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, 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: 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.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.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.Hearing: The ability or act of sensing and transducing ACOUSTIC STIMULATION to the CENTRAL NERVOUS SYSTEM. It is also called audition.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.Cochlear Microphonic Potentials: The electric response of the cochlear hair cells to acoustic stimulation.Auditory Threshold: The audibility limit of discriminating sound intensity and pitch.Acoustic Stimulation: Use of sound to elicit a response in the nervous system.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.Electric Capacitance: The ability of a substrate to retain an electrical charge.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.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.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.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.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.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.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.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.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 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.Perceptual Masking: The interference of one perceptual stimulus with another causing a decrease or lessening in perceptual effectiveness.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.Psychoacoustics: The science pertaining to the interrelationship of psychologic phenomena and the individual's response to the physical properties of sound.Auditory Perception: The process whereby auditory stimuli are selected, organized, and interpreted by the organism.Noise: Any sound which is unwanted or interferes with HEARING other sounds.LizardsPitch Perception: A dimension of auditory sensation varying with cycles per second of the sound stimulus.Evoked Potentials, Auditory: The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.Sound Spectrography: The graphic registration of the frequency and intensity of sounds, such as speech, infant crying, and animal vocalizations.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).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.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.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)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.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).Hair Color: Color of hair or fur.Auditory Cortex: The region of the cerebral cortex that receives the auditory radiation from the MEDIAL GENICULATE BODY.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Space Perception: The awareness of the spatial properties of objects; includes physical space.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.Hair Diseases: Diseases affecting the orderly growth and persistence of hair.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.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.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.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.Hair Removal: Methods used to remove unwanted facial and body hair.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.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Gene Frequency: The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.Hair Dyes: Dyes used as cosmetics to change hair color either permanently or temporarily.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.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.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.Hearing Loss: A general term for the complete or partial loss of the ability to hear from one or both ears.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.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.Deafness: A general term for the complete loss of the ability to hear from both ears.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.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).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.Neomycin: Antibiotic complex produced by Streptomyces fradiae. It is composed of neomycins A, B, and C. It acts by inhibiting translation during protein synthesis.TurtlesMicroscopy, 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.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)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.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.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.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.Endolymph: The lymph fluid found in the membranous labyrinth of the ear. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Neurons, Efferent: Neurons which send impulses peripherally to activate muscles or secretory cells.Regeneration: The physiological renewal, repair, or replacement of tissue.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.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.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.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.Animals, Newborn: Refers to animals in the period of time just after birth.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.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.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.Alopecia: Absence of hair from areas where it is normally present.Pyridinium CompoundsSemicircular 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.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.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.Gerbillinae: A subfamily of the Muridae consisting of several genera including Gerbillus, Rhombomys, Tatera, Meriones, and Psammomys.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.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)Electric Conductivity: The ability of a substrate to allow the passage of ELECTRONS.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.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.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.Batrachoidiformes: An order of bottom fishes with short, small, spinous dorsal fins. It is comprised of one family (Batrachoididae) and about 70 species.Electric Stimulation: Use of electric potential or currents to elicit biological responses.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.Basic Helix-Loop-Helix Transcription Factors: A family of DNA-binding transcription factors that contain a basic HELIX-LOOP-HELIX MOTIF.Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Mice, Inbred C57BLKinetics: The rate dynamics in chemical or physical systems.Biophysical Processes: Physical forces and actions in living things.Labyrinth Diseases: Pathological processes of the inner ear (LABYRINTH) which contains the essential apparatus of hearing (COCHLEA) and balance (SEMICIRCULAR CANALS).Aminoglycosides: Glycosylated compounds in which there is an amino substituent on the glycoside. Some of them are clinically important ANTIBIOTICS.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.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.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Ear: The hearing and equilibrium system of the body. It consists of three parts: the EXTERNAL EAR, the MIDDLE EAR, and the INNER EAR. Sound waves are transmitted through this organ where vibration is transduced to nerve signals that pass through the ACOUSTIC NERVE to the CENTRAL NERVOUS SYSTEM. The inner ear also contains the vestibular organ that maintains equilibrium by transducing signals to the VESTIBULAR NERVE.Anion Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of negatively charged molecules (anions) across a biological membrane.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Vestibular Nerve: The vestibular part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The vestibular nerve fibers arise from neurons of Scarpa's ganglion and project peripherally to vestibular hair cells and centrally to the VESTIBULAR NUCLEI of the BRAIN STEM. These fibers mediate the sense of balance and head position.Dihydrostreptomycin Sulfate: A semi-synthetic aminoglycoside antibiotic that is used in the treatment of TUBERCULOSIS.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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.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.Neurons, Afferent: Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.Calbindin 2: A calbindin protein that is differentially expressed in distinct populations of NEURONS throughout the vertebrate and invertebrate NERVOUS SYSTEM, and modulates intrinsic neuronal excitability and influences LONG-TERM POTENTIATION. It is also found in LUNG, TESTIS, OVARY, KIDNEY, and BREAST, and is expressed in many tumor types found in these tissues. It is often used as an immunohistochemical marker for MESOTHELIOMA.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Mice, Mutant Strains: Mice bearing mutant genes which are phenotypically expressed in the animals.Vibration: A continuing periodic change in displacement with respect to a fixed reference. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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.Ion Channels: Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Potassium Channels: Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Scalp: The outer covering of the calvaria. It is composed of several layers: SKIN; subcutaneous connective tissue; the occipitofrontal muscle which includes the tendinous galea aponeurotica; loose connective tissue; and the pericranium (the PERIOSTEUM of the SKULL).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.Epithelium: One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Potassium: An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.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)Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Sensory Receptor Cells: Specialized afferent neurons capable of transducing sensory stimuli into NERVE IMPULSES to be transmitted to the CENTRAL NERVOUS SYSTEM. Sometimes sensory receptors for external stimuli are called exteroceptors; for internal stimuli are called interoceptors and proprioceptors.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Myosins: A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyze MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.Cell Death: The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.Plant Roots: The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)Mice, Inbred CBABiophysics: The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.Quaternary Ammonium Compounds: Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.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.In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Xanthenes: Compounds with three aromatic rings in linear arrangement with an OXYGEN in the center ring.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Usher Syndromes: Autosomal recessive hereditary disorders characterized by congenital SENSORINEURAL HEARING LOSS and RETINITIS PIGMENTOSA. Genetically and symptomatically heterogeneous, clinical classes include type I, type II, and type III. Their severity, age of onset of retinitis pigmentosa and the degree of vestibular dysfunction are variable.Cell Count: The number of CELLS of a specific kind, usually measured per unit volume or area of sample.S100 Calcium Binding Protein G: A calbindin protein found in many mammalian tissues, including the UTERUS, PLACENTA, BONE, PITUITARY GLAND, and KIDNEYS. In intestinal ENTEROCYTES it mediates intracellular calcium transport from apical to basolateral membranes via calcium binding at two EF-HAND MOTIFS. Expression is regulated in some tissues by VITAMIN D.Synaptic Transmission: The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.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.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Tympanic Membrane: An oval semitransparent membrane separating the external EAR CANAL from the tympanic cavity (EAR, MIDDLE). It contains three layers: the skin of the external ear canal; the core of radially and circularly arranged collagen fibers; and the MUCOSA of the middle ear.Cell Line: Established cell cultures that have the potential to propagate indefinitely.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.Zebrafish Proteins: Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).Calcium Channels: Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.Hearing Loss, High-Frequency: Hearing loss in frequencies above 1000 hertz.Green Fluorescent Proteins: Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Afferent Pathways: Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.Potassium Channels, Calcium-Activated: Potassium channels whose activation is dependent on intracellular calcium concentrations.Large-Conductance Calcium-Activated Potassium Channels: A major class of calcium activated potassium channels whose members are voltage-dependent. MaxiK channels are activated by either membrane depolarization or an increase in intracellular Ca(2+). They are key regulators of calcium and electrical signaling in a variety of tissues.Echolocation: An auditory orientation mechanism involving the emission of high frequency sounds which are reflected back to the emitter (animal).Retina: The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.Fluorescent Dyes: Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.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).Neural Inhibition: The function of opposing or restraining the excitation of neurons or their target excitable cells.Visual Cortex: Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.Ear, Middle: The space and structures directly internal to the TYMPANIC MEMBRANE and external to the inner ear (LABYRINTH). Its major components include the AUDITORY OSSICLES and the EUSTACHIAN TUBE that connects the cavity of middle ear (tympanic cavity) to the upper part of the throat.Nerve Tissue ProteinsStereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Receptors, Notch: A family of conserved cell surface receptors that contain EPIDERMAL GROWTH FACTOR repeats in their extracellular domain and ANKYRIN repeats in their cytoplasmic domains. The cytoplasmic domain of notch receptors is released upon ligand binding and translocates to the CELL NUCLEUS where it acts as transcription factor.Cations: Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.Nerve Regeneration: Renewal or physiological repair of damaged nerve tissue.Rana pipiens: A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.Ganglia, Sensory: Clusters of neurons in the somatic peripheral nervous system which contain the cell bodies of sensory nerve axons. Sensory ganglia may also have intrinsic interneurons and non-neuronal supporting cells.Cell Transdifferentiation: A naturally occurring phenomenon where terminally differentiated cells dedifferentiate to the point where they can switch CELL LINEAGES. The cells then differentiate into other cell types.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.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Ions: An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.Orientation: Awareness of oneself in relation to time, place and person.Amino Acid Transport Systems, Acidic: Amino acid transporter systems capable of transporting acidic amino acids (AMINO ACIDS, ACIDIC).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.Stem Cells: Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.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.Barium: An element of the alkaline earth group of metals. It has an atomic symbol Ba, atomic number 56, and atomic weight 138. All of its acid-soluble salts are poisonous.Cell Polarity: Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.Cell Membrane Permeability: A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.Xenopus laevis: The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.PAX2 Transcription Factor: A paired box transcription factor that is essential for ORGANOGENESIS of the CENTRAL NERVOUS SYSTEM and KIDNEY.Cesium: A member of the alkali metals. It has an atomic symbol Cs, atomic number 50, and atomic weight 132.91. Cesium has many industrial applications, including the construction of atomic clocks based on its atomic vibrational frequency.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.

*Cochlear amplifier

The main component of the cochlear amplifier is the outer hair cell (OHC) which increases the amplitude and frequency ... The Physical Basis of the Action of the Cochlea Kemp 1978 : Stimulated acoustic emissions from within the human auditory system ... selectivity of sound vibrations using electromechanical feedback. The cochlear amplifier was first proposed in 1948 by T. Gold ... This, in turn, influences the deflection of the hair bundles of the inner hair cells. These cells are in contact with afferent ...

*Peter Dallos

Demonstration that in the absence of outer hair cells there is a significant threshold shift, change in frequency selectivity, ... first intracellular recordings from hair cells in the low-frequency regions of the cochlea [2.8] First recordings from auditory ... First explanation of what determines low-frequency auditory threshold [2.5] Discovery that inner hair cells respond to basilar ... notably 50-60 dB amplification by outer hair cells [2.7] First intracellular recordings from outer hair cells in vivo; ...

*Robert Fettiplace

... showed that each hair cell is sharply tuned to a characteristic frequency and that much of the frequency selectivity in the ... These experiments, which were the first to give extensive quantitative records from auditory receptors, ... In 1976, he and Andrew Crawford developed a method of recording the electrical responses of hair cells in the isolated cochlea ... Another important development was the use of new methods of imaging hair cell stereociliary bundles and delivering force ...

*Critical band

This is because the frequency selectivity and the tuning of the basilar membrane is reduced as the outer hair cells are damaged ... In a 'normal' ear the auditory filter has a shape similar to the one shown below. This graph reflects the frequency selectivity ... When only the outer hair cells are damaged the filter is broader on the low frequency side. When both the outer and inner hair ... There are approximately between 15,000 and 16,000 of these hair cells in one ear. Outer hair cells have stereocilia projecting ...

*Auditory masking

The ability to hear frequencies separately is known as frequency resolution or frequency selectivity. When signals are ... 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 in the frequency domain is known as simultaneous masking, frequency masking or spectral masking. Auditory ... By experimenting with conditions where one sound can mask a previously heard signal, the frequency selectivity of the auditory ...

*Computational auditory scene analysis

... the signal is broken up into different frequencies that are naturally selected by the cochlea and hair cells. Because of the ... frequency selectivity of the basilar membrane, a filter bank is used to model the membrane, with each filter associated with a ... Additional models of the hair cells include the Meddis hair cell model which pairs with the gammatone filter bank, by modeling ... Meddis, R., Hewitt, M., Shackleton, T. (1990). "Implementation details of a computational model of the inner hair-cell/auditory ...

*Feature detection (nervous system)

... like in auditory systems of other vertebrates, primary sensory afferent neurons, which receive inputs from hair cells from a ... regions of the auditory pathway reveals that there are neurons with even higher levels of frequency and amplitude selectivity. ... One class of pyramidal cell, E-cells, respond to increases; a second, I-cells, respond to decreases in stimulus amplitude ... A cortical cell is not sufficiently precise or finely tuned enough for specific objects, and to some degree most cells respond ...

*Conspecific song preference

... in the auditory pathway. Avian hair cells have been extensively studied in the cochlea of the barn owl, and it is now known ... and different isoforms cause the hair cell to preferentially respond to different resonant frequencies. Species-specific ... Selectivity for conspecific song in the zebra finch auditory forebrain. Journal of Neurophysiology 89:472-487. Boumans, T., C. ... that both the morphological structure of hair cell papillae and the ion channels that characterize hair cell membranes confer ...

*Tectorial membrane

It overlies the sensory inner hair cells and electrically-motile outer hair cells of the organ of Corti and during acoustic ... enhanced frequency selectivity in Tecb−/− mice, which lack expression of β-tectorin. In vitro investigations of the mechanical ... 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 ...

*Hair cell

They have also improved frequency selectivity (frequency discrimination), which is of particular benefit for humans, because it ... For algal 'hair cells', see Trichocyte (disambiguation).. Hair cells are the sensory receptors of both the auditory system and ... Hair cell. Section through the spiral organ of Corti. Magnified. ("Outer hair cells" labeled near top; "inner hair cells" ... The inner hair cells are located at the termination of the "inner hair cell nerves" and the outer hair cells are located at the ...

*Hair cell

They have also improved frequency selectivity (frequency discrimination), which is of particular benefit for humans, because it ... Through mechanotransduction, hair cells detect movement in their environment. In mammals, the auditory hair cells are located ... The human cochlea contains on the order of 3,500 inner hair cells and 12,000 outer hair cells at birth. The outer hair cells ... Nerve fiber innervation is much denser for inner hair cells than for outer hair cells. A single inner hair cell is innervated ...

*Sensorineural hearing loss

... rather than accurate thresholds for those frequencies with non-functioning hair cells. Mid-frequency dead regions, with a small ... Thus, an increase in firing rate of the auditory neurons connected to the hair cell occurs. On the other hand, the bending of ... This selectivity to certain frequencies can be illustrated by neural tuning curves. These demonstrate the frequencies a fiber ... Sensory hearing loss often occurs as a consequence of damaged or deficient cochlear hair cells.[disputed - discuss] Hair cells ...

*Neuronal encoding of sound

The auditory hair cells in the cochlea are at the core of the auditory system's special functionality (similar hair cells are ... The mechanism that determines the selectivity of each type of neuron for a specific hair cell has been proposed by two ... the kinocilium exists and is believed to play a role in hair cell degeneration that is caused by exposure to high frequencies. ... Cochlear hair cells are organized as inner hair cells and outer hair cells; inner and outer refer to relative position from the ...

*Otoacoustic emission

... outer hair cells are the elements that enhance cochlear sensitivity and frequency selectivity and hence act as the energy ... Auditory brainstem response Entoptic phenomenon Maryanne Amacher, a composer who used this phenomenon in her music Pure tone ... broad frequency range) or toneburst (brief duration pure tone) stimulus. The evoked response from a click covers the frequency ... The sounds are frequency-stable between 500 Hz and 4500 Hz to have unstable volumes between -30 dB SPL and +10 dB SPL. The ...

*KCNB1

... auditory outer hair cells, stem cells, the retina, and organs such as the heart and pancreas. Modulation of K+ channel activity ... This general sequence comprises the selectivity of the potassium channel. Depending on the channel, the alpha subunits are ... Specifically, the KCNB1 delayed rectifier channel conducts a potassium current (K+). This mediates high frequency firing due to ... In human pancreatic ß cells, KCNB1, which mediates potassium efflux, produces a downstroke of the action potential in the cell ...

*Superior olivary complex

... which innervates cochlear outer hair cells. These cells contain electromotile fibers, and act as mechanical amplifiers/ ... Made up of a heterogeneous population of cells, this nucleus projects to many auditory nuclei, and forms the medial ... Tsuchitani C, Boudreau JC (1967). "Encoding of stimulus frequency and intensity by cat superior olive S-segment cells". J ... and may form the basis for ICC duration selectivity. Notably, SPON neurons do not receive descending inputs from the IC, and it ...

*Listener fatigue

Charron, S., & Botte, M. C. (1988). Frequency-selectivity in loudness adaptation and auditory fatigue. [Article]. Journal of ... Outer hair cells serve as acoustic amplifiers for stimulation of the inner hair cells. Outer hair cells respond primarily to ... The stereocilia (hair cells) of the inner ear can become subjected to bending from loud noises. Because they are not ... With the resultant oxygen tension and diminished blood supply reaching the outer hair cells, their response to sound levels is ...

*Sex differences in sensory systems

Of the three main classes of primary auditory units (low, mid, and high frequency), the high frequency units in females are ... Selectivity of the peripheral auditory system of spadefoot toads (Scaphiopus couchi) for sounds of biological significance. J. ... Altogether, sex specific tuning differences in the primary auditory neurons of the basilar papilla and duration sensitive cells ... The sexually dimorphic sensilla are called male specific type-1 trichoid sensilla, a type of hair-like olfactory sensilla. In ...

*Sense

The lateral line is also sensitive to low-frequency vibrations. The mechanoreceptors are hair cells, the same mechanoreceptors ... van Kleef, J.; Berry, R.; Stange, G. (2008). "Directional Selectivity in the Simple Eye of an Insect". Journal of Neuroscience ... Hearing or audition (adjectival form: auditory) is the sense of sound perception. Hearing is all about vibration. ... The receptors of the electrical sense are modified hair cells of the lateral line system. Polarized light direction/detection ...

*Receptive field

The auditory system processes the temporal and spectral (i.e. frequency) characteristics of sound waves, so the receptive ... classified receptive fields of cells in the visual cortex into simple cells, complex cells, and hypercomplex cells. Simple cell ... This region can be a hair in the cochlea or a piece of skin, retina, tongue or other part of an animal's body. Additionally, it ... McGugin, RW; Gatenby, JC; Gore, JC; Gauthier, I. "High-resolution imaging of expertise reveals reliable object selectivity in ...

*Drosophila melanogaster

Each photoreceptor cell consists of two main sections, the cell body and the rhabdomere. The cell body contains the nucleus, ... Wild-type flies show an activity rhythm with a frequency of about a day (24 hours). They found mutants with faster and slower ... Lehnert, B. P.; Baker, A. E.; Gaudry, Q; Chiang, A. S.; Wilson, R. I. (2013). "Distinct roles of TRP channels in auditory ... These changes include increased selectivity for courting only intraspecifically, as well as decreased courtship times. Sexually ...

*Mosquito

2005) observed a suppression of antibody-specific T cell responses mediated by mosquito saliva and dependent on mast cells and ... In all mosquito species, the antennae of the males in comparison to the females are noticeably bushier and contain auditory ... Frequency of Mosquito Wings. Hypertextbook.com (2000-05-31). Retrieved on 2013-04-01. ... though they often relax their selectivity when they experience severe competition for food, defensive activity on the part of ...
Tuning of the outer hair cell motor by membrane cholesterol.: Cholesterol affects diverse biological processes, in many cases by modulating the function of inte
Regeneration of sensory hair cells in the mature avian inner ear was first described just over 20 years ago. Since then, it has been shown that many other non-mammalian species either continually produce new hair cells or regenerate them in response to trauma. However, mammals exhibit limited hair cell regeneration, particularly in the auditory epithelium. In birds and other non-mammals, regenerated hair cells arise from adjacent non-sensory (supporting) cells. Hair cell regeneration was initially described as a proliferative response whereby supporting cells re-enter the mitotic cycle, forming daughter cells that differentiate into either hair cells or supporting cells and thereby restore cytoarchitecture and function in the sensory epithelium. However, ...
Natures fastest motors are the cochlear outer hair cells (OHCs). These sensory cells use a membrane protein, Slc26a5 (prestin), to generate mechanical force at high frequencies, which is essential for explaining the exquisite hearing sensitivity of mammalian ears. Previous studies suggest that Slc26a5 continuously diffuses within the membrane, but how can a freely moving motor protein effectively convey forces critical for hearing? To provide direct evidence in OHCs for freely moving Slc26a5 molecules, we created a knockin mouse where Slc26a5 is fused with YFP. These mice and four other strains expressing fluorescently labeled membrane proteins were used to examine their lateral diffusion in the OHC lateral wall. All five proteins showed minimal diffusion, but did move after pharmacological disruption of membrane-associated structures with a cholesterol-depleting agent and salicylate. Thus, our results demonstrate that OHC lateral wall structure constrains ...
The hair cells of the inner ear seem to be specified properly as they express many of the typical hair cell markers such as myosin VI/VIIa, Math1 and Brn3c. Thus, Gfi1 is not required for the specification of hair cells as they are formed in both the vestibule and the cochlea. However, the loss of Gfi1 seems to affect the vestibular and cochlear hair cells differently. In the vestibule, the hair cells are morphologically abnormal at the earliest stages of hair cell differentiation and at all subsequent stages. In addition, hair cells are not specifically localized to a lumenal monolayer, and are more variable in size and shape. This disorganization of hair cells in the vestibule may account for the ataxic behavior of the mice. In the cochlea, Gfi1 is required for the ...
One of the most common complaints of adults visiting an audiology clinic is difficulty in understanding speech in the presence of background noise. Performance in noise is often attributed to sensorineural hearing loss. However, there are many individuals with normal hearing who report difficulty hearing in background noise, which demonstrates how inadequate a typical audiometric evaluation is in evaluating the demands of speech comprehension in complex listening situations. It is also unclear which anatomical structures are responsible for our performance in background noise. 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.. Previous studies have suggested that the eighth cranial nerve, or Auditory Nerve (AN), may play a role in speech ...
OBJECTIVE/HYPOTHESIS: Hair cells of the mammalian auditory system do not regenerate, and therefore their loss leads to irreversible hearing loss. Aminoglycosides, among other substances, can irreversibly damage hair cells. Somatostatin, a peptide with hormone/neurotransmitter properties, has neuroprotective effects by binding to its receptor. In this study, we tested whether somatostatin can protect hair cells from gentamicin-induced damage in vitro. STUDY DESIGN: This study confirmed the expression of somatostatin receptor mRNA within the cochlea and analyzed the effect of somatostatin on gentamicin-induced hair cell damage and death in vitro. METHODS: Expression of somatostatin receptor mRNA in the rat cochlea was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). Protection of auditory hair cells from ...
TY - JOUR. T1 - Letter to the Editor regarding "Effects of caffeic acid on cisplatin-induced hair cell damage in HEI-OC1 auditory cells". AU - Kim, Shin Hye. AU - Choi, June. AU - Park, Moo Kyun. PY - 2016/2/1. Y1 - 2016/2/1. UR - http://www.scopus.com/inward/record.url?scp=84969724108&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=84969724108&partnerID=8YFLogxK. U2 - 10.1016/j.ijporl.2015.12.010. DO - 10.1016/j.ijporl.2015.12.010. M3 - Letter. C2 - 26786961. AN - SCOPUS:84969724108. VL - 81. JO - International Journal of Pediatric Otorhinolaryngology. JF - International Journal of Pediatric Otorhinolaryngology. SN - 0165-5876. ER - ...
Postembryonic production of hair cells, the highly specialized receptors for hearing, balance and motion detection, occurs in a precisely controlled manner in select species, including avians. Notch1, Delta1 and Serrate1 mediate cell specification in several tissues and species. We examined expression of the chicken homologs of these genes in the normal and drug-damaged chick inner ear to determine if signaling through this pathway changes during hair cell regeneration. In untreated post-hatch chicks, Delta1 mRNA is abundant in a subpopulation of cells in the utricle, which undergoes continual postembryonic hair cell production, but it is absent from all cells in the basilar papilla, which is mitotically quiescent. By 3 days after drug-induced hair cell injury, Delta1 expression is highly upregulated in areas of cell proliferation in both the utricle and basilar papilla. Delta1 mRNA levels ...
Death of sensory hair cells in the inner ear results in two global health problems that millions of people around the world suffer: hearing loss and balance disorders. Hair cells convert sound vibrations and head movements into electrical signals that are conveyed to the brain, and as a result of aging, exposure to noise, modern drugs or genetic predisposition, hair cells die. In mammals, the great majority of hair cells are produced during embryogenesis, and hair cells that are lost after birth are not replaceable. However, in the last decades, researches have shown some model organisms that retain the ability to regenerate hair cells damaged after embryogenesis, such as Zebrafish and chicken, providing clues as to the cellular and molecular mechanisms that may block hair cell regeneration ...
In fish, amphibians, and birds, regeneration of sensory hair cells through asymmetric cell divisions of supporting cells can contribute to recovery of hearing and balance after hair cell loss caused by trauma or toxicity (1, 2). Mammalian hair cells do not spontaneously regenerate, even though supporting cells in vestibular sensory epithelia retain a limited ability to divide (3, 4). Consequently, hair cell death in mammals often leads to permanent impairment of hearing and balance.. As the inner ear develops, hair cell progenitor cells exit from the cell cycle and, like neurons, terminally differentiate. Negative cell cycle regulators apparently maintain the postmitotic status of hair cells and contribute to their terminal differentiation. The cyclin-dependent kinase inhibitors p27Kip1 and p19Ink4d ...
The goal of Ruben Stepanyans lab The goal of the labs research is to study hair cell mechanosensitivity and calcium homeostasis in normal and pathological conditions. Mechanosensitivity of hair cells is necessary for our hearing while calcium is an essential modulator of mechano-electrical transduction. During excessively loud sounds and noise a substantial amount of calcium ions enter hair cells through mechanotransduction channels. Therefore it is important for hair cells to be able to buffer and extrude excessive Ca2; compromised calcium balance is a significant factor leading to hair cell death. 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. A particular interest of the lab is ...
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Mature mammals exhibit very limited capacity for regeneration of auditory hair cells, while all non-mammalian vertebrates examined can regenerate them. In an effort to find therapeutic targets for deafness and balance disorders, scientists have examined gene expression patterns in auditory tissues under different developmental and experimental conditions. Microarray technology has allowed the large-scale study of gene expression profiles (transcriptomics) at whole-genome levels, but since mRNA expression does not necessarily correlate with protein expression, other methods, such as microRNA analysis and proteomics, are needed to better understand the process of hair cell regeneration. These technologies and some of the results of them are discussed in this review. Although there is a considerable amount of variability found between studies owing to different species, tissues and treatments, there is some concordance between ...
Stereocilia are actin-based protrusions on auditory sensory hair cells that are deflected by sound waves to initiate the conversion of mechanical energy to neuronal signals. Stereocilia maintenance is essential because auditory hair cells are not renewed in mammals. This process requires both β-actin and γ-actin as knock-out mice lacking either isoform develop distinct stereocilia pathology during aging. In addition, stereocilia integrity may hinge on immobilizing actin, which outside of a small region at stereocilia tips turns over with a very slow, months-long half-life. Here, we establish that β-actin and the actin crosslinking protein fascin-2 cooperate to maintain stereocilia length and auditory function. We observed that mice expressing mutant fascin-2 (p.R109H) or mice lacking β-actin share a common phenotype including progressive, high-frequency hearing loss together ...
During this work we investigated organization, molecular composition and function of hair cell ribbon synapses. We demonstrated RIBEYE, Bassoon and Piccolo to be components of IHC synaptic ribbons. In the present study we showed that anchoring of IHC ribbons is impaired in mouse mutants for the presynaptic scaffolding protein Bassoon. The lack of active, zone-anchored synaptic ribbons reduced the presynaptic readily releasable vesicle pool, and impaired synchronous auditory signalling as revealed by recordings of exocytic IHC capacitance changes and sound-evoked activation of spiral ganglion neurons. Both exocytosis of the hair cell releasable vesicle pool and the number of synchronously activated spiral ganglion neurons co-varied with the number of anchored ribbons during development. Interestingly, ribbon-deficient IHCs were still capable of sustained exocytosis with normal Ca2+-dependence. Endocytic membrane retrieval was intact, but an accumulation of ...
Hair cells, the sensory receptors of the auditory, vestibular, and lateral-line organs, may be damaged by a number of agents including aminoglycoside antibiotics and severe overstimulation. In the avian cochlea, lost hair cells can be replaced by regeneration. These new hair cells appear to be derived from a support cell precursor which is stimulated to divide by events associated with hair cell loss. Little is known about the timing and sequencing of events leading to new hair cell production. In this study cell cycle-associated events in the avian cochlea were analyzed at early and late time intervals following a single high dose of gentamicin. This single dose protocol has been shown to consistently result in extensive morphological damage and hair cell loss in the proximal region of the cochlea while sparing a morphologically undamaged ...
Exposure to aminoglycoside antibiotics can lead to the generation of toxic levels of reactive oxygen species (ROS) within mechanosensory hair cells of the inner ear that have been implicated in hearing and balance disorders. Better understanding of the origin of aminoglycoside-induced ROS could focus the development of therapies aimed at preventing this event. In this work, we used the zebrafish lateral line system to monitor the dynamic behavior of mitochondrial and cytoplasmic oxidation occurring within the same dying hair cell following exposure to aminoglycosides. The increased oxidation observed in both mitochondria and cytoplasm of dying hair cells was highly correlated with mitochondrial calcium uptake. Application of the mitochondrial uniporter inhibitor Ru360 reduced mitochondrial and cytoplasmic oxidation, suggesting that mitochondrial calcium drives ROS generation during aminoglycoside-induced ...
in Ear, Nose, & Throat Journal (1998), 77(4), 276280282-5. Regeneration/repair and protection of auditory hair cells and auditory neurons is an exciting, rapidly evolving field. Simultaneous developments in the fields of otobiology and surgical otology have led ... [more ▼]. Regeneration/repair and protection of auditory hair cells and auditory neurons is an exciting, rapidly evolving field. Simultaneous developments in the fields of otobiology and surgical otology have led to new and exciting possibilities in inner ear medicine and surgery; specifically, the treatment or prevention of a variety of types of hearing losses in the foreseeable future. Sensorineural hearing loss in humans is commonly associated with a loss of auditory hair cells. It has been generally accepted that hearing loss resulting from ...
Wnt signaling is a highly conserved pathway crucial for development and homeostasis of multicellular organisms. Secreted Wnt ligands bind Frizzled receptors to regulate diverse processes such as axis patterning, cell division, and cell fate specification. They also serve to govern self-renewal of somatic stem cells in several adult tissues. The complexity of the pathway can be attributed to the myriad of Wnt and Frizzled combinations as well as its diverse context-dependent functions. In the developing mouse inner ear, Wnt signaling plays diverse roles, including specification of the otic placode and patterning of the otic vesicle. At later stages, its activity governs sensory hair cell specification, cell cycle regulation, and hair cell orientation. In regenerating sensory organs from non-mammalian species, Wnt signaling can also regulate the extent of proliferative hair cell regeneration. This review describes the current knowledge of the ...
Hearing loss is often the result of the death of the mechanosensory hair cells of the inner ear. Hair cells are sensitive to a number of environmental insults including aging, noise trauma, and ototoxic drugs. Ototoxic drugs include the aminoglycoside antibiotics and the antineoplastic agent cisplatin. These ototoxic drugs are highly therapeutic, but significant side effects, including ototoxicity and nephrotoxicity. We have previously shown that induction of heat shock proteins (HSPs) inhibits both aminoglycoside- and cisplatin-induced hair cell death in whole organ cultures of adult mouse utricles (1). In addition overexpression of HSP70 inhibits aminoglycoside-induced hearing loss in vivo (2). Our goal is to translate these findings into a clinical co-therapy aimed at inhibiting ototoxic drug-induced hearing loss in humans. Here we have examined the ability of celastrol, a pharmacological HSP inducer, to inhibit ...
The site of transduction is in the organ of Corti (spiral organ). It is composed of hair cells held in place above the basilar membrane like flowers projecting up from soil, with their exposed short, hair-like stereocilia contacting or embedded in the tectorial membrane above them. The inner hair cells are the primary auditory receptors and exist in a single row, numbering approximately 3,500. The stereocilia from inner hair cells extend into small dimples on the tectorial membranes lower surface. The outer hair cells are arranged in three or four rows. They number approximately 12,000, and they function to fine tune incoming sound waves. The longer stereocilia that project from the outer hair cells actually attach to the tectorial membrane. All of the stereocilia are mechanoreceptors, and when bent by ...
Cochlear hair cells are mechanoreceptors of the auditory system and cannot spontaneously regenerate in adult mammals; thus hearing loss due to hair cell damage is permanent. In contrast, hair cells...
The sensory epithelia of the inner ear are composed of mechanosensory hair cells and supporting cells, organised into a checkerboard-like pattern. Hair cells are essential for hearing and their loss after exposure to excessive noise (watch your iPods!) and during ageing is the main cause of deafness in humans. This is because in the mammalian auditory organ, the full complement of hair cells is produced during embryonic development. In contrast, reptiles, fish and birds can regenerate their hair cells throughout adult life. In these species, the supporting cells act as tissue stem cells following hair cell loss. Supporting cells can i) re-enter the cell cycle to produce new hair cells and supporting cells, or ii) convert ...
Inner ear hair cells. Coloured scanning electron micrograph (SEM) of sensory outer hair cells (stereocilia) from the organ of corti, in the cochlea of the inner ear. These cells are surrounded by a fluid called the endolymph. As sound enters the ear it causes waves to form in the endolymph, which in turn cause these hairs to move. The movement is converted into an electrical signal, which is passed to the brain. Each V-shaped arrangement of hairs lies on the top of a single cell. Magnification: x5,000 when printed 10cm tall. - Stock Image P434/0062
Inner ear hair cells convert the mechanical stimuli of sound, gravity, and head movement into electrical signals. This mechanotransduction process is initiated by opening of cation channels near the tips of hair cell stereocilia. Since the identity of these ion channels is unknown, and mutations in the gene encoding transmembrane channel-like 1 (TMC1) cause hearing loss without vestibular dysfunction in both mice and humans, we investigated the contribution of Tmc1 and the closely related Tmc2 to mechanotransduction in mice. We found that Tmc1 and Tmc2 were expressed in mouse vestibular and cochlear hair cells and that GFP-tagged TMC proteins localized near stereocilia tips. Tmc2 expression was transient in early postnatal mouse cochlear hair cells but persisted in vestibular hair cells. While mice with a targeted deletion of Tmc1 (Tmc1Δ mice) were deaf and ...
Inner ear hair cells convert the mechanical stimuli of sound, gravity, and head movement into electrical signals. This mechanotransduction process is initiated by opening of cation channels near the tips of hair cell stereocilia. Since the identity of these ion channels is unknown, and mutations in the gene encoding transmembrane channel-like 1 (TMC1) cause hearing loss without vestibular dysfunction in both mice and humans, we investigated the contribution of Tmc1 and the closely related Tmc2 to mechanotransduction in mice. We found that Tmc1 and Tmc2 were expressed in mouse vestibular and cochlear hair cells and that GFP-tagged TMC proteins localized near stereocilia tips. Tmc2 expression was transient in early postnatal mouse cochlear hair cells but persisted in vestibular hair cells. While mice with a targeted deletion of Tmc1 (Tmc1Δ mice) were deaf and ...
Inner ear hair cells convert the mechanical stimuli of sound, gravity, and head movement into electrical signals. This mechanotransduction process is initiated by opening of cation channels near the tips of hair cell stereocilia. Since the identity of these ion channels is unknown, and mutations in the gene encoding transmembrane channel-like 1 (TMC1) cause hearing loss without vestibular dysfunction in both mice and humans, we investigated the contribution of Tmc1 and the closely related Tmc2 to mechanotransduction in mice. We found that Tmc1 and Tmc2 were expressed in mouse vestibular and cochlear hair cells and that GFP-tagged TMC proteins localized near stereocilia tips. Tmc2 expression was transient in early postnatal mouse cochlear hair cells but persisted in vestibular hair cells. While mice with a targeted deletion of Tmc1 (Tmc1Δ mice) were deaf and ...
Inner ear hair cells convert the mechanical stimuli of sound, gravity, and head movement into electrical signals. This mechanotransduction process is initiated by opening of cation channels near the tips of hair cell stereocilia. Since the identity of these ion channels is unknown, and mutations in the gene encoding transmembrane channel-like 1 (TMC1) cause hearing loss without vestibular dysfunction in both mice and humans, we investigated the contribution of Tmc1 and the closely related Tmc2 to mechanotransduction in mice. We found that Tmc1 and Tmc2 were expressed in mouse vestibular and cochlear hair cells and that GFP-tagged TMC proteins localized near stereocilia tips. Tmc2 expression was transient in early postnatal mouse cochlear hair cells but persisted in vestibular hair cells. While mice with a targeted deletion of Tmc1 (Tmc1Δ mice) were deaf and ...
Inner ear hair cells convert the mechanical stimuli of sound, gravity, and head movement into electrical signals. This mechanotransduction process is initiated by opening of cation channels near the tips of hair cell stereocilia. Since the identity of these ion channels is unknown, and mutations in the gene encoding transmembrane channel-like 1 (TMC1) cause hearing loss without vestibular dysfunction in both mice and humans, we investigated the contribution of Tmc1 and the closely related Tmc2 to mechanotransduction in mice. We found that Tmc1 and Tmc2 were expressed in mouse vestibular and cochlear hair cells and that GFP-tagged TMC proteins localized near stereocilia tips. Tmc2 expression was transient in early postnatal mouse cochlear hair cells but persisted in vestibular hair cells. While mice with a targeted deletion of Tmc1 (Tmc1Δ mice) were deaf and ...
Photograph of a receptor cell, known as an outer hair cell (OHC), in the mammalian cochlea with its large nucleus (N) located at the base of the cell. Receptor cells in the cochlea have structures known as stereocilia (S) at their apex. These structures convert the mechanical energy of sound to an electrochemical signal that can be processed by the peripheral and central auditory nerves. Outer hair cells have an additional feature; they can contract and extend in response to hyper- and depolarization of the cell. Their motility is regulated by signals from the brain, thereby allowing for the fine-tuning of mechanical signals that impinge on the cochlea. The photo was taken at a magnification of 7100 X using an electron microscope by Margaret Harvey, Senior Biological Scientist. Check out the link to see an outer hair cells response to music: https://www.youtube.com/watch?v=c91ubWbScs4 ...
Inner ear hair cells. Coloured scanning electron micrograph (SEM) of sensory hair cells in the cochlea of the inner ear. The crescent-shaped arrangements of hairs across top are the stereocilia. Each crescent lies atop a single cell. Magnification: x1000 when printed at 10 centimetres wide. - Stock Image F004/3259
Link to Pubmed [PMID] - 26568308. Elife 2015;4. We show that a cage-shaped F-actin network is essential for maintaining a tight spatial organization of Cav1.3 Ca(2+) channels at the synaptic ribbons of auditory inner hair cells. This F-actin network is also found to provide mechanosensitivity to the Cav1.3 channels when varying intracellular hydrostatic pressure. Furthermore, this F-actin mesh network attached to the synaptic ribbons directly influences the efficiency of otoferlin-dependent exocytosis and its sensitivity to intracellular hydrostatic pressure, independently of its action on the Cav1.3 channels. We propose a new mechanistic model for vesicle exocytosis in auditory hair cells where the rate of vesicle recruitment to the ribbons is directly controlled by a synaptic F-actin network and changes in intracellular hydrostatic pressure.. http://www.ncbi.nlm.nih.gov/pubmed/26568308 ...
Conchae is a snail shaped organ which has 2 1/2 (2S) turns. The oval window opens into the vestibule to cochlea through the scala vestibule.The bony part of the cochlea make turns around a central pillar called modiolus. The modiolus at its upper end diverge into Y shaped membranes called vestibular membrane and basilar membrane. On the one side of the modiolus and vestibular membrane lie the scala vestibuli. On the other side of modiolus and basilar membrane lies the scala tympani. Scala vestibuli and tympani communicates with each other only at the apex of cochlea which is helicotrema. Between the vestibular membrane and basilar membrane lies the membranous cochlea which is called scala media (cochlear duct). On the internal surface of basilar membrane lies coiled and arranged in coiled form cells called hair cells and supporting cells. Hair cells are further divided into inner and outer ...
Conchae is a snail shaped organ which has 2 1/2 (2S) turns. The oval window opens into the vestibule to cochlea through the scala vestibule.The bony part of the cochlea make turns around a central pillar called modiolus. The modiolus at its upper end diverge into Y shaped membranes called vestibular membrane and basilar membrane. On the one side of the modiolus and vestibular membrane lie the scala vestibuli. On the other side of modiolus and basilar membrane lies the scala tympani. Scala vestibuli and tympani communicates with each other only at the apex of cochlea which is helicotrema. Between the vestibular membrane and basilar membrane lies the membranous cochlea which is called scala media (cochlear duct). On the internal surface of basilar membrane lies coiled and arranged in coiled form cells called hair cells and supporting cells. Hair cells are further divided into inner and outer ...
TY - JOUR. T1 - Use of organotypic cultures of Cortis organ to study the protective effects of antioxidant molecules on cisplatin-induced damage of auditory hair cells. AU - Kopke, Richard D.. AU - Liu, Wei. AU - Gabaizadeh, Ramin. AU - Jacono, Andrew. AU - Feghali, Joseph. AU - Spray, David. AU - Garcia, Phil. AU - Steinman, Howard. AU - Malgrange, Bridgitte. AU - Ruben, Robert J.. AU - Rybak, Leonard. AU - Van De Water, Thomas R.. PY - 1997/9/1. Y1 - 1997/9/1. N2 - Hypothesis: Cisplatin causes the generation of reactive oxygen species (ROS), which interferes with the antioxidant defense system of Cortis organ and results in damage to the hair cells. Background: Cisplatin is a widely used chemotherapeutic agent with the dose-limiting side effect of ototoxicity. Evidence is accumulating that cisplatin interferes with the antioxidant defense system of Cortis organ. Methods: Organotypic explants of P-3 rat organ of Corti were ...
We measured robust MET currents in both IHCs and OHCs of Myo3a−/−Myo3b−/− mice. The amplitude and sensitivity of these MET currents were smaller and more variable from cell to cell than those of control hair cells, but their kinetics and adaptation characteristics were normal, which appears to rule out an implication of these myosins in MET adaptation (Schneider et al., 2006). Incidentally, MET also occurred in the supernumerary stereocilia of circular OHC bundles, which display inward current responses when deflected in the direction opposite to the kinocilium. The MET currents of Myo3a−/−Myo3b−/− hair cells were consistent with an altered mechanical response of hair bundles due to their abnormal shapes, whereas the MET channels are otherwise properly functioning. Finally, the absence of an abnormal auditory phenotype in Myo3a-cKO Myo3b−/− mice, which lack both myosins IIIa and IIIb from P13, precludes a ...
CRITIQUE: Hair Cell Micromechanics and Otoacoustic Emissions is replete with highly detailed explanations of hair cell motility and the chemical and genetic forces behind it. It is an excellent guide for the scientist and clinician seeking a better understanding of hair cell mechanics. This books highly focused collection of scientific works successfully makes the argument toward the goal of expanding clinical applications. Although the body of the book is about hair cell mechanics and the heart is otoacoustic emissions, the reader will find that the soul is in the discussion of how OAEs can be utilized in the clinic. The innovative concepts presented here are worthy not just for scientific informations sake, but as valuable tools necessary to expand the audiologists prominence in the clinical arena. This book demonstrates that, audiologically, we live in an exciting time as we are able to witness the emergence and development of such ...
OHCs and inner hair cells (IHCs), do not regenerate once they are damaged or lost. For this reason, progressive loss of OHCs, in addition to loss of IHCs, leads to much of the etiology of age-related hearing loss.. "… attempts to direct stem cells towards hair cell fates have, so far, resulted only in the formation of immature cells that lack many of the markers of mature IHCs or OHCs," note the authors.. In order for scientists to research and develop treatments for age-related hearing loss, it is important to first gain a better understanding of the maturation process in the cells involved.. In light of this, researchers identified a set of OHC-enriched genes through RNA sequencing. They honed in on the gene Ikzf2 (which encodes Helios), because it was markedly enriched at all tested maturation timepoints, starting from postnatal day 4.. Then, through a series of genomic and functional approaches, the ...
TY - JOUR. T1 - Multi-isotope imaging mass spectrometry reveals slow protein turnover in hair-cell stereocilia. AU - Zhang, Duan Sun. AU - Piazza, Valeria. AU - Perrin, Benjamin J.. AU - Rzadzinska, Agnieszka K.. AU - Poczatek, J. Collin. AU - Wang, Mei. AU - Prosser, Haydn M.. AU - Ervasti, James M.. AU - Corey, David P.. AU - Lechene, Claude P.. PY - 2012/1/26. Y1 - 2012/1/26. N2 - Hair cells of the inner ear are not normally replaced during an animals life, and must continually renew components of their various organelles. Among these are the stereocilia, each with a core of several hundred actin filaments that arise from their apical surfaces and that bear the mechanotransduction apparatus at their tips. Actin turnover in stereocilia has previously been studied by transfecting neonatal rat hair cells in culture with a β-actin-GFP fusion, and evidence was found that actin is replaced, from the top down, in 2-3 days. ...
A 3,673-bp murine cDNA predicted to encode a glycosylphosphatidylinositol-anchored protein of 1,088 amino acids was isolated during a study aimed at identifying transcripts specifically expressed in the inner ear. This inner ear-specific protein, otoancorin, shares weak homology with megakaryocyte potentiating factor/mesothelin precursor. Otoancorin is located at the interface between the apical surface of the inner ear sensory epithelia and their overlying acellular gels. In the cochlea, otoancorin is detected at two attachment zones of the tectorial membrane, a permanent one along the top of the spiral limbus and a transient one on the surface of the developing greater epithelial ridge. In the vestibule, otoancorin is present on the apical surface of nonsensory cells, where they contact the otoconial membranes and cupulae. The identification of the mutation (IVS12+2T>C) in the corresponding gene OTOA in one consanguineous Palestinian family affected by nonsyndromic recessive deafness ...
Institutions: MRC Mammalian Genetics Unit and Mouse Genome Centre, MRC Institute of Hearing Research Genetic deafness is highly prevalent in the human population, affecting 1 in 2000 births. Many of these show primary abnormalities of the sensory epithelia of the inner ear, as do several mouse mutants. In the whirler (wi) mutant the stereocilia of the inner hair cells of the cochlear duct are considerably shorter than wild-type while outer hair cell stereocilia take on a more rounded U shape compared to the normal V or W shape. Cloning of the defective gene underlying wi will provide insight into the molecular processes involved in normal development of stereocilia as well as providing valuable insights into the causes of neuroepithelial deafness. The wi non-recombinant region is contained within a minimal tiling path consisting of 2 BACs and a PAC. One of the BACs has been used in transgenic rescue experiments and been shown to rescue the inner ...
Na+ concentrations in endolymph should be controlled to maintain hair cell function since the transduction channels of hair cells are cation-permeable but not K+-selective. membrane saccular extramacular epithelium semicircular canal duct epithelium and endolymphatic sac. ENaC activity is usually controlled by a number of signal pathways but most notably by genomic regulation of channel numbers in the membrane via glucocorticoid signaling. Nonselective cation channels in the apical membrane of outer sulcus epithelial cells and vestibular transitional cells mediate Na+ and parasensory K+ absorption. The K+-mediated transduction current in hair cells is also accompanied by a Na+ flux since the transduction channels are nonselective cation channels. Cation absorption by all of these cells is BMS-387032 usually regulated by extracellular ATP via apical nonselective cation ...
TY - JOUR. T1 - Hematopoietic stem cells prevent hair cell death after transient cochlear ischemia through paracrine effects. AU - Yoshida, Tadashi. AU - Hata, Ryuji. AU - Hakuba, Nobuhiro. AU - Cao, Fang. AU - Zhu, Pengxiang. AU - Sakanaka, Masahiro. AU - Gyo, Kiyofumi. PY - 2007/11/13. Y1 - 2007/11/13. N2 - Background and aims: Idiopathic sudden hearing loss (ISHL) is usually unilateral and can be anything within a range of a slight impairment of hearing to virtual deafness. One of the most common etiologies for ISHL is circulatory disturbance (most often vertebrobasilar ischemia). Vertebrobasilar ischemia (VBI) causes deafness because most of the auditory system including the inner ears is supplied from the vertebrobasilar system. ISHL of vascular cause is important for neurologists to recognize, because it sometimes appears as a warning sign of impending vertebrobasilar ischemic stroke. Previously, we produced cochlear ischemia by occluding both ...
To understand the basic biological property of hair cells (HCs) from lower vertebrates, we examined transcriptomes of adult zebrafish HCs. GFP-labeled HCs were isolated from the utricle, saccule, and lagena, the three inner-ear sensory epithelia of a pou4f3 promoter-driven GAP-GFP line of transgenic zebrafish. 2,000 HCs and 2,000 non-sensory cells from the inner ear were individually collected by suction pipet technique. RNA sequencing was performed and the resulting sequences were mapped, analyzed, and compared. Comparisons allow us to identify enriched genes in HCs, which may underlie HC specialization.
Recessive mutations at the mouse pirouette (pi) locus result in hearing loss and vestibular dysfunction due to neuroepithelial defects in the inner ear. Using a positional cloning strategy, we have identified mutations in the gene Grxcr1 (glutaredoxin cysteine-rich 1) in five independent allelic strains of pirouette mice. We also provide sequence data of GRXCR1 from humans with profound hearing loss suggesting that pirouette is a model for studying the mechanism of nonsyndromic deafness DFNB25. Grxcr1 encodes a 290 amino acid protein that contains a region of similarity to glutaredoxin proteins and a cysteine-rich region at its C terminus. Grxcr1 is expressed in sensory epithelia of the inner ear, and its encoded protein is localized along the length of stereocilia, the actin-filament-rich mechanosensory structures at the apical surface of auditory and vestibular hair cells. The precise architecture of hair cell stereocilia is ...
We used electron tomography of frog saccular hair cells to reconstruct presynaptic ultrastructure at synapses specialized for sustained transmitter release. Synaptic vesicles at inhibited synapses were abundant in the cytoplasm and covered the synaptic body at high density. Continuous maximal stimul …
A team of UH researchers led by Brian McDermott, PhD, Assistant Professor, Otolaryngology, Genetics and Genome Sciences and Neuroscience, School of Medicine, published the cover article in the January 1, 2014, issue of the Journal of Neuroscience based on their work studying mechanosensitive hair bundles in zebrafish. Zebrafish provide a useful model for studying hearing loss, as the hair cells are very similar to human cells, and their development can be studied from the larval stage in the optically transparent fish. Using these models, Dr. McDermotts team demonstrated that the protein ACF7 links hair cell microtubules to actin on the cuticular plate. The work provides new insight into the cytoskeleton and genesis of hair cells and, potentially, could help reveal underlying genetic causes of deafness. This is just one area of research in the zebrafish lab, which has recently been expanded ...
A mathematical model of cochlear processing is developed to account for the nonlinear dependence of frequency selectivity on intensity in inner hair cell and auditory nerve fiber responses. The model describes the transformation from acoustic stimulus to intracellular hair cell potentials in the cochlea. It incorporates a linear formulation of basilar membrane mechanics and subtectorial fluid-cilia displacement coupling, and simplified description of the inner hair cell nonlinear transduction process. The analysis at this stage is restricted to low-frequency single tones. The computed responses to single tone inputs exhibit the experimentally observed nonlinear effects of increasing intensity such as the increase in the bandwidth of frequency selectivity and the downward shift of the best frequency. In the model, the first effect is ...
Link to Pubmed [PMID] - 25122888. J. Neurosci. 2014 Aug;34(33):10853-69. The hair cell ribbon synapses of the mammalian auditory and vestibular systems differ greatly in their anatomical organization and firing properties. Notably, vestibular Type I hair cells (VHC-I) are surrounded by a single calyx-type afferent terminal that receives input from several ribbons, whereas cochlear inner hair cells (IHCs) are contacted by several individual afferent boutons, each facing a single ribbon. The specificity of the presynaptic molecular mechanisms regulating transmitter release at these different sensory ribbon synapses is not well understood. Here, we found that exocytosis during voltage activation of Ca(2+) channels displayed higher Ca(2+) sensitivity, 10 mV more negative half-maximum activation, and a smaller dynamic range in VHC-I than in IHCs. VHC-I had a larger number of Ca(2+) channels per ribbon (158 vs 110 ...
0108] In an embodiment, the polypeptide product which is encoded by the nucleic acid molecule may be a neurotrophic factor. In one embodiment the nucleic acid may encode a neurotrophic factor for spiral ganglion cells or cochlear hair cells. As used herein a "neurotrophic factor" is a polypeptide possessing at least one activity selected from promoting the growth and survival of developing neurons, maintaining/supporting mature neurons, and/or directing neural growth towards the source of the neurotrophic factor, and/or supporting the survival of spiral ganglion cells, and/or supporting the survival of cochlear hair cells. According to an embodiment, the neurotrophic factor is a polypeptide possessing at least one activity selected from promoting or maintaining neurite outgrowth from spiral ganglion cells and/or directing neurite outgrowth from spiral ganglion cells towards ...
TY - JOUR. T1 - Mutation screening of the PCDH15 gene in Spanish patients with usher syndrome type I. AU - Jaijo, Teresa. AU - Oshima, Aki. AU - Aller, Elena. AU - Carney, Carol. AU - Usami, Shin Ichi. AU - Millán, José M.. AU - Kimberling, William J.. PY - 2012/6/23. Y1 - 2012/6/23. N2 - Purpose: PCDH15 codes for protocadherin-15, a cell-cell adhesion protein essential in the morphogenesis and cohesion of stereocilia bundles and in the function or preservation of photoreceptor cells. Mutations in the PCDH15 gene are responsible for Usher syndrome type I (USH1F) and non-syndromic hearing loss (DFNB23). The purpose of this work was to perform PCDH15 mutation screening to identify the genetic cause of the disease in a cohort of Spanish patients with Usher syndrome type I and establish phenotype-genotype correlation. Methods: Mutation analysis of PCDH15 included additional exons recently identified and was performed by direct sequencing. The screening was performed in 19 probands with USH ...
Inner ear structures are compared among three major genera of the deep-sea fish family Melamphaidae (bigscales and ridgeheads). Substantial interspecific variation is found in the saccular otoliths, including the presence of a unique otolithic spur in the genera Melamphaes and Poromitra. The variation in the saccular otolith is correlated with an increase in the number of hair bundle orientation groups on the sensory epithelia from the genera Scopelogadus to Poromitra to Melamphaes. The diverse structural variations found in the saccule may reflect the evolutionary history of these species. The sensory hair cell bundles in this family have the most variable shapes yet encountered in fish ears. In the saccule, most of the hair bundles are 15-20 μm high, an exceptional height for fish otolithic end organs. These bundles have large numbers of stereovilli, including some that reach the length of the kinocilium. In the utricle, the striolar region separates into ...
About 95 percent of sound input to the brain comes from the ears inner hair cells.. "These inner hair cells are like spark plugs in an 8-cylinder engine," says Salvi. "A car wont run well if you remove half of those spark plugs, but people can still present with normal hearing thresholds if theyve lost half or even three-quarters of their inner hair cells.". Ear damage reduces the signal that goes the brain. That results in trouble hearing, but thats not whats happening here, because the brain "has a central gain control, like a radio, the listener can turn up the volume control to better hear a distant station." Salvi says.. Sound is converted to neural activity by the inner hair cells in the auditory part of the ear, called the cochlea.. Sound-evoked neural activity then travels from the cochlea to the auditory nerve and into the central ...
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Ben Creisler [email protected] A new paper (in open access) that may be of interest: Eric G. Ekdale (2015) Form and function of the mammalian inner ear. Journal of Anatomy (advance online publication) DOI: 10.1111/joa.12308 http://onlinelibrary.wiley.com/doi/10.1111/joa.12308/abstract http://onlinelibrary.wiley.com/doi/10.1111/joa.12308/epdf The inner ear of mammals consists of the cochlea, which is involved with the sense of hearing, and the vestibule and three semicircular canals, which are involved with the sense of balance. Although different regions of the inner ear contribute to different functions, the bony chambers and membranous ducts are morphologically continuous. The gross anatomy of the cochlea that has been related to auditory physiologies includes overall size of the structure, including volume and total spiral length, development of internal cochlear structures, including the primary and secondary bony laminae, morphology of the spiral nerve ganglion, and the nature of ...
To generate Ih activation curves with minimal contamination, tail currents were measured at −74 mV, near the reversal potential for the potassium-selective inward rectifier, IK1. The tail current was sampled at the moment of the step to −74 mV and plotted against prepulse potential. Conductance was calculated by dividing the Ih tail current by the difference (30 mV) between the step potential (−74 mV) and the experimentally determined reversal potential (−44 mV, as measured from type II hair cells in the presence of 500 μm BaCl2, which blocked IK1). Type II vestibular hair cells had a maximum conductance of 4.4 ± 2.6 nS, a half-activation voltage (V1/2) of −99 ± 6 mV, and a slope factor (S) of 8.5 ± 1.9 mV (n = 41; Fig. 2C). Under our experimental conditions, the conductance of Ih was slightly larger than previously reported in mouse vestibular hair cells (Rüsch et al., 1998), perhaps due to differences in ...
The effects of micro-gravity on the biophysical properties of frog labyrinthine hair cells have been examined by analysing calcium and potassium currents in isolated cells by the patch-clamp technique. The entire, anaesthetised frog was exposed to vector-free gravity in a "random positioning machine" (RPM) and the functional modification induced on single hair cells, dissected from the crista ampullaris, were subsequently studied in vitro. The major targets of microgravity exposure were the calcium/potassium current system and the IA kinetic mechanism. The amplitude of ICa was significantly reduced in micro-gravity conditioned cells. The delayed current, IKD (a complex of IKV and IKCa), was drastically reduced, mostly in its IKCa component. Micro-gravity also affected IKD kinetics by shifting the steady-state inactivation curve towards negative potentials and increasing the sensitivity of inactivation ...
Hairs form and develop in scalp. To be able to prevent hair loss and for the hair remains healthy; it plays an important role to protect scalp against the negative conditions which may arise and meet its needs.. NHTLAB Tablet with its special formulation, fights many factors which cause hair loss and aims at normalizing life cycle of hair and stopping the hair loss. Efficiency of NHTLAB Tablet on hair and scalp briefly is as follows:. Increases the production of the cells which are found in hair follicles and produce new hairs, and supports the formation of new hairs,. Supports hair transplantation after treatment process, helps hair follicles to take hold and improve rapidly.. Protects hair follicles against toxic effects of DHT, stops hair loss and helps ...
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 vision and hearing. ...
Looking for basilar membrane of cochlear duct? Find out information about basilar membrane of cochlear duct. structure composed mostly of lipid lipids, a broad class of organic products found in living systems. Most are insoluble in water but soluble in nonpolar... Explanation of basilar membrane of cochlear duct
At least 30 million Americans suffer from significant hearing loss and balance disorders, Lovett says. One-third of people above age 65 and half of people above age 75 have significant hearing loss. About 80 percent of these problems result from the loss of, or damage to, sensory hair cells. "The cochlea and utricle function nearly identically in birds and humans," says Mark E. Warchol, Ph.D., associate research scientist at the Central Institute for the Deaf and a research associate professor of otolaryngology and of anatomy and neurobiology at Washington University and a co-author of the paper. "But key differences exist between them allow birds to regenerate these cells. If we can understand those differences, perhaps we can learn how to replace lost or damaged sensory hair cells in humans ...
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The Snail/Gfi1 (SNAG) family of zinc finger proteins is a group of transcriptional repressors. Gfi1 is expressed in the hematopoietic and nervous system. Consequently, mutations of Gfi1 cause defects in hematopoiesis and inner ear development. In the Gfi1P2A/P2A mouse strain, a point mutation has been inserted in the SNAG domain that replaces a proline at amino acid position 2 by alanine (P2A). This completely abrogates the activity of Gfi1 as transcriptional repressor. Commercial Opportunities Gfi1 and its paralogue Gfi1b have overlapping, however differential functions in hematopoiesis. Loss of Gfi1 in mice affects pre-T-cell differentiation, the development of neutrophil granulocytes and inner ear hair cells, whereas in contrast loss of Gfi1b impairs the development of erythroid cells and megacaryocytes. Therefore, Gfi1P2A/P2A mice can be used as a model to study and treat deafness as a consequence of defects of inner ear development as well as defects of ...
Androgenetic Alopecia). The most common type of hair loss seen in women is androgenetic alopecia, also known as female pattern alopecia or baldness. This is seen as hair thinning predominantly over the top and sides of the head. It affects approximately one-third of all susceptible women, but is most commonly seen after menopause, although it may begin as early as puberty. Normal hair fall is approximately 100-125 hairs per day. Fortunately, these hairs are replaced. True hair loss occurs when lost hairs are not regrown or when the daily hair shed exceeds 125 hairs. Genetically, hair loss can come from either parents side of the family.. There are two different types of hair loss, medically known as anagen effluvium and Telogen effluvium. Anagen effluvium is generally due to internally administered medications, such as ...
Looking for online definition of cupular cecum of the cochlear duct in the Medical Dictionary? cupular cecum of the cochlear duct explanation free. What is cupular cecum of the cochlear duct? Meaning of cupular cecum of the cochlear duct medical term. What does cupular cecum of the cochlear duct mean?
But what are hair follicles anyway? Essentially, a follicle is a cell-lined sac from which strands of hair grow. Oil glands called the sebaceous glands are attached to the follicles and produce a fatty substance called sebum that cimbs up the follicle to our scalp. There the sebum oils our skin and hair.. But when hair follicles dont get enough nourishment, they can die. They simply become thinner and thinner until they eventually fall off our heads. When this happens, our scalp loses hair and we see baldness.. But when our hair thins out this doesnt necessarily mean our hair follicles are dead. Sometimes, for many different reasons, our hair follicles go into a resting phase and new hair growth temporarily stops. In the hair cycle, theres a resting phase called the telogen phase. But in this phase, while the old hair rests, ...
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Propecia Hair Gets Worse Before It Gets Better. FollicleRx - Promotes Healthy Hair GrowthWe are going to review FollicleRx, a product that promotes healthy hair follicles, but first we must discuss about hair loss and hair itself. Hair is a significant Depression And Hair Loss - Hair Loss Hell BlogGreat post linking D and hair loss! Looking back I realize the worse the PPD the more the hair fallout, a vicious cycle for sure. Now Im older and the genetic form Basics Of Hair Loss - Hair Sciences AcademyOn the other hand, any woman with the Hypothyroid Hair Loss Trigger, its the start of an even worse situation. Where youre not only experiencing the symptoms you Rosemary Oil For Hair Loss? Not So Fast (See Photos order cialis Read time: 20 minutes The Rosemary Oil, Minoxidil, ...
Tragi hairs can be numerous in some people and also very prominent. This condition is more often found in men than women. In some extreme cases, the ear hair can be quite long, recorded as being 5.2 inches by the Guinness World Records in 2003 for Radhakant Baijpai. Since then, the 64-year-old (in 2015) grocers ear hair has continued to grow to almost 10 inches long.. Ear hair is generally identified as the terminal hair developing from the follicles inside the ear canal. However, in its broader sense, ear hair may include the fine vellus hair covering much of the ear (particularly at the prominent parts of the anterior ear), as well as the terminal, or tragi hair.. Hair growth within the ear canal itself is limited to the cartilaginous ear canal: roughly the outer one-third of the ear canal. The inner two-thirds of the ear canal, called the bony ear canal, ...
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by Carolyn Y. Johnson / Globe StaffA year ago, I wrote about promising work toward developing a drug that could help treat hearing loss. A group of researchers at Massachusetts Eye and Ear Infirmary had discovered that an experimental drug originally developed with the intent of treating Alzheimers disease could regenerate the delicate hair cells inside ears and restore rudimentary hearing when administered to deaf mice.
It seems we have come full circle regarding our understanding of the cellular basis of audition in the cochlea. As early as the 1950s, the spiral ganglion was proposed to play the primary role in the ability to understand speech, leading to the development of the cochlear implant, which is arguably the most clinically successful biotechnological implant available in any field.. However, the discovery of otoacoustic emissions in the 1970s and outer hair cells motile abilities in the 1980s led to a paradigm shift that attributed to outer hair cells a primary role in the fine-tuning of the speech signal essential for understanding spoken language. More recently, several strong lines of evidence in animal models have suggested a significant part for the spiral ganglion to play in speech understanding, particularly in the presence of background noise.. Moderate noise exposure that causes a loss of up to 50 percent of spiral ganglion ...
Hair dying traces its roots to antiquity with evidence of use in ancient Egypt and the Roman Empire. Today, hair dying is an estimated $7 billion industry worldwide. Altering the natural color of hair is popular with both men and women but does have some health risks.. Hair has two major parts - the hair follicle and the hair shaft. The hair follicle is located at the root of the hair and attaches each hair to the scalp. The hair shaft sticks out of the follicle. Hair follicles contain living cells, but hair shafts do not. Hair color comes from the pigment melanin, which is made by cells in the hair follicle. Hair turns gray when the production of melanin decreases or stops. Hair dyes remove the natural ...
DISCUSSION. Although the ototoxic effects of aminoglycosides were first described in the 1940s, the underlying mechanisms remain unclear. Hearing damage associated with aminoglycoside use can include permanent hearing loss and tinnitus secondary to the degradation of sensorineural hair cells of the cochlea and/or vestibule. Damage to cochlear hair cells is thought to be mediated by oxidative stress, starting at the base where high-frequency sounds are decoded and advancing to the apex6,8,13,14,15. In the present study, we identified hearing complaints after aminoglycoside use in 27% of medical records analyzed, similar to what has been described in the literature (27.8%)11. Higher frequencies of TB and hearing complaints among male subjects in our study were also consistent with previous reports. This finding may be related to the increased tendency for ototoxicity risk factor exposure in men compared to women4,11,13.. In ...
The precise mechanical behavior of the basilar membrane (BM) at low frequencies is still unknown. To address this issue we use an in vitro preparation of the guinea pig temporal bone to investigate the mechanical behaviour of the organ of Corti at the apex of the cochlea. Confocal laser interferometry is used to record the nanometre displacements of both Hensens cells (HeC) and the BM in response to sound and electrical stimulation. We show that at low frequencies, the BM exhibits greatly reduced sound-evoked movement (similar to 35dB less) and no current-evoked movement, when compared to the HeC at the same position along the spiral. The BM best frequency is found to be an average of 52Hz (0.35 octave) higher than the HeC best frequency. In addition, we demonstrate that BM motion is not affected by inhibition of somatic electromotility or by blocking the mechanoelectrical transduction channels. We therefore propose that the BM primarily acts as a passive ...
TY - JOUR. T1 - Short-term plasticity and modulation of synaptic transmission at mammalian inhibitory cholinergic olivocochlear synapses. AU - Katz, Eleonora. AU - Elgoyhen, Ana Belén. PY - 2014/12/2. Y1 - 2014/12/2. N2 - The organ of Corti, the mammalian sensory epithelium of the inner ear, has two types of mechanoreceptor cells, inner hair cells (IHCs) and outer hair cells (OHCs). In this sensory epithelium, vibrations produced by sound waves are transformed into electrical signals. When depolarized by incoming sounds, IHCs release glutamate and activate auditory nerve fibers innervating them and OHCs, by virtue of their electromotile property, increase the amplification and fine tuning of sound signals. The medial olivocochlear (MOC) system, an efferent feedback system, inhibits OHC activity and thereby reduces the sensitivity and sharp tuning of cochlear afferent fibers. During neonatal development, IHCs ...
Male pattern baldness or Androgenic alopecia is a common problem where the patients are misled by improper marketing by beneficiaries. Male pattern baldness follows a genetic pattern commonly. However the onset could be advanced by external factors like improper nutrition, unhealthy parlour procedures, dandruff, cheap shampoos etc. Hair Transplantation Chennai as a result in permanent restoration lost hair surgically. Hair transplantation does not halt the on-going hair loss. Therefore medical management is an essential part of hair restoration procedure. Patients experiencing early thinning or hair loss should start medical treatment. Currently there are only two FDA approved medication in various combinations. This included Minoxidil and Fenestride. These medications help to prevent hair loss by blocking the action of androgens on hair follicles and also increase density ...
Can we heal hearing loss, ringing and vertigo naturally? Studies show that with the right nutrients, we can help repair hearing and ringing in the ears; and even vertigo maybe remedied by simple physical positions or "maneuvers".. Hearing is the ability to perceive sound by detecting vibrations and changing pressure through the ear. The inner and outer hair cells of the ear are very important and if damaged, hearing loss can occur. According to the NeuroScience Department at the U of WI, "When you are exposed to loud music or noise, it is your hair cells which are damaged. Hearing loss occurs because loud sounds are really just large pressure waves (like when you stand next to a subwoofer and can "feel" the bass). These large pressure waves bend the stereocilia too far, sometimes to the point where they are damaged. This kills the hair cell.". The regular use of aspirin, NSAIDs or acetaminophen can also increase the risk of ...
Most hair dyes in the stores are chemical based and using them is dangerous to health but all thanks to natural hair practice, today, we can dye or color our hair to different shades with out fear of adverse effects as is with the chemical store bought products.. Henna is a natural hair dye that even comes with a lot of benefits for hair. It is also one of the ingredients that is used for a lot of beauty reasons. Henna has been one of the best hair care ingredients available to us. Since ancient times, henna has been used as a hair dye.. However, it would be interesting to know that henna has numerous other hair benefits. Apart from coloring your hair, henna is also good for treating other hair problems. If applied on the hair, henna helps strengthen the hair, nourishes the scalp and softens the ...
Female-pattern baldness is different than that of male pattern baldness. The hair thins all over the head, in a diffused manner but the frontal hairline does not regress. There may be a moderate loss of hair on the crown, but this rarely progresses to total or near baldness as it may in men.. Female-pattern baldness hair loss is permanent. The hair loss is usually mild to moderate. No treatment is required if the person is comfortable with her appearance. It can be treated with medication or hair restoration. Some women however lose hair in a pattern similar to men.. Failure to grow a new hair is closely linked with genetic predisposition, aging, and levels of endocrine hormones. Changes in the levels of the androgens can affect hair production. For example, after the hormonal changes of menopause, many women find that the hair on the head ...
Can Methotrexate Cause Curly Hair. The Girl With Arthritis: My Methotrexate HairMy Methotrexate Hair which can also cause hair loss. It did. but I heard that buy viagra with paypal cancer patients who took chemo and lost their hair get curly hair as methotrexate and hair coloring , Arthritis Informationmethotrexate and hair CathyWhy did you stop. Are you saying i cant color my hair now. I have lots of long curly hair and it would cost a fortune for me Would you take methotrexate for this? - CurlTalkHome CurlTalk Life Non-hair discussion Would you take methotrexate for this? 3C curly/wavy/kinky hair. Mercury and other metals can cause Can Methotrexate cause Hair Loss? - TreatoCan Methotrexate cause Hair Loss? Hair Loss is a known side effect of Methotrexate. ...
Hearing is a unique sensory feature providing the individual with acoustic information about the surrounding environment. Humans rely on hearing to localize potential dangers and it is essential for communication and social interaction. Hearing impairment is the most common sensory deficit and affects approximately 360 million people world-wide according to the World Health Organization. Therefore, it is of great importance to understand the underlying mechanisms that enable hearing. At inner hair cell ribbon synapses, which are the first relay station of the auditory pathway, CaV1.3 calcium channels are presynaptic key elements modulating calcium-influx exocytosis coupling. In order to indefatigably respond to incoming sound waves, these CaV1.3 channels exhibit weak inactivation kinetics, but the underlying mechanisms are not understood. In the course of this study, a mutation in the gene encoding for calcium binding protein 2 (CaBP2) was shown to cause recessive, ...
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 hair bundle cause non-syndromic deafness at the DFNB16 locus". Nat ...
Release of neurotrophin-3 (NT3) and brain-derived neurotrophic factor (BDNF) from hair cells in the cochlea is essential for the survival of spiral ganglion neurons (SGNs). Loss of hair cells associated with a sensorineural hearing loss therefore results in degeneration of SGNs, potentially reducing the performance of a cochlear implant. Exogenous replacement of either or both neurotrophins protects SGNs from degeneration after deafness. We previously incorporated NT3 into the conducting polymer polypyrrole (Ppy) synthesized with para-toluene sulfonate (pTS) to investigate whether Ppy/pTS/NT3-coated cochlear implant electrodes could provide both neurotrophic support and electrical stimulation for SGNs. Enhanced and controlled release of NT3 was achieved when Ppy/pTS/NT3-coated electrodes were subjected to electrical stimulation. Here we describe the release dynamics and biological properties of Ppy/pTS with incorporated BDNF. Release studies ...
The vomeronasal organ (VNO) is a chemosensory structure involved in the detection of pheromones in most mammals. The VNO sensory epithelium contains both neurons and supporting cells. Data suggest that vomeronasal neurons represent the pheromonal transduction sites, whereas scarce information is available on the functional properties of supporting cells. To begin to understand their role in VNO physiology, we have characterized with patch-clamp recording techniques the electrophysiological properties of supporting cells isolated from the neuroepithelium of the mouse VNO. Supporting cells were distinguished from neurons by their typical morphology and by the lack of immunoreactivity for Ggamma8 and OMP, two specific markers for vomeronasal neurons. Unlike glial cells in other tissues, VNO supporting cells exhibited a depolarized resting potential (about -29 mV). A Goldman-Hodgkin-Katz analysis for resting ion ...
Platelet-rich plasma (PRP) is what we use to treat hair loss here at The Beauty Medics because its such an effective yet entirely natural treatment. PRP contains essential proteins known as growth factors that naturally stimulate the hair to start growing again by targeting the damaged hair follicles.. The great thing is that PRP is in your own blood, and thats what Dr. Bokhari and his team will use here to treat your hair loss. Your blood has two key components, red blood cells and plasma, and the plasma contains the platelets we use to stimulate hair growth and reverse any balding.. If you think it sounds too good to be true, youll be delighted to hear that numerous scientific studies have found PRP therapy to be effective in treating hair loss. A peer review of 14 published studies found that treatment with PRP is effective in promoting lost hair regrowth, decreasing ...
Our aims are to identify the molecular mechanisms that regulate the expression of Fgf20 during the embryonic development of the cochlea; to determine how FGF20 regulates sensory progenitor cell growth and the differentiation of cochlear outer hair and supporting cells in the organ of Corti; and to identify the specific genes and pathways that act downstream of FGF20 during cochlear development using Next Gen mRNA sequencing. We are testing the hypothesis that FGF signaling can enhance sensory cell regeneration following ototoxic damage.. 2. Regulation of neuronal excitability by intracellular FGFs.. We are studying a unique subfamily of FGFs that act intracellularly (iFGFs) in neurons and cardiomyocytes and that are important for regulating cell excitability through interactions with voltage gated sodium channels. Disruption of FGF14, one of four iFGFs, results in an anatomically normal mouse with severe neurobehavioral phenotypes including ataxia, seizure, paroxysmal ...
TAPES, BONDS, HAIR EXTENSIONS. We have a full line of tapes, bonds and other products either specifically for hair loss or good for long term maintenance of a hair system.. We use a new system for hair extensions - we believe is the best method in use today. Previous methods are more cumbersome and bulky. We also found hair weaving to be extremely time consuming and leaves a thick ridge along the weaving path. In addition, we no longer do or recommend hair weaving due to the risk of traction alopecia.. Check out the PHOTOS on this website of our new hair extension process and youll see the natural and beautiful results.. USEFUL LINKS:. Maria Jaggard Salon - Additional Information on Maria Jaggard Salon products & services. www.MariaJaggard.com. Wikipedia Reference on Hair Loss. www.Wikipedia.org/Hair_Loss. National Alopecia Areata Foundation. www.NAAF.org. ...
Scalp is where the hair is formed and grown. In order to prevent hair loss and maintain healthy hairs, protecting scalp against possible negative outcomes and procuring its needs play a major role. Hair loss is an incidence which occurs when one or more phenomenon effect the scalp negatively. Depending on the phenomenon which occurred; life cycle of the hair starts to deteriorate. To prevent hair loss; scalp should be protected against the factors which cause hair loss. NHTLAB SHAMPOO, thanks to its special formulation; fights against many reasons which cause hair loss and aims at normalizing the life cycle of the hair and stop hair loss. NHTLAB Shampoos effects on scalp and hair can be summarized as follows.. It supports the growth of new hair by increasing the production of the cells that ...
The most common type hair problems diagnosed in females is Androgenetic alopecia inherited. However, this is most common cause of hair problems in males as well. Androgenic alopecia in females is seen as hair thinning which means the number of hair on female head heavily reduces. Since the reason of hair loss varies individual to individual and hence proper medical help is of utmost importance.. Some other common causes of hair problems of females are mentioned here:. 1.Alopecia areata- This is patchy loss of hair from the scalp. Sometime eyebrows and other hair bearing parts begin losing hair. This type of hair loss is considered to be due to autoimmune.. 2.Traction alopecia- This type of hair loss occurs because of continuous traction pressure on hair follicles. Sometime this may occur because of tight ...
Several studies have demonstrated a link between diabetes and the dysfunction of the inner ear. Few studies, however, have reported the signalling mechanisms involved in metabolic control in human inner ear cells. Knowledge of the expression and role of the insulin receptor and downstream signalling components in the inner ear is sparce. Our immunohistochemistry approach has shown that the insulin receptor, insulin receptor substrate 1 (IRS1), protein kinase B (PKB) and insulin-sensitive glucose transporter (GLUT4) are expressed in the sensory epithelium of the human saccule, which also exhibits expression of a calcium-sensitive cAMP/cGMP phosphodiesterase 1C (PDE1C) and the vasopressin type 2 receptor. IRS1 and PDE1C are selectively expressed in sensory epithelial hair cells, whereas the other components are expressed in sensory epithelial supporting cells or in both cell types, as judged from co-expression or non-co-expression with glial ...
Several studies have noted an association between age and dizziness.6-8 ,12 ,14 The US NHANES reported that age was significantly associated with vestibular dysfunction.6 GNT-HIS also reported that moderate-to-severe dizziness or vertigo increased with age and the prevalence reached 37% in the age group 60 years and older.14 Hannaford et al7 showed that problems of balance increased with age. Our study also showed that the prevalence of dizziness and vestibular dysfunction in the 60-69 years and more than 70 years age segments is significantly higher than for those in the 40-49 years age segment. In multivariable analysis, dizziness and objective vestibular dysfunction assessed by the modified Romberg test showed a significant association with age (tables 1 and 2). The increase in prevalence with age can be explained by changes associated with the ageing of the vestibular system such as reduction of vestibular hair cells, degeneration of the cupula and otolith, and the ...
The findings shown that proanthocyanidins induced the growth of hair by converting your hair-cycle activity from your resting telogen hair cycle phase for the active growing anagen hair cycle phase. In line with Natural News, because hair consists of protein, fat, water and carbohydrates, a protein deficiency might result in weak hair or baldness. This is often particularly true for vegetarians. Adding protein to your diet may help to enrich the fitness of the hair. But additionally, there are certain medications that causes such a thinning hair, on top of that. Calcium channel blockers are certainly one such medication. Once conditions have improved, the hair is likely to re-grow. Hair disorders might result in hair loss. According to the University of Maryland Medical Center, a hair condition called ...
Last week, I put up a post about good moisturizers for low porosity hair. This time, I want to talk about high porosity hair (you didnt think I would leave this out did you?). If you dont know how to test the difference, read this post. Unlike low porosity hair, high porosity hair absorbs moisture really well. However, it also loses moisture easily. Because the hair cuticles are often open, its hard for high porous hair to retain moisture. High porous hair can be attributed to heat damage, poor hair maintenance, harsh hair dyes or just good ole genes. Its usually thin and can break easily if not properly maintained. High porosity hair needs heavier products and sealants to aid in retaining moisture. Products that contain butters and thicker oils like shea butter, mango butter, babassu oil, olive oil and avocado oil can help to retain ...
FRIDAY, April 29, 2016 (HealthDay News) -- Black women who like to wear their hair pulled back tightly may be increasing their risk of hair loss, new research suggests. A team of researchers from Johns Hopkins School of Medicine in Baltimore reviewed 19 studies and found a "strong association" between scalp-pulling hair styles and traction alopecia, which is gradual hair loss from damage to the hair follicle from tension at the hair root.. Traction alopecia is the most common type of hair loss among black American women, affecting about one out of three, the researchers said.. The study did not prove a definitive cause-and-effect connection. But, styles linked with this type of hair loss include braids, tight ponytails, dreadlocks, weaves and extensions, especially if hair has been chemically straightened, the review said.. "Hair is a ...
Both topical minoxidil and oral finasteride can be used to slow or even halt the loss of hair due to male pattern baldness, or androgenic alopecia. Both medications should also be used to slow the hair follicle miniaturation process that eventually results in hair loss. Shock loss is a phenomenon oberserved in some post-transplant patients, in which existing hair in the thinning regions that was transplanted is partially lost. Here are our thoughts about preventing post-transplant shock loss.. 1. Finasteride is effective at reducing the amount of shedding of normal hairs in the thinning zones after hair transplantation. 2. The timing of hair transplantation is important - if you are a young person experiencing early hair loss and have a large density of miniaturized hairs (impending hair loss), then hair transplant surgery ...
Loss of hair is a very natural and common phenomenon. According to experts, losing about 100 strands of hair approximately in a day is quite common. Therefore, there is nothing to worry about. Losing hair in bulks can be a real cause of concern, as this might harm your physical appearance.. As per various studies released by doctors and hair care experts, it has been observed that onions form to be a major ingredient which can augment growth of healthy hair follicles to a large extent. Considered to be one of the best of natural remedies, onions are suggested by doctors to be used on scalp in case you suffer from issues related to hair loss.. Besides, using such natural ingredients, hair care experts suggest that, you take proper care of your hair. This is because hair is an important component of your personality, and hence losing hair till ...
Melanotan 2 (a.k.a. Melanotan II) is a synthetic (man-made) member of the melanocortin family of naturally occurring proteins. The melanocortins are hormones and signaling peptides critical to the production of melanin (pigment molecule and in the regulation of homeostatis, appetite, and sexual arousal. Melanocortins mediate their effects by binding to melanocortin receptors.. The Effects of Melanocortins. Melanocortin (MC) receptors are found on cells throughout the body. Five different MC receptors, labeled (1) through (5), have been identified thus far. Understanding how those receptors work has allowed scientists to explore the effects of melanocortin and thus melanotan 2. Here are the effects of each MC receptor.. MC(1): MC(1) is found in melanocytes, skin cells that are responsible for the production of melanin, the pigment that imparts a dark color to the skin. It is also found on hair cells and is partially responsible, though not ...

Ocasys: Toon vak Auditory BiophysicsOcasys: Toon vak Auditory Biophysics

... frequency selectivity). 4. Transduction (hair cell micromechanics, mechanosensory ion channels; signal-to-noise of ionic ... 1. Anatomy and physiology of the auditory system (peripheral ear; hydrodynamical frequency separation; organ of Corti; the ... 7. Auditory modeling (description of auditory processing based on a classical cascaded model of peripheral hearing). 8. Hearing ... hair cell physiology). 5. Nonlinear cochlear phenomena (two-tone suppression; combination tones; combination tones; suppression ...
more infohttps://www.rug.nl/ocasys/rug/vak/show?code=KIM.AB09

β Subunits Modulate Alternatively Spliced, Large Conductance, Calcium-Activated Potassium Channels of Avian Hair Cells |...β Subunits Modulate Alternatively Spliced, Large Conductance, Calcium-Activated Potassium Channels of Avian Hair Cells |...

1980) The frequency selectivity of auditory nerve fibres and hair cells in the cochlea of the turtle. J Physiol (Lond) 306:79- ... Electrical tuning confers frequency selectivity onto sensory hair cells in the auditory periphery of frogs, turtles, and chicks ... The relationship between the time constant of deactivation and hair cell tuning frequency for turtle hair cells (Art and ... low-frequency) hair cells have higher levels than do basal hair cells (Ramanathan et al., 1999). Thus, one possibility is that ...
more infohttp://www.jneurosci.org/content/20/5/1675

Xpert search results for Environmental engineXpert search results for Environmental engine

When the hair cells are depolarised, chemical transmitter is released from the hair cells to the cells of the auditory nerve ... 4 Neural processing of auditory information. In this section we will look at how the frequency selectivity found along the ... We know that each hair cell occurs in a localised region of the cochlea, and that auditory nerve fibres contacting each hair ... In addition to being sensory receptors, hair cells are also presynaptic terminals. The membrane at the base of each hair cell ...
more infohttps://www.nottingham.ac.uk/xpert/scoreresults.php?keywords=Environmental%20engine&start=4460&end=4480

Adaptation in auditory hair cells.  - PubMed - NCBIAdaptation in auditory hair cells. - PubMed - NCBI

... motility of outer hair cells to produce an active process that supplies amplification and augments frequency selectivity in the ... Adaptation in auditory hair cells.. Fettiplace R1, Ricci AJ.. Author information. 1. Department of Physiology, University of ... The narrow stimulus limits of hair cell transduction, equivalent to a total excursion of about 100nm at the tip of the hair ... Changing the conductance or kinetics of the MET channels can vary their resonant frequency. The tuning information conveyed in ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/12965292?dopt=Abstract

Xpert search results for Environmental engiXpert search results for Environmental engi

4 Neural processing of auditory information. In this section we will look at how the frequency selectivity found along the ... The nerve that communicates with or innervates the hair cells along the basilar membrane is called the vestibulocochlear nerve ... modified by the auditory nerve and how information about the intensity of the signal is encoded in the response of the auditory ...
more infohttps://www.nottingham.ac.uk/xpert/scoreresults.php?keywords=Environmental%20engi&start=4220&end=4240

Cochlear amplifier - WikipediaCochlear amplifier - Wikipedia

The main component of the cochlear amplifier is the outer hair cell (OHC) which increases the amplitude and frequency ... The Physical Basis of the Action of the Cochlea Kemp 1978 : Stimulated acoustic emissions from within the human auditory system ... selectivity of sound vibrations using electromechanical feedback. The cochlear amplifier was first proposed in 1948 by T. Gold ... This, in turn, influences the deflection of the hair bundles of the inner hair cells. These cells are in contact with afferent ...
more infohttps://en.wikipedia.org/wiki/Cochlear_amplifier

York University: Christopher Bergevins HomepageYork University: Christopher Bergevin's Homepage

Dynamics of auditory hair cells (Cell Dynamics Workshop 2014, slides) * Interrelations between otoacoustic emission delays and ... Frequency selectivity in Old World monkeys corroborates sharp cochlear tuning in humans (2011) Joris PX*, Bergevin C*, Kalluri ... Frequency selectivity measured behaviorally in the ferret using forward masking (British Soc. Audiol. 2013, poster - pdf) ... Active nonlinear oscillators underlying peripheral auditory transduction (BSC 2015, abstract) * The notion of "frequency ...
more infohttp://www.yorku.ca/cberge/

Frontiers | Signal Processing in Periodically Forced Gradient Frequency Neural Networks | Frontiers in Computational...Frontiers | Signal Processing in Periodically Forced Gradient Frequency Neural Networks | Frontiers in Computational...

... poised near Hopf bifurcation points and tuned to tonotopically distributed frequencies have been used as models of auditory ... Here we provide a dynamical systems analysis of a canonical model for gradient frequency neural networks driven by a periodic ... Here we provide a dynamical systems analysis of a canonical model for gradient frequency neural networks driven by a periodic ... poised near Hopf bifurcation points and tuned to tonotopically distributed frequencies have been used as models of auditory ...
more infohttps://www.frontiersin.org/articles/10.3389/fncom.2015.00152/full

Auditory sensitivity of larval zebrafish (Danio rerio) measured using a behavioral prepulse inhibition assay | Journal of...Auditory sensitivity of larval zebrafish (Danio rerio) measured using a behavioral prepulse inhibition assay | Journal of...

2004) Evolution of sensory hair cells. In Evolution of the Vertebrate Auditory System (ed. Manley, G. A., Popper, A. N. and Fay ... such as those with reduced auditory sensitivity or frequency selectivity, and ultimately used to investigate the genetic basis ... auditory-evoked potential. d.p.f.. days post-fertilization. h.p.f.. hours post-fertilization. M-cell. Mauthner cell. PPI. ... 2009). Response of mechanosensory hair cells of the zebrafish lateral line to aminoglycosides reveals distinct cell death ...
more infohttp://jeb.biologists.org/content/216/18/3504

Peter Dallos - WikipediaPeter Dallos - Wikipedia

Demonstration that in the absence of outer hair cells there is a significant threshold shift, change in frequency selectivity, ... first intracellular recordings from hair cells in the low-frequency regions of the cochlea [2.8] First recordings from auditory ... First explanation of what determines low-frequency auditory threshold [2.5] Discovery that inner hair cells respond to basilar ... notably 50-60 dB amplification by outer hair cells [2.7] First intracellular recordings from outer hair cells in vivo; ...
more infohttps://en.wikipedia.org/wiki/Peter_Dallos

A Biophysical Model of Cochlear Processing: Intensity Dependence of Pure Tone Responses.A Biophysical Model of Cochlear Processing: Intensity Dependence of Pure Tone Responses.

... is developed to account for the nonlinear dependence of frequency selectivity on intensity in inner hair cell and auditory ... In the model, the first effect is primarily due to the saturating effect of the hair cell nonlinearity. The second results from ... The model describes the transformation from acoustic stimulus to intracellular hair cell potentials in the cochlea. It ... intensity such as the increase in the bandwidth of frequency selectivity and the downward shift of the best frequency. ...
more infohttps://drum.lib.umd.edu/handle/1903/4459

Transduction channels gating can control friction on vibrating hair-cell bundles in the ear. - Semantic ScholarTransduction channels' gating can control friction on vibrating hair-cell bundles in the ear. - Semantic Scholar

... friction impedes movements of the hair bundle and thus constrains the sensitivity and frequency selectivity of auditory ... propose that this intrinsic source of friction may contribute to the process that sets the hair cells characteristic frequency ... We characterized friction by analyzing hysteresis in the force-displacement relation of single hair-cell bundles in response to ... of the transduction channels produce internal frictional forces that can dominate viscous drag on the micrometer-sized hair ...
more infohttps://www.semanticscholar.org/paper/Transduction-channels%27-gating-can-control-friction-Bormuth-Barral/09dc624869123c1a4fcf6077ee2ef6ffd1504e65

Community Academic Profiles - Faculty & Researchers - Stanford MedicineCommunity Academic Profiles - Faculty & Researchers - Stanford Medicine

... we found that individual hair cells displayed frequency selectivity in synaptic exocytosis within the frequency range sensed by ... The cell membranes in the hair bundle of an auditory hair cell confront a difficult task as the bundle oscillates in response ... Hair-Bundle Mechanics. Auditory and balance organs rely on hair cells to convert mechanical vibrations into electrical signals ... Frequency-Selective Exocytosis by Ribbon Synapses of Hair Cells in the Bullfrogs Amphibian Papilla JOURNAL OF NEUROSCIENCE ...
more infohttps://med.stanford.edu/profiles/pulmonary/daibhid-o-maoileidigh

Imaging and vibrometry of the mouse cochlear apex using spectral domain optical coherence tomographyImaging and vibrometry of the mouse cochlear apex using spectral domain optical coherence tomography

... movements thus describe how the forces produced by outer hair cells improve the auditory sensitivity and frequency selectivity ... This presumably propels fluid and drives the stimulation of inner hair cell stereociliary bundles. Because inner hair cells ... As well, there was a traveling wave that emanated from the point of outer hair cell attachment and moved radially. ... of the intracochlear structures of live and dead normal hearing mice and found that active force generation by outer hair cells ...
more infohttps://scholarship.rice.edu/handle/1911/76774

A phenomenological model for the responses of auditory-nerve fibers. II. Nonlinear tuning with a frequency glide. - Semantic...A phenomenological model for the responses of auditory-nerve fibers. II. Nonlinear tuning with a frequency glide. - Semantic...

Instantaneous frequency glides in the reverse-correlation (revcor) function of the models response to broadband noise were ... The ability of this model to process arbitrary sound inputs makes it a useful tool for studying peripheral auditory processing. ... The incorporation of both the level-independent frequency glide and the level-dependent compressive nonlinearity into a ... but the instantaneous frequency profile in the revcor function was independent of sound pressure level, consistent with ...
more infohttps://www.semanticscholar.org/paper/A-phenomenological-model-for-the-responses-of-II.-a-Tan-Carney/bb98de71db9994899ba4d4dbf363bec3d7b0ca01

Noninvasive in vivo imaging reveals differences between tectorial membrane and basilar membrane traveling waves in the mouse...Noninvasive in vivo imaging reveals differences between tectorial membrane and basilar membrane traveling waves in the mouse...

This technology will clearly be important for studies of the auditory system because although inner hair cells furnish the ... 2014) Frequency selectivity without resonance in a fluid waveguide. Proc Natl Acad Sci USA 111(40):14548-14552. ... BM, basilar membrane; IHC, inner hair cells; OHC, outer hair cells; RM, Reissners membrane; SM, scala media; ST, scala tympani ... 1982) Hair-cell innervation by spiral ganglion cells in adult cats. Science 217(4555):175-177. ...
more infohttps://www.pnas.org/content/112/10/3128

MIT TechTV - Using Psychoacoustics to Explore Cochlear Function:Basic Mechanisms and Applications to Hearing AidsMIT TechTV - Using Psychoacoustics to Explore Cochlear Function:Basic Mechanisms and Applications to Hearing Aids

Inner hair cells on the basilar membrane send signals to the auditory nerve, and if theyre impaired, then the message they ... Moore and other researchers are trying to tailor hearing aids that compensate for reduced frequency selectivity and for ... which plays a crucial role as a frequency analyzer. Two classes of hair cells lying on top of the membrane serve distinctive ... Injuries to the outer hair cells result in a higher than normal threshold for detecting sounds, and inability to hear high and ...
more infohttp://techtv.mit.edu/tags/9157-impairments/videos/16194-using-psychoacoustics-to-explore-cochlear-function-basic-mechanisms-and-applications-to-hearing-aids

Daibhid O Maoileidighs Profile | Stanford ProfilesDaibhid O Maoileidigh's Profile | Stanford Profiles

... we found that individual hair cells displayed frequency selectivity in synaptic exocytosis within the frequency range sensed by ... The cell membranes in the hair bundle of an auditory hair cell confront a difficult task as the bundle oscillates in response ... Hair-Bundle Mechanics. Auditory and balance organs rely on hair cells to convert mechanical vibrations into electrical signals ... Frequency-Selective Exocytosis by Ribbon Synapses of Hair Cells in the Bullfrogs Amphibian Papilla JOURNAL OF NEUROSCIENCE ...
more infohttps://profiles.stanford.edu/daibhid-o-maoileidigh

FrançaisFrançais

We find that oscillations of the hair bundle allow the hair cell to actively resonate with its mechanical input at the expense ... with exquisite sensitivity and sharp frequency selectivity to weak sound stimuli. Curiously, the ear does not work as a high- ... fidelity sound receiver, introducing in the auditory percept "phantom" tones that are not present in the sound input. In this ... In particular, I will show that hair cells can power spontaneous oscillations of their mechanoreceptive hair bundles, a tuft of ...
more infohttp://lptms.u-psud.fr/fr/activites/seminaires/seminaires-de-lannee-2013/

Using Psychoacoustics to Explore Cochlear Function: Basic Mechanisms and Applications to Hearing Aids - VideoLectures.NETUsing Psychoacoustics to Explore Cochlear Function: Basic Mechanisms and Applications to Hearing Aids - VideoLectures.NET

Two classes of hair cells lying on top of the membrane serve distinctive purposes, and damage to them leads to common types of ... Two classes of hair cells lying on top of the membrane serve distinctive purposes, and damage to them leads to common types of ... Injuries to the outer hair cells result in a higher than normal threshold for detecting sounds, and inability to hear high and ... Injuries to the outer hair cells result in a higher than normal threshold for detecting sounds, and inability to hear high and ...
more infohttp://videolectures.net/mitworld_moore_upec/

Compressive nonlinearity in the hair bundles active response to mechanical stimulation | PNASCompressive nonlinearity in the hair bundle's active response to mechanical stimulation | PNAS

Frequency selectivity is one of the principal benefits of the cochlear active process (reviewed in ref. 3). Finally, hair ... What is the effect of the active process that powers spontaneous hair-bundle oscillation on a hair cells mechanical ... 2000) in Auditory Worlds: Sensory Analysis and Perception in Animals and Man, eds Manley G A, Fastl H, Kössl M, Oeckinghaus H, ... Frequency Tuning of Responses.. A hair bundle was most sensitive to small stimuli when stimulated near its frequency of ...
more infohttps://www.pnas.org/content/98/25/14386?ijkey=1f17b6f4da5ed9c5f0dc362770d226db5954afde&keytype2=tf_ipsecsha

Auditory Hair Cells and Sensory Transduction - Oxford Research Encyclopedia of NeuroscienceAuditory Hair Cells and Sensory Transduction - Oxford Research Encyclopedia of Neuroscience

The proximal stimulus for all hair cells is deflection of the mechanosensitive hair bundle. Hair cells convert mechanical ... All these organs have a common receptor cell type, which is called the haircell, for the bundle of enlarged microvilli ... and then deliver these physical stimuli to the hair bundles. ... information contained within the temporal pattern of hair ... These forces ensure the optimal sensitivity and sharp frequency selectivity of the mammalian cochlea. ...
more infohttp://neuroscience.oxfordre.com/view/10.1093/acrefore/9780190264086.001.0001/acrefore-9780190264086-e-85?rskey=tVdbVi&result=3

Auditory Hair Cells and Sensory Transduction - Oxford Research Encyclopedia of NeuroscienceAuditory Hair Cells and Sensory Transduction - Oxford Research Encyclopedia of Neuroscience

The proximal stimulus for all hair cells is deflection of the mechanosensitive hair bundle. Hair cells convert mechanical ... All these organs have a common receptor cell type, which is called the haircell, for the bundle of enlarged microvilli ... and then deliver these physical stimuli to the hair bundles. ... information contained within the temporal pattern of hair ... These forces ensure the optimal sensitivity and sharp frequency selectivity of the mammalian cochlea. ...
more infohttp://oxfordre.com/neuroscience/abstract/10.1093/acrefore/9780190264086.001.0001/acrefore-9780190264086-e-85?rskey=Vu1hB6&result=3

Auditory Hair Cells and Sensory Transduction - Oxford Research Encyclopedia of NeuroscienceAuditory Hair Cells and Sensory Transduction - Oxford Research Encyclopedia of Neuroscience

The proximal stimulus for all hair cells is deflection of the mechanosensitive hair bundle. Hair cells convert mechanical ... All these organs have a common receptor cell type, which is called the haircell, for the bundle of enlarged microvilli ... and then deliver these physical stimuli to the hair bundles. ... information contained within the temporal pattern of hair ... These forces ensure the optimal sensitivity and sharp frequency selectivity of the mammalian cochlea. ...
more infohttp://neuroscience.oxfordre.com/view/10.1093/acrefore/9780190264086.001.0001/acrefore-9780190264086-e-85?rskey=unSHlI&result=3

Regulation of alpha9/10-nAChR and SK2 function and localization at auditory synap - Elizabeth SchollRegulation of alpha9/10-nAChR and SK2 function and localization at auditory synap - Elizabeth Scholl

... developing hair cells will be essential for developing strategies to promote synapse formation in regenerating hair cells and ... These synapses are required for normal hearing sensitivity, frequency selectivity and tonotopic map formation during ... In Aim 1 studies, immunofluorescence and confocal microscopy will be used to identify protein components of the avian hair cell ... The proposed studies will: 1) define the molecular composition of Olivocochlear postsynaptic sites in hair cells, 2) test our ...
more infohttp://grantome.com/grant/NIH/F31-DC010114-02
  • Here we provide a dynamical systems analysis of a canonical model for gradient frequency neural networks driven by a periodic signal. (frontiersin.org)
  • This analysis will lead to deeper understanding of the diverse behaviors of neural systems under periodic forcing and can inform the design of oscillatory network models of auditory signal processing. (frontiersin.org)
  • B. L. Lonsbury-Martin, and M. B. Meikle, Neural correlates of auditory fatigue: frequency-dependent changes in activity of single cochlear nerve fibers, J. Neurophysiology , 41:987 (1978). (springer.com)
  • As a Postdoctoral Associate and Research Associate in The Rockefeller University, he developed models of cochlear mechanics, hair-bundle motility, and synaptic dynamics. (stanford.edu)
  • Our increased understanding of the central role that passive and active outer hair cell mechanics play in hearing is also relevant to broader research questions based on the ability of otoacoustic emissions to monitor the status of the mechanisms responsible for the fine qualities of human hearing. (asha.org)
  • By contrast, OHCs are signal amplifiers that generate force using active hair-bundle motility and somatic electromotility, the latter in response to depolarization that follows hair bundle displacement. (oxfordre.com)
  • Energy Output from a Single Outer Hair Cell. (semanticscholar.org)
  • As well, there was a traveling wave that emanated from the point of outer hair cell attachment and moved radially. (rice.edu)
  • The finding that prestin, a membrane protein embedded in the lateral wall of the outer hair cell, is the molecular mechanism of electromotility has allowed a more complete understanding of the beginning stages of both the normal hearing process and the development of hearing loss. (asha.org)
  • Networks of oscillators poised near Hopf bifurcation points and tuned to tonotopically distributed frequencies have been used as models of auditory processing at various levels, but systematic investigation of the dynamical properties of such oscillatory networks is still lacking. (frontiersin.org)
  • In Aim 1 studies, immunofluorescence and confocal microscopy will be used to identify protein components of the avian hair cell postsynaptic complex. (grantome.com)
  • In response to the quietest sounds we can hear, the hair cell's mechanical sensor, the hair bundle, moves by less than one-billionth of a meter. (stanford.edu)
  • Farther down the road are implantable hearing aids that use mechanical vibration to transmit a wide frequency range without distortion, and beyond that, the possibility of regenerating hair cells: -Don't bother with aids at all, let's fix the ear," says Moore. (mit.edu)
  • Hair cells convert mechanical information contained within the temporal pattern of hair bundle deflections into electrical signals, which they transmit to the brain for interpretation. (oxfordre.com)
  • Overall, these studies will provide novel insights into molecular mechanisms that direct functional Olivocochlear synapse assembly in sensory hair cells. (grantome.com)
  • Elucidating these mechanisms in normal developing hair cells will be essential for developing strategies to promote synapse formation in regenerating hair cells and restore hearing in animal models of sensorineural hearing loss, a permanent condition that affects millions of Americans. (grantome.com)
  • Molecular insights and the need to find a cure for hearing impairment caused by ototoxic drugs, noise, and aging--afflicting over 1 billion people worldwide--has boosted interest in examining the genes and molecular mechanisms underlying different biological properties of hair cells, as well as exploring strategies to regenerate and/or repair lost or injured hair cells using stem cell and gene therapies. (frontiersin.org)
  • 1. Genes and molecular mechanisms underlying hair cell differentiation, development, and regeneration as well as morphological and functional specializations. (frontiersin.org)
  • Simulation results show a continuum of cell types and behaviours: chopper-like behaviour arises for a wide range of parameters, suggesting that multiple mechanisms may underlie this behaviour. (imperial.ac.uk)
  • The proposed studies will: 1) define the molecular composition of Olivocochlear postsynaptic sites in hair cells, 2) test our hypothesis that specific adapter proteins bind to a9/10-nAChRs and SK2 channels and tether them to the postsynaptic scaffold, and 3) test the in vivo roles of the adapter proteins and the scaffold protein adenomatous polyposis coli (APC) in regulating the synaptic localization of a9/10-nAChRs and SK2. (grantome.com)
  • We will use retroviral-mediated expression of dominant negative peptides in vivo that selectively block the targeted protein interactions: We will test for changes in the synaptic localization of a9/10-nAChRs and SK2 in hair cells expressing the dominant negative versus control peptides using immunofluorescence and quantitative confocal microscopy. (grantome.com)
  • This positive feedback mechanism is achieved through a somatic motor and a hair bundle motor which operate independently of one another. (wikipedia.org)
  • The somatic motor is the OHC cell body and its ability to elongate or contract longitudinally due to changes in membrane potential. (wikipedia.org)
  • By comparing models with experimental observations, we are learning how a hair bundle's geometry, material properties, and ability to move spontaneously determine its function. (stanford.edu)
  • As reported by the motion of an attached glass fiber, an active hair bundle from the bullfrog's sacculus oscillates spontaneously. (pnas.org)
  • Furthermore, hair cells in lower vertebrates are able to be spontaneously regenerated once lost. (frontiersin.org)
  • Scientists are learning how to compensate for these dead regions by moving sounds to other frequencies that will be audible. (mit.edu)
  • A bundle is most sensitive to stimulation at its frequency of spontaneous oscillation. (pnas.org)
  • All β-containing channels were predicted to lie within the apical (low-frequency) 30% of the epithelium, consistent with previous in situ hybridization studies. (jneurosci.org)
  • As seen through scanning electron micrograph imagery, the apical side of the OHC is mechanically coupled to the reticular lamina while the basal side of the OHC is coupled to the Deiter's cell cupula. (wikipedia.org)
  • All these organs have a common receptor cell type, which is called the hair cell , for the bundle of enlarged microvilli protruding from its apical surface. (oxfordre.com)
  • Tight junctions that ring the apical surfaces of hair cells and supporting cells separate the endolymph from the perilymph , a fluid similar to normal extracellular solution that bathes the basolateral surfaces of hair cells. (oxfordre.com)
  • We denote by X ( t ) the displacement of a hair bundle's top relative to its mean position after subtraction of drift. (pnas.org)
  • Oscillatory instability at the Hopf bifurcation is a dynamical phenomenon that has been suggested to characterize active non-linear processes observed in the auditory system. (frontiersin.org)
  • IHCs, the primary sensory cells of the inner ear, make synaptic contact with VIIIth nerve afferents and are responsible for the transmission of the signal to the central nervous system (CNS). (oxfordre.com)
  • Other research involving the central auditory nervous system uncovered significant findings as well. (asha.org)
  • Recent efforts in "training" the ear to be more resistant to intense sounds through prophylactic noise exposure have discovered that the cochlear efferent system, which comprises a major portion of the descending central auditory nervous system, may play a crucial role in protecting individuals from noise-induced hearing loss in noisy work and recreational environments. (asha.org)
  • The auditory system processes temporal information at multiple scales, and disruptions to this temporal processing may lead to deficits in auditory tasks such as detecting and discriminating sounds in a noisy environment. (imperial.ac.uk)