Outer hair cells hair cells auditory outer. Medical search

Hair Cells, Auditory, Outer: 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.Hair Cells, Auditory: 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.Hair Cells, Auditory, Inner: 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.Hair: A filament-like structure consisting of a shaft which projects to the surface of the SKIN from a root which is softer than the shaft and lodges in the cavity of a HAIR FOLLICLE. It is found on most surfaces of the body.Cochlea: 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.Organ of Corti: 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.Hair Cells, Vestibular: Sensory cells in the acoustic maculae with their apical STEREOCILIA embedded in a gelatinous OTOLITHIC MEMBRANE. These hair cells are stimulated by the movement of otolithic membrane, and impulses are transmitted via the VESTIBULAR NERVE to the BRAIN STEM. Hair cells in the saccule and those in the utricle sense linear acceleration in vertical and horizontal directions, respectively.Saccule and Utricle: 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.Basilar Membrane: A basement membrane in the cochlea that supports the hair cells of the ORGAN OF CORTI, consisting keratin-like fibrils. It stretches from the SPIRAL LAMINA to the basilar crest. The movement of fluid in the cochlea, induced by sound, causes displacement of the basilar membrane and subsequent stimulation of the attached hair cells which transform the mechanical signal into neural activity.Electric Capacitance: The ability of a substrate to retain an electrical charge.Hair Follicle: A tube-like invagination of the EPIDERMIS from which the hair shaft develops and into which SEBACEOUS GLANDS open. The hair follicle is lined by a cellular inner and outer root sheath of epidermal origin and is invested with a fibrous sheath derived from the dermis. (Stedman, 26th ed) Follicles of very long hairs extend into the subcutaneous layer of tissue under the SKIN.Tectorial Membrane: 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.Mechanotransduction, Cellular: 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.Ear, Inner: The essential part of the hearing organ consists of two labyrinthine compartments: the bony labyrinthine and the membranous labyrinth. The bony labyrinth is a complex of three interconnecting cavities or spaces (COCHLEA; VESTIBULAR LABYRINTH; and SEMICIRCULAR CANALS) in the TEMPORAL BONE. Within the bony labyrinth lies the membranous labyrinth which is a complex of sacs and tubules (COCHLEAR DUCT; SACCULE AND UTRICLE; and SEMICIRCULAR DUCTS) forming a continuous space enclosed by EPITHELIUM and connective tissue. These spaces are filled with LABYRINTHINE FLUIDS of various compositions.Hearing: The ability or act of sensing and transducing ACOUSTIC STIMULATION to the CENTRAL NERVOUS SYSTEM. It is also called audition.Stereocilia: 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.Cochlear Microphonic Potentials: The electric response of the cochlear hair cells to acoustic stimulation.Evoked Potentials, Auditory, Brain Stem: 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.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Otoacoustic Emissions, Spontaneous: 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.Cochlear Diseases: Pathological processes of the snail-like structure (COCHLEA) of the inner ear (LABYRINTH) which can involve its nervous tissue, blood vessels, or fluid (ENDOLYMPH).Anion Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of negatively charged molecules (anions) across a biological membrane.Spiral Ganglion: 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.Molecular Motor Proteins: Proteins that are involved in or cause CELL MOVEMENT such as the rotary structures (flagellar motor) or the structures whose movement is directed along cytoskeletal filaments (MYOSIN; KINESIN; and DYNEIN motor families).Hearing Loss: A general term for the complete or partial loss of the ability to hear from one or both ears.Hearing Loss, Noise-Induced: 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.Auditory Threshold: The audibility limit of discriminating sound intensity and pitch.Cochlear Nerve: 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.Stria Vascularis: 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.Hair Cells, Ampulla: Sensory cells in the ampullary crest of each of the semicircular ducts, with their apical STEREOCILIA embedded in a wedge-shaped gelatinous cupula. These hair cells sense the movement of ENDOLYMPH resulting from angular acceleration of the head, and send signals via the VESTIBULAR NERVE to the brain to maintain balance.Neurons, Efferent: Neurons which send impulses peripherally to activate muscles or secretory cells.Chinchilla: 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.Gerbillinae: A subfamily of the Muridae consisting of several genera including Gerbillus, Rhombomys, Tatera, Meriones, and Psammomys.Deafness: A general term for the complete loss of the ability to hear from both ears.Bacterial Outer Membrane Proteins: Proteins isolated from the outer membrane of Gram-negative bacteria.Acoustic Stimulation: Use of sound to elicit a response in the nervous system.Vestibule, Labyrinth: 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.Hair Color: Color of hair or fur.Hair Diseases: Diseases affecting the orderly growth and persistence of hair.Transcription Factor Brn-3C: A POU domain factor that activates neuronal cell GENETIC TRANSCRIPTION of GENES encoding NEUROFILAMENT PROTEINS, alpha internexin, and SYNAPTOSOMAL-ASSOCIATED PROTEIN 25. Mutations in the Brn-3c gene have been associated with DEAFNESS.Lateral Line System: Aquatic vertebrate sensory system in fish and amphibians. It is composed of sense organs (canal organs and pit organs) containing neuromasts (MECHANORECEPTORS) that detect water displacement caused by moving objects.Cochlear Duct: 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.Pyridinium Compounds Hearing Loss, Sensorineural: 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.Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Presbycusis: 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.Efferent Pathways: 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.Cilia: Populations of thin, motile processes found covering the surface of ciliates (CILIOPHORA) or the free surface of the cells making up ciliated EPITHELIUM. Each cilium arises from a basic granule in the superficial layer of CYTOPLASM. The movement of cilia propels ciliates through the liquid in which they live. The movement of cilia on a ciliated epithelium serves to propel a surface layer of mucus or fluid. (King & Stansfield, A Dictionary of Genetics, 4th ed)Noise: Any sound which is unwanted or interferes with HEARING other sounds.Hair Removal: Methods used to remove unwanted facial and body hair.Microscopy, Electron, Scanning: Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.Labyrinth Supporting Cells: 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.KCNQ Potassium Channels: A family of delayed rectifier voltage-gated potassium channels that share homology with their founding member, KCNQ1 PROTEIN. KCNQ potassium channels have been implicated in a variety of diseases including LONG QT SYNDROME; DEAFNESS; and EPILEPSY.Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Hair Dyes: Dyes used as cosmetics to change hair color either permanently or temporarily.Dihydrostreptomycin Sulfate: A semi-synthetic aminoglycoside antibiotic that is used in the treatment of TUBERCULOSIS.Sound: 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.Hair Preparations: Hair grooming, cleansing and modifying products meant for topical application to hair, usually human. They include sprays, bleaches, dyes, conditioners, rinses, shampoos, nutrient lotions, etc.Patch-Clamp Techniques: An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.Acoustic Maculae: The sensory areas on the vertical wall of the saccule and in the floor of the utricle. The hair cells in the maculae are innervated by fibers of the VESTIBULAR NERVE.Salicylates: The salts or esters of salicylic acids, or salicylate esters of an organic acid. Some of these have analgesic, antipyretic, and anti-inflammatory activities by inhibiting prostaglandin synthesis.Vestibulocochlear Nerve Diseases: 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.Animals, Newborn: Refers to animals in the period of time just after birth.Sodium Salicylate: A non-steroidal anti-inflammatory agent that is less effective than equal doses of ASPIRIN in relieving pain and reducing fever. However, individuals who are hypersensitive to ASPIRIN may tolerate sodium salicylate. In general, this salicylate produces the same adverse reactions as ASPIRIN, but there is less occult gastrointestinal bleeding. (From AMA Drug Evaluations Annual, 1992, p120)Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Auditory Pathways: 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.Olivary Nucleus: 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.Rana catesbeiana: A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.Vestibulocochlear Nerve: 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.Electric Conductivity: The ability of a substrate to allow the passage of ELECTRONS.Gentamicins: A complex of closely related aminoglycosides obtained from MICROMONOSPORA purpurea and related species. They are broad-spectrum antibiotics, but may cause ear and kidney damage. They act to inhibit PROTEIN BIOSYNTHESIS.Neomycin: Antibiotic complex produced by Streptomyces fradiae. It is composed of neomycins A, B, and C. It acts by inhibiting translation during protein synthesis.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Turtles Amplifiers, Electronic: Electronic devices that increase the magnitude of a signal's power level or current.Organ Culture Techniques: A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)Evoked Potentials, Auditory: The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.Perilymph: 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)Vibration: A continuing periodic change in displacement with respect to a fixed reference. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Hearing Loss, Central: Hearing loss due to disease of the AUDITORY PATHWAYS (in the CENTRAL NERVOUS SYSTEM) which originate in the COCHLEAR NUCLEI of the PONS and then ascend bilaterally to the MIDBRAIN, the THALAMUS, and then the AUDITORY CORTEX in the TEMPORAL LOBE. Bilateral lesions of the auditory pathways are usually required to cause central hearing loss. Cortical deafness refers to loss of hearing due to bilateral auditory cortex lesions. Unilateral BRAIN STEM lesions involving the cochlear nuclei may result in unilateral hearing loss.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Endolymph: The lymph fluid found in the membranous labyrinth of the ear. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Rod Cell Outer Segment: The portion of a retinal rod cell situated between the ROD INNER SEGMENT and the RETINAL PIGMENT EPITHELIUM. It contains a stack of photosensitive disk membranes laden with RHODOPSIN.Scala Tympani: 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).Hearing Disorders: Conditions that impair the transmission of auditory impulses and information from the level of the ear to the temporal cortices, including the sensorineural pathways.Mice, Mutant Strains: Mice bearing mutant genes which are phenotypically expressed in the animals.Acoustic Impedance Tests: Objective tests of middle ear function based on the difficulty (impedance) or ease (admittance) of sound flow through the middle ear. These include static impedance and dynamic impedance (i.e., tympanometry and impedance tests in conjunction with intra-aural muscle reflex elicitation). This term is used also for various components of impedance and admittance (e.g., compliance, conductance, reactance, resistance, susceptance).Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Regeneration: The physiological renewal, repair, or replacement of tissue.Audiometry, Evoked Response: A form of electrophysiologic audiometry in which an analog computer is included in the circuit to average out ongoing or spontaneous brain wave activity. A characteristic pattern of response to a sound stimulus may then become evident. Evoked response audiometry is known also as electric response audiometry.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Mechanoreceptors: Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.Vestibular Nucleus, Lateral: Vestibular nucleus lying immediately superior to the inferior vestibular nucleus and composed of large multipolar nerve cells. Its upper end becomes continuous with the superior vestibular nucleus.Kanamycin: 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.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Mice, Inbred CBA Alopecia: Absence of hair from areas where it is normally present.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Microscopy, Confocal: A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.Phalloidine: Very toxic polypeptide isolated mainly from AMANITA phalloides (Agaricaceae) or death cup; causes fatal liver, kidney and CNS damage in mushroom poisoning; used in the study of liver damage.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Zebrafish: An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.Biophysics: The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.Audiometry, Pure-Tone: Measurement of hearing based on the use of pure tones of various frequencies and intensities as auditory stimuli.Round Window, Ear: 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.Cell Movement: The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.Basic Helix-Loop-Helix Transcription Factors: A family of DNA-binding transcription factors that contain a basic HELIX-LOOP-HELIX MOTIF.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Echolocation: An auditory orientation mechanism involving the emission of high frequency sounds which are reflected back to the emitter (animal).Temporal Bone: 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).Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Mice, Inbred C57BL Ion Channel Gating: The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Synapses: Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Otolithic Membrane: A gelatinous membrane overlying the acoustic maculae of SACCULE AND UTRICLE. It contains minute crystalline particles (otoliths) of CALCIUM CARBONATE and protein on its outer surface. In response to head movement, the otoliths shift causing distortion of the vestibular hair cells which transduce nerve signals to the BRAIN for interpretation of equilibrium.Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Audiometry: 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.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Elasticity: Resistance and recovery from distortion of shape.Semicircular Canals: Three long canals (anterior, posterior, and lateral) of the bony labyrinth. They are set at right angles to each other and are situated posterosuperior to the vestibule of the bony labyrinth (VESTIBULAR LABYRINTH). The semicircular canals have five openings into the vestibule with one shared by the anterior and the posterior canals. Within the canals are the SEMICIRCULAR DUCTS.Tinnitus: 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.Electrophysiological Processes: The functions and activities of living organisms or their parts involved in generating and responding to electrical charges .Acoustics: 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)Neurons, Afferent: Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.Acetylcholine: A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Mammals: Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.Nonlinear Dynamics: The study of systems which respond disproportionately (nonlinearly) to initial conditions or perturbing stimuli. Nonlinear systems may exhibit "chaos" which is classically characterized as sensitive dependence on initial conditions. Chaotic systems, while distinguished from more ordered periodic systems, are not random. When their behavior over time is appropriately displayed (in "phase space"), constraints are evident which are described by "strange attractors". Phase space representations of chaotic systems, or strange attractors, usually reveal fractal (FRACTALS) self-similarity across time scales. Natural, including biological, systems often display nonlinear dynamics and chaos.Batrachoidiformes: An order of bottom fishes with short, small, spinous dorsal fins. It is comprised of one family (Batrachoididae) and about 70 species.Chlorpromazine: The prototypical phenothiazine antipsychotic drug. Like the other drugs in this class chlorpromazine's antipsychotic actions are thought to be due to long-term adaptation by the brain to blocking DOPAMINE RECEPTORS. Chlorpromazine has several other actions and therapeutic uses, including as an antiemetic and in the treatment of intractable hiccup.

Prestin

... is essential in auditory processing. It is specifically expressed in the lateral membrane of outer hair cells (OHCs) of ... It is highly expressed in the outer hair cells, and is not expressed in the nonmotile inner hair cells. Immunolocalization ... Liberman MC, Gao J, He DZ, Wu X, Jia S, Zuo J (2002). "Prestin is required for electromotility of the outer hair cell and for ... Liberman MC, Gao J, He DZ, Wu X, Jia S, Zuo J (September 2002). "Prestin is required for electromotility of the outer hair cell ...

Spiral ganglion

They innervate the outer hair cells, with each Type II neuron sampling many (15-20) outer hair cells. In addition, outer hair ... Their dendrites make synaptic contact with the base of hair cells, and their axons are bundled together to form the auditory ... JB Nadol Jr (1990). "Synaptic morphology of inner and outer hair cells of the human organ of Corti". J Elect Micr Tech. Slide ... and exclusively innervate the inner hair cells. They are myelinated, bipolar neurons. Type II spiral ganglion cells make up the ...

Audiology and hearing health professionals in developed and developing countries

... and auditory brainstem response (ABR). An OAE is an electrophysiologic measure of the integrity of the outer hair cells in the ... OAEs are an objective tool that can be used to measure the integrity of the outer hair cells in the cochlear; however, test ... Roeser, R. J., & Clark, J. L. (2004). Screening for auditory disorders. Auditory Disorders in School Children, 105. McPherson, ... However, 500 Hz has been found to identify the auditory impact of otitis media with effusion in children and should be included ...

Interaural time difference

Type I fibres innervate the base of one or two inner hair cells and Type II fibres innervate the outer hair cells. Both leave ... The auditory nerve fibres, known as the afferent nerve fibres, carry information from the organ of Corti to the brainstem and ... The AVCN also contain cells with more complex firing patterns than bushy cells called multipolar cells, these cells have ... The type I fibres are thicker than the type II fibres and may also differ in how they innervate the inner hair cells. Neurons ...

Cochlear nerve

Type II neurons make up the remaining 5-10% of the neurons and innervate the outer hair cells. They have relatively small ... The peripheral axons of auditory nerve fibers form synaptic connections with the hair cells of the cochlea via ribbon synapses ... Each type I axon innervates only a single inner hair cell, but each inner hair cell is innervated by up to 30 such nerve fibers ... Type I neurons make up 90-95% of the neurons and innervate the inner hair cells. They have relatively large diameters, are ...

Organ of Corti

The organ of Corti is also capable of modulating the auditory signal. The outer hair cells (OHCs) can amplify the signal ... and one row of inner hair cells (IHCs). Separating these hair cells are supporting cells: Deiters cells, also called phalangeal ... known as hair cells. Strategically positioned on the basilar membrane of the organ of Corti are three rows of outer hair cells ... "Epithelial supporting cells can differentiate into outer hair cells and Deiters' cells in the cultured organ of Corti". ...

Hearing loss

One example is auditory neuropathy, a variety of hearing loss in which the outer hair cells of the cochlea are intact and ... A 2005 study achieved successful regrowth of cochlea cells in guinea pigs.[119] However, the regrowth of cochlear hair cells ... "Functional auditory hair cells produced in the mammalian cochlea by in utero gene transfer". Nature. 455 (7212): 537-41. ... using stem cells. Also reported in 2013 was regrowth of hair cells in deaf adult mice using a drug intervention resulting in ...

Sensory neuron

... inner and outer. The inner hair cells are the sensory receptors . Problems with sensory neurons associated with the auditory ... This mechanoelectrical transduction is mediated with hair cells within the ear. Depending on the movement, the hair cell can ... The five basic classes of neurons within the retina are photoreceptor cells, bipolar cells, ganglion cells, horizontal cells, ... which poison hair cells. Through the use of these toxins, the K+ pumping hair cells cease their function. Thus, the energy ...

Basilar membrane

... which are transmitted to the auditory pathway. The outer hair cells feed back energy to amplify the traveling wave, by up to 65 ... the hair cells that are equipped with "Stereocilia". There are approximately 15,000 hair cells in each human ear (see figure). ... lie about 3,500 inner hair cells spaced in a single row. Each cell is attached to a tiny triangular frame. The 'hairs' are ... Due to its location, the basilar membrane places the hair cells in a position where they are adjacent to both the endolymph and ...

Cochlear amplifier

... waves between rows of outer hair cells{?} Braun 1994 : Tuned hair cells for hearing, but tuned basilar membrane for overload ... The Physical Basis of the Action of the Cochlea Kemp 1978 : Stimulated acoustic emissions from within the human auditory system ... In the mammalian cochlea, amplification occurs in the outer hair cells of the Organ of Corti. These cells sit directly above a ... This, in turn, influences the deflection of the hair bundles of the inner hair cells. These cells are in contact with afferent ...

Electrocochleography

It is dominated by the outer hair cells of the organ of Corti. The magnitude of the recording is dependent on the proximity of ... The depolarized hair cell releases neurotransmitters across a synapse to primary auditory neurons of the spiral ganglion. Upon ... the hair cells attached to this membrane are rhythmically pushed up against the tectorial membrane, bending the hair cell ... particularly in patients who are hard of hearing Diagnosis of auditory neuropathy The basilar membrane and the hair cells of ...

Presbycusis

... it contains hair cells with stereocilia, which extend to the tectorial membrane. The organ's outer hair cells play a ... Auditory hair cell loss is permanent damage due to the inability of these cells to regenerate. Therefore, deafness due to this ... Hair cell development is mediated by Notch signaling, which exerts lateral inhibition onto hair cells. Notch signaling in ... If the outer hair cells are damaged, they do not regenerate. This results in a loss of sensitivity of hearing, as well as an ...

Auditory masking

Damage to the cochlea and the outer hair cells in the cochlea can impair the ability to tell sounds apart (Moore 1986). This ... Auditory masking occurs when the perception of one sound is affected by the presence of another sound. Auditory masking in the ... This can be explained by the auditory system having an auditory filter which is centered over the frequency of the tone. The ... which means they can hear the signal more clearly hence causing an improvement of auditory performance. Auditory masking is ...

Auditory system

Efferent synapses occur on outer hair cells and on afferent (towards the brain) dendrites under inner hair cells The cochlear ... Outer hair cells are a motor structure. Sound energy causes changes in the shape of these cells, which serves to amplify sound ... which is what elicits the hair cells' electrical responses. Inner hair cells, like the photoreceptor cells of the eye, show a ... There are far fewer inner hair cells in the cochlea than afferent nerve fibers - many auditory nerve fibers innervate each hair ...

Auditory fatigue

The outer hair cells, or OHCs, can be thought of as microamplifiers that provide stimulation to the inner hair cells. The OHCs ... The remainder of this article mainly references the cochlea, outer hair cells, and organ of Corti. In general, structural ... are the most fragile of the hair cells, hence their involvement in auditory fatigue and other hearing impairments. Temporary ... Auditory fatigue is defined as a temporary loss of hearing after exposure to sound. This results in a temporary shift of the ...

Olivocochlear system

The MOCS gives rise to a frequency-specific innervation of the cochlea, in that MOC fibres terminate on the outer hair cells at ... Apr 2000). "Auditory perception in vestibular neurectomy subjects". Hear Res. 142 (1-2): 102-12. doi:10.1016/S0378-5955(00) ... This enhancement may be caused by the activity of the MOCS on the outer hair cells resulting in antimasking. Although Scharf et ... Electrophysiological responses recorded from outer hair cells following ACh stimulation therefore show a small inward current ( ...

Neuronal encoding of sound

Cochlear hair cells are organized as inner hair cells and outer hair cells; inner and outer refer to relative position from the ... The auditory hair cells in the cochlea are at the core of the auditory system's special functionality (similar hair cells are ... Outer hair cells primarily provide amplification of traveling waves that are induced by sound energy, while inner hair cells ... Type II neurons can be physiologically manipulated to innervate inner hair cells provided outer hair cells have been destroyed ...

Auditory neuropathy

... (AN) is a variety of hearing loss in which the outer hair cells within the cochlea are present and ... the inner hair cells of the cochlea, the synapse between the inner hair cells and the auditory nerve, or a lesion of the ... Also known as auditory neuropathy/auditory dys-synchrony (AN/AD) or auditory neuropathy spectrum disorder (ANSD). A neuropathy ... Audiologist Auditory brainstem response Auditory neuropathy spectrum disorder Auditory processing disorder Cochlear implant ...

Peter Dallos

Properties of auditory nerve responses in the absence of outer hair cells, J.Neurophysiol. 41: 365-383 (1978) Dallos, P., J. ... notably 50-60 dB amplification by outer hair cells [2.7] First intracellular recordings from outer hair cells in vivo; first ... Absence of cochlear outer hair cells: Effect on behavioural auditory threshold, Nature 253: 44-46 (1975) Dallos, P. and D. ... Discovery that inner hair cells respond to basilar membrane velocity [2.6] Demonstration that in the absence of outer hair ...

KCNB1

... auditory outer hair cells, stem cells, the retina, and organs such as the heart and pancreas. Modulation of K+ channel activity ... In human pancreatic ß cells, KCNB1, which mediates potassium efflux, produces a downstroke of the action potential in the cell ... These neuronal modifications may explain the atrophy of cell layer volume and late stage cell death observed in HAD disease. ... Yang SN, Shi Y, Yang G, Li Y, Yu J, Berggren PO (November 2014). "Ionic mechanisms in pancreatic β cell signaling". Cellular ...

Critical band

When only the outer hair cells are damaged the filter is broader on the low frequency side. When both the outer and inner hair ... Auditory filters are closely associated with masking in the way they are measured and also the way they work in the auditory ... There are approximately between 15,000 and 16,000 of these hair cells in one ear. Outer hair cells have stereocilia projecting ... This is because the frequency selectivity and the tuning of the basilar membrane is reduced as the outer hair cells are damaged ...

Taicatoxin

... on the outer hair cells of guinea pig prevented the cell shortening induced by high K+ (50 mM) and the cell elongation induced ... "Biophysical and pharmacological characterization of voltage-gated calcium currents in turtle auditory hair cells". J. Physiol. ... TCX is involved in the outer hair cell motility too, by blocking the calcium traffic and preventing the cell shortening and ... "Taicatoxin inhibits the calcium-dependent slow motility of mammalian outer hair cells". Hear. Res. 203 (1-2): 172-9. doi: ...

Computational auditory scene analysis

Additional models of the hair cells include the Meddis hair cell model which pairs with the gammatone filter bank, by modeling ... Consisting of three areas, the outer, middle and inner ear, the auditory periphery acts as a complex transducer that converts ... Meddis, R., Hewitt, M., Shackleton, T. (1990). "Implementation details of a computational model of the inner hair-cell/auditory ... The axons of these cells make up the auditory nerve, encoding the rectified stimulus. The auditory nerve responses select ...

Tectorial membrane

It overlies the sensory inner hair cells and electrically-motile outer hair cells of the organ of Corti and during acoustic ... Of these the limbal zone is the thinnest (transversally) and overlies the auditory teeth of Huschke with its inside edge ... stimulation stimulates the inner hair cells through fluid coupling, and the outer hair cells via direct connection to their ... However, recent genetic , mechanical and mathematical studies have highlighted the importance of the TM for healthy auditory ...

Dirty drug

Kanamycin is an aminoglycoside antibiotic which induces deafness through blockage of the outer hair cells of the cochlea; yet ... Kanamycin requires close clinical supervision because of its potential toxicity and adverse side effects to the auditory and ...

Jonathan Ashmore

After a short postdoctoral research fellowship supervised by Abdus Salam[8] at the International Centre for Theoretical Physics in Trieste, Italy he retrained as a physiologist at UCL, gaining a Master of Science degree in 1974[2] which led to work with Paul Fatt and Gertrude Falk[12] between 1974 and 1977 in the Biophysics Department. Ashmore was appointed a Lecturer in Physiology at the University of Bristol in 1983 an promoted to Reader in 1988, before moving back to UCL in 1993.[8][2]. Ashmore has worked on dissecting the cellular mechanisms of hearing by studying the organ of Corti in the mammalian cochlea[13] especially the guinea pig (Cavia porcellus).[14][15] This structure in the inner ear increases the selectivity and sensitivity of our hearing through an in-built cochlear amplifier.[16] He showed that specialised cells known as outer hair cells are responsible for ...

Hair cell

Research on the regrowth of cochlear cells may lead to medical treatments that restore hearing. Unlike birds and fish, humans and other mammals are generally incapable of regrowing the cells of the inner ear that convert sound into neural signals when those cells are damaged by age or disease.[4][20] Researchers are making progress in gene therapy and stem-cell therapy that may allow the damaged cells to be regenerated. Because hair cells of auditory and vestibular systems in birds and fish have been found to regenerate, their ability has been studied at length.[4][21] In addition, lateral line hair cells, which have a mechanotransduction function, have been shown to regrow in organisms, such as the zebrafish.[22]. ...

Capacitance

Any two adjacent conductors can function as a capacitor, though the capacitance is small unless the conductors are close together for long distances or over a large area. This (often unwanted) capacitance is called parasitic or "stray capacitance". Stray capacitance can allow signals to leak between otherwise isolated circuits (an effect called crosstalk), and it can be a limiting factor for proper functioning of circuits at high frequency.. Stray capacitance between the input and output in amplifier circuits can be troublesome because it can form a path for feedback, which can cause instability and parasitic oscillation in the amplifier. It is often convenient for analytical purposes to replace this capacitance with a combination of one input-to-ground capacitance and one output-to-ground capacitance; the original configuration - including the input-to-output capacitance - is often referred to as a pi-configuration. Miller's theorem can be used to effect this replacement: it states that, if the ...

TECTA

Alpha-tectorin is a protein that in humans is encoded by the TECTA gene. The tectorial membrane is an extracellular matrix of the inner ear that contacts the stereocilia bundles of specialized sensory hair cells. Sound induces movement of these hair cells relative to the tectorial membrane, deflects the stereocilia, and leads to fluctuations in hair-cell membrane potential, transducing sound into electrical signals. Alpha-tectorin is one of the major noncollagenous components of the tectorial membrane. Mutations in the TECTA gene have been shown to be responsible for autosomal dominant nonsyndromic hearing impairment and a recessive form of sensorineural pre-lingual non-syndromic deafness. GRCh38: Ensembl release 89: ENSG00000109927 - Ensembl, May 2017 GRCm38: Ensembl release 89: ENSMUSG00000037705 - Ensembl, May 2017 "Human PubMed ...

Hair cell

Lateral line

The major unit of functionality of the lateral line is the neuromast. The neuromast is a mechanoreceptive organ which allows the sensing of mechanical changes in water. There are two main varieties of neuromasts located in animals, canal neuromasts and superficial or freestanding neuromasts. Superficial neuromasts are located externally on the surface of the body, while canal neuromasts are located along the lateral lines in subdermal, fluid filled canals. Each neuromast consists of receptive hair cells whose tips are covered by a flexible and jellylike cupula. Hair cells typically possess both glutamatergic afferent connections and cholinergic efferent connections.[12] The receptive hair cells are modified epithelial cells and typically possess bundles of 40-50 microvilli ...

Ribbon synapse

The ribbon synapse is a type of neuronal synapse characterized by the presence of an electron-dense structure, the synaptic ribbon, that holds vesicles close to the active zone. It is characterized by a tight vesicle-calcium channel coupling that promotes rapid neurotransmitter release and sustained signal transmission. Ribbon synapses undergo a cycle of exocytosis and endocytosis in response to graded changes of membrane potential. It has been proposed that most ribbon synapses undergo a special type of exocytosis based on coordinated multivesicular release. This interpretation has recently been questioned at the inner hair cell ribbon synapse, where it has been instead proposed that exocytosis is described by uniquantal (i.e., univesicular) release shaped by a flickering vesicle fusion pore. These unique features specialize the ribbon synapse to enable extremely fast, precise and sustained neurotransmission, which is critical for the perception of complex senses such as ...

Artificial hair integrations

... , more commonly known as hair extensions or hair weaves, add length and/or fullness to human hair. Hair extensions are usually clipped on to other hair by incorporating additional human or synthetic hair. Natural human hair can be permed, dyed, and flat ironed whereas synthetic hair cannot. The methods include tape in extensions, clip in or clip on extensions, fusion method, weaving method, and wigs. A hair weave is human or artificial hair utilized for the integration with one's natural hair. Weaves can alter one's appearance for long or short periods of time by adding further hair to one's natural ...

STRC

Stereocilin is a protein that in humans is encoded by the STRC gene. This gene encodes a protein that is associated with the hair bundle of the sensory hair cells in the inner ear. The hair bundle is composed of stiff microvilli called stereocilia and is involved with mechanoreception of sound waves. This gene is part of a tandem duplication on chromosome 15; the second copy is a pseudogene. Mutations in this gene cause autosomal recessive non-syndromic deafness. GRCh38: Ensembl release 89: ENSG00000242866 - Ensembl, May 2017 GRCm38: Ensembl release 89: ENSMUSG00000033498 - Ensembl, May 2017 "Human PubMed Reference:". "Mouse PubMed Reference:". Verpy E, Masmoudi S, Zwaenepoel I, Leibovici M, Hutchin TP, Del Castillo I, Nouaille S, Blanchard S, Laine S, Popot JL, Moreno F, Mueller RF, Petit C (Nov 2001). "Mutations in a new gene encoding a protein of the ...

Semicircular canals

The semicircular ducts provide sensory input for experiences of rotary movements. They are oriented along the pitch, roll, and yaw axes. Each canal is filled with a fluid called endolymph and contains motion sensors within the fluids. At the base of each canal, the bony region of the canal is enlarged which opens into the utricle and has a dilated sac at one end called the osseous ampullae. Within the ampulla is a mound of hair cells and supporting cells called crista ampullaris. These hair cells have many cytoplasmic projections on the apical surface called stereocilia which are embedded in a gelatinous structure called the cupula. As the head rotates the duct moves but the endolymph lags behind owing to inertia. This deflects the cupula and bends the stereocilia within. The bending of these stereocilia alters an electric signal that is ...

Semicircular canals

Abdominal hair

... is the hair that grows on the abdomen of humans and non-human mammals, in the region between the pubic area and the thorax (chest). The growth of abdominal hair follows the same pattern on nearly all mammals, vertically from the pubic area upwards and from the thorax downwards to the navel. The abdominal hair of non-human mammals is part of the pelage, (hair or fur). Before puberty, the abdominal region of both males and females is covered with very fine vellus hair. In response to rising levels of androgens (mainly testosterone) during and after puberty, the skin of the abdomen begins to produce coarser, longer and more pigmented hair (terminal hair). This process primarily affects men. Initially hair grows in a vertical line from the ...

Hair care

Genetics and health are factors in healthy hair. Proper nutrition is important for hair health. The living part of hair is under the scalp skin where the hair root is housed in the hair follicle. The entire follicle and root are fed by a supply of arteries, and blood carries nutrients to the follicle/root. Any time an individual has any kind of health concern from stress, trauma, medications of various sorts, chronic medical conditions or medical conditions that come and then wane, heavy metals in waters and food, smoking etc. these and more can affect the hair, its growth, and its appearance. Generally, eating a full diet that contains protein, fruits, vegetables, fat, and carbohydrates is important (several vitamins and minerals require fat in order to be delivered or absorbed by the body). Any deficiency ...

Auditory Neuropathy Spectrum Disorder (ANSD)

Some kids have hearing loss due to auditory neuropathy spectrum disorder (ANSD), a problem in the transmission of sound from ... the outer hair cells contract back and forth and amplify the sound. When the vibrations are big enough, the inner hair cells ... but because of damage to the inner row of hair cells or synapses between the inner hair cells and the auditory nerve, or damage ... Often it can help when the outer hair cells dont work as they should and cant amplify sound. In some cases of ANSD, hearing ...

kidshealth.org

Effect of absence of cochlear outer hair cells on behavioural auditory threshold. - PubMed - NCBI

Effect of absence of cochlear outer hair cells on behavioural auditory threshold.. Ryan A, Dallos P. ...

ncbi.nlm.nih.gov

Study of cochlear microphonic potentials in auditory neuropathy

The CM is a potential generated from the outer hair cells (OHC) and inner hair cells (IHC) of the cochlea and its absence is ... outer hair cells; IHC, inner hair cells; CAP, Composite Action Potential. ... Describe a new form of hearing dysfunction characterized by absent ABR, with evidence of function of the outer hair cells of ... Brief report: the cochlear microphonic as an indication of outer hair cell function. Ear Hear. 2001;22:75-7. [ Links ] ...

scielo.br

Frontiers | GC-B Deficient Mice With Axon Bifurcation Loss Exhibit Compromised Auditory Processing | Frontiers in Neural...

However, efferent cholinergic feedback to inner and outer hair cells was reduced in GC-B KO mice, linked to very likely reduced ... However, efferent cholinergic feedback to inner and outer hair cells was reduced in GC-B KO mice, linked to very likely reduced ... In the inner ear, the cochlear hair cells in GC-B KO mice were nevertheless similar to those from wildtype mice, justified by ... In the inner ear, the cochlear hair cells in GC-B KO mice were nevertheless similar to those from wildtype mice, justified by ...

frontiersin.org

Olivocochlear suppression of outer hair cells in vivo: evidence for combined action of BK and SK2 channels throughout the...

Hair Cells, Auditory, Outer/metabolism. *Hair Cells, Auditory, Outer/physiology*. *Large-Conductance Calcium-Activated ... Olivocochlear suppression of outer hair cells in vivo: evidence for combined action of BK and SK2 channels throughout the ... Olivocochlear suppression of outer hair cells in vivo: evidence for combined action of BK and SK2 channels throughout the ... Olivocochlear suppression of outer hair cells in vivo: evidence for combined action of BK and SK2 channels throughout the ...

ncbi.nlm.nih.gov

Auditory Neuropathy Spectrum Disorder (ANSD)

... the outer hair cells contract back and forth and amplify the sound. When the vibrations are big enough, the inner hair cells ... but because of damage to the inner row of hair cells or synapses between the inner hair cells and the auditory nerve, or damage ... Often it can help when the outer hair cells dont work as they should and cant amplify sound. In some cases of ANSD, hearing ... Otoacoustic emission (OAE): This test measures how well the outer hair cells in the cochlea function. Its done when the child ...

kidshealth.org

Age-Related Cochlear Synaptopathy: An Early-Onset Contributor to Auditory Functional Decline | Journal of Neuroscience

1978) Properties of auditory nerve responses in absence of outer hair cells. J Neurophysiol 41:365-383, pmid:650272. ... 2008) in The senses: a comprehensive reference, Perspectives on auditory neuropathy: disorders of inner hair cell, auditory ... 2005) Hair cell synaptic ribbons are essential for synchronous auditory signalling. Nature 434:889-894, doi:10.1038/nature03418 ... 2002) Prestin is required for electromotility of the outer hair cell and for the cochlear amplifier. Nature 419:300-304, doi: ...

jneurosci.org

Observations on Structure and Function of the Olivocochlear Projections in Cat | SpringerLink

Auditory Nerve Outer Hair Cell Efferent Terminal Efferent Innervation Classic Terminal These keywords were added by machine and ... Kimura, R.S. and Wersall, I. (1962) Termination of the olivocochlear bundle in relation to the outer hair cells of the organ of ... Bredberg, G. (1977) Ultrastructural features of the small nerve endings high up on the outer hair cells. In: Psychophysics and ... a system of relatively large myelinated fibers whose major peripheral target is the bases of outer hair cells (OHCs) [Kimura ...

link.springer.com

Federal Register :: Takes of Marine Mammals Incidental to Specified Activities; Pile Placement for Fishermen's...

Irreparable damage to the inner or outer cochlear hair cells may cause PTS; however, other mechanisms are also involved, such ... PTS is considered auditory injury (Southall et al., 2007) and occurs in a specific frequency range and amount. ... Each foundation would consist of a three-legged structure, made up of three hollow steel pipes with an outer diameter of about ... NMFS considers TTS as Level B harassment that is mediated by physiological effects on the auditory system; however, NMFS does ...

federalregister.gov

Federal Register :: Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental...

Irreparable damage to the inner or outer cochlear hair cells may cause PTS; however, other mechanisms are also involved, such ... NMFS considers TTS as Level B harassment that is mediated by physiological effects on the auditory system; however, NMFS does ... Based on available behavioral data, audiograms have been derived using auditory evoked potentials, anatomical modeling, and ... though animals are less sensitive to sounds at the outer edge of their functional range Start Printed Page 16306and most ...

federalregister.gov

'auditory cortex' Protocols and Video...

Auditory Brainstem Response and Outer Hair Cell Whole-cell Patch Clamp Recording in Postnatal Rats, The Use of Magnetic ... auditory cortex include Functional Imaging of Auditory Cortex in Adult Cats using High-field fMRI, Mapping the After- ... an Auditory Attention Example, Behavioral Determination of Stimulus Pair Discrimination of Auditory Acoustic and Electrical ... Infant Auditory Processing and Event-related Brain Oscillations, Vagus Nerve Stimulation as a Tool to Induce Plasticity in ...

jove.com

000152 - B6(Cg)-Cys1|cpk|/J

absent cochlear outer hair cells*in the upper portion of the first turn of the cochlea outer hair cells are absent ... increased or absent threshold for auditory brainstem response*hearing is impaired with auditory evoked potential indicating ... absent cochlear outer hair cells*in the upper portion of the first turn of the cochlea outer hair cells are absent ... in the second cochlear turn the inner and outer hair cells are normal but debris is seen in Nuels space and the outer pillar ...

jax.org

Box 9.1 Biophysics of Outer Hair Cells.. Box 9.2 Genetics and Deafness. ... 10.3 The Avian Auditory Pathway and the Mapping of Auditory Space by the Barn Owl. ... These show the similarities in the molecular architecture and in the physiology of sensory cells across species and across ... Chapter 9: Equilibrium and Hearing: The Uses of Hair Cells.. 9.1 Anatomy and Physiology of Hair Cells. ...

wiley.com

CLI Midterm Flashcards

Inner Hair Cells. Definition. receives mechanical vibrations from outer hair cells, converts mechanical energy into neural ... Outer Ear:. Auditory Canal (Ear Canal). Definition. closed duct (or pipe) terminated by the tympanic membrane; generates ... Outer Hair Cells. Definition. referred to as the cochlear amplifier, provides sharper tuning of audio signals; increases ... membrane separating two fluid-filled tubes along the length of the cochlea; serves as a base for auditory sensory cells; ...

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Supra-Threshold Hearing and Fluctuation Profiles: Implications for Sensorineural and Hidden Hearing Loss | SpringerLink

An important topic in contemporary auditory science is supra-threshold hearing. Difficulty hearing at conversational speech ... Mechanoelectrical transduction in auditory hair cells. In: Eatock RA, Fay RR (eds) Vertebrate hair cells. Springer, New York, ... Dallos P (1986) Neurobiology of cochlear inner and outer hair cells: intracellular recordings. Hear Res 22:185-198Google ... Russell IJ, Richardson GP, Cody AR (1986) Mechanosensitivity of mammalian auditory hair cells in vitro. Nature 321:517-519 ...

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Hearing Flashcards by Brooke Ward | Brainscape

Auditory receptors: inner and outer hair cells. 12 Where do the inner and outer hair cells sit in relation to other inner ear ... Describe the difference in function between the inner and outer hair cells? ... Describe how opening and closing of K channels within a hair cell is achieved? ... Briefly describe how different elements of the anatomy of the auditory system are involved in sound perception? ...

brainscape.com

Free Speech Therapy Flashcards about Audiology

If you were to lose all of your outer hair cells. there would be about a 40 to 50 dB hearing loss. ... The auditory brainstem response (ABR). is abnormal, often absent, when a tumor is present in the internal auditory meatus. ... Removing hair cells would result in. sensorineural hearing loss. The elastic pressure release for inward motions of the ... The structure important for shearing the hair cell stereocilia is the. tectorial membrane. ...

studystack.com

Center for Hearing and Balance

Electron microscopy (EM) reconstructions of an auditory outer hair cell (Fuchs lab) ... The Center for Hearing and Balance faculty provides a comprehensive course on Structure and Function of the Auditory and ... Research is centered on auditory (hearing) and vestibular (balance) function in normal subjects and in patients with hearing or ...

hopkinsmedicine.org

Newborn Infant Hearing Screening: Key Issues

... auditory neuropathy). Auditory neuropathy is a neural hearing loss that leaves cochlear (outer hair cell) function intact. It ... OAEs are not sensitive to disorders central to the outer hair cells, such as auditory neuropathy. OAEs will be absent when ... OAEs are a direct measure of outer hair cell and cochlear function in response to acoustic stimulation. They yield an indirect ... Auditory Brainstem Response (ABR) ABR activity is a direct measurement of the neural response to sound that is generated along ...

asha.org

002267 - STOCK Bdnf|tm1Jae|/J

loss of outer hair cell innervation in the apex, middle and basal turns of the cochlea ... Normal - mice respond to auditory stimuli. (MGI Ref ID J:17123). *nervous system phenotype*Normal - no differences are seen in ... Normal - innervation of the cochlear inner and outer hair cells appears similar to controls ... abnormal type I vestibular cell*no nerve chalicies are found associated with type I hair cells of the vestibule ...

jax.org

CG-MED-49 Auditory Brainstem Responses (ABRs) and Evoked Otoacoustic Emissions (OAEs) for Hearing Disorders

Auditory neuropathy: A type of hearing impairment where outer hair cell function is normal but neural transmission in the ... OAE measures the preneural status of the peripheral auditory system to the outer hair cells of the inner ear (cochlea). OAE may ... TEOAEs reflecting cochlear (outer hair cell) activity are generally recorded across a frequency range of 500 to approximately ... Conversely, because OAEs originate from the outer hair cells of the cochlea; virtually any insult to the cochlea ranging from ...

unicare.com

Audiology | Faculty | Department of Otolaryngology | CWRU

Outer hair cells, one of the two types of auditory hair cell in mammalian cochlea, rely on mobile calcium buffers and plasma ... outer hair cells. Generally, hearing loss occurs at the higher frequencies first, and it is basal outer hair cells, which are ... Fast adaptation and Ca2+-sensitivity of the mechanotransducer require myosin-XVa in inner but not outer cochlear hair cells. ... TRPA1-mediated accumulation of aminoglycosides in mouse cochlear outer hair cells. J Assoc Res Otolaryngol. 2011. 12(6):729-40. ...

casemed.case.edu

Selective Ablation of Pillar and Deiters' Cells Severely Affects Cochlear Postnatal Development and Hearing in Mice | Journal...

1996) Mechanical properties of the lateral cortex of mammalian auditory outer hair cells. Biophys J 71:421-429. ... IHC, inner hair cell; IPC, inner PC; OPC, outer PC; GER, greater epithelial ridge; HeC, Hensen cell. B, Representative optical ... 1985) Outer hair cell loss and supporting cell expansion following chronic gentamicin treatment. Hear Res 19:171-182. ... 1999) KCNQ4, a novel potassium channel expressed in sensory outer hair cells, is mutated in dominant deafness. Cell 96:437-446. ...

jneurosci.org

Open Access Animal Physiology - Dove Press Open Access Publisher

Auditory sensitivity and the outer hair cell system in the CBA mouse model of age-related hearing loss Robert D Frisina, ... Auditory selectivity for the acoustic properties of conspecific mate-attracting signals in lower vertebrates and songbirds ...

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Frontiers | Non-Monotonic Relation between Noise Exposure Severity and Neuronal Hyperactivity in the Auditory Midbrain |...

The model is based on previous models of the effects of loss of inner and outer hair cells and damage to hair cell stereocilia ... Dallos P, Harris D. Properties of auditory nerve responses in absence of outer hair cells. J Neurophysiol (1978) 41:365-83. ... The degree of outer hair cell loss, for example, only shows a moderate correlation to hearing threshold shifts (14), and ... The gray lines show the effects of 13.3, 26.7, and 40 dB threshold increase through damage to outer hair cells. (C) Color coded ...

frontiersin.org

These findings suggest that GC-B-controlled axon bifurcation of spiral ganglion neurons is important for proper activation of second-order neurons in the hindbrain and is a prerequisite for proper temporal auditory processing likely by establishing accurate efferent top-down control circuits. (frontiersin.org)
Immunostained cochlear whole mounts and plastic-embedded sections were studied by confocal and conventional light microscopy to quantify hair cells, cochlear neurons, and synaptic structures, i.e., presynaptic ribbons and postsynaptic glutamate receptors. (jneurosci.org)
It has been known for decades that loss of auditory nerve fibers, the primary sensory neurons connecting the hair cells to the auditory brainstem, need not affect threshold sensitivity when the degeneration is diffusely distributed along the cochlear spiral ( Schuknecht and Woellner, 1953 ). (jneurosci.org)
More recently, thresholds were shown to be insensitive to widespread loss of the inner hair cell (IHC) synapses of these neurons that can occur after noise exposures causing only temporary threshold elevations ( Kujawa and Liberman, 2009 ). (jneurosci.org)
Guinan, J.J. and Gifford, M.L. (1988) Effects of eleclrical stimulation of efferent olivocochlear neurons in cat auditory nerve fiberslIl.Tuning curves and thresholds at CF. Hearing Res. (springer.com)
It has been proposed that when HCs are irreversibly damaged by noise or ototoxic drugs, surrounding SCs seal the epithelial surface and likely extend the survival of auditory neurons. (jneurosci.org)
Sound coding with current prostheses is based on electrical stimulation of auditory neurons and has limited frequency resolution due to broad current spread within the cochlea. (jci.org)
Optogenetic stimulation of spiral ganglion neurons (SGNs) activated the auditory pathway, as demonstrated by recordings of single neuron and neuronal population responses. (jci.org)
Exposure to loud sound damages the postsynaptic terminals of spiral ganglion neurons (SGNs) on cochlear inner hair cells (IHCs), resulting in loss of synapses, a process termed synaptopathy. (pnas.org)
Spiral ganglion neurons (SGNs) are bipolar neurons in the cochlea that conduct auditory information from the sensory hair cells to the brain. (pnas.org)
Furthermore, pRb −/− hair cells are able to transduce mechanical stimuli and appear capable of forming synapses with ganglion neurons. (pnas.org)
Clinical Applications Individuals with sensorineural hearing loss (SNHL) have lost the function of most cochlear hair cells , although some of the cochlear neurons remain and are functional. (thefreedictionary.com)
The cochlea is innervated by neurons that relay sound information from hair cells to central auditory targets. (biologists.org)
Type II neurons make a distinctive 90° turn towards the cochlear base to synapse with 10-15 outer hair cells. (biologists.org)
Discovering the roles of inner hair cells (IHCs), outer hair cells (OHCs), and auditory neurons in speech understanding in quiet and in the presence of background noise is currently a hot topic in the scientific community. (lww.com)
Sensorineural (nerve) deafness is loss of auditory function because of loss of cochlear hair cells or auditory nerve neurons. (vin.com)
Neurons in the cochlear efferent system communicate with the sensory hair cells by releasing the chemical acetylcholine. (webwire.com)
Type I neurons make up 90-95% of the neurons and innervate the inner hair cells. (wikipedia.org)
Type II neurons make up the remaining 5-10% of the neurons and innervate the outer hair cells. (wikipedia.org)
At later developmental stages, Gfi1 expression in the ear is refined to the hair cells and neurons throughout the inner ear. (biologists.org)

Olivocochlear suppression of outer hair cells in vivo: evidence for combined action of BK and SK2 channels throughout the cochlea. (nih.gov)
The inner ear is made up of a snail-shaped chamber called the cochlea , which is filled with fluid and lined with four rows of tiny hair cells. (kidshealth.org)
Cochlear synaptic loss progresses from youth (4 weeks) to old age (144 weeks) and is seen throughout the cochlea long before age-related changes in thresholds or hair cell counts. (jneurosci.org)
Hashimoto, S., Kimura, R.S. and Takasaka, T. (1990) Computer-aided three-dimensional reconstrucon of the inner hair cells and their nerve endings in the guinea pig cochlea. (springer.com)
Outer hair cells, one of the two types of auditory hair cell in mammalian cochlea, rely on mobile calcium buffers and plasma membrane calcium pumps to regulate calcium levels. (case.edu)
OAE measures the preneural status of the peripheral auditory system to the outer hair cells of the inner ear (cochlea). (unicare.com)
ABR measures the neural status of the cochlea, the auditory nerve, may be used to and assess auditory neuropathy. (unicare.com)
Prestin is the motor protein of the outer hair cells of the inner ear of the mammalian cochlea. (wikipedia.org)
It is specifically expressed in the lateral membrane of outer hair cells (OHCs) of the cochlea. (wikipedia.org)
In mammals , the auditory hair cells are located within the spiral organ of Corti on the thin basilar membrane in the cochlea of the inner ear . (wikipedia.org)
The human cochlea contains on the order of 3,500 inner hair cells and 12,000 outer hair cells at birth. (wikipedia.org)
The outer hair cells mechanically amplify low-level sound that enters the cochlea . (wikipedia.org)
The inner hair cells transform the sound vibrations in the fluids of the cochlea into electrical signals that are then relayed via the auditory nerve to the auditory brainstem and to the auditory cortex . (wikipedia.org)
Background]Notch signaling plays a crucial role in the fate determination of cochlear progenitor cells, hair cells, and supporting cells in the developing cochlea. (nii.ac.jp)
Defining the cellular environment in the organ of Corti following extensive hair cell loss: a basis for future sensory cell replacement in the Cochlea. (biomedsearch.com)
BACKGROUND: Following the loss of hair cells from the mammalian cochlea, the sensory epithelium repairs to close the lesions but no new hair cells arise and hearing impairment ensues. (biomedsearch.com)
In the cochlea, the sound waves are detected by hair cells and perceived as sound. (ndcs.org.uk)
Those vibrations stimulate the hair cells of the cochlea, a pea-sized, spiral-shaped structure deep in the inner ear. (unc.edu)
The cochlea sends signals to the auditory nerve which are transmitted to the brain where sounds are interpreted. (unc.edu)
But when their inner ear fluids are stimulated, the hair cells of the cochlea do not respond or have such a limited response that electrical signals are prevented from reaching the brain. (unc.edu)
The passageways of the cochlea are lined with over 15,000 microscopic haircells (called inner and outer hair cells) that convert sound vibrations from the ossicles into nerve pulses which are then sent to the brain. (hearingdirect.com)
The ear, the middle ear, the outer ear, the middle ear and the cochlea. (coursera.org)
The vibrations move through the fluid in the cochlea in the inner ear, stimulating thousands of tiny hair cells. (hear-it.org)
We demonstrate that this axon turning event requires planar cell polarity (PCP) signaling and is disrupted in Vangl2 and Celsr1 knockout mice, and that VANGL2 acts non-autonomously from the cochlea to direct turning. (biologists.org)
Hair cells, basilar membrane, the cochlea and others are all tools which the brain uses in order to translate the outer world into neuronal activity. (coursera.org)
Sudden unilateral hearing loss may result from etiologies affecting cochlea, eighth nerve, or more central auditory tracts. (biomedsearch.com)
A hair cell bundle consists of stereocilia rows with precisely graded heights according to the cell's location along the cochlea, suggesting that the exact shape of the bundle is crucial for the normal function of the hair cell ( Engström and Engström, 1978 ). (elifesciences.org)
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. (usf.edu)
Receptor cells in the cochlea have structures known as stereocilia (S) at their apex. (usf.edu)
The fluids of the cochlea bend the receptors of tiny hair cells, triggering electrical signals in the auditory nerve, which travel to the brain. (healthyhearing.com)
In the presence of sounds that are too loud, the vibrations get larger, causing fluid motion in the cochlea that can bend the hair cells to the point of breaking. (healthyhearing.com)
The ear has three compartments: (1) the outer ear, including the pina and the ear canal down to the tympanic membrane, (2) the air-filled middle ear, including the three ossicles (malleus, incus, and stapes) and the connection to the pharynx (the auditory canal), and (3) the fluid-filled inner ear or cochlea, which contains the organ of Corti and the initial portion of the auditory nerve. (vin.com)
Conductive deafness is blockage of sound transmission through the outer and/or middle ear without damage to the cochlea. (vin.com)
Primary deafness results from destruction of hair cells in the cochlea without antecedent events. (vin.com)
Secondary deafness occurs when hair cells die as a consequence of other damage in the cochlea, most commonly to the stria vascularis. (vin.com)
The stapes footplate transmits these sounds into the fluids of the cochlea, where three outer sets and one inner set of hair cells bend in response and create a charge that stimulates the nerve endings on the bottom of each cell. (nydailynews.com)
Hair cells in the cochlea can be damaged by various causes. (hindawi.com)
Tiny hair cells in the cochlea of the inner ear transform the mechanical vibrations of sound into neural impulses that travel to the auditory center of the brain. (webwire.com)
Specifically, we are interested in agents that block or enhance the action of receptors on outer hair cells of the cochlea, which enhance hearing and decrease hearing loss. (rochester.edu)
To design and discover agents that block or enhance receptor action on cochlear outer hair cells, we are cloning neurotransmitter receptors expressed in the hair cells, and modulating expression of these receptors by viral-mediated gene transfer into the cochlea. (rochester.edu)
Sound entering the cochlea is detected by the vibration of tiny, hair-like cilia that extend from cochlear hair cells. (biologynews.net)
The main site of damage is the outer hair cells but damage may occur to the inner hair cells, type I cells in the spiral ganglion, the stria vascularis and cochlea nerve. (starship.org.nz)
The cochlear nerve carries auditory sensory information from the cochlea of the inner ear directly to the brain . (wikipedia.org)
The peripheral axons of auditory nerve fibers form synaptic connections with the hair cells of the cochlea via ribbon synapses using the neurotransmitter glutamate . (wikipedia.org)
The cell bodies of the cochlear nerve lie within the cochlea and collectively form the spiral ganglion , named for the spiral shape it shares with the cochlea. (wikipedia.org)
Each type I axon innervates only a single inner hair cell, but each inner hair cell is innervated by up to 30 such nerve fibers, depending on species and location within the cochlea. (wikipedia.org)
The receptors (hair cells) are arranged in several rows along the length of the basilar membrane, one of the two partitions which spiral around the bony cochlea. (insulation.org)
In the cochlea, mechanical energy from sound pressure is transformed into electrical energy that is carried by the auditory nerve to the brain. (insulation.org)
Although Gfi1 -deficient mice initially specify inner ear hair cells, these hair cells are disorganized in both the vestibule and cochlea. (biologists.org)
The outer hair cells of the cochlea are improperly innervated and express neuronal markers that are not normally expressed in these cells. (biologists.org)

While it is known that increased hearing thresholds can trigger increases in spontaneous neural activity in the central auditory system, i.e., a putative neural correlate of tinnitus, the central effects of HHL have not yet been investigated. (frontiersin.org)
Our results demonstrate that HHL is sufficient to induce changes in central auditory processing, and they also indicate a non-monotonic relationship between cochlear damage and neuronal hyperactivity, suggesting an explanation for why tinnitus might occur without obvious hearing loss and conversely why hearing loss does not always lead to tinnitus. (frontiersin.org)
942 words - 4 pages Auditory Processing Disorder (APD), also known as central auditory processing disorder (CAPD), is a neurological defect that affects how the brain processes spoken language. (brightkite.com)
These several projections show the complexity of the connections in the central auditory system. (brightkite.com)
These structures convert the mechanical energy of sound to an electrochemical signal that can be processed by the peripheral and central auditory nerves. (usf.edu)
Loss of the Cochlear Amplifier Prestin Reduces Temporal Processing Efficacy in the Central Auditory System. (rochester.edu)
The cochlear nucleus is the first 'relay station' of the central auditory system and receives mainly ipsilateral afferent input. (wikipedia.org)

To better understand this variability in outcomes, the authors used functional near-infrared spectroscopy to image activity within regions of the auditory cortex and compare the results to behavioral measures of speech perception.The authors studied 32 deaf adults hearing through cochlear implants and 35 normal-hearing controls. (stanford.edu)
Auditory cortex activation to natural speech and simulated cochlear implant speech measured with functional near-infrared spectroscopy. (stanford.edu)
We used a 140 channel fNIRS system to measure activation within the auditory cortex in 19 normal hearing subjects while they listed to speech with different levels of intelligibility. (stanford.edu)
That is the signal that the auditory nerve carries up to the brain and cortex, which decodes the noise into what we recognize as the cry of a baby, the lunch whistle or the rapping of LL Cool J. While "use it or lose it" is the creed for maintaining muscle strength, the cochlea's nerve cells burn out with repeated stress. (nydailynews.com)

Immunolocalization shows prestin is expressed in the lateral plasma membrane of the outer hair cells, the region where electromotility occurs. (wikipedia.org)
The expression pattern correlates with the appearance of outer hair cell electromotility. (wikipedia.org)
Prestin is a transmembrane protein that mechanically contracts and elongates leading to electromotility of outer hair cells (OHC). (wikipedia.org)
Although previously thought to be absent, anion transport has also been shown to be an important aspect of prestin's ability to drive electromotility of hair cells. (wikipedia.org)
In the inner ear, regulates sound transduction and auditory neurotransmission, outer hair cell electromotility, inner ear gap junctions, and K(+) recycling. (nih.gov)
Prestin is a "motor" protein that gives rise to electromotility in outer hair cells. (yale.edu)
Prestin is a membrane protein necessary for outer hair cell (OHC) electromotility and normal hearing. (sigmaaldrich.com)
and 2) elucidation of the structural and molecular basis of electromotility, a voltage-dependent force-generating mechanism present in cochlear outer hair cells. (nih.gov)
Water permeability of cochlear outer hair cells: characterization and relationship to electromotility. (nih.gov)

Fast outer hair cell motility : how fast is fast? (nii.ac.jp)
There exists two and possibly three kinds of motility of the outer hair cells (OHC). (springer.com)
Sound-induced motility of isolated cochlear outer hair cells is frequency-specific. (springer.com)
Potassium-depolarization induces motility in isolated outer hair cells by an osmotic mechanism. (springer.com)
Members of this family are structurally well conserved and can mediate the electroneutral exchange of chloride and carbonate across the plasma membrane of mammalian cells, two anions found to be essential for outer hair cell motility. (wikipedia.org)
The amplification may be powered by the movement of their hair bundles, or by an electrically driven motility of their cell bodies. (wikipedia.org)
Its an unusual phenomenon in that motility in outer hair cells can be rapid, upto 20KHz, which is orders of magnitude faster than conventional motor proteins like myosin. (yale.edu)
Specifically, they wanted to distinguish between two amplification theories-called "stereociliary motility" and "somatic motility"-that have resulted from previous studies of the auditory machinery. (biologynews.net)
The somatic motility theory proposes that the sound signal is amplified by an amplifier protein, called prestin, embedded in the hair cell membrane. (biologynews.net)
This motility is also called 'dancing' because when you electrically stimulate an outer hair cell with a sound, the cell body spontaneously elongates and contracts along with the sound," said Jian Zuo, Ph.D., associate member of the St. Jude Department of Development Neurobiology. (biologynews.net)
While the knockout experiments were strong evidence for the role of somatic motility, the affected mice also showed structural abnormalities in their outer hair cells, Zuo said, thus complicating the interpretation. (biologynews.net)
The new experiments, Zuo said, thus firmly establish that the "dancing" somatic motility of the outer hair cells is critical to cochlear amplification. (biologynews.net)
He did postdoctoral research on membrane structure and intercellular junctions with Pedro Pinto da Silva at the NCI and cell structure and motility with Thomas Reese at the NINDS. (nih.gov)
and in 1983, motility was shown in outer hair cells. (foyles.co.uk)

Auditory Neuropathy/Dyssynchrony is a disorder characterized by the presence of Otoacoustic Emissions and Cochlear Microphonic Potentials, an absence or severe alteration of Brainstem Evoked Auditory Potential, auditory thresholds incompatible with speech thresholds and altered acoustic reflexes. (scielo.br)
Determine the characteristics of the Cochlear Microphonic in Auditory Neuropathy/Dyssynchrony using an integrative review. (scielo.br)
The presence of the Cochlear Microphonic is a determining finding in the differential diagnosis of Auditory Neuropathy/Dyssynchrony. (scielo.br)
The amplitude of the Cochlear Microphonic in Auditory Neuropathy/Dyssynchrony shows no significant difference from that of normal individuals. (scielo.br)
The duration of the Cochlear Microphonic is longer in individuals with Auditory Neuropathy/Dyssynchrony. (scielo.br)
Some cases are due to auditory neuropathy spectrum disorder (ANSD), a problem in the transmission of sound from the ear's innermost part (the inner ear) to the brain. (kidshealth.org)
The definition has been expanded from congenital permanent bilateral, unilateral sensory, or permanent conductive hearing loss to include neural hearing loss (eg, "auditory neuropathy/dyssynchrony") in infants admitted to the NICU. (aappublications.org)
Auditory neuropathy (AN) is when the nerve system of the inner ear doesn't process sounds coming from the outer ear. (denverhealth.org)
Admission to a neonatal intensive care unit is an established risk factor for hearing loss in infants, particularly for auditory neuropathy . (cps.ca)
Prenatal low dosage dioxin (TCDD) exposure impairs cochlear function resulting in auditory neuropathy. (rochester.edu)
Objectives Aetiological assessment of 71 probands whose clinical presentation suggested a genetic syndrome or auditory neuropathy. (bmj.com)
Conclusions DNA sequencing in patients whose clinical presentation suggested a genetic syndrome or auditory neuropathy provided opportunities for aetiological assessment and more precise genetic counselling of patients and families. (bmj.com)

Finally, the acoustic startle response (ASR) - one of the fastest auditory responses - and the prepulse inhibition of the ASR indicated significant changes in temporal precision of auditory processing. (frontiersin.org)
Cochlear hair cell and neuronal function was assessed via distortion product otoacoustic emissions and auditory brainstem responses, respectively. (jneurosci.org)
Warren, E.H. and Liberman, M.C. (1989) Effects of contralateral sound on auditory nerve responses.I.Conlributions of cochlear efferents. (springer.com)
This document addresses the use of auditory brainstem responses (ABRs) and evoked otoacoustic emissions (OAEs) for the evaluation of hearing disorders. (unicare.com)
Deafferentation of ANFs was confirmed through measurement of auditory brainstem responses and cochlear immunohistochemistry. (frontiersin.org)
Evoked mechanical responses isolated cochlear outer hair cells. (springer.com)
Measurements of auditory brainstem responses revealed better hearing in the MDL28170-treated animals than in the vehicle controls. (nii.ac.jp)
A phenomenological model was developed to describe responses of high-spontaneous-rate auditory-nerve (AN) fibers, including several nonlinear response properties. (yale.edu)
1 . Zhang X, Heinz MG, Bruce IC, Carney LH (2001) A phenomenological model for the responses of auditory-nerve fibers: I. Nonlinear tuning with compression and suppression. (yale.edu)

However, previous work has uncovered widespread loss of cochlear afferent synapses and progressive cochlear nerve degeneration in noise-exposed ears with recovered thresholds and no hair cell loss ( Kujawa and Liberman 2009 ). (jneurosci.org)
Comparatively little is known about the effects of aging per se on the IHC-afferent synapse, and normal synaptic aging has been largely overlooked as a contributor to auditory functional decline. (jneurosci.org)
this contrasts inner hair cells (IHC) that have only afferent innervation (30+ nerve fibers per one hair) but are heavily connected. (wikipedia.org)
Thus, DT-injected mice were deaf because they had no afferent auditory input despite OHCs continuing to receive normal auditory mechanical stimulation and having normal function. (sigmaaldrich.com)
Damaged hair cells can lead to additional destruction of parts of the auditory afferent pathway sequentially, which is called secondary degeneration. (hindawi.com)

Objective audiometry measures otoacoustic emissions, testing the functioning of the external hair sensory cells. (hear.com)
Two case studies are presented in which the measurement of otoacoustic emissions helped rule out outer hair cell cochlear pathology. (biomedsearch.com)

ABR is also referred to as auditory evoked response (AER) auditory evoked potential (AEP), brainstem evoked auditory potential (EAP), brainstem auditory evoked potential (BAEP), brainstem auditory evoked response (BAER), and evoked response audiometry. (unicare.com)

The efferent projections to the inner ear are composed of two fundamentally different fiber types [Warr and Guinan, ' a system of relatively large myelinated fibers whose major peripheral target is the bases of outer hair cells (OHCs) [Kimura and Wersall, 'and a system of smaller. (springer.com)
OHCs) and the low-threshold auditory nerve fibers (ANFs) are spared. (asp.org)
Injection of diphtheria toxin (DT) into adult CBA mice produced significant loss of inner hair cells without affecting OHCs. (sigmaaldrich.com)

The auditory efferent system is hypothesized to maintain and enhance neural fluctuation profiles. (springer.com)
Neural innervation to the outer HCs is disrupted in Prox1DTA mice and auditory brainstem response thresholds in adults are 40-50 dB higher than in controls. (jneurosci.org)
Stellate (chopper) cells encode sound spectra (peaks and valleys) by spatial neural firing rates based on auditory input strength (rather than frequency). (wikipedia.org)
NICU infants admitted for more than 5 days are to have auditory brainstem response (ABR) included as part of their screening so that neural hearing loss will not be missed. (aappublications.org)
Acute extracellular recordings from the auditory midbrain (inferior colliculus) demonstrated increases in spontaneous neuronal activity (a putative neural correlate of tinnitus) in both groups. (frontiersin.org)
Hair cells of the inner ear perform the essential conversion of mechanical stimuli to neural signals for the senses of hearing and balance. (pnas.org)
A single row of inner hair cells transmits most of the neural information about sound signals to the brain. (wisegeek.com)

In contrast, many pRb −/− vestibular hair cells survive and continue to divide in adult mice. (pnas.org)
Significantly, adult pRb −/− vestibular hair cells are functional, and pRb −/− mice maintain partial vestibular function. (pnas.org)
Liu XP, Koehler KR, Mikosz AM, Hashino E, Holt JR. Functional development of mechanosensitive hair cells in stem cell-derived organoids parallels native vestibular hair cells. (childrenshospital.org)

This delay in sound response was accompanied by a weaker sensitivity of the auditory steady state response to amplitude-modulated sound stimuli. (frontiersin.org)
It is thought that this tonic release is what allows the hair cells to respond so quickly in response to mechanical stimuli. (wikipedia.org)
Hearing sensitivity was measured using pip-train test stimuli and auditory evoked potential recording. (biologists.org)
Like the phenomenology of visual perception, these aspects of auditory perception appear to have arisen from the need to contend with sensory stimuli that are inherently unable to specify their physical sources, leading to the evolution of a common strategy to deal with this fundamental challenge. (coursera.org)
An overview of the organization of the human auditory system, and how sound signals are transformed into sound stimuli. (coursera.org)
During early postnatal development, pRb −/− hair cells continue to divide and can transduce mechanical stimuli. (pnas.org)
In these sensory organs, the hair cells are the receptors containing the key mechanoelectrical transduction elements that convert mechanical stimuli into electrical signals. (nih.gov)
Remarkably, auditory hair cells can also detect stimuli with amplitudes over a million times greater, and thus can signal the booming cannons of Tchaikovsky's 1812 Overture as well. (childrenshospital.org)
This extraordinary dynamic range is the result of a sensory transduction process that utilizes several feedback mechanisms to precisely reposition and tune the mechanosensitive apparatus within the optimal range allowing detection of auditory stimuli that span the breadth of amplitudes and frequencies humans encounter daily. (childrenshospital.org)

The inner ear functions as the sensorineural receptor organ of the auditory system, converting an acoustic waveform into an electrochemical stimulus that can be transmitted to the CNS. (medscape.com)
Destruction of hair cells can lead to sensorineural hearing loss . (wisegeek.com)

The quickness of the hair cell response may also be due to the fact that it can increase the amount of neurotransmitter release in response to a change as little as 100 μV in membrane potential. (wikipedia.org)
The basic principles of this local control are illustrated in the images below and are outlined as follows: First, an anatomic barrier exists between perilymph and endolymph, and it consists of Reissner membrane, the stria vascularis, and the reticular lamina formed by tight junctions between the apices of hair cells and the adjacent supporting cells (see the image above). (medscape.com)
The outer ear includes the pinna (also called the auricle), the ear canal and the eardrum (also called the tympanic membrane). (hearingdirect.com)
from the apical end of each cell about 100 stereocilia extend from the surface and make contact with the tectorial membrane. (thefreedictionary.com)
The eardrum, in the outer ear, is a thin, fibrous membrane that can be easily damaged. (brightkite.com)
Compartmentalization of membrane transport and signaling processes is of pivotal importance to eukaryotic cell function. (bioportfolio.com)
Electrical resonance results when the inherent oscillation in the membrane potential of hair cells corresponds to sound of a particular frequency. (yale.edu)
The inherent oscillation in membrane potential in a hair cell is brought about by an inward Calcium current and an outward Potassium current (calcium dependent). (yale.edu)
Twelve weeks after kanamycin treatment, the round window membrane injection group showed severe subject differences in hair cells and SGC damage, whereas the gelfoam group showed consistent and severe damage in hair cells and SGCs. (hindawi.com)
When triggered, the acetylcholine receptors swing open to allow calcium to flow into the cell, thereby triggering changes in membrane resting potential. (webwire.com)
Excessive noise exposure will injure the hair cells along the basilar membrane and result in noise-induced hearing loss (NIHL). (insulation.org)
In addition, the organ of Corti lies on the basilar membrane , and contains hair cells , tectorial membrane, and a number of supporting cells. (wisegeek.com)
Furthermore, the basilar membrane serves as a sound frequency analyzer that distributes the sound stimulus along the hair cells. (wisegeek.com)
In turn, the hair cell stereocilia bend, causing a change in membrane potential that results in the transduction of sound. (wisegeek.com)
Hair cells that respond to high frequencies are usually damaged first, because the basilar membrane moves vigorously when responding to high frequencies. (wisegeek.com)

However, when the facial nerve function is affected, it causes concern for an abnormality in the cerebellopontine angle or in the internal auditory canal. (lww.com)
The MRI of this young patient showed a very narrow internal auditory canal. (lww.com)
A normal internal auditory canal measures 3 mm or larger in the anterior posterior-dimension. (lww.com)
This child's MRI, however, showed that hers measured less than 2 mm in the most medial internal auditory canal on the left side ( Fig. 2 ). (lww.com)
The congenital narrowing of the internal auditory canal can cause abnormalities in the development of the facial and cochlear nerves. (lww.com)
The CT scan showed the congenitally narrowed internal auditory canal with some anomalies of the vestibule and horizontal canal ( Fig. 3 ). (lww.com)
Congenital stenosis of the internal auditory canal is a rare anomaly that most commonly affects the cochlear nerve. (lww.com)
A study of five patients with congenitally narrowed internal auditory canal found none had facial weakness ( Otol Neurotol . (lww.com)
Corti ganglion - an elongated ganglion of bipolar sensory nerve cell bodies on the cochlear part of the vestibulocochlear nerve in the spiral canal of the modiolus. (thefreedictionary.com)
The OAE measurements are carried out using a small probe in the outer auditory canal. (hear.com)
Sound waves travel from the outer ear and in through the auditory canal, causing the eardrum to vibrate. (hear-it.org)
It vibrates in resonance to sound waves coming through the external auditory canal, and is the ear's only defense against damaging. (brightkite.com)
and a connected handle to enable a user of the test instrument to insert the coil(s) into at least the outer ear canal and to direct electromagnetic signals at different directions relative to the middle ear. (google.com)
Sound waves enter the outer ear and travel through the ear canal. (healthyhearing.com)
This travels in parallel with the vestibular nerves through the internal auditory canal , through which it connects to the brainstem. (wikipedia.org)

As described below, this fluctuation-profile coding mechanism benefits from both saturation of inner hair cell (IHC) transduction and average rate saturation associated with the IHC-AN synapse . (springer.com)
Mechanosensitivity of hair cells is necessary for our hearing while calcium is an essential modulator of mechano-electrical transduction. (case.edu)
As a model for DFNA36, we used Beethoven mice 5 , which harbor a point mutation in Tmc1 , a gene required for hearing that encodes a pore-forming subunit of mechanosensory transduction channels in inner-ear hair cells 6 . (nature.com)
TMC1 forms the pore of mechanosensory transduction channels in vertebrate inner ear hair cells. (nature.com)
Damage of hair cells is irreversible, and this results in a compromised sound transduction due to loss of sensitivity and disorder in amplification function, causing deafness and sound distortion, respectively. (wisegeek.com)
Dr. Kachar's laboratory uses advanced microscopy imaging in combination with cell biology techniques to study cellular and molecular mechanisms that underlie mechano-transduction in auditory and vestibular sensory organs. (nih.gov)
These junctions support the voltage and potassium concentration gradients that define the endocochlear potential, a critical condition for mechanoelectrical transduction by the hair cells. (nih.gov)
Sensory transduction in the ear beings with deflection of mechanosensitive organelles that project from the apical surface of inner ear hair cells. (childrenshospital.org)

Simplified, nerve fibers' signals are transported by bushy cells to the binaural areas in the olivary complex, while signal peaks and valleys are noted by stellate cells, and signal timing is extracted by octopus cells. (wikipedia.org)
There, hair cells break them into electrical signals. (denverhealth.org)
The coded electrical signals travel from the speech processor to a transmitting coil, across the skin, to an implanted receiver where the electrical signals are delivered from the auditory nerve to the brain. (unc.edu)
In this paper, one probe (TPPA-VCh) with fluorescence and Surface-enhanced Raman Scattering (SERS) two readout signals, which has high sensitivity and specificity to glutathione in both vitro and cell. (bioportfolio.com)
Researchers at EPFL and the University of Bern have developed a groundbreaking method for studying the electrical signals of cardiac muscle cells. (phys.org)
The auditory system converts sound into electrical signals. (coursera.org)
14 . The apparatus of claim 13 wherein the electronic assembly further comprises a microphone for receiving auditory signals and which is in electrical communication with the processor. (google.com)
Damaged hair cells are unable to trigger electrical signals to the brain, impeding hearing. (healthyhearing.com)
The exquisite sensitivity of the auditory system can initiate signals that encode the faint pizzicato of a classical violin. (childrenshospital.org)

Although thresholds and hair cell counts are important metrics in the assessment of sensory dysfunction, they are less informative when the dominant pathology is not sensory in nature. (jneurosci.org)
Such difficulty in listeners with normal thresholds has received more attention recently, especially associated with descriptions of synaptopathy, the loss of auditory nerve (AN) fibers as a result of noise exposure or aging. (springer.com)

Here, we measure, as a function of cochlear frequency, the magnitude of BK and SK2 expression in outer hair cells and the strength of in vivo OC suppression in BK(+/+) mice vs. BK(-/-) lacking the obligatory α-subunit (Meredith AL, Thorneloe KS, Werner ME, Nelson MT, Aldrich RW. (nih.gov)
Indeed, mice with a spontaneous GC-B loss of function mutation ( Npr2 cn/cn ) display an impaired bifurcation of auditory nerve (AN) fibers. (frontiersin.org)
In the inner ear, the cochlear hair cells in GC-B KO mice were nevertheless similar to those from wild type mice, justified by the typical expression of functionally relevant marker proteins. (frontiersin.org)
However, efferent cholinergic feedback to inner and outer hair cells was reduced in GC-B KO mice, linked to very likely reduced rapid efferent feedback. (frontiersin.org)
We used the Cre/loxP system in mice to specifically ablate pillar cells (PCs) and Deiters' cells (DCs). (jneurosci.org)
Prox1DTA mice injected with tamoxifen at postnatal days 0 (P0) and P1 show significant DC and outer PC loss at P2-P4, that reaches ∼70% by 1 month. (jneurosci.org)
Remarkably, in Prox1DTA mice, the auditory epithelium preserves the ability to seal the reticular lamina and spiral ganglion neuron counts are normal, a key requirement for cochlear implant success. (jneurosci.org)
We identified a PAM variant of Staphylococcus aureus Cas9 (SaCas9-KKH) that selectively and efficiently disrupted the mutant allele, but not the wild-type Tmc1/TMC1 allele, in Beethoven mice and in a DFNA36 human cell line. (nature.com)
Furthermore, optogenetic stimulation of SGNs restored auditory activity in deaf mice. (jci.org)
Optical activation of the auditory pathway in ChR2 transgenic mice. (jci.org)
In CBA/CaJ mice, a 2-h exposure to 100-dB sound pressure level octave band (8 to 16 kHz) noise results in no permanent threshold shift but does cause significant synaptopathy and a reduction in auditory brainstem response (ABR) wave-I amplitude. (pnas.org)
In the auditory hair cells of young postnatal mice and rats, a reduction in mechanotransducer current, via pharmacological channel blockers or disruption of tip links, leads to stereocilia shape changes and shortening. (elifesciences.org)
C57BL/6J mice were administered a subretinal injection of B16F10 melanoma cells and divided into two groups: treatment and control. (jove.com)
Supporting cells, which are located under the inner hair cell, were also considered as an important factor that can contribute to the degree and time of secondary degeneration in both animals and humans [ 9 , 10 ], and this was further supported by a study with transgenic mice [ 11 ]. (hindawi.com)
To explore the role of the alpha-10 subunit in vivo, Elgoyhen and her colleagues knocked out the gene for the subunit in mice and studied the effects on the structure and function of hair cells. (webwire.com)
Although the genetically altered mice hear normally, said Elgoyhen, they have deficits in processing sound that reflect specific defects in the outer hair cell efferent system. (webwire.com)
Gfi1 was first identified as causing interleukin 2-independent growth in T cells and lymphomagenesis in mice. (biologists.org)
Furthermore, Gfi1 mutant mice lose all cochlear hair cells just prior to and soon after birth through apoptosis. (biologists.org)

Third, the role of the auditory efferent system, which receives inputs from L/MSR fibers, is revisited in the context of fluctuation-profile coding. (springer.com)
Briefly describe how different elements of the anatomy of the auditory system are involved in sound perception? (brainscape.com)
The auditory system is the sensory system for the sense of hearing. (wikipedia.org)
It includes both the sensory organs (the ears) and the auditory parts of the sensory system. (wikipedia.org)
Stimulated acoustic emissions from within the human auditory system. (springer.com)
The purpose of the workshop is to bring together mathematicians, biologists and engineers who work on different aspects of the auditory system. (umn.edu)
Why Do We know So Much More About the Visual Than the Auditory System and What Can We Do About It? (umn.edu)
Hair cells are the sensory receptors of both the auditory system and the vestibular system in the ears of all vertebrates . (wikipedia.org)
The Auditory System and Human Sound-Localization Behavior provides a comprehensive account of the full action-perception cycle underlying spatial hearing. (schweitzer-online.de)
It highlights the interesting properties of the auditory system, such as its organization in azimuth and elevation coordinates. (schweitzer-online.de)
Visual and auditory pathways, heart, central nervous system (CNS), and skeletal muscle are the tissues mostly involved, because of their dependence on aerobic energy production [ 1 ]. (hindawi.com)
entails a description of the human auditory system. (coursera.org)
So let me talk first about the Peripheral Components of the auditory system. (coursera.org)
Recently, evidence is beginning to accumulate on the deleterious effects that styrene exposures have on the auditory system. (cdc.gov)
Finally, noise- styrene exposures can have synergistic effects on the auditory system. (cdc.gov)
Phys.org) -The mammalian auditory system is one of the most sensitive detectors found in nature. (phys.org)
I'm going to emphasize the auditory system, which is my research subject. (coursera.org)
Energy in the auditory system contains information about the world. (brightkite.com)
This finding tells us that the alpha-10 subunit represents a special structure that is key to the abilities of the mammalian auditory system. (webwire.com)
Researchers suspect the system may serve several purposes, such as helping to improve signal detection in noisy environments, protecting the inner ear from noise damage, or decreasing auditory input when attention must be focused elsewhere. (webwire.com)
Drug-induced damage to these structures of the auditory and balance system can result in hearing loss, tinnitus , and dysequilibrium or dizziness . (medscape.com)
Hence, Gfi1 is expressed in the developing nervous system, is required for inner ear hair cell differentiation, and its loss causes programmed cell death. (biologists.org)

The loss of threshold sensitivity that accompanies auditory aging is primarily peripheral in origin, and often sensory (i.e., related to hair cell damage or loss) in nature. (jneurosci.org)
Unlike the typical dendrite, the peripheral process generates and conducts action potentials , which then "jump" across the cell body (or soma ) and continue to propagate along the central axon. (wikipedia.org)
Topically applied ethanolic extract of propolis (EEP) with HXS or PPD reduced the lipid peroxidation in skin and total number of inflammatory cells in skin and peritoneal cavity, functional activity of macrophages, the number of micronuclei in mouse peripheral blood reticulocytes and enzymatic activity of ALP and AST. (blogspot.com)
The conception of the meeting owes much to earlier meetings held in Boston in 1985 (Peripheral Auditory Mechallisms, Eds. (foyles.co.uk)
Methods Sanger sequencing was performed on DNA isolated from peripheral blood or lymphoblastoid cell lines. (bmj.com)

Moreover, noise exposure that does not cause hearing threshold loss can still lead to "hidden hearing loss" (HHL), i.e., functional deafferentation of auditory nerve fibers (ANFs) through loss of synaptic ribbons in inner hair cells. (frontiersin.org)
Matt Nadol J.B., Jr., Synaptic morphology of inner and outer hair cells of the human organ of Corti, Journal of electron microscopy technique, 15, 187-196, 1990. (auditory.org)
The central axons form synaptic connections with cells in the cochlear nucleus of the brainstem. (wikipedia.org)

Our study demonstrates a strategy for optogenetic stimulation of the auditory pathway in rodents and lays the groundwork for future applications of cochlear optogenetics in auditory research and prosthetics. (jci.org)
Angiopoietin-Tie Signaling Pathway in Endothelial Cells: A Computational Model. (jhu.edu)
To support this K + gradient, spiral ligament fibrocytes (SLFs) and strial cells require a large and continuous supply of K + . Recent evidence has discovered a K + recycling pathway, whereby K + is reabsorbed from the perilymph through a K/Cl cotransporter in the supporting cells (Tectal and Dieter's cells) of the organ of Corti. (medscape.com)
Cochlear hair cell damage can subsequently progress towards the proximal part of the auditory pathway including the nerve fiber, spiral ganglion cells (SGCs), and cochlear nucleus, which is also known as secondary degeneration [ 1 ]. (hindawi.com)

Actin-bundling protein TRIOBP forms resilient rootlets of hair cell stereocilia essential for hearing. (case.edu)
They derive their name from the tufts of stereocilia called hair bundles that protrude from the apical surface of the cell into the fluid-filled cochlear duct . (wikipedia.org)
The deflection of the hair-cell stereocilia opens mechanically gated ion channels that allow any small, positively charged ions (primarily potassium and calcium ) to enter the cell. (wikipedia.org)
Mechanotransducer channels at the tips of sensory stereocilia of inner ear hair cells are gated by the tension of 'tip links' interconnecting stereocilia. (elifesciences.org)
Here, we show that this constitutive Ca 2+ influx, usually considered as potentially deleterious for hair cells, is in fact essential for stereocilia stability. (elifesciences.org)
Each hair cell has tiny projections called stereocilia, which are arranged in a bundle with rows of increasing height like a staircase and are connected to each other by tiny filaments called tip-links. (elifesciences.org)
When sound waves hit the stereocilia, the tension on the tip-links increases, which opens "mechanotransduction" channels on the shorter stereocilia that allow calcium ions to flow into the cells. (elifesciences.org)
When the drugs were rinsed out of the hair cells, the stereocilia went back to their normal shape. (elifesciences.org)
Sequestering of free calcium ions inside the hair cells had a similar effect on the shape of stereocilia. (elifesciences.org)
The sense of hearing depends on stereocilia, the microvilli-like mechanosensory projections at the apical surface of inner ear hair cells. (elifesciences.org)
Mammalian auditory hair cells do not regenerate and, therefore, have to maintain their precisely arranged stereocilia throughout the lifespan of the organism. (elifesciences.org)
They are elongated cells with hairlike extensions called stereocilia. (wisegeek.com)

Those electrodes stimulate the auditory nerve fibers directly, from within the inner ear. (unc.edu)
In this respect, auditory nerve fibers are somewhat unusual in that action potentials pass through the soma. (wikipedia.org)
There, its fibers synapse with the cell bodies of the cochlear nucleus . (wikipedia.org)
The lower ends of hair cells are attached to nerve fibers that relay information to and from the brain via the eighth cranial nerve , which controls auditory functions. (wisegeek.com)

Kimura, R.S. and Wersall, I. (1962) Termination of the olivocochlear bundle in relation to the outer hair cells of the organ of Corti in guinea pig. (springer.com)
Fibroblast Growth Factor Receptor 3 regulates microtubule formation and cell surface mechanical properties in the developing organ of Corti. (case.edu)
The organ of Corti, the auditory sensory organ in mammals, is a highly specialized epithelium in structure ( Fig. 1 A ) and function. (jneurosci.org)
Vestibular duct perilymph vibrations bend organ of Corti outer cells (4 lines) causing prestin to be released in cell tips. (wikipedia.org)
Acoustic stimulation causes tonotopic alterations in the ength of isolated outer hair cells from guinea pig hearing organ. (springer.com)
The columnar supporting cells became covered with non-specialised cells migrating from the outermost region of the organ of Corti. (biomedsearch.com)
CONCLUSIONS/SIGNIFICANCE: The lack of dedifferentiation amongst supporting cells and their replacement by cells from the outer side of the organ of Corti are factors that may need to be considered in any attempt to promote endogenous hair cell regeneration. (biomedsearch.com)
Corti pillars - cells forming the outer and inner walls of the tunnel in the organ of Corti. (thefreedictionary.com)
Outer hair cells are the primary targets within the organ of Corti, although the spiral ganglions are not spared. (cdc.gov)
Prestin is a recently described protein in outer hair cells that is responsible for the sharp tuning seen in the hearing organ of mammals. (yale.edu)
The role of Prestin (in Collaboration with Dr Joseph Santos Saatchi, Prof in Otolaryngology see www.yaleearlab.org) Prestin is a recently described protein in outer hair cells that is responsible for the sharp tuning seen in the hearing organ of mammals. (yale.edu)
The organ of Corti (or spiral organ) is the organ in the inner ear of mammals that contains auditory sensory cells, or hair cells. (sciencephoto.com)
The inset shows at high magnification the hairs on two cells from the first row in the second turn of the organ of Corti. (sciencephoto.com)
These receptor cells are specialized for hearing and are found along the full length of the organ of Corti. (wisegeek.com)
In humans, the organ of Corti contains 3,500 inner hair cells and 15,000 outer hair cells that are stimulated and highly sensitive to sounds. (wisegeek.com)

The tiny VAT-positive puncta (open arrows) are located well below the OHC bases, within the outer spiral bundles. (nih.gov)
This causes the cells to be chemically elongated and shrunk (somatic motor), and hair bundles to shift which, in turn, electrically effects the basilar membrane's movement (hair-bundle motor). (wikipedia.org)
It is affected by the closing mechanism of the mechanical sensory ion channels at the tips of the hair bundles. (wikipedia.org)
The stereociliary theory holds that amplification is produced by intricate vibrations of the bundles of cilia extending from the outer hair cells. (biologynews.net)
Rapid renewal of auditory hair bundles. (nih.gov)

The fifth edition of this successful introductory text on hearing sciences includes auditory, anatomy, physiology, psychoacoustics, and perception content.Fundamentals of Hearingis one of only a few textbooks that covers all of hearing at an introductory level. (ecampus.com)
In many cases, the loss of cochlear hair cells is the main contributor to loss of sound perception. (hindawi.com)
Researchers have established how a molecule in the inner ear of mammals helps fine-tune auditory perception. (webwire.com)

Auditory mechanotransduction in the absence of functional myosin-XVa. (case.edu)
Therefore, the functional adult vestibular pRb −/− hair cells, derived from proliferation of postnatal hair cells, are largely integrated into vestibular pathways. (pnas.org)
This study reveals essential yet distinct roles of pRb in cochlear and vestibular hair cell maturation, function, and survival and suggests that transient block of pRb function in mature hair cells may lead to propagation of functional hair cells. (pnas.org)
Their development involves permanent exit from the cell cycle, fate determination, and differentiation into a functional hair cell. (pnas.org)
In mouse embryos, therefore, early differentiation and functional maturation of hair cells are pRb-independent. (pnas.org)
Koehler KR, Nie J, Longworth-Mills E, Liu XP, Lee J, Holt JR, Hashino E. Generation of inner ear organoids containing functional hair cells from human pluripotent stem cells. (childrenshospital.org)

Prestin is essential in auditory processing. (wikipedia.org)
A targeted gene disruption strategy of prestin showed a >100-fold (or 40 dB) loss of auditory sensitivity. (wikipedia.org)
Based upon the generated voltage and the depolarized or hyperpolarized state of the cell, prestin will transition through two distinct steps, representing the three-state model of prestin modulation. (wikipedia.org)
It is suggested that prestin contains an intrinsic anion-uptake mechanism based upon research showing concentration dependent [14C]formate uptake in Chinese hamster ovary (CHO) cells. (wikipedia.org)
Activity-dependent regulation of prestin expression in mouse outer hair cells. (sigmaaldrich.com)
To test whether centrally mediated feedback regulates prestin, we developed a novel model of inner hair cell loss. (sigmaaldrich.com)

However, threshold sensitivity loss is not the only, and arguably not the primary, handicapping dysfunction of auditory aging. (jneurosci.org)
Of these children, approximately 70% have nonsyndromic deafness, most often related to cochlear hair cell dysfunction because of errors in production of the gap junction protein connexin 26. (cps.ca)

The clinical free radical scavenger, edaravone, protects cochlear hair cells from acoustic trauma. (thefreedictionary.com)
Oto-acoustic emissions are the best objective screening test in infants as they are thought to reflect outer hair cell activity. (starship.org.nz)
The cochlear nerve (also auditory or acoustic neuron ) is one of two parts of the vestibulocochlear nerve , a cranial nerve present in amniotes , the other part being the vestibular nerve. (wikipedia.org)

A fast motile response in guinea pig outer hair cells: the cellular basis of the cochlear amplifier. (springer.com)

Liberman, M.C. (1978) Auditory nerve response from cats raised in a low-noise environment. (springer.com)

Much experimental effort has focused on correlating such age-related threshold shifts with hair cell loss, and therapeutic interventions have concentrated on improving "audibility" through amplification. (jneurosci.org)
Audiologists with skills and expertise in evaluating newborn and young infants with hearing loss should provide audiology diagnostic and auditory habilitation services (selection and fitting of amplification device). (aappublications.org)
This gives rise to a resonance and amplification of signal with consequent transmitter release from these cells. (yale.edu)
In their studies, Zuo and his colleagues have sought to establish the mechanism by which outer hair cells produce such amplification. (biologynews.net)

When someone has ANSD, sound enters the ear normally, but because of damage to the inner row of hair cells or synapses between the inner hair cells and the auditory nerve, or damage to the auditory nerve itself, sound isn't properly transmitted from the inner ear to the brain. (kidshealth.org)
However, recent rodent research has demonstrated that noise exposures causing only temporary threshold shifts can induce a permanent loss of ~50% of synapses on inner hair cells (IHCs) that is undetectable by audiograms. (asp.org)
Noise can cause excitotoxic trauma to cochlear synapses by triggering excessive release of the neurotransmitter glutamate from the auditory sensory hair cells. (pnas.org)

Molecular remodeling of tip links underlies mechanosensory regeneration in auditory hair cells. (case.edu)

His laboratory also studies permeability barriers in auditory and non-auditory epithelial tissues focusing on the molecular basis of tight junction adhesion and permeability. (nih.gov)

Generally, hearing loss occurs at the higher frequencies first, and it is basal outer hair cells, which are the most vulnerable to a variety of insults, including loud noise and ototoxic drugs. (case.edu)
Outer HC loss follows at P14 and is almost complete at 1 month, while inner HCs remain intact. (jneurosci.org)
Results]The effect of the sustained local delivery of MDL28170, a gamma-secretase inhibitor, on hearing and hair cell induction was tested in a guinea pig model with noise-induced hearing loss. (nii.ac.jp)
This study defines characteristics of the auditory sensory epithelium after hair cell loss. (biomedsearch.com)
Treatment with an aminoglycoside-diuretic combination produced loss of all outer hair cells within 48 hours in both strains. (biomedsearch.com)
Cochlear damage was assessed by auditory brainstem response threshold shifts and outer hair cell loss. (cdc.gov)
This hearing loss is largely brought about by a loss in hair cells in the auditory epithelium. (yale.edu)
Subjective tinnitus is often accompanied by hearing loss due to hair cell nerve damage. (banishtinnitus.net)
The long-term goal of my laboratory is to understand the role of cochlear outer hair cells in hearing and hearing loss both at the molecular and at the systems level. (rochester.edu)
Although the number one effect of excessive noise exposure is hearing loss, other adverse non-auditory effects have been documented in the workplace including, but not limited to, psychological stress, poor job performance, hypertension and industrial accidents. (insulation.org)

Research is centered on auditory (hearing) and vestibular (balance) function in normal subjects and in patients with hearing or balance disorders. (hopkinsmedicine.org)
A piezoelectric model of outer hair cell function. (semanticscholar.org)
article{Mountain1994APM, title={A piezoelectric model of outer hair cell function. (semanticscholar.org)
A simple piezoelectric model of outer hair cell function is presented which integrates existing data from isolated OHC experiments. (semanticscholar.org)
All patients had hearing abnormalities, but only four had abnormal outer hair cell function. (lww.com)
Their function is assisted by a Na + /Cl - /K + cotransporter located in the marginal cells. (medscape.com)
Most cochlear implant candidates have normal outer and middle ear function. (unc.edu)
Until today we have focused mainly on the function of single cells and small networks. (coursera.org)
Our group recently presented preliminary data https://www.researchgate.net/publication/294732622_Speech_Detection_in_the_Presence_Of_Background_Noise_Is_Effected_by_both_Spiral_Ganglion_and_Outer_Hair_Cell_Function in this realm at the 2016 annual meetings of the Association for Research in Otolaryngology, the American Auditory Society, and the American Academy of Audiology. (lww.com)
Function of Golgi-centrosome proximity in RPE-1 cells. (bioportfolio.com)
These results suggest that Golgi-centrosome proximity per se is not necessary for the normal function of RPE-1 cells. (bioportfolio.com)
Abnormal Golgi morphology and decreased COPI function in cells with low levels of SMN. (bioportfolio.com)
We will study the hypothesis that long-term Tekturna treatment will improve endothelial function and the production and function of endothelial progenitor cells (EPCs) in patients with ea. (bioportfolio.com)
These alterations only compromised prestin's function as an amplifier but did not otherwise affect the outer hair cell structure or function, the researchers' analysis showed. (biologynews.net)
Gene therapy restores auditory and vestibular function in a mouse model of Usher syndrome type 1c. (childrenshospital.org)

6.2 Detection of Osmotic Swelling by Hypothalamic Cells in Mammals. (wiley.com)
Outer hair cells are found only in mammals. (wikipedia.org)
While hearing sensitivity of mammals is similar to that of other classes of vertebrates, without functioning outer hair cells, the sensitivity decreases by approximately 50 dB [ citation needed ] . (wikipedia.org)

Instead, the influx of positive ions from the endolymph in the scala media depolarizes the cell, resulting in a receptor potential . (wikipedia.org)
In mammalian outer hair cells, the receptor potential triggers active vibrations of the cell body. (wikipedia.org)
The receptor cells look different from one another, and they exhibit different receptor proteins. (webwire.com)
In earlier studies, researchers found that two main subunits, alpha-9 and alpha-10, make up the nicotinic acetylcholine receptor of hair cells. (webwire.com)
With these experiments, we have demonstrated that the receptor really needs the alpha-10 subunit to drive inhibition of outer hair cell activity. (webwire.com)
Maturation of suprathreshold auditory nerve activity involves cochlear CGRP-receptor complex formation. (rochester.edu)

When the vibrations are big enough, the inner hair cells translate them into electrical nerve impulses in the auditory nerve, which connects the inner ear to the brain. (kidshealth.org)
The outer ear sends vibrations to the inner ear. (denverhealth.org)
Two kinds of cells, the inner and outer hair cells, work together to transduce mechanical vibrations into action potentials. (phys.org)

Anatomy 41

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Analytical, Diagnostic and Therapeutic Techniques and Equipment 17

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