Dept. of Genetics), is using Next-Gen sequencing to profile the transcriptome of the chick cochlea throughout the time course of regeneration. Additional data suggest that the lack of FGF signaling in the mature mammalian ear may be one factor that limits regenerative ability in mammals. We are presently collaborating with the Orntiz lab (Dept. of Developmental Biology) to determine whether reactivating FGF signaling in the injured mouse cochlea can evoke some degree of sensory repair ...
Department of Physiology, Medical School, University Walk, Bristol. 1. Outer hair cells from the cochlea of the guinea-pig were isolated and their motile properties studied in short-term culture by the whole-cell variant of the patch recording technique. 2. Cells elongated and shortened when subjected to voltage steps. Cells from both high- and low-frequency regions of the cochlea responded with an elongation when hyperpolarized and a shortening when depolarized. The longitudinal motion of the cell was measured by a differential photosensor capable of responding to motion frequencies 0-40 kHz. 3. Under voltage clamp the length change of the cell was graded with command voltage over a range +/- 2 microns (approximately 4% of the length) for cells from the apical turns of the cochlea. The mean sensitivity of the movement was 2.11 nm/pA injected current, or 19.8 nm/mV membrane polarization. 4. The kinetics of the cell length change during a voltage step were measured. Stimulated at their basal end, ...
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Chris - We all take our ears for granted, I think. How do they actually work?Bob - Basically, sound is vibration in the air and it is picked up by the floppy bit on the side of your head. This is called the pinna. Sound is then transmitted to the inner ear, inside of which theres a membrane which is thin and stiff at one end and wobbly at the other end. The thin, stiff bit
J:173382 Basch ML, Ohyama T, Segil N, Groves AK, Canonical Notch Signaling Is Not Necessary for Prosensory Induction in the Mouse Cochlea: Insights from a Conditional Mutant of RBPj{kappa}. J Neurosci. 2011 Jun 1;31(22):8046-58 ...
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This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may have an effect on your browsing experience ...
In chapter 3, The Sense of Sensibility, author Wendy Jones uses scenes from one of Jane Austens most celebrated novels to illustrate the functioning of the bodys stress response system.. 0 Comments. ...
In chapter 3, The Sense of Sensibility, author Wendy Jones uses scenes from one of Jane Austens most celebrated novels to illustrate the functioning of the bodys stress response system.. 0 Comments. ...
Subject: Re: physiological or ecological basis of auditory sharpness From: Eckard Blumschein ,Eckard.Blumschein(at)E-TECHNIK.UNI-MAGDEBURG.DE, Date: Tue, 17 Sep 2002 08:15:58 +0200 Yes, undoubtedly, high CFs are required for localization. I would like to mention a nice tutorial by Duda: http://www-engr.sjsu.edu/~knapp/HCIROD3D/3D_psych/reverb.htm He includes an explanation of IED (interaural envelope delay) and Franssen effect, and he summarizes: With some risk of oversimplification, we can generalize and say that in reverberant environments it is the high-frequency energy, not the low-frequency energy, that is important for localization. The question was: What might be the basis of (the extremely unpleasant) auditory sharpness evoked by spectral components... As we understand from the tutorial, the basal turn of cochlea is designed for localization of single events like clicks or bat calls rather than for recognition of any continuous tone. Maybe, Duda intentionally wrote high-frequency ...
Theres much more to our ears than meets the eye! The human ear contains a chain of important links that work together to help us hear the world around us. From the ears tiny bones to its fluid-filled cochlea, each part is important. In this title, young readers will learn about the small wonders inside the human ear.
TY - JOUR. T1 - Do optimal conditions improve distortion product otoacoustic emission test performance?. AU - Kirby, Benjamin J.. AU - Kopun, Judy G.. AU - Tan, Hongyang. AU - Neely, Stephen T.. AU - Gorga, Michael P.. PY - 2011/3. Y1 - 2011/3. N2 - OBJECTIVES: To determine whether an optimal distortion product otoacoustic emission (DPOAE) protocol that (1) used optimal stimulus levels and primary-frequency ratios for each f2, (2) simultaneously measured 2f2 - f1 and 2f1 - f2 distortion products, (3) controlled source contribution, (4) implemented improved calibration techniques, (5) accounted for the influence of middle ear reflectance, and (6) applied multivariate analyses to DPOAE data results in improved accuracy in differentiating between normal-hearing and hearing-impaired ears, compared with a standard clinical protocol. DESIGN: Data were collected for f2 frequencies ranging from 0.75 to 8 kHz in 28 normal-hearing and 78 hearing-impaired subjects. The protocol included a control ...
TY - JOUR. T1 - Regeneration of Stereocilia of Hair Cells by Forced Atoh1 Expression in the Adult Mammalian Cochlea. AU - Yang, Shi Ming. AU - Chen, Wei. AU - Guo, Wei Wei. AU - Jia, Shuping. AU - Sun, Jian He. AU - Liu, Hui Zhan. AU - Young, Wie Yen. AU - He, David Z.Z.. PY - 2012/9/27. Y1 - 2012/9/27. N2 - The hallmark of mechanosensory hair cells is the stereocilia, where mechanical stimuli are converted into electrical signals. These delicate stereocilia are susceptible to acoustic trauma and ototoxic drugs. While hair cells in lower vertebrates and the mammalian vestibular system can spontaneously regenerate lost stereocilia, mammalian cochlear hair cells no longer retain this capability. We explored the possibility of regenerating stereocilia in the noise-deafened guinea pig cochlea by cochlear inoculation of a viral vector carrying Atoh1, a gene critical for hair cell differentiation. Exposure to simulated gunfire resulted in a 60-70 dB hearing loss and extensive damage and loss of ...
TY - JOUR. T1 - Electrically stimulated increases in cochlear blood flow. T2 - I. frequency and intensity effects. AU - Sillman, Jonathon S.. AU - LaRouere, Michael J.. AU - Masta, Robert I.. AU - Miller, Josef M.. AU - Nuttall, Alfred L.. PY - 1989/4. Y1 - 1989/4. N2 - Charge-balanced, sinusoidal current was passed differentially between the apex and round window of the guinea pig cochlea. Cochlear blood flow was measured using a laser Doppler flow monitor. Systemic blood pressure was monitored from a cannula within the common carotid artery. Electrical stimulation increased cochlear blood flow, while systemic blood pressure was unaffected. A cochlear blood flow response parameter, normalized for transient changes in systemic blood pressure, was defined. The magnitude of the response parameter was found to be frequency selective and was also found to be an increasing function of current intensity, with maximum responses obtained with 500 Hz sinusoids. This cochlear blood flow response was not ...
Hearing depends on correct functioning of the cochlear hair cells, and their innervation by spiral ganglion neurons. Most of the insight into the embryological and molecular development of this sensory system has been derived from animal studies. In contrast, little is known about the molecular expression patterns and dynamics of signaling molecules during normal fetal development of the human cochlea. In this study, we investigated the onset of hair cell differentiation and innervation in the human fetal cochlea at various stages of development. At 10 weeks of gestation, we observed a prosensory domain expressing SOX2 and SOX9/SOX10 within the cochlear duct epithelium. In this domain, hair cell differentiation was consistently present from 12 weeks, coinciding with downregulation of SOX9/SOX10, to be followed several weeks later by downregulation of SOX2. Outgrowing neurites from spiral ganglion neurons were found penetrating into the cochlear duct epithelium prior to hair cell differentiation, and
Auditory hair cells are the sensory cells that transduce sound waves into electric signals, and are located in the cochlea, the organ responsible for hearing, in the inner ear. The loss of the hair cells is the leading cause of hearing impairment. The mammalian cochlea cannot regenerate its complement of mature hair cells and therefore hearing impairment caused by hair cell loss is difficult to cure. The developmental process of cochlea, including hair cells, is complex and has not been sufficiently elucidated yet. A better understanding of it would provide clues that could lead to new strategies for hair cell regeneration. The mammalian cochlea is highly developed and hair cells are regularly arranged in rows. Research on cochlear development has shown that the cochlea is highly sensitive to disorders caused by abnormal cellular differentiation and tissue organization. This seminar will present our research on mammalian cochlear development and to discuss the approach to hair cell ...
TY - JOUR. T1 - Targeted PCR Array Analysis of Genes in Innate Immunity and Glucocorticoid Signaling Pathways in Mice Cochleae Following Acoustic Trauma. AU - Maeda, Yukihide. AU - Kariya, Shin. AU - Omichi, Ryotaro. AU - Noda, Yohei. AU - Sugaya, Akiko. AU - Fujimoto, Shohei. AU - Nishizaki, Kazunori. PY - 2018/8/1. Y1 - 2018/8/1. N2 - Aim: To comprehensively analyze cochlear gene expressions related to innate immunity and glucocorticoid signaling at onset of acute noise-induced hearing loss (NIHL). Background: Recent studies suggested innate immunity is involved in the cochlear pathology of NIHL. Glucocorticoids may modulate immune actions in cochleae. Methods: Mice were exposed to 120 dB-octave band noise for 2 hours. Twelve hours later, a targeted PCR array analyzed cochlear expressions of 84 key genes in inflammation and immune pathways and 84 genes in the glucocorticoid signaling pathway. Real-time RT-PCR was used to analyze expression of two immune-related genes, Ccl12 and Glycam1, in ...
Afferent synapses between inner hair cells (IHCs) and spiral ganglion neurons in the cochlea translate sound information into a discrete spike code, providing us the opportunity to directly observe the output of the cochlea. The availability of mutant strains with genetic hearing impairment makes the mouse a valuable species to investigate the molecular mechanisms of cochlear function. In this thesis, mouse was used as a model species to study cochlear sound encoding by recording single unit activities from auditory nerve fibers (ANFs) in vivo. First, developmental changes of ANF responses before and after hearing onset were characterized as an introduction on how normal ANF responses mature during the early postnatal age. Spontaneous bursting activity from ANFs/cochlear nucleus neurons was observed before hearing onset. After hearing onset, the average spontaneous and evoked spike rates of single ANFs increased, while tuning threshold and frequency selectivity improved between p14-15 to p20-21. ...
Our knowledge of the fine structure of the Human Spiral Ganglion (HSG) is still inadequate and new treatment techniques for deafness using electric stimulation, call for further information and studies on the neuronal elements of the human cochlea. This thesis presents results of analyses of human cochlear tissue and specimens obtained during neurosurgical transpetrosal removal of life-threatening meningeomas. The use of surgical biopsies produced a well-preserved material suitable for ultrastructural and immunohistochemical studies on the human inner ear. The SG was studied with respect to fine structure, using TEM technique and the immunostaining pattern of synaptophysin, which is an integral membrane protein of neuronal synaptic vesicles. The immunostaining patterns of the tight junctional protein ZO-1 and the gap junctional proteins Cx26 and Cx43 in the human cochlea were also studied. The ultrastructural morphology revealed an absence of myelination pattern in the HSG, thus differing from ...
The mechanism of hearing loss arises from trauma to stereocilia of the cochlea, the principal fluid filled structure of the inner ear. The pinna combined with the middle ear amplifies sound pressure levels by a factor of twenty, so that extremely high sound pressure levels arrive in the cochlea, even from moderate atmospheric sound stimuli. Underlying pathology to the cochlea are reactive oxygen species, which play a significant role in noise-induced necrosis and apoptosis of the stereocilia. Exposure to high levels of noise have differing effects within a given population, and the involvement of reactive oxygen species suggests possible avenues to treat or prevent damage to hearing and related cellular structures.. The elevated sound levels cause trauma to the cochlear structure in the inner ear, which gives rise to irreversible hearing loss. A very loud sound in a particular frequency range can damage the cochleas hair cells that respond to that range thereby reducing the ears ability to ...
Ben Creisler [email protected] A new paper (in open access) that may be of interest: Eric G. Ekdale (2015) Form and function of the mammalian inner ear. Journal of Anatomy (advance online publication) DOI: 10.1111/joa.12308 http://onlinelibrary.wiley.com/doi/10.1111/joa.12308/abstract http://onlinelibrary.wiley.com/doi/10.1111/joa.12308/epdf The inner ear of mammals consists of the cochlea, which is involved with the sense of hearing, and the vestibule and three semicircular canals, which are involved with the sense of balance. Although different regions of the inner ear contribute to different functions, the bony chambers and membranous ducts are morphologically continuous. The gross anatomy of the cochlea that has been related to auditory physiologies includes overall size of the structure, including volume and total spiral length, development of internal cochlear structures, including the primary and secondary bony laminae, morphology of the spiral nerve ganglion, and the nature of cochlear ...
The K+ circulation in the cochlea is thought to be tightly regulated in the inner compartment of the cochlea by a transport network in the stria vascularis of the cochlea (Wangemann 2006). In the OHC case, K+ passes through the transduction channels and is released into the intercellular space of organ of Corti through several types of K+ channel at the base of the hair cell. These channels include KCNQ4 channels (Kharkovets et al. 2006) and calcium-activated SK and BK channels (Marcotti et al. 2004). From there, K+ is taken up by the supporting cells via the K-Cl cotransporters (Boettger et al. 2002). The supporting cells of the organ of Corti form an extensive epithelial tissue gap-junction system that is essential for buffering extracellular K+ ions in the organ of Corti into the perilymph (Kikuchi et al. 2000). From perilymph, K+ is actively pumped by the K+/Na+ ATPase and K+/Na+/2Cl− cotransporter back into the type II fibrocytes of the spiral ligament and from there back via the stria ...
This study was designed to determine whether the sympathetic nervous system exerts a protective or enhancing effect in acoustic overstimulation. The compound action potential of the cochlea (CAP) was recorded in guinea pigs while the cervical sympathetic nervous system (SNS) was electrically stimulated or after it was surgically eliminated. The stimulation or the elimination of the cervical SNS has no effect on the threshold of CAP. The threshold shift in CAP after acoustic overstimulation (110, 115, or 130 dB SPL for 10 min) was measured in the cervical SNS stimulation group, in the cervical SNS elimination group, and in the control group. When the animal was under insufficient sedation, there was no difference among these three groups. However, the CAP threshold shift was significantly smaller in the cervical SNS stimulation group than in the other two groups when the animals were sufficiently sedated. The cervical SNS stimulation had some protective effect on the susceptibility to acoustic trauma
On the basis of recent advances in auditory physiology, new tests of cochlear function have been developed using measures of otoacoustic emissions. In the present report, the clinical potential for each of the four basic emission types is examined. In addition, the practical advantages of examining the ear with two specific types of evoked emissions, transiently evoked and distortion-product otoacoustic emissions, are reviewed in detail. Finally, the future role of tests of otoacoustic emissions in the diagnosis of hearing impairment is discussed. The current view is that evoked emissions hold promise as an essential part of the clinical examination of the auditory system.. ...
J Physiol Sci. 2021 Sep 3;71(1):28. doi: 10.1186/s12576-021-00814-0.. ABSTRACT. Damage to the cochlear sensory epithelium is a key contributor to noise-induced sensorineural hearing loss (SNHL). KCNQ4 plays an important role in the cochlear potassium circulation and outer hair cells survival. As miR-153 can target and regulate KCNQ4, we sought to study the role of miR-153 in SNHL. 12-week-old male CBA/J mice were exposed to 2-20 kHz broadband noise at 96 dB SPL to induce temporary threshold shifts and 101 dB SPL to induce permanent threshold shifts. Hearing loss was determined by auditory brainstem responses (ABR). Relative expression of miR-153 and KCNQ4 in mice cochlea were determined by Real-Time quantitative PCR. miR-153 mimics were co-transfected with wild type or mutated KCNQ4 into HEK293 cells. Luciferase reporter assay was used to validate the binding between miR-153 and KCNQ4. AAV-sp-153 was constructed and administrated intra-peritoneally 24- and 2-h prior and immediately after noise ...
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Kiluchi, T. (1995) Gap junction in the rat cochlea immunohisto-chemical and ultrastructural analysis. Anatomy and Embryology, 2, 101-118.
Prevention of auditory hair cell death offers therapeutic potential to rescue hearing. Pharmacological blockade of JNK/c-Jun signaling attenuates injury-induced hair cell loss, but with unsolved mechanisms. We have characterized the c-Jun stress response in the mouse cochlea challenged with acoustic overstimulation and ototoxins, by studying the dynamics of c-Jun N-terminal phosphorylation. It occurred acutely in glial-like supporting cells, inner hair cells and in the cells of the cochlear ion trafficking route, and was rapidly downregulated after exposures. Notably, death-prone outer hair cells lacked c-Jun phosphorylation. As phosphorylation was triggered also by non-traumatic noise levels and as none of the cells showing this activation were lost, c-Jun phosphorylation is a biomarker for cochlear stress rather than an indicator of a death-prone fate of hair cells. Preconditioning with a mild noise exposure before a stronger traumatizing noise exposure attenuated the cochlear c-Jun stress ...
Cochlear Hair Cells are tuned to respond to different sound frequencies. These cells are arrayed in a tonotopic gradient, with low frequency responders at the apical end of the cochlea and high frequency responders at the basal end. Birds and reptiles uses alternative splicing of BK Channel as one facet of tuning these hair cells to transduce different sound frequencies. Isolation of cochlear cell mRNA has revealed that each cell expresses a different subset of BK Channel mRNA. BK channels (aka Slo channels) are tuned via alternative splicing of α subunit exons, thereby controlling regulatory properties, conductance and voltage sensitivity of the channel. BK Channels are present in muscle tissue and in the cochlea.. ...
TY - JOUR. T1 - Short-term plasticity and modulation of synaptic transmission at mammalian inhibitory cholinergic olivocochlear synapses. AU - Katz, Eleonora. AU - Elgoyhen, Ana Belén. PY - 2014/12/2. Y1 - 2014/12/2. N2 - The organ of Corti, the mammalian sensory epithelium of the inner ear, has two types of mechanoreceptor cells, inner hair cells (IHCs) and outer hair cells (OHCs). In this sensory epithelium, vibrations produced by sound waves are transformed into electrical signals. When depolarized by incoming sounds, IHCs release glutamate and activate auditory nerve fibers innervating them and OHCs, by virtue of their electromotile property, increase the amplification and fine tuning of sound signals. The medial olivocochlear (MOC) system, an efferent feedback system, inhibits OHC activity and thereby reduces the sensitivity and sharp tuning of cochlear afferent fibers. During neonatal development, IHCs fire Ca2+ action potentials which evoke glutamate release promoting activity in the ...
Sensorineural hearing loss (sometimes called nerve deafness) occurs when the cilia (hair cells) of the inner ear (the cochlea) do not function properly. In an undamaged ear, the pressure from sound waves goes into your pinna (the outer ear, the part you can see), makes the eardrum move back and forth, is passed along the small bones of the middle ear (the smallest bones in your body!), and then transfers to the middle ear, where those sound waves cause actual waves in the fluid-filled cochlea. The waves of fluid cause the hair cells to move. This sets off a beautiful chemical chain reaction, which ultimately causes stimulation of the auditory nerve (cranial nerve VIII), which sends the sensation of sound to the brain. The hair cells in the cochlea are tonotopically arranged, meaning that each region corresponds to different tones, going from high frequency sounds at the basal end to low frequency sounds at the apex of the cochlea, which looks like a snail shell. Think of a piano keyboard ...
It has been shown that the membrane motor in the outer hair cell is driven by the membrane potential. Here we examine whether the motility satisfies the reciprocal relationship, the characteristic of piezoelectricity, by measuring charge displacement induced by stretching the cell with known force. …
Intracellular recordings were made from the low frequency region (third turn) of the guinea pig cochlea. Response characteristics are compared to gross potentials obtained from the organ of Corti fluid space. Inner hair cells (IHCs) possess relatively low (median, -32 mV) initial membrane potentials, whereas that of outer hair cells (OHCs) is higher (median, -53.5 mV). In response to tone burst stimuli, both cell types produce a combination of AC and DC responses. The latter are depolarizing for IHCs but may be of either polarity for OHCs. In terms of their AC responses, IHCs are about 12 dB more sensitive than OHCs. At low sound levels these cells are more linear than high frequency hair cells (Russell, I. J., and P. M. Sellick (1978) J. Physiol. (Lond.) 284: 261-290), judging from the relation between AC and DC response components. At high sound levels pronounced response saturation is seen. The overall tuning properties of the two hair cell types are rather similar, even though IHCs exhibit ...
The cochlea remains one of the last inaccessible organs to visualize function or to perform surgical procedures. Buried deep within the temporal bone and being encased in a hard bony shell while being super sensitive to vibration and overstimulation create an almost insurmountable set of logistical problems. We are developing the surgical approach and imaging technologies needed to overcome these difficulties. Using animal models for live-cell imaging will provide unprecedented levels of detail about how the cochlea functions. Success with surgical approaches will be tested for their translational validity and may provide new access for surgeons when investigating hearing loss. The images shown here depict the custom-designed 2-photon imaging system used for viewing cellular function in vivo. The lightpath for imaging is also shown in cartoon form. Examples of multiple inner hair cells responding to sound stimulation are also presented. In, mouse we can now access the cochlea with no detectable ...
Neurons in the developing auditory system fire bursts of action potentials before the onset of hearing. This spontaneousactivity promotes the survival and maturation of auditory neurons and the refinement of synaptic connections in auditory nuclei; however, the mechanisms responsible for initiating this activity remain uncertain. Previous studies indicate that inner supporting cells (ISCs) in the developing cochlea periodically release ATP, which depolarizes inner hair cells (IHCs), leading to bursts of action potentials in postsynaptic spiral ganglion neurons (SGNs). To determine when purinergic signaling appears in the developing cochlea and whether it is responsible for initiating auditory neuron activity throughout the prehearing period, we examined spontaneousactivity from ISCs, IHCs, and SGNs in cochleae acutely isolated from rats during the first three postnatal weeks. We found that ATP was released from ISCs within the cochlea from birth until the onset of hearing, which led to periodic ...
Mechanical responses in the basal turn of the guinea-pig cochlea are measured with low-level broad-band noise as the acoustical stimulus [for details see de Boer and Nuttall, J. Acoust. Soc. Am. 101, 3583-3592 (1997)]. Results are interpreted within the framework of a classical three-dimensional model of the cochlea that belongs to a very wide class of nonlinear models. The use of linear-systems analysis for this class of nonlinear models has been justified earlier [de Boer, Audit. Neurosci. 3, 377-388 (1997)]. The data are subjected to inverse analysis with the aim to recover the effective basilar-membrane impedance. This is a parameter function that, when inserted into the model, produces a model response, the resynthesized response, that is similar to the measured response. With present-day solution methods, resynthesis leads back to an almost perfect replica of the original response in the spatial domain. It is demonstrated in this paper that this also applies to the response in the frequency
Photograph of a receptor cell, known as an outer hair cell (OHC), in the mammalian cochlea with its large nucleus (N) located at the base of the cell. Receptor cells in the cochlea have structures known as stereocilia (S) at their apex. These structures convert the mechanical energy of sound to an electrochemical signal that can be processed by the peripheral and central auditory nerves. Outer hair cells have an additional feature; they can contract and extend in response to hyper- and depolarization of the cell. Their motility is regulated by signals from the brain, thereby allowing for the fine-tuning of mechanical signals that impinge on the cochlea. The photo was taken at a magnification of 7100 X using an electron microscope by Margaret Harvey, Senior Biological Scientist. Check out the link to see an outer hair cells response to music: https://www.youtube.com/watch?v=c91ubWbScs4 ...
About 95 percent of sound input to the brain comes from the ears inner hair cells.. These inner hair cells are like spark plugs in an 8-cylinder engine, says Salvi. A car wont run well if you remove half of those spark plugs, but people can still present with normal hearing thresholds if theyve lost half or even three-quarters of their inner hair cells.. Ear damage reduces the signal that goes the brain. That results in trouble hearing, but thats not whats happening here, because the brain has a central gain control, like a radio, the listener can turn up the volume control to better hear a distant station. Salvi says.. Sound is converted to neural activity by the inner hair cells in the auditory part of the ear, called the cochlea.. Sound-evoked neural activity then travels from the cochlea to the auditory nerve and into the central auditory pathway of the brain. Halfway up the auditory pathway the information is relayed into a structure known as the inferior colliculus, before ...
The researchers show that this is due to a molecular signalling pathway in the cochlea, mediated by a chemical compound called ATP, released by the cochlear tissue with noise and activating specific ATP receptors in the cochlear cells.. Interestingly, if the pathway is removed, such as by genetic manipulations, this adaptive mechanism doesnt occur and the ear becomes very vulnerable to longer term noise exposure and the effects of age, eventually resulting in permanent hearing loss.. In other words the adaptive mechanism also protects the ear, says Professor Thorne.. The second paper, done in collaboration with United States colleagues, reveals a new genetic cause of deafness in humans which involves exactly the same mechanism.. People (two families in China) who had a mutation in the ATP receptor showed a rapidly progressing hearing loss which was accelerated if they worked in noisy environments.. This work is important because it shows that our ears naturally adapt to their environment, ...
INTRODUCTION: the aim of this study was to investigate cochlear functions in patients with hyperemesis gravidarum (HG). METHODES: twenty-nine HG patients (58 ears) and 31 healthy control subjects (62 ears) were included. Audiometry testings at 250 and 500 Hz and 1, 2, 4, 8, 10, 12, 14, 16 kHz were performed to the patients and controls. RESULTS: mean age of patients with HG was 26,5 4,4 years and the mean age of control group was 28,0 4,2 years. At the time of the tests mean gestational age of the HG group and controls were 9 and 11 weeks respectively. No differences were observed between the groups in tympanic membrane status, orother otolaringological evaluations. No significant differences were observed in audiometric tests at any frequencies between the groups (p values for all>0.05). CONCLUSION: there was not a difference between pregnant cases with HG and cases with normal pregnancy in terms of audimetric tests. Cochlear functions are not affectedremarkably in women with HG.
Omics group organizes Cochlea national symposiums, conferences across the globe in association with popular Cochlea associations and companies. OMICS group planned its conferences, and events in america, europe, middle east and asia pacific. locations which are popular with international conferences, symposiums and events are china, canada, dubai, uae, france, spain, india, australia, italy, germany, singapore, malaysia, brazil, south korea, san francisco, las vegas, san antonio, omaha, orlando, raleigh, santa clara, chicago, philadelphia, baltimore, united kingdom, valencia, dubai, beijing, hyderabad, bengaluru and mumbai
During normal hearing, sound waves travel through the ear canal and strike the eardrum causing it to vibrate. The eardrum is attached to three tiny bones in the middle ear. The last bone, the stapes, pushes on a fluid-filled chamber in the inner ear, called the cochlea. This fluid movement causes sensitive hair cells within the cochlea to bend. When the hair cells bend, they generate an electrical signal that is sent to the brain. Disease, damage, or deformity of the cochlear hair cells is a common cause of hearing impairment or deafness. These malfunctioning hair cells may send intermittent or unclear signals to the auditory nerve, or send no signal at all. A device called a cochlear implant can restore hearing by replacing these damaged structures with a wire that is implanted in the cochlea. In order to stimulate the hearing process, sound waves are first received by a microphone unit, or speech processor, that hangs over the back of the ear. Within the processor, sound is filtered and ...
TY - JOUR. T1 - Genetic variation of cisplatin-induced ototoxicity in non-cranial-irradiated pediatric patients using a candidate gene approach. T2 - The International PanCareLIFE Study. AU - PanCareLIFE consortium. AU - Clemens, Eva. AU - Broer, Linda. AU - Langer, Thorsten. AU - Uitterlinden, André G. AU - de Vries, Andrica C H. AU - van Grotel, Martine. AU - Pluijm, Saskia F M. AU - Binder, Harald. AU - Byrne, Julianne. AU - Broeder, Eline van Dulmen-den. AU - Crocco, Marco. AU - Grabow, Desiree. AU - Kaatsch, Peter. AU - Kaiser, Melanie. AU - Kenborg, Line. AU - Winther, Jeanette F. AU - Rechnitzer, Catherine. AU - Hasle, Henrik. AU - Kepak, Tomas. AU - van der Kooi, Anne-Lotte F. AU - Kremer, Leontien C. AU - Kruseova, Jarmila. AU - Kuehni, Claudia E. AU - van der Pal, Heleen. AU - Parfitt, Ross. AU - Deuster, Dirk. AU - Matulat, Peter. AU - Spix, Claudia. AU - Tillmanns, Amelie. AU - Tissing, Wim J E. AU - Maier, Lara. AU - Am Zehnhoff-Dinnesen, Antoinette. AU - Zolk, Oliver. AU - van den ...
1 Department of Otolaryngology, Keio University, Tokyo, Japan.. Understanding developmental process of organs and tissue generations is particularly of great importance not only for its scientific value but also its application towards regenerative therapeutics because re-tracking organogenesis is a feasible strategy for regeneration. Particularly, recent advances in cell therapy using stem/progenitor cells enable us to cure damaged, and even lost, organs; In these process, several sources are being used for producing graft cells including tissue precursors, mesenchymal stem cells and even human ES/iPS cells.. To manipulate these cells to obtain appropriate cell types efficiently, detailed knowledge of molecular mechanisms and pathways underlying developmental process in each organogenesis is indispensable. However, we know little about the process, especially in human cochlear development, because of the rarity of chance to assess human fetal samples. In this perspective, non-human primates are ...
The rate of longitudinal flow of perilymph has been measured using an ionic tracer technique. Spread of the tracer trimethylphenylammonium (TMPA) along the perilymphatic scalae was monitored with ion-selective microelectrodes following injection of a
Wild-type (right) Kcnq1tm1Kpfe/Kcnq1tm1Kpfe (left) comparisons of the midmodular sections of the cochlea at P0 (A), P3 (B) and P70 (C). Note the collapse of Reissners membrane at P3 (B) and degeneration of inner and outer hair cells at P70 (C). D-F: Details of the saccule at P0 (D), P8 (E) and P70 (F ...
Rattay, F., Lutter, P., and Naves Leao, R. (2000).The electrically stimulated cochlea: Calculation of the potential distribution in the inner ear and the excitation of the auditory nerve. Presented at the 3rd Mathmod, IMACS Symposium on Math. Modelling, Vienna ...
Cochlea, filled with fluids called perilymph and endolymph, a spiral-shaped cavity in the ear that translates sound waves into electrical nerve impulses and sends them to the cerebral cortex for interpretation. - Stock Image P434/0097
The cochlea is arranged like a rolled-up piano keyboard, as shown in box A in the figure below. Lining the cochlea are many thousands of hair cells that convert the sound into electrical signals. Cochlear implants only have up to a couple of dozen electrodes, each of which performs a similar function to a hair…
The origins of our inner ear lie hundreds of millions of years back in evolution, when primitive fish began to develop hollows in the skin that were sensitive to waves of pressure from water around them, as well as to waters movement as they pitched and rolled. With time the nerves became more refined, the hollows became tubes of seawater, and those tubes eventually closed off and buried themselves in the head. Further on in evolution, bones that were originally related to the jaw migrated and miniaturized, becoming the amplifying bones of the ear. The tubes dedicated to sensing rotational movement became our semicircular canals (balance), and its theorized that parts involved in sensing the pressure waves became our cochleas (hearing). In the composition of their salts, the fluids of our inner ear still carry the memory of that primordial ocean.. Within the human cochlea is a thin sensitive membrane, around thirty to thirty-five millimeters long, wound into a spiral and bathed in this salty ...
This site contains information on the otoacoustic emissions, details on available OAE hardware and software and on-line OAE lectures and white papers
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Will we be able to restore hearing loss? It was recently found that we as humans do possess an ability to regenerate cells in our intestines. A similarity between these cells in the intestine and cells found in the cochlea led researchers to discover a drug that could regenerate cochlea cells.
Animals are able to detect, perceive, and react to a wide range of stimuli in their environment. Although sensory information always flows from peripheral sensory organs into the central nervous system, each system exhibits specialized features, highlighted by differences at the circuit level. For instance, in the cochlea, sound information is organized according to frequency and must be communicated with exquisite speed and precision, thereby permitting animals to localize sounds based on miniscule differences in timing. In the retina, on the other hand, a wide variety of neuronal subtypes cooperate to detect and encode aspects of the visual scene, such as the onset of light or direction-selective motion. Accordingly, neurons in the cochlea and retina exhibit fundamentally distinct morphologies and patterns of connectivity. Spiral ganglion neurons (SGNs), the primary sensory neurons of the inner ear, have quite simple bipolar shapes, with unbranched peripheral processes projecting like spokes ...
Low incidence disabilities in education and what medical supports are available - Assignment Example There are specialized interventions that cater for students with hearing impairments in the society. This involves cochlear implants that provide a sense of sound to low incidence students that have a problem with hearing. The surgical electronic device is essential for students with partial damages on the sensory hair cells in the cochlea. Its relevance in hearing is evident in different ways. In this case, adults benefit immediately through experiencing improvement in the first three months of implantation. The children may improve at a slower pace since they need a lot of training during implantations process. In general, victims who undergo cochlea implantation perceive loud, medium and soft sounds as they understand speech through lip reading (Niparko, 2009). At the same time, there are autism interventions that involve communication and behavioral strategies. In most cases, this treatment ...
We suggest that one role of regulated surface AMPAR expression is to limit excitotoxicity that might be induced during acoustic overstimulation. Intense acoustic stimulation can produce histological signs thought to be associated with excitotoxicity, which include vacuolization in the auditory nerve terminals and in the satellite cells near the ganglion cell bodies (Sun et al. 2001; Wang et al. 2002). The noise exposure we employed normally induces removal of surface AMPARs and does not induce signs of excitotoxicity. But when the removal of surface AMPARs was blocked with myr-Dyn, these same stimuli generated excitotoxic responses. In neuronal cultures from the CNS, excitotoxicity can be observed as a calpain-mediated cell death (Bano et al. 2005; Lankiewicz et al. 2000). We showed that a brief exposure to glutamate receptor agonists at concentrations that induce surface AMPAR removal without generating cell death can induce cell death when removal of surface AMPARs is blocked by ...
Susan wrote: actually, thats not quite true. one of the beauties of the critical band theory is that it *does* address the shape and size of the filters. fletcher, in his original theory, assumed they were symmetrical, but did not know for sure. when patterson and moore created psychophysical tuning curves they were asymmetrical, so patterson controlled for off-freq listening by using notched noise. when he did that, it forced the subjects to listen to the filter centered on fs and the bands were shown to be symmetrical. - Actually, what I said is accurate. However, the response suggests the literature I made reference to may not well known or how it shows CB theory has a weakness. The work I made reference to agrees with the Fletcher and Patterson work in that there is a mechanism (yes, probably peripheral) that aids in the selectivity of the auditory system. What the data also shows, however, is that the auditory system processes information OUTSIDE the critical band and it affects the ...
All of these structures together constitute the cochlea. In mammals (other than monotremes), the cochlea is extended still ... which generally detect lower-frequency sounds than the cochlea. The cochlea of birds is similar to that of crocodiles, ... The cochlea propagates these mechanical signals as waves in the fluid and membranes and then converts them to nerve impulses ... Boettcher's cells are found in the organ of Corti where they are present only in the lower turn of the cochlea. They lie on the ...
However, in a normally functioning cochlea, complex broadband signals are decomposed by the filtering on the basilar membrane ( ... Bacon S (2004). Compression: From Cochlea to Cochlear Implants. Springer Handbook of Auditory Research. Springer. ISBN ... Manley GA (2017). Understanding the Cochlea. Springer Handbook of Auditory Research. Springer. ISBN 9783319520711. Kale S, ... BM) within the cochlea into a series of narrowband signals. Therefore, the waveform at each place on the BM can be considered ...
In the mammalian cochlea, wave amplification occurs via the outer hair cells of the organ of Corti. These cells sit directly ... These waves exert a pressure on the basilar and tectorial membranes of the cochlea which vibrate in response to sound waves of ... The Physical Basis of the Action of the Cochlea D. T. Kemp 1978 : Stimulated acoustic emissions from within the human auditory ... Sound waves enter the scala vestibuli of the cochlea and travel throughout it, carrying with them various sound frequencies. ...
... cochlea Reeve, 1849: synonym of Turritella cochlea Reeve, 1849 Turritella acicula Stimpson, 1851: synonym of Turritellopsis ... Turritella cochlea Reeve, 1849. Retrieved through: World Register of Marine Species on 19 May 2010. Turritella columnaris ... 1951 Turritella cochlea Reeve, 1849 Turritella columnaris Kiener, 1843 Turritella communis Risso, 1826 Turritella concava ...
Within the inner ear sits the cochlea. The cochlea is a snail-shaped formation that enables sound transmission via a ... The cochlea is a complex structure, consisting of three layers of fluid. The scala vestibuli and scala media are separated by ... When a sound is presented to the human ear, the time taken for the wave to travel through the cochlea is only 5 milliseconds. ... They are non-linear, level-dependent and the bandwidth decreases from the base to apex of the cochlea as the tuning on the ...
The basilar membrane is widest (0.42-0.65 mm) and least stiff at the apex of the cochlea, and narrowest (0.08-0.16 mm) and ... The basilar membrane is a stiff structural element within the cochlea of the inner ear which separates two liquid-filled tubes ... Deiters cells Holmes M, Cole JS (1983). "Pseudoresonance in the cochlea". In de Boer E, Viergever MA (eds.). Mechanics of ... Fay RR, Popper AN, Bacon SP (2004). Compression: From Cochlea to Cochlear Implants. Springer. ISBN 0-387-00496-3. Oghalai JS ( ...
The Cochlea. New York: Springer. pp. 435-502. ISBN 978-0-387-94449-4. OCLC 33243443. Warr, WB.; Beck, JE.; Neely, ST. (1997). " ... The MOCS gives rise to a frequency-specific innervation of the cochlea, in that MOC fibres terminate on the outer hair cells at ... In the cats without efferent input to the cochlea, elevated thresholds of the AN, a decreased sharpness of the tuning curves, ... The olivocochlear system is a component of the auditory system involved with the descending control of the cochlea. Its nerve ...
de cochlea/snail-shell; 48. de castanea/chestnut; 49. de pluuia/rain; 50. de uino/wine; 50a. de charta/[wood-pulp] paper; 51. ...
During this period he published a paper with Carver Mead describing an analog cochlea which modeled the propagation of sound in ... Lyon, R. F.; Mead, C. (1988). "An analog electronic cochlea" (PDF). IEEE Transactions on Acoustics, Speech, and Signal ... Hamilton, Tara Julia (6 February 2009). "The silicon cochlea: 20 years on" (PDF). The Neuromorphic Engineer. doi:10.2417/ ... and Compression in the Cochlea". IEEE International Conference on Acoustics, Speech, and Signal Processing. 7: 1282-1285. doi: ...
Their hearing can be measured at the round window as cochlear microphonics and summating potential (of the cochlea), and ... Johnstone, J. R. & Johnstone, B. M. (1969). "Electrophysiology of the lizard cochlea". Experimental Neurology. 24 (1): 99-109. ...
The cochlear duct (or scala media) is an endolymph filled cavity inside the cochlea, located between the tympanic duct and the ... Cross section of the cochlea. Cross section at avatar.com.au. ...
An analog ear or analog cochlea is a model of the ear or of the cochlea (in the inner ear) based on an electrical, electronic ... A modern theory of the dynamics of the cochlea, accounting for the hydrodynamics of the cochlear ducts and the dynamics of the ... Peterson, L. C.; Bogert, B. P. (1950). "A Dynamical Theory of the Cochlea". The Journal of the Acoustical Society of America. ... This window connects to the cochlea which is a long dual channel arrangement consisting of two channels separated by the ...
The tectorial membrane (TM) is one of two acellular membranes in the cochlea of the inner ear, the other being the basilar ... This raises the possibility that the TM may be involved in the longitudinal propagation of energy in the intact cochlea. MIT ... Cross section of the cochlea. Thalmann, I.; Thallinger, G.; Comegys, T.H.; Thalmann, R. (1986). "Collagen - The Predominant ... and traditionally was neglected or downplayed in many models of the cochlea. However, recent genetic , mechanical and ...
The spiral (cochlear) ganglion is a group of neuron cell bodies in the modiolus, the conical central axis of the cochlea. These ... Diagrammatic longitudinal section of the cochlea Organ of corti This article incorporates text in the public domain from page ... ISBN 0-387-97800-3. H Spoendlin (1972). "Innervation densities of the cochlea". Acta Otolaryngol. 73 (2): 235-48. doi:10.3109/ ... Neurons whose cell bodies lie in the spiral ganglion are strung along the bony core of the cochlea, and send fibers (axons) ...
Cross section of the cochlea. Histology and Virtual Microscopy Learning Resources University of Michigan Medical School; ...
In 1988, Richard F. Lyon and Carver Mead described the creation of an analog cochlea, modelling the fluid-dynamic traveling- ... Lyon had previously described a computational model for the work of the cochlea. Such technology had potential applications in ... Lyon, R. F.; Mead, C. (1988). "An analog electronic cochlea" (PDF). IEEE Transactions on Acoustics, Speech, and Signal ... Wen, Bo; Boahen, Kwabena (December 2009). "A Silicon Cochlea With Active Coupling". IEEE Transactions on Biomedical Circuits ...
Iupiter et cochlea - mentioned under Zeus and the Tortoise 58. Satyrus et homo - The Satyr and the Traveller 59. Mures et feles ... cochleae. 33. cornix et hirundo. 34. Mercurius et statuarius - The Statue of Hermes 35. Pater et filii - The Farmer and his ...
Diagrammatic longitudinal section of the cochlea. This article incorporates text in the public domain from page 1054 of the ...
The cochlea and vestibule, viewed from above. Transverse section of the cochlear duct of a fetal cat. Interior of right osseous ... The vestibular duct or scala vestibuli is a perilymph-filled cavity inside the cochlea of the inner ear that conducts sound ... Diagrammatic longitudinal section of the cochlea. Tympanic duct Slide from University of Kansas Diagram at Indiana University ...
One such mechanism is the opening of ion channels in the hair cells of the cochlea in the inner ear. Air pressure changes in ... The cochlea thus acts as an 'acoustic prism', distributing the energy of each Fourier component (which represent particular ... At the end of the ossicular chain, movement of the stapes footplate within the oval window of the cochlea, in turn, generates a ... Hair cells in the cochlea are stimulated when the basilar membrane is driven up and down by differences in the fluid pressure ...
Sensorineural hearing ability is mediated by the inner ear composed of the cochlea with its internal basilar membrane and ... and the cochlea, which enables hearing. The ears of vertebrates are placed somewhat symmetrically on either side of the head, ...
The cochlea consists of three fluid-filled spaces: the vestibular duct, the cochlear duct, and the tympanic duct. Hair cells ... The cochlea is a spiral shell-shaped organ responsible for the sense of hearing. These structures together create the ... The development of inner ear structures such as the cochlea is regulated by Dlx5/Dlx6, Otx1/Otx2 and Pax2, which in turn are ... In 1961, he was awarded the Nobel Prize in Physiology or Medicine for his research on the function of the cochlea in the ...
Histology: A Test and Atlas[page needed] Raphael Y, Altschuler RA (June 2003). "Structure and innervation of the cochlea". ...
The inner ear has two major parts, the cochlea and the vestibular organ. They are connected in a series of canals in the ... It is found within the scala tympani and scala vestibuli of the cochlea. The ionic composition of perilymph is comparable to ... Konishi T, Hamrick PE, Walsh PJ (1978). "Ion transport in guinea pig cochlea. I. Potassium and sodium transport". Acta ... http://oto.wustl.edu/cochlea/intro3.htm[permanent dead link]. ...
... has a high positive potential (80-120 mV in the cochlea), relative to other nearby fluids such as perilymph, due to ... synd/2926 at Who Named It? Konishi T, Hamrick PE, Walsh PJ (1978). "Ion transport in guinea pig cochlea. I. Potassium and ... https://web.archive.org/web/20051030092447/http://oto.wustl.edu/cochlea/res1.htm Longitudinal Flow of Endolymph at wustl.edu. ...
The cochlea and vestibule, viewed from above. Diagrammatic longitudinal section of the cochlea. Scala vestibuli Slide from ... Scala tympani labeled at right, inside cochlea. Transverse section of the cochlear duct of a fetal cat. ...
nov., Kluyvera cochleae sp. nov., and Kluyvera georgiana sp. nov". International Journal of Systematic Bacteriology. 46 (1): 50 ...
The cochlea and vestibule, viewed from above. Transverse section through head of fetal sheep, in the region of the labyrinth. X ...
The cochlea of the inner ear, a marvel of physiological engineering, acts as both a frequency analyzer and nonlinear acoustic ... The cochlea has over 32,000 hair cells. Outer hair cells primarily provide amplification of traveling waves that are induced by ... The basal end of the cochlea, where sounds enter from the middle ear, encodes the higher end of the audible frequency range ... The auditory hair cells in the cochlea are at the core of the auditory system's special functionality (similar hair cells are ...
Housley, G D; Ashmore, J F (1992). "Ionic currents of outer hair cells isolated from the guinea-pig cochlea". The Journal of ... Ashmore, J. F.; Meech, R. W. (1986). "Ionic basis of membrane potential in outer hair cells of guinea pig cochlea". Nature. 322 ... Ashmore has worked on dissecting the cellular mechanisms of hearing by studying the organ of Corti in the mammalian cochlea ... Jagger, Daniel James (1996). Modulation of ion channels in outer hair cells from the mammalian cochlea. ethos.bl.uk (PhD thesis ...
The cochlea is a portion of the inner ear that looks like a snail shell (cochlea is Greek for snail.) The cochlea receives ... The name cochlea derives from Ancient Greek κοχλίας (kokhlias) spiral, snail shell. The cochlea (plural is cochleae) is a ... Cochlea at the US National Library of Medicine Medical Subject Headings (MeSH) "Promenade Round the Cochlea" by R. Pujol, S. ... The cochlea and vestibule, viewed from above. Cross-section of the cochlea. Bony labyrinth Membranous labyrinth Cochlear ...
Turritella cochlea is a species of sea snail, a marine gastropod mollusk in the family Turritellidae. Reeve, 1849 Conch. Icon. ... Turritella cochlea Reeve, 1849. Retrieved through: World Register of Marine Species on 17 May 2010. v t e. ...
The cochlea is a spiral tube that is… ... The cochlea contains the sensory organ of hearing. It bears a ... In human ear: Cochlea. The cochlea contains the sensory organ of hearing. It bears a striking resemblance to the shell of a ... human cochlea and semicircular canalsDissection of the human cochlea and semicircular canals.. Courtesy of Lars-Goran Johnsson ... inner ear, which contains the cochlea. The cochlea is a complex coiled structure. It consists of a long membrane, known as the ...
The cochlea looks like a spiral-shaped snail shell deep in your ear. ... Cochlea. Say: ko-klee-uh. The cochlea looks like a spiral-shaped snail shell deep in your ear. And it plays an important part ... There, the tiny hairs that line the cochlea move and shake, sending messages to your brain that you hear a sound. And this all ... After the eardrum takes in a sound, the sound gets turned into a vibration that travels to the cochlea. ...
The spiral ganglion is one of the two ganglion parts that make up the acoustic nerve complex (a group of ganglion cells closely applied to the cranial edge of the auditory vesicle). The spiral ganglion fibers create the cochlear nerve.. ...
The membrane is joined to the bony shelf of the cochlea and passes like a roof over the receptor cells, making contact with the ...
... you probably noticed that I work on hair cell regeneration in the cochlea. But, perhaps, some readers are not familiar with the ... which is located near the base of the cochlea for high frequencies and higher in the cochlea for low frequencies, which let ... small frequency-specific disturbances are transmitted into the fluid-filled spaces in the cochlea. Each part of the cochlea ... But your link Promenade Round the Cochlea was also very very good, with an animation that explains a bit how the sound is ...
Sound, in a form of a mechanical wave, enters the cochlea at the round window. The cochlea is filled with fluid and the ... but rather into a natural crevice in the cochlea that allows for the hydrodynamic nature of the cochlea to be maintained. Still ... As a result of facilitated activity of the SGC in one cochlea only and stimulation through a very limited number of stimulating ... The cochlear implant can include an electrode array that is implantable in the cochlea of the implantee and which is adapted to ...
This action is passed onto the cochlea, a fluid-filled snail-like structure that contains the organ of Corti, the organ for ... Fibers near the upper end of the cochlea resonate to lower frequency sound. Those near the oval window respond to higher ... It consists of tiny hair cells that line the cochlea. These cells translate vibrations into electrical impulses that are ...
Fenestra of cochlea definition at Dictionary.com, a free online dictionary with pronunciation, synonyms and translation. Look ... Words nearby fenestra of cochlea. fend for oneself, Fénelon, feneration, fenestella, fenestra, fenestra of cochlea, fenestra of ...
1A as a typical data set in sensitive cochleae. The initial CAP threshold for this cochlea was 15 dB SPL at 18 kHz before the ... Near the 16-kHz CF location (≈2,550 μm), the velocity in the insensitive cochlea is ,30 dB less than in the sensitive cochlea. ... Near the 16-kHz CF location (≈2,550 μm), the velocity in the insensitive cochlea is ,30 dB less than in the sensitive cochlea. ... The overall peak in the sensitive cochlea (solid lines) disappeared in the insensitive cochlea (dashed lines). The wider ...
T he cochlea is the most anterior and medial part of the vestibulocochlear labyrinth. It lies anteromedial to the vestibule and ... The position of the cochlea was determined on bone window CT scans. The position of the cochlear nucleus was identified on the ... If hearing is to be preserved, care should be taken to avoid injuring the cochlea and the semicircular canals. Such drilling is ... 1 It has been shown that the components of the cochlea are likely to be damaged by radiation exposure after fractionated ...
Spiral ligament of cochlea definition at Dictionary.com, a free online dictionary with pronunciation, synonyms and translation ...
19.7: The Cochlea The cochlea is a coiled structure in the inner ear that contains hair cells-the sensory receptors of the ... Therefore, the cochlea plays a vital role both in the transduction of sound information into neural signals and the initial ... The basilar membrane extends from the basal end of the cochlea near the oval window to the apical end at its tip. Although the ... Ultimately, the primary auditory cortex contains a "map" of inputs from the basal to the apical end of the cochlea. The neurons ...
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Artificial cochlea tells tones apart. TRN March 9/16, 2005. TRN Categories: MicroElectroMechanical Systems (MEMS); Applied ... This micromechanical microphone mimics the cochlea, the tapered part of the biological ear that distinguishes different ...
Previous message: Audiogram defects (was Re: Cochlea -- quality of filtering) *Next message: Audiogram defects (was Re: Cochlea ... Previous message: Audiogram defects (was Re: Cochlea -- quality of filtering) *Next message: Audiogram defects (was Re: Cochlea ... Audiogram defects (was Re: Cochlea -- quality of filtering). BJPARKER bjparker at aol.com Sun Sep 24 11:45:18 EST 1995 * ...
Segmentation of Cochlea in 3D » Segmentation of a Knee Bone in 3D » Component Analysis & Selection in 3D » ... Segmentation of Cochlea in 3D The Wolfram Language includes a variety of 3D segmentation techniques such as clustering, region ... Extract the cochlea by selecting the largest component and multiply the selected segment by the original volume to visualize ... Apply image foresting segmentation and connected components to obtain an initial segmentation of a cochlea. ...
In chapter 3, "The Sense of Sensibility," author Wendy Jones uses scenes from one of Jane Austens most celebrated novels to illustrate the functioning of the bodys stress response system.. 0 Comments. ...
But a cochlea implant looks a bit like a normal hearing aid. Its worn behind the ear and theres a microphone attached to it. ... As a result of damage or losing certain parts of the cochlea, in the same way that phantom pain hurts, the tinnitis is the ... Lets have a listen to what a piece of music would sound like if youre listening to it with a cochlea implant. [sound] That ... Chris - So when we lose them and we want to restore them using this cochlea implant technology, how does that work? What does ...
Lgr5-positive supporting cells generate new hair cells in the postnatal cochlea.. Bramhall NF1, Shi F2, Arnold K3, Hochedlinger ... The prevalence of hearing loss after damage to the mammalian cochlea has been thought to be due to a lack of spontaneous ... These data suggest that the neonatal mammalian cochlea has some capacity for hair cell regeneration following damage alone and ... Lgr5-Positive Supporting Cells Generate New Hair Cells in the Postnatal Cochlea ...
cochleae than in either Pou4f3DTR/+. or Pou4f3DTR/+. Fgfr3-iCre. Ctnnb1fl(ex3)/+. cochleae. Data represent the mean ± SD. **. P ... cochlea. Some Atoh1+Gfi1+Sox2+ (myosin 7a-) cells (arrowheads), which were rarely seen in the Pou4f3DTR/+. cochlea, were also ... cochlea. Mechanistically, Sox2haplo or damaged neonatal cochleae showed lower levels of Sox2 and Hes5, but not of Wnt target ... cochlea, some transitional cells (Atoh1+Gfi1+Sox2+myosin 7a+, arrows) were detected in the apical and middle turns of the ...
... cochlea. Mechanistically, Sox2haplo or damaged neonatal cochleae showed lower levels of Sox2 and Hes5, but not of Wnt target ... Sox2haplo cochleae had delayed terminal mitosis and ectopic sensory cells, yet normal auditory function. Sox2haplo amplified ... and expanded domains of damage-induced Atoh1+ transitional cell formation in neonatal cochlea. Wnt activation via β-catenin ...
... Development. 2015 Feb 1;142(3):555-66. doi: 10.1242 ... To address this issue, we evaluated PCP defects in cochlea from a selection of mice with mutations in cilia-related genes. ...
... we stained the cochleae of mouse and rat with the antibodies used in this study (Figures 6(c) and 6(d)). In the mouse cochlea, ... revealed the same expression patterns of KIAA1199 in the common marmoset cochlea. (c) Immunohistochemistry with the cochleae of ... Distinct Expression Pattern of a Deafness Gene, KIAA1199, in a Primate Cochlea. Makoto Hosoya,1 Masato Fujioka,1 Hideyuki Okano ... Figure 1: Expression of KIAA1199 in the cochlea of the common marmoset. (a and b) KIAA1199 expression is observed in the ...
Macromolecular and electrical coupling between inner hair cells in the rodent cochlea. Access & Citations. * 2160 Article ...
Afferent synapses on both free-standing and tectorial hair cells in the alligator lizards cochlea are described quantitatively ... Patterns of afferent synaptic contacts in the alligator lizards cochlea J Comp Neurol. 1986 Jun 8;248(2):263-71. doi: 10.1002/ ... Afferent synapses on both free-standing and tectorial hair cells in the alligator lizards cochlea are described quantitatively ...
The cochlea is located in the inner ear and is the main hearing organ. Outer and inner hair cells detect and transmit ... Malformations of the Cochlea. Sometimes, the cochlea does not develop as it should. Incomplete or malformed cochleas may result ... The Cochlea: How We Hear. The cochleas hair cells detect the presence of sound waves and transmit the information to the ... The cochlea is a spiral organ shaped like a nautilus shell in the inner ear. The cochlea contains the organ of Corti, with ...
The cochlea of the cat is longer than that of the guinea pig, but the guinea pig has a ratio of 7.2 and can hear down to 47 Hz ... Spiral-shaped cochleae are exclusive to mammals. Birds and reptiles generally have plate-like or slightly curved versions of ... As a result, the sensory cells near the outer end of the cochlea detect high-pitched sounds, like the notes of a piccolo, while ... "It turns out that it is the curvature of the cochlea, not its size, that is highly correlated to the low-frequency hearing ...
After I was diagnosed with brain cancer and started to lose my mental health, the importance of my job came into clear focus.. 0 Comments. ...
  • The prevalence of hearing loss after damage to the mammalian cochlea has been thought to be due to a lack of spontaneous regeneration of hair cells , the primary receptor cells for sound. (nih.gov)
  • The complex anatomy of the mammalian cochlea is most readily understood by representation in three-dimensions. (nih.gov)
  • Schematic of the synaptic interactions among hair cells, cochlear nerve afferents, and olivocochlear efferent fibers in the mammalian cochlea. (jneurosci.org)
  • Students can easily identify the general structures of the mammalian cochlea, including the details of Corti's organ. (carolina.com)
  • The cochlea, the mammalian auditory organ, is a spiral-shaped structure in the inner ear that is responsible for hearing. (cshlpress.com)
  • An adult mammalian cochlea lacks regenerative potential and therefore hair cell loss is irreversible and leads to hearing loss. (frontiersin.org)
  • In the mammalian cochlea, stereociliary bundles located on mechanosensory hair cells within the sensory epithelium are unidirectionally oriented. (biologists.org)
  • We propose that Wnt signaling across the region of developing outer hair cells gives rise to planar polarity in the mammalian cochlea. (biologists.org)
  • Planar polarity is evident in the mechanosensory hair cells within the sensory epithelium of the mammalian cochlea, the organ of Corti. (biologists.org)
  • The mammalian organ of Corti (OC) comprises two types of mechanosensory hair cells (HCs) along with underlying support cells that together are responsible for transducing auditory signals within the sensory epithelium of the cochlea ( supplementary material Fig. S1). (biologists.org)
  • The mammalian cochlea is a complex macroscopic structure due to its helical shape and the microscopic arrangements of the individual layers of cells. (lzh.de)
  • Based on work in intact cochlear tissue, it is thought that Notch signaling might restrict supporting cell plasticity in the mammalian cochlea. (pubmedcentralcanada.ca)
  • Notch prosensory effects in the Mammalian cochlea are partially mediated by Fgf20. (semanticscholar.org)
  • The mammalian cochlea is a highly sensitive transducer which converts acoustic vibration into electrical signal. (ntu.edu.sg)
  • The findings provide understanding of an arched membrane in mammalian cochlea and enables development for application of the cochlear mechanics in areas such as microfluidics and artificial cochlear development where limitations on the channel width are critical. (ntu.edu.sg)
  • In a mammalian cochlea, the middle ear acts as a force transducer (acoustic--acoustic) which converts high amplitude--low power into low amplitude--high power vibration in order to match the impedance between air and fluid. (ntu.edu.sg)
  • Thus, the effects of Glu in the mammalian cochlea appear to be complex and on balance seem inconsistent with the effects predicted for an excitatory transmitter. (uni-regensburg.de)
  • In the cochlea (the specialized auditory end organ of the inner ear), the frequency of a pure tone is reported by the location of the reacting neurons in the basilar membrane, and the loudness of the sound is reported by the rate of discharge of nerve impulses. (britannica.com)
  • Unlike behavioral curves, however, the curves obtained by plotting the sound required to produce an arbitrary amount of electrical potential of the cochlea do not represent auditory thresholds. (britannica.com)
  • Inner hair cells send auditory information to the brain, while outer hair cells act to stabilize or intensify the vibrations transmitted throughout the cochlea. (scienceblogs.com)
  • 9. An implantable apparatus of claim 6 wherein the prosthesis includes an electrode array that is implantable in the cochlea of the implantee and is adapted to deliver both plasticity informative stimuli and auditory informative stimuli to the cochlea of the implantee. (google.ca)
  • Therefore, high frequencies activate auditory nerve cells at the basal end of the cochlea, while low frequencies activate those at the apical end. (jove.com)
  • The cochlea is a coiled structure in the inner ear that contains hair cells-the sensory receptors of the auditory system. (jove.com)
  • This tonotopy is maintained throughout the auditory pathway, with information from different regions of the cochlea traveling in organized, parallel pathways through the brain. (jove.com)
  • Ultimately, the primary auditory cortex contains a "map" of inputs from the basal to the apical end of the cochlea. (jove.com)
  • Sox2haplo cochleae had delayed terminal mitosis and ectopic sensory cells, yet normal auditory function. (jci.org)
  • The sound waves travel through the cochlea and excite hair cells at specific locations along the cochlea, and the information from these cells is picked up by the auditory nerve and carried to the brain. (hubpages.com)
  • Animals with tightly coiled cochleae tend to have greater hearing ranges, but previous attempts to associate these auditory effects with the physical characteristics of the cochlea have proven unsatisfactory because they did not take a critical acoustic effect into account. (innovations-report.com)
  • These findings demonstrate that macrophages contribute to the regulation of glial cell number during postnatal development of the cochlea and that glial cells play a critical role in hearing onset and auditory nerve maturation. (frontiersin.org)
  • They also consider the properties of other cochlear components, including the tectorial membrane, the synaptic connections with auditory neurons, and the resident macrophages, as well as the development and evolution of the cochlea as a whole. (cshlpress.com)
  • The structural integrity of cochlea is crucial for a precise auditory function. (spiedigitallibrary.org)
  • MethodsSections from the auditory end organs were subjected to immunohistochemical staining in order to identify OCT2 in cochlea from untreated rats, guinea pigs, and a pig. (diva-portal.org)
  • The "Sonar Hopf" cochlea is a recently much advertised engineering design of an auditory sensor. (uzh.ch)
  • Auditory brainstem implant in bilateral and completely ossified cochleae. (curehunter.com)
  • To report and evaluate the results of auditory brainstem implantation in a case of postmeningitis hearing loss with totally ossified cochleae on both sides. (curehunter.com)
  • Auditory brainstem implantation is an efficient means of auditory rehabilitation in cases of bilateral total hearing loss with totally ossified cochleae. (curehunter.com)
  • In first steps in hearing, the cochlea converts sound waves coming from the outside of the ear into electrical activity of the auditory nerve. (royalsocietypublishing.org)
  • Thirdly, we evaluated the effects of tinnitus inducing drugs (salicylate and quinine) on both cochlea and auditory cortex. (nii.ac.jp)
  • Furthermore, normal cellular patterning in the cochlea, the organ of Corti, is crucial for auditory function as any patterning defects result in hearing deficit. (escholarship.org)
  • The motion of the stapes against the oval window sets up waves in the fluids of the cochlea, causing the basilar membrane to vibrate. (britannica.com)
  • Model showing the distribution of frequencies along the basilar membrane of the cochlea. (britannica.com)
  • Sound waves are transmitted to the cochlea in the inner ear by the ossicles vibrating the oval window, which pushes fluid through the cochlea, causing the basilar membrane to vibrate. (jove.com)
  • This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane. (jove.com)
  • The basilar membrane extends from the basal end of the cochlea near the oval window to the apical end at its tip. (jove.com)
  • Although the cochlea itself narrows towards the apical end, the basilar membrane has the opposite geometry-becoming wider and more flexible towards the apical end. (jove.com)
  • Because of the tonotopy of the basilar membrane, hair cells are maximally stimulated by different frequencies depending on where they are in the cochlea. (jove.com)
  • Bob - Yes, that's a membrane called the basilar membrane inside the cochlea. (thenakedscientists.com)
  • As the cochlea spirals, the basilar membrane becomes less stiff and wider, so lower frequency sound waves are funneled further along the basilar membrane. (hubpages.com)
  • B) A decalcified cochlea cleared in MSBB and imaged by oblique lighting clearly displays the modiolus, basilar lamina, spiral limbus and other structures. (nih.gov)
  • We recorded the vibrations at adjacent positions on the basilar membrane in sensitive gerbil cochleae and tested the putative power amplification in two ways. (eur.nl)
  • The variation of dynamic structural properties of the basilar membrane contributes to the frequency-mapping and sensitivity of the cochlea. (ntu.edu.sg)
  • The present research analyses the mechanism of an arched basilar membrane in contributing to the sharp frequency tuning in a gerbil cochlea. (ntu.edu.sg)
  • Among the more commonly researched species, the basilar membrane in human cochlea varies significantly in width (300% increase) and thickness (75% decrease) from its basal to apical end. (ntu.edu.sg)
  • In order to understand the difference between the two types of basilar membranes, effects of the bending stiffness and radial tension on the acoustic traveling wave in the passive gerbil cochlea is analyzed. (ntu.edu.sg)
  • For integration of cochlea mechanics design into microfluidic applications and the development of artificial cochlea, a method of fabricating and bonding the thin, flexible, anisotropic, 3-dimensional basilar membrane is required as the boundary conditions and properties of the basilar membrane are critical to the frequency tuning of the cochlea. (ntu.edu.sg)
  • Specifically, it is the shape of the cochlea - the snail-shell-shaped organ in the inner ear that converts sound waves into nerve impulses that the brain deciphers - which proves to be surprisingly important. (innovations-report.com)
  • In 2006 Manoussaki and her NIH collaborators published a paper proposing that the helical shape of the cochlea enhances low-frequency sounds through an effect analogous to the well-known "whispering gallery effect" in which soft sounds that travel along curved walls in a large chamber remain loud enough that they can be heard clearly on the opposite side of the room. (innovations-report.com)
  • The first focus of this work aims at defining automatic image processing methods adapted to the spiral shape of the cochlea to study the cochlear shape variability from high-resolution μCT images. (archives-ouvertes.fr)
  • The high-quality, sterling silver jewelry is inspired by the shape of the cochlea, the part of the ear that gives us the ability to interpret sound. (audbling.com)
  • human cochlea and semicircular canals Dissection of the human cochlea and semicircular canals. (britannica.com)
  • KIAA1199 was later identified by cDNA microarray analysis as a cochlea-specific gene that was abundantly expressed in the human cochlea [ 4 ], and the protein it encodes has been found to play a central role in hyaluronan binding and depolymerization [ 5 ]. (hindawi.com)
  • The electrical, acoustical, and mechanical elements of the cochlea are explicitly integrated into a transmission-line model to develop a physiological interpretation of the human cochlea insofar. (diva-portal.org)
  • This technique can also be applied in larger specimens up to cm3 such as the human cochlea. (lzh.de)
  • The results show comparative sensitivity between gerbil and human cochlea. (ntu.edu.sg)
  • Parvalbumin-β was also found in both inner and outer hair cells of the guinea pig cochlea. (jneurosci.org)
  • Volume flow rate of perilymph in the guinea-pig cochlea. (biomedsearch.com)
  • Ex vivo mouse and guinea pig cochlea samples were soaked in EDTA solutions for decalcification, and swept source optical coherence tomography (OCT) was used as imaging modality to monitor the decalcified samples consecutively. (spiedigitallibrary.org)
  • The monitored noninvasive cross-sectional images showed that the mouse and guinea pig cochlea samples had to be decalcified for subsequent 7 and 14 days, respectively, to obtain the optimal optical clearing results. (spiedigitallibrary.org)
  • ObjectiveTo locate the organic cation transporter 2 (OCT2) in the cochlea of three different species and to modulate the ototoxicity of cisplatin in the guinea pig by pretreatment with phenformin, having a known affinity for OCT2. (diva-portal.org)
  • Histological reconstructions and microCT of guinea pig cochleae stimulated with an infrared laser suggest that the orientation of the beam from the optical fiber determined the site of stimulation in the cochlea. (ovid.com)
  • AP tuning curves from normal and pathological human and guinea pig cochleas. (semanticscholar.org)
  • The cochlea contains the sensory organ of hearing. (britannica.com)
  • A core component of the cochlea is the Organ of Corti, the sensory organ of hearing, which is distributed along the partition separating the fluid chambers in the coiled tapered tube of the cochlea. (wikipedia.org)
  • This action is passed onto the cochlea, a fluid-filled snail-like structure that contains the organ of Corti, the organ for hearing. (medlineplus.gov)
  • Hearing involves thousands of tiny hair cells inside the cochlea, a snail-shaped organ in the inner ear. (nih.gov)
  • There are a limited number of these sensory cells, and they are closely packed within the cochlea in a region called the organ of Corti. (nih.gov)
  • The cochlea is a spiral organ shaped like a nautilus shell in the inner ear. (hubpages.com)
  • The cochlea contains the organ of Corti, with 'hair cells' that detect sound waves in fluid that fills the inner ear organs. (hubpages.com)
  • Tiny bones in the ear amplify and transmit these vibrations to the fluid in the cochlea, creating pressure waves that travel along a narrowing canal in the coiled tube-like organ. (innovations-report.com)
  • While β-catenin-deficient cochleae expressed FGF8 and FGFR3, both of which are essential for pillar cell specification, the radial patterning of organ of Corti was disrupted, revealed by aberrant expression of cadherins and the pillar cell markers P75 and Lgr6. (pnas.org)
  • The capsule may be trimmed to allow the cochlea to lie on the coverslip, or sliced (e.g., along the dashed line) to open the capsule to allow the organ of Corti to be viewed by high NA objectives with short working distances. (nih.gov)
  • Cochlear implants (CI) are used to treat hearing loss by surgically inserting an electrode array into the organ of hearing, the cochlea. (archives-ouvertes.fr)
  • The primary transducers of sound are the mechanosensory hair cells, residing within the sensory epithelia of the hearing organ, the cochlea. (frontiersin.org)
  • The large volume of fluid space within the cochlea makes cryoembedding and sectioning of the organ more problematic than that of other, more homogeneous tissues. (histosearch.com)
  • The cochlea in the inner ear is a sensory organ responsible for hearing. (keyence.com)
  • Recent studies have demonstrated the importance of R- spondins, a novel family of secreted proteins, in canonical Wnt signaling and FGF signaling, two pathways that play significant roles in the development of the cochlea, the hearing organ. (escholarship.org)
  • Within the organ of Corti, a single row of inner hair cells and three rows of outer hair cells extend along the basal-to-apical axis of the cochlea. (escholarship.org)
  • The demonstration shows the structure of the cochlea and how it processes sound. (lessonplanet.com)
  • Not only does this help to give a better understanding of the structure of the cochlea, but also of the localization. (keyence.com)
  • Wihan Kim, Sangmin Kim, John S. Oghalai, and Brian E. Applegate, "Endoscopic optical coherence tomography enables morphological and subnanometer vibratory imaging of the porcine cochlea through the round window," Opt. (osapublishing.org)
  • Imaging the internal structure of the rat cochlea using optical coherence tomography at 0.827 microm and 1.3 microm. (escholarship.org)
  • The purpose of this study was to use high-speed optical coherence tomography (OCT) to obtain cross-sectional images of the rat cochlea. (escholarship.org)
  • Lgr5-positive supporting cells generate new hair cells in the postnatal cochlea. (nih.gov)
  • Methodology/Principal Findings: A combination of quantitative RT-PCR, subcellular fractionation and Western blotting, along with in situ hybridization studies show IGF-I and its high affinity receptor to be strongly expressed in the embryonic and postnatal mouse cochlea. (whiterose.ac.uk)
  • In addition, we demonstrated that ATP-dependent Ca2+ signaling activity in cochlear non-sensory cells is spatially graded from the apex to the base of the cochlea during the first postnatal week. (unipd.it)
  • A cross section through one of the turns of the cochlea (inset) showing the scala tympani and scala vestibuli, which contain perilymph, and the cochlear duct, which is filled with endolymph. (britannica.com)
  • The mechanical vibrations of the stapes footplate at the oval window creates pressure waves in the perilymph of the scala vestibuli of the cochlea. (britannica.com)
  • The stapes (stirrup) ossicle bone of the middle ear transmits vibrations to the fenestra ovalis (oval window) on the outside of the cochlea, which vibrates the perilymph in the vestibular duct (upper chamber of the cochlea). (wikipedia.org)
  • The fluid inside the cochlea (endolymph) is more positively charged than perilymph fluid, and helps to regulate the electrochemical signals required by the outer hair cells. (hubpages.com)
  • Cochlea, filled with fluids called perilymph and endolymph, a spiral-shaped cavity in the ear that translates sound waves into electrical nerve impulses and sends them to the cerebral cortex for interpretation. (sciencephoto.com)
  • When the cochlea was sealed (with recording electrodes in place) and cerebrospinal fluid pressure was released, there was no significant basally-directed flow of perilymph in scala tympani. (biomedsearch.com)
  • The ossicles are essential for efficient coupling of sound waves into the cochlea, since the cochlea environment is a fluid-membrane system, and it takes more pressure to move sound through fluid-membrane waves than it does through air. (wikipedia.org)
  • Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. (jove.com)
  • When sound waves hit the cochlea, they cause the fluid inside it to vibrate: the hair cells detect these vibrations and convert them into electrical signals that are sent along neurons to the brain. (elifesciences.org)
  • Furthermore, immunolabeling allows visualization of inner hair cells (otoferlin) or spiral ganglion cells (neurofilament) within the whole cochlea. (lzh.de)
  • c ) The three-dimensional equivalent electrical circuit of the whole cochlea built from the element circuit in ( b ) by its longitudinal electrical coupling in the selected nodes. (royalsocietypublishing.org)
  • The spiral canal of the cochlea is a section of the bony labyrinth of the inner ear that is approximately 30 mm long and makes 2¾ turns about the modiolus. (wikipedia.org)
  • The cochlea is spiraled around a bony structure called the modiolus. (hubpages.com)
  • Modiolus not labeled, but is represented at the axis of the spiral of the cochlea at the left. (wikidoc.org)
  • The modiolus is a conical shaped central axis in the cochlea . (wikidoc.org)
  • A) Shadows of the modiolus and pigmentation of the stria vascularis are the only internal structures visible from a non-cleared cochlea lying in PBS. (nih.gov)
  • Play media The cochlea is filled with a watery liquid, the endolymph, which moves in response to the vibrations coming from the middle ear via the oval window. (wikipedia.org)
  • The sensory cells of the cochlea are called "hair cells," so named for their hair-like projections which protrude into the fluid filled space (endolymph) in V-shapes. (scienceblogs.com)
  • Using the Lgr5 knock-in mouse line we show that loss of LGR5 function increases Wnt/β-catenin activity in the embryonic cochlea, resulting in a mild overproduction of inner and outer hair cells (OHC). (frontiersin.org)
  • Altogether, our findings suggest that LGR4 and LGR5 play an important role in the regulation of hair cell differentiation in the embryonic cochlea. (frontiersin.org)
  • The expression of both proteins decreases after birth and in the cochlea of E18.5 embryonic Igf1(-/-) null mice, the balance of the main IGF related signalling pathways is altered, with lower activation of Akt and ERK1/2 and stronger activation of p38 kinase. (whiterose.ac.uk)
  • The cochlea receives sound in the form of vibrations, which cause the stereocilia to move. (wikipedia.org)
  • As the vibrations of the stapes cause it to "hit" on the cochlea's round window, small frequency-specific disturbances are transmitted into the fluid-filled spaces in the cochlea. (scienceblogs.com)
  • Hair cells are arranged inside the cochlea, which convert sound vibrations into nerve impulses. (keyence.com)
  • Here I report a "snapshot" (the instantaneous waveform of cochlear partition vibration) measured in the basal turn of the sensitive gerbil cochlea using a scanning laser interferometer. (pnas.org)
  • The aim of this study was to measure the magnitude and phase of the transverse velocity of BM vibration and to calculate the instantaneous waveforms, or "snapshots," of the vibration, by using a scanning laser interferometer microscope in the sensitive gerbil cochlea. (pnas.org)
  • s 3-Dimensional, push-pull mechanism, two-box model and compared to the bandwidth of gerbil cochlea. (ntu.edu.sg)
  • In particular, the stereociliary bundles present on hair cells located throughout the cochlea are all oriented towards the outer border of the cochlear duct ( Fig. 1 ). (biologists.org)
  • The stapes sits atop the round window, which is a small membrane-covered hole in the base of the cochlea. (scienceblogs.com)
  • The vibration propagates from the base of the cochlea to its apex along the cochlear partition. (pnas.org)
  • Four rows of hair cells (called stereocilia) are located along the length of the cochlea. (hubpages.com)
  • There are approximately 20,000 hair cells located along the entire length of the cochlea, which detect a wide range of frequencies: the human ear has the capability of detecting sounds from approximately 200Hz-20,000Hz. (hubpages.com)
  • The canal is one of two main chambers that are created by an elastic membrane that runs the length of the cochlea. (innovations-report.com)
  • Microscope slide showing a longitudinal section of the mammal cochlea. (carolina.com)
  • Our results demonstrated that when electrodes were completely sealed into the cochlea, the rate of longitudinal volume flow in scala tympani was extremely slow, approximately 1.6 nl/min in the apical direction. (biomedsearch.com)
  • A ) Pou4f3 DTR/+ Fgfr3-iCre Ctnnb1 fl(ex3)/+ and Pou4f3 DTR/+ Sox2 CreERT2/+ Ctnnb1 fl(ex3)/+ mice were injected with DT on P1, followed by tamoxifen administration on P2, and cochleae were examined on P4. (jci.org)
  • To address this issue, we evaluated PCP defects in cochlea from a selection of mice with mutations in cilia-related genes. (nih.gov)
  • Expression analysis of KIAA1199 protein in the cochlea has been performed in mice and rats [ 1 , 11 ], where different distribution patterns for each species were described, suggesting the possibility of an even greater difference in primates. (hindawi.com)
  • Using this method, difficulties in imaging of internal cochlea microstructures of mice could be evaded. (spiedigitallibrary.org)
  • Using TCF/Lef:H2B-GFP reporter mice and transfection of an independent TCF/Lef reporter construct, we describe the pattern of canonical Wnt activity in the developing mouse cochlea. (biologists.org)
  • Consistent with this, mice that were genetically modified to lack a growth factor called neurotrophin-3 had cochleae that did not work properly and had fewer synapses between hair cells and neurons compared to control mice. (elifesciences.org)
  • Transient receptor potential vanilloid 4 mRNA and protein were expressed in inner hair cells, outer hair cells, and spiral ganglion neurons on the basis of the findings of reverse transcriptase-polymerase chain reaction, single-cell reverse transcriptase-polymerase chain reaction, and immunohistochemistry, whereas they were negative in transient receptor potential vanilloid 4 −/− mice cochleae. (ovid.com)
  • The role of Rspo2 in the development of the mouse cochlea was investigated in this study by examining the Rspo2-/- mice. (escholarship.org)
  • Vice versa, we found defective gap junction coupling and intercellular IP3-dependent Ca2+ signaling the cochlea of mice with targeted ablation Cx26 or Cx30, as well as in mice knock in for a point mutation (Cx30T5M) associated with human congenital deafness. (unipd.it)
  • Above is an illustration showing the outer and middle ear, and below is one of the inner ear and cochlea. (scienceblogs.com)
  • Several days later, the cochleae had fewer outer hair cells than normal. (nih.gov)
  • As a result, the sensory cells near the outer end of the cochlea detect high-pitched sounds, like the notes of a piccolo, while those at the inner end of the spiral detect lower-frequency sounds, like the booming of a bass drum. (innovations-report.com)
  • A fine fissure in the lower part of the first turn of the cochlea , formed by a spiral lamina which projects from the outer wall of the cochlea but does not quite reach the osseous spiral lamina , thus leaving a narrow gap . (biology-online.org)
  • The cochlea also contains a specific population of hair cells, the outer hair cells (OHCs), which is thought to amplify the BM motion. (royalsocietypublishing.org)
  • We investigated functional expression of transient receptor potential vanilloid 4 in inner hair cells, outer hair cells, and spiral ganglion neurons of the mouse cochlea. (ovid.com)
  • In the Rspo2 mutant cochleae, there was an extra row of outer hair cells along with an extra row of support cells in the apical half of the cochlea. (escholarship.org)
  • Hydrogen-rich water, which is a potent antioxidant agent, was investigated for its protective effects against ischemic damage of the cochlea in gerbils. (readbyqxmd.com)
  • Here we show that β-catenin is required for specification of hair cell and supporting cell subtypes and radial patterning of the cochlea in vivo. (pnas.org)
  • To improve the outcomes of hearing restoration in deaf patients, it is important to understand the anatomic structure and composition of the cochlea ex vivo. (lzh.de)
  • Brain Research Protocols Volume 6, Issue 3, February 2001, Pages 159-166 Cryoembedding and sectioning of cochleas for immunocytochemistry and in situ hybridization Donna S. Whitlon, Renee Szakaly, Mary A. Greiner Abstract Current emphasis on biochemical and molecular aspects of cochlear anatomy underscores the necessity for high quality cryostat sections of the inner ear. (histosearch.com)
  • Each part of the cochlea corresponds to a different frequency range, high frequencies at the base of the coil and low frequencies at the top. (scienceblogs.com)
  • This micromechanical microphone mimics the cochlea, the tapered part of the biological ear that distinguishes different frequencies. (trnmag.com)
  • The detection location for various sound frequencies along the length of an uncoiled cochlea. (hubpages.com)
  • Sox2haplo amplified and expanded domains of damage-induced Atoh1+ transitional cell formation in neonatal cochlea. (jci.org)
  • By contrast, β-cateninGOF caused proliferation when either Sox2haplo or damage was present, and transitional cell formation when both were present in neonatal, but not mature, cochlea. (jci.org)
  • Mechanistically, Sox2haplo or damaged neonatal cochleae showed lower levels of Sox2 and Hes5, but not of Wnt target genes. (jci.org)
  • β-Catenin stabilization and Sox2 haploinsufficiency coordinate to increase transitional cell formation in the damaged neonatal mouse cochlea. (jci.org)
  • The cochlea (plural is cochleae) is a spiraled, hollow, conical chamber of bone, in which waves propagate from the base (near the middle ear and the oval window) to the apex (the top or center of the spiral). (wikipedia.org)
  • Low frequency sounds are detected near the apex of the cochlea. (hubpages.com)
  • Deviations towards the apex of the cochlea were assigned a positive value and deviations towards the base were assigned a negative value. (biologists.org)
  • A team led by Dr. Matthew W. Kelley of NIH's National Institute on Deafness and Other Communication Disorders (NIDCD) has been studying how the cochlea develops. (nih.gov)
  • It turns out that it is the curvature of the cochlea, not its size, that is highly correlated to the low-frequency hearing limit," says Daphne Manoussaki, assistant professor of mathematics at Vanderbilt University, who headed the new study with Richard S. Chadwick, a section chief at the National Institute on Deafness and Other Communication Disorders (one of the National Institutes of Health, or NIH). (innovations-report.com)
  • Defects in the cellular or molecular components of the cochlea can lead to deafness and other hearing impairments. (cshlpress.com)
  • If you read the 'About' page, or anything about me, you probably noticed that I work on hair cell regeneration in the cochlea. (scienceblogs.com)
  • Studies of the cochlea revealed that the extra neurotrophin-3 had boosted the regeneration of synapses damaged by the noise. (elifesciences.org)
  • The inner hair cells provide the main neural output of the cochlea. (wikipedia.org)
  • The membrane is joined to the bony shelf of the cochlea and passes like a roof over the receptor cells, making contact with the tips of their hairs. (innerbody.com)
  • It consists of tiny hair cells that line the cochlea. (medlineplus.gov)
  • Scientists mapped how sensory cells develop in the mouse cochlea, a key sound-sensing structure in the inner ear. (nih.gov)
  • Single-cell RNA sequencing helped scientists map how sensory hair cells (pink) develop in a newborn mouse cochlea. (nih.gov)
  • In their new study, they analyzed the gene activity of 30,000 cells from the mouse cochlea to create a developmental map. (nih.gov)
  • B , D , and F ) As with Pou4f3 DTR/+ cochlea, some transitional cells (Atoh1 + Gfi1 + Sox2 + myosin 7a + , arrows) were detected in the apical and middle turns of the Pou4f3 DTR/+ Fgfr3-iCre Ctnnb1 fl(ex3)/+ cochlea. (jci.org)
  • Some Atoh1 + Gfi1 + Sox2 + (myosin 7a - ) cells (arrowheads), which were rarely seen in the Pou4f3 DTR/+ cochlea, were also noted in the supporting cell layer of apical and middle turns. (jci.org)
  • C , E , and G ) In the Pou4f3 DTR/+ Sox2 CreERT2/+ Ctnnb1 fl(ex3)/+ cochlea, a marked increase in transitional cells was observed in all 3 turns. (jci.org)
  • H ) Quantification revealed that significantly more transitional cells were detected in all 3 turns in the Pou4f3 DTR/+ Sox2 CreERT2/+ Ctnnb1 fl(ex3)/+ cochleae than in either Pou4f3 DTR/+ or Pou4f3 DTR/+ Fgfr3-iCre Ctnnb1 fl(ex3)/+ cochleae. (jci.org)
  • In the common marmoset cochlea, KIAA1199 protein expression was more widespread than in rodents, with all epithelial cells, including hair cells, expressing KIAA1199. (hindawi.com)
  • Afferent synapses on both free-standing and tectorial hair cells in the alligator lizard's cochlea are described quantitatively. (nih.gov)
  • The risks and efficacy of transplanting two varieties of stem cells into mouse cochlea have been evaluated by Japanese researchers. (medindia.net)
  • However, there is a risk of tumor growth associated with transplanting iPS cells into mouse cochleae. (medindia.net)
  • They noted that the number of cells able to be transplanted into cochleae is limited because of the cochleae's tiny size. (medindia.net)
  • Thus, the number of settled cells is low.They also noted the formation of a teratoma (encapsulated tumor) in some cochlea after transplantation with one group of iPS cells. (medindia.net)
  • Stem Cells and the Bird Cochlea-Where Is Everybody? (cshlpress.com)
  • ResultsOrganic cation transporter 2 was found in the supporting cells and in type I spiral ganglion cells in the cochlea of all species studied. (diva-portal.org)
  • In the developing cochlea, Wnt/β-catenin signaling positively regulates the proliferation of precursors and promotes the formation of hair cells by up-regulating Atoh1 expression. (frontiersin.org)
  • The loss of LGR4 function prolonged the proliferation in the mid-basal turn of E13 cochleae, causing an increase in the number of SOX2-positive precursor cells within the pro-sensory domain. (frontiersin.org)
  • It has been demonstrated that INS can be utilized to stimulate spiral ganglion cells in the cochlea. (ovid.com)
  • The cochlea contains many thousands of hair cells organized in extensive arrays, embedded in an electrically coupled system of supporting cells. (royalsocietypublishing.org)
  • However, it is unresolved how Notch signaling functions in the hair cell-damaged cochlea and the molecular and cellular changes induced in supporting cells in response to hair cell trauma are poorly understood. (pubmedcentralcanada.ca)
  • This causes hair cells inside the cochlea to be susceptible to fluorescence blurring during fluorescence observation, and are therefore observed mainly with laser confocal microscopes. (keyence.com)
  • Some hearing loss can be attributed to the death of hair cells in a part of the inner ear called the cochlea. (elifesciences.org)
  • Increasing evidence suggests that hearing loss also results from damage to the synapses that connect the hair cells and the neurons in the cochlea. (elifesciences.org)
  • The hair-cell concentration of calbindin-D28k but not of parvalbumin-β increased from the low- to high-frequency end of the cochlea. (jneurosci.org)
  • β-Catenin-deleted cochleae displayed disrupted compartment borders containing ectopic hair cell and supporting cell subtypes, whereas inhibiting transcriptional and preserving cell adhesion-mediated activities of β-catenin maintained radial patterning and cell identity. (pnas.org)
  • Moreover, we provide evidence that Notch signaling is active in the hair cell damaged cochlea and identify Hes1, Hey1, Hey2, HeyL, and Sox2 as targets and potential Notch effectors of this hair cell-independent mechanism of Notch signaling. (pubmedcentralcanada.ca)
  • There, the tiny hairs that line the cochlea move and shake, sending messages to your brain that you hear a sound. (kidshealth.org)
  • 4. An implantable apparatus of claim 1 wherein the stimuli is delivered to the cochlea, inferior colliculus, the Subthalamic Nucleus (STN), the Globus Pallidus (GPi), and/or the Thalamus of the implantee. (google.ca)
  • one called the cochlea nucleus, and there's another one called the inferior colliculus. (thenakedscientists.com)
  • The acoustic vibration enters via the stapes and travels in the scala fluid along the cochlea from its basal to apical end. (ntu.edu.sg)
  • The cochlea looks like a spiral-shaped snail shell deep in your ear . (kidshealth.org)
  • Turritella cochlea is a species of sea snail, a marine gastropod mollusk in the family Turritellidae. (wikipedia.org)
  • The name "cochlea" means "snail" and refers to its coiled shaped. (scienceblogs.com)
  • Three-dimensional imaging of the intact mouse cochlea by fluorescent laser scanning confocal microscopy. (nih.gov)
  • A maximum intensity projection (MIP) from an intact mature mouse cochlea imaged through its entire volume. (nih.gov)
  • Canonical Notch signaling is not necessary for prosensory induction in the mouse cochlea: insights from a conditional mutant of RBPjkappa. (semanticscholar.org)
  • The present study aimed to examine Cx26 expression and aberrant methylation the Cx26 promoter region in the cochlea from rats exposed to chronic prenatal hypoxia. (readbyqxmd.com)
  • The cochleae of Sprague- Dawley rats were imaged within 2 to 4 hours after death. (escholarship.org)
  • The end of the cochlea nearest the oval window is stiff and narrow, which funnels high frequency sounds to the first sections of the cochlea. (hubpages.com)
  • The lengthwise partition that divides most of the cochlea is itself a fluid-filled tube, the third duct. (wikipedia.org)
  • Hitherto, only one histological technique based on confocal laser scanning microscopy and optical clearing has been developed for in toto optical imaging of the murine cochlea. (lzh.de)
  • Here, we demonstrate scanning laser optical tomography (SLOT) as a valuable imaging technique to visualize the murine cochlea in toto without any physical slicing. (lzh.de)
  • These images reflect the ability of OCT to provide images of the internal cochlea structure with micron scale resolution and at near-real time frame rates. (escholarship.org)
  • For more on the anatomy of the cochlea, please check out a link on my BlogRoll (sidebar to the left) called Promenade 'Round the Cochlea. (scienceblogs.com)
  • The cochlea was completely destructed after 1 month, however acoustic stimuli induced no response at the maximum sound intensity. (nii.ac.jp)
  • We therefore examined expression of KIAA1199 protein by immunohistochemistry in cochlea from a nonhuman primate, the common marmoset ( Callithrix jacchus ). (hindawi.com)
  • The cochleae were examined with light microscopy, electron microscopy and immunohistochemistry for Bax, cleaved caspase-3 and Bcl-2. (biologists.org)
  • Our method for cryoembedding of cochleas for immunocytochemistry and in situ hybridization uses slow infiltration with increasing concentrations of sucrose followed by degassed embedding medium before final orientation and freezing. (histosearch.com)
  • subunits of Na,K-ATPase were studied in the rat cochlea using in situ mRNA hybridization. (eurekamag.com)
  • This suggests that the administration of amikacine induced destruction not only cochlea but also vestibule. (nii.ac.jp)
  • We tried to determine the appropriate dosage which destruct cochlea without destruct vestibule. (nii.ac.jp)
  • The purpose of this study was to examine the underlying mechanisms of vestibular evoked myogenic potential(VEMP) by performing single unit recording from vestibular nerve in response to the loud sound after total destruction of cochlea Firstly, we tried to destruct cochlea by administration of aminoglycoside. (nii.ac.jp)
  • The aim of this study is to assess the influence of experimental sepsis on hearing thresholds and to evaluate pathological changes in the cochlea. (biologists.org)
  • Bone remodeling within the otic capsule has been reported to be inhibited especially at or near the cochlea, except under some pathological conditions such as otosclerosis, Paget's disease, or mastoiditis, when bone remodeling can occur. (readbyqxmd.com)