• primary audito
  • The inferior colliculus in turn projects to the medial geniculate nucleus, a part of the thalamus where sound information is relayed to the primary auditory cortex in the temporal lobe. (wikipedia.org)
  • Sound is believed to first become consciously experienced at the primary auditory cortex. (wikipedia.org)
  • Around the primary auditory cortex lies Wernickes area, a cortical area involved in interpreting sounds that is necessary to understand spoken words. (wikipedia.org)
  • When groups of auditory neurons are presented with harmonics, each neuron fires at one frequency and when combined, the entire harmonic is encoded into the primary auditory cortex of the brain. (wikipedia.org)
  • nerve
  • Simplified, nerve fibers' signals are transported by bushy cells to the binaural areas in the olivary complex, while signal peaks and valleys are noted by stellate cells, and signal timing is extracted by octopus cells. (wikipedia.org)
  • In humans and other vertebrates, hearing is performed primarily by the auditory system: mechanical waves, known as vibrations are detected by the ear and transduced into nerve impulses that are perceived by the brain (primarily in the temporal lobe). (wikipedia.org)
  • The sound information from the cochlea travels via the auditory nerve to the cochlear nucleus in the brainstem. (wikipedia.org)
  • citation needed] The inner hair cells transform the sound vibrations in the fluids of the cochlea into electrical signals that are then relayed via the auditory nerve to the auditory brainstem and to the auditory cortex. (wikipedia.org)
  • The axons of these cells make up the auditory nerve, encoding the rectified stimulus. (wikipedia.org)
  • The auditory nerve responses select certain frequencies, similar to the basilar membrane. (wikipedia.org)
  • Most CASA systems represent the firing rate in the auditory nerve rather than a spike-based. (wikipedia.org)
  • Based on the assumption that there are three reservoirs of transmitter substance within each hair cell, and the transmitters are released in proportion to the degree of displacement to the basilar membrane, the release is equated with the probability of a spike generated in the nerve fiber. (wikipedia.org)
  • Important model of pitch perception by unifying 2 schools of pitch theory: Place theories (emphasizing the role of resolved harmonics) Temporal theories (emphasizing the role of unresolved harmonics) The correlogram is generally computed in the time domain by autocorrelating the simulated auditory nerve firing activity to the output of each filter channel. (wikipedia.org)
  • It has been seen that when being played a pure tone, auditory nerve fibers will fire at the same frequency as the tone. (wikipedia.org)
  • In 1980, Don Johnson experimentally revealed phase-locking in the auditory nerve fibers of the adult cat. (wikipedia.org)
  • In the presence of -40 to -100 decibel single tones lasting 15 or 30 seconds, recordings from the auditory nerve fibers showed firing fluctuations in synchrony with the stimulus. (wikipedia.org)
  • regeneration
  • Molecular remodeling of tip links underlies mechanosensory regeneration in auditory hair cells. (nih.gov)
  • Thus, our findings provide a molecular mechanism for regeneration and maintenance of mechanosensory function in postmitotic auditory hair cells and could help identify elusive components of the mechanotransduction machinery. (nih.gov)
  • CONCLUSIONS/SIGNIFICANCE: The lack of dedifferentiation amongst supporting cells and their replacement by cells from the outer side of the organ of Corti are factors that may need to be considered in any attempt to promote endogenous hair cell regeneration. (biomedsearch.com)
  • It is thought that the lack of auditory hair cell regeneration in mammals is due to extrinsic factors. (pubmedcentralcanada.ca)
  • 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. (mdpi.com)
  • Although there is a considerable amount of variability found between studies owing to different species, tissues and treatments, there is some concordance between cellular pathways important for hair cell regeneration. (mdpi.com)
  • Since gene expression and proteomics data is now commonly submitted to centralized online databases, meta-analyses of these data may provide a better picture of pathways that are common to the process of hair cell regeneration and lead to potential therapeutics. (mdpi.com)
  • currents
  • Whole-cell patch-clamp recordings demonstrate that these transient PCDH15/PCDH15 links mediate mechanotransduction currents of normal amplitude but abnormal Ca(2+)-dependent decay (adaptation). (nih.gov)
  • Peak Ca 2+ and Ba 2+ currents of mature du/du inner hair cells (IHCs) were reduced by 30-40%, respectively, and gating properties, such as the voltage of half-maximum activation and voltage sensitivity, were altered, indicating that Ca v 1.3 channels normally coassemble with α 2 δ2 at IHC presynapses. (jneurosci.org)
  • Using a mouse model with a mutant, nonfunctional α 2 δ2 protein, we showed that the α 2 δ2 protein is necessary for normal calcium currents and exocytosis in inner hair cells. (jneurosci.org)
  • It has been shown that taicatoxin blocks the calcium currents in heart cells with IC50 between 10-500 nM. (wikipedia.org)
  • receptors
  • This sensory map exaggerates certain regions that have many peripheral sense cells like the lips and hands while reduces the relative space for processing areas with few receptors like the back. (wikipedia.org)
  • system
  • Using Cre/loxP based labeling system we demonstrate that inhibition of Notch signaling with a γ- secretase inhibitor (GSI) results in the trans-differentiation of supporting cells into hair cell-like cells. (pubmedcentralcanada.ca)
  • Hence, Gfi1 is expressed in the developing nervous system, is required for inner ear hair cell differentiation, and its loss causes programmed cell death. (biologists.org)
  • This is evident in the visual system of humans where sharp lines can be detected between bright and dark regions because of simple cells which inhibit their neighbors. (wikipedia.org)
  • Hair cells in the auditory system display tonotopic organization. (wikipedia.org)
  • The auditory system is the sensory system for the sense of hearing. (wikipedia.org)
  • It includes both the sensory organs (the ears) and the auditory parts of the sensory system. (wikipedia.org)
  • Based on feedback from the visual system, the lens of the eye adjusts its thickness to focus light on the photoreceptive cells of the retina, also known as the rods and cones, which detect the photons of light and respond by producing neural impulses. (wikipedia.org)
  • The effect of this system is to non-linearly amplify quiet sounds more than large ones so that a wide range of sound pressures can be reduced to a much smaller range of hair displacements. (wikipedia.org)
  • CASA differs from the field of blind signal separation in that it is (at least to some extent) based on the mechanisms of the human auditory system, and thus uses no more than two microphone recordings of an acoustic environment. (wikipedia.org)
  • Since CASA serves to model functionality parts of the auditory system, it is necessary to view parts of the biological auditory system in terms of known physical models. (wikipedia.org)
  • The neuronal encoding of sound is the representation of auditory sensation and perception in the nervous system. (wikipedia.org)
  • Thus what is known now of the auditory system has changed in the recent times and thus conceivably in the next two years or so, much of this will change. (wikipedia.org)
  • stereocilia
  • Mouse models carrying mutations for the nine Usher-associated genes have splayed stereocilia, and some show delayed maturation of ribbon synapses suggesting these proteins may play different roles in terminal differentiation of auditory hair cells. (biomedsearch.com)
  • Collectively, these findings establish the existence of a differential vesicular trafficking mechanism for specific Usher protein variants in mouse cochlear hair cells, with the apical variants playing a potential role in endosomal recycling and stereocilia development/maintenance, and the basolateral variants involved in vesicle docking and/or fusion through SNAP25-mediated interactions. (biomedsearch.com)
  • At the same stage, we also observed gaint stereocilia and stereocilia fusion in auditory hair cells by sanning electron microscopy. (egms.de)
  • They derive their name from the tufts of stereocilia called hair bundles that protrude from the apical surface of the cell into the fluid-filled cochlear duct. (wikipedia.org)
  • The deflection of the hair-cell stereocilia opens mechanically gated ion channels that allow any small, positively charged ions (primarily potassium and calcium) to enter the cell. (wikipedia.org)
  • midbrain
  • The use of interaural cross-correlation mechanism has been supported through physiological studies, paralleling the arrangement of neurons in the auditory midbrain. (wikipedia.org)
  • exocytosis
  • 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. (pasteur.fr)
  • 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. (wikipedia.org)
  • pathway
  • A candidate pathway for limiting supporting cell plasticity is the Notch signaling pathway, an evolutionarily conserved cell-cell communication mechanism known to regulate sensory-neural development . (pubmedcentralcanada.ca)
  • Neurons in higher auditory pathway centers are tuned to specific stimuli features, such as periodicity, sound intensity, amplitude and frequency modulation. (wikipedia.org)
  • startle
  • The inferior colliculus integrates auditory input with limited input from other parts of the brain and is involved in subconscious reflexes such as the auditory startle response. (wikipedia.org)
  • Neural
  • The neural plate is the source of the majority of neurons and glial cells of the CNS. (wikipedia.org)
  • During this time, the walls of the neural tube contain neural stem cells, which drive brain growth as they divide many times. (wikipedia.org)
  • Stellate (chopper) cells encode sound spectra (peaks and valleys) by spatial neural firing rates based on auditory input strength (rather than frequency). (wikipedia.org)
  • Some key players in several neural systems include Ca2+ions (see Calcium in biology) that send negative feedback in second messenger pathways that allow the neural receptor cells to close or open channels in response to the changes of ion flow. (wikipedia.org)
  • Differentiation
  • There was no evidence of significant de-differentiation of the specialised columnar supporting cells. (biomedsearch.com)
  • Knock-out of β-catenin inhibited hair-cell, as well as pillar-cell, differentiation from sensory progenitors but was not required to maintain a hair-cell fate once specified. (jneurosci.org)
  • Constitutive activation of β-catenin expanded sensory progenitors by inducing additional cell division and resulted in the differentiation of extra hair cells. (jneurosci.org)
  • Auditory sensory progenitors exit the cell cycle at embryonic day (E)13.5-E14.5 in a gradient from apex to base, opposite their differentiation gradient from base to apex. (jneurosci.org)
  • Much work has shown that Gfi1 and Gfi1b , a second mouse homolog, play pivotal roles in blood cell lineage differentiation. (biologists.org)
  • cortex
  • This article traces the route that sound waves first take from generation at an unknown source to their integration and perception by the auditory cortex. (wikipedia.org)
  • basilar
  • This causes the cells to be chemically elongated and shrunk (somatic motor), and hair bundles to shift which, in turn, electrically effects the basilar membrane's movement (hair-bundle motor). (wikipedia.org)
  • The basilar papilla is up to about 10mm long and contains up to 16500 hair cells. (wikipedia.org)
  • bundles
  • The amplification may be powered by the movement of their hair bundles, or by an electrically driven motility of their cell bodies. (wikipedia.org)
  • It is affected by the closing mechanism of the mechanical sensory ion channels at the tips of the hair bundles. (wikipedia.org)
  • frequency
  • This single synapse carries information regarding frequency, intensity and timing that is used by the CNS for to extract all information provided by the auditory modality. (grantome.com)
  • This tonotopic arrangement means that cells are laid out to range from low frequency to high frequency and processed in that same organization within the brain. (wikipedia.org)
  • calcium
  • Taicatoxin acts on the voltage-dependent L-type calcium channels from the heart, and on the small conductance Ca2+-activated K+ channels in the chromaffin cells and in the brain. (wikipedia.org)
  • Calcium ion influx plays an important role for the hair cells to adapt to the amplification of the signal. (wikipedia.org)
  • Hearing
  • Focusing on the use of genomics data in her research, she outlined new ways to understand the development of hair cells that are essential to hearing. (umaryland.edu)
  • Eventually, she says, it might be possible to use our increased understanding of RFX transcription factor to treat hearing loss, by either protecting hair cells from death or fostering their growth. (umaryland.edu)
  • 2003 ) found an ortholog of Drosophila NOMPC, TRPN1, and showed that it was expressed in hair cells and needed for proper hearing and balance. (jneurosci.org)
  • Sensory hearing loss often occurs as a consequence of damaged or deficient cochlear hair cells. (wikipedia.org)
  • The auditory, or "acoustic" abnormalities observed with the syndrome include sensorineural hearing loss and hoarseness. (wikipedia.org)
  • neurotransmitter
  • The quickness of the hair cell response may also be due to the fact that it can increase the amount of neurotransmitter release in response to a change as little as 100 μV in membrane potential. (wikipedia.org)
  • Information is conveyed from photoreceptor cells to bipolar cells via the release of the neurotransmitter glutamate at the ribbon synapse. (wikipedia.org)
  • embryonic development
  • We show that Gfi1 mRNA is expressed in many areas that give rise to neuronal cells during embryonic development in mouse, and that Gfi1 protein has a more restricted expression pattern. (biologists.org)
  • patterns
  • 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. (mdpi.com)
  • The lessened severity of Cx30 knockout in comparison to Cx26 knockout is supported by a study examining the time course and patterns of hair cell degeneration in the cochlea. (wikipedia.org)
  • Since the hair cells produce spike patterns, each filter of the model should also produce a similar spike in the impulse response. (wikipedia.org)