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 CompoundsHearing 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.TurtlesAmplifiers, 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 CBAAlopecia: 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 C57BLIon 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.
... 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 ...
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 ...
... 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 ...
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 ...
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 ...
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". ...
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 ...
... 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 ...
... 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 ...
... 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 ...
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 ...
... 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 ...
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 ...
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 ...
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 ...
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 ( ...
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 ...
... (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 ...
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 ...
... 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 ...
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 ...
... 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: ...
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 ...
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 ...
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 ...
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 ...
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]. ...
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 ...
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 ...
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]. ...
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 ...
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 ...
... , 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 ...
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 ...
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 ...
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 ...
... 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 ...
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 ...
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 ...
Effect of absence of cochlear outer hair cells on behavioural auditory threshold.. Ryan A, Dallos P. ...
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 ] ...
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 ...
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 ...
... 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 ...
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: ...
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 ...
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 ...
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 ...
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 ...
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 ...
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. ...
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; ...
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 ...
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? ...
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. ...
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 ...
... 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 ...
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 ...
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 ...
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. ...
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. ...
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 ...
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 ...
  • 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)
  • 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)
  • 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)
  • 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)