Critical role for cochlear hair cell BK channels for coding the temporal structure and dynamic range of auditory information for central auditory processing

Background: Amblyaudia is a weakness in the listener’s binaural processing of auditory information. Subjects with amblyaudia also demonstrate binaural integration deficits and may display similar patterns in their evoked responses in terms of latency and amplitude of these responses. The purpose of this study was to identify the presence of amblyaudia in a population of young children subjects and to measure mismatch negativity (MMN), P300 and cortical auditory evoked potentials (CAEPs) for those individuals.Methods: Subjects included in this study were divided into 2 groups control group that consisted of 20 normal hearing subjects with normal developmental milestones and normal speech development. The study group (GII) consisted of 50 subjects with central auditory processing disorders (CAPDs) diagnosed by central auditory screening tests. Results: With using dichotic tests including dichotic digits test (DDT) and competing sentence test (CST), we could classify these cases into normal, dichotic dysaudia, amblyaudia, and amblyaudia plus with percentages (40%, 14%, 38%, 8% respectively). Using event related potentials, we found that P300 and MMN are more specific in detecting neurocognitive dysfunction related to allocation of attentional resources and immediate memory in these cases.Conclusions: The presence of amblyaudia in cases of central auditory processing disorders (CAPDs) and event related potentials is an objective tool for diagnosis, prognosis and follow up after rehabilitation.

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Ototoxicity: The Radical Drum Beat and Rhythm of Cochlear Hair Cell Life and Death

International Journal of Toxicology ◽

10.1177/1091581818761128 ◽

2018 ◽

Vol 37 (3) ◽

pp. 195-206 ◽

Cited By ~ 4

Author(s):

David V. Gauvin ◽

Joshua Yoder ◽

Zachary J. Zimmermann ◽

Rachel Tapp

Keyword(s):

Cell Death ◽

Hair Cell ◽

Nuclear Dna ◽

Processing System ◽

Pharmaceutical Product ◽

Direct Access ◽

Auditory Information ◽

Life And Death ◽

Cochlear Hair Cell ◽

Sensory Processes

The function and structure of the auditory information processing system establishes a unique sensory environment for the “perfect storm.” The battle between life and death pits the cascade of an apoptotic storm, programmed cell death cascades, against simple cell death (necrosis) pathways. Live or die, the free radical biology of oxygen and hydroxylation, and the destruction of transition metal migration through the mechanical gate sensory processes of the hair cell lead to direct access to the cytoplasm, cytoplasmic reticulum, and mitochondria of the inner workings of the hair cells. These lead to subsequent interactions with nuclear DNA resulting in permanent hearing loss. The yin and yang of pharmaceutical product development is to document what kills, why it kills, and how do we mitigate it. This review highlights the processes of cell death within the cochlea.

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Central auditory processing in bilinguals

Auditory and Vestibular Research ◽

10.18502/avr.v30i3.6529 ◽

2021 ◽

Author(s):

Jamileh Chupani ◽

Mohanna Javanbakht ◽

Yones Lotfi

Keyword(s):

Temporal Processing ◽

Auditory Processing ◽

Cognitive Abilities ◽

Dichotic Listening ◽

Poor Performance ◽

Attention And Memory ◽

Auditory Information ◽

Central Auditory Processing ◽

Speech In Noise ◽

Listening Studies

Background and Aim: The majority of the world’s population is bilingual. Bilingualism is a form of sensory enrichment that translates to gains in cognitive abilities; these cognitive gains in attention and memory are known to modulate subcortical processing of auditory stimuli. Second language acquisition has a broad impact on various psychological, cognitive, memory, and linguistic processes. Central auditory processing (CAP) is the perceptual processing of auditory information. Due to its importance in bilingualism, this study aimed to review the CAP of bilinguals. Recent Findings: The CAP was studied in three areas: dichotic listening, temporal processing, and speech in noise perception. Regarding dichotic listening, studies have shown that bilinguals have better performance in staggered spondaic word (SSW) test, consonant-vowel dichotic test, dichotic digits test (DDT), and disyllable dichotic test than monolinguals, although similar results have also been reported in SSW and DDT. Regarding temporal processing, the results of bilinguals do not differ from those of monolinguals, although in some cases, it is better in bilinguals. Regarding speech in noise perception, the results between bilinguals and monolinguals are varied depending on the amount of linguistic information available in the stimuli. Conclusion: Bilingualism has a positive effect on dichotic processing, no effect on temporal processing, and varied effect on speech in noise perception. Bilinguals have poor performance using meaningful speech and better performance using meaningless speech. Keywords: Central auditory processing; bilingual; dichotic listening; temporal processing; speech in noise perception

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Hair cell BK channels interact with RACK1, and PKC increases its expression on the cell surface by indirect phosphorylation

AJP Cell Physiology ◽

10.1152/ajpcell.00062.2012 ◽

2012 ◽

Vol 303 (2) ◽

pp. C143-C150 ◽

Cited By ~ 8

Author(s):

Alexei Surguchev ◽

Jun-Ping Bai ◽

Powrnima Joshi ◽

Dhasakumar Navaratnam

Keyword(s):

Hair Cell ◽

Hair Cells ◽

High Frequency ◽

Messenger Rna ◽

Critical Role ◽

Phosphorylation Site ◽

Surface Expression ◽

Bk Channels ◽

Bk Channel ◽

Α Subunit

Large conductance (BK) calcium activated potassium channels (Slo) are ubiquitous and implicated in a number of human diseases including hypertension and epilepsy. BK channels consist of a pore forming α-subunit (Slo) and a number of accessory subunits. In hair cells of nonmammalian vertebrates these channels play a critical role in electrical resonance, a mechanism of frequency selectivity. Hair cell BK channel clusters on the surface and currents increase along the tonotopic axis and contribute significantly to the responsiveness of these hair cells to sounds of high frequency. In contrast, messenger RNA levels encoding the Slo gene show an opposite decrease in high frequency hair cells. To understand the molecular events underlying this paradox, we used a yeast two-hybrid screen to isolate binding partners of Slo. We identified Rack1 as a Slo binding partner and demonstrate that PKC activation increases Slo surface expression. We also establish that increased Slo recycling of endocytosed Slo is at least partially responsible for the increased surface expression of Slo. Moreover, analysis of several PKC phosphorylation site mutants confirms that the effects of PKC on Slo surface expression are likely indirect. Finally, we show that Slo clusters on the surface of hair cells are also increased by increased PKC activity and may contribute to the increasing amounts of channel clusters on the surface of high-frequency hair cells.

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Time Course of Early Audiovisual Interactions during Speech and Nonspeech Central Auditory Processing: A Magnetoencephalography Study

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2008.21019 ◽

2009 ◽

Vol 21 (2) ◽

pp. 259-274 ◽

Cited By ~ 8

Author(s):

Ingo Hertrich ◽

Klaus Mathiak ◽

Werner Lutzenberger ◽

Hermann Ackermann

Keyword(s):

Visual Processing ◽

Auditory Processing ◽

Time Course ◽

Visual Motion ◽

Sensory Information ◽

Visual Speech ◽

Dipole Source ◽

Auditory Information ◽

Central Auditory Processing ◽

Motion Onset

Cross-modal fusion phenomena suggest specific interactions of auditory and visual sensory information both within the speech and nonspeech domains. Using whole-head magnetoencephalography, this study recorded M50 and M100 fields evoked by ambiguous acoustic stimuli that were visually disambiguated to perceived /ta/ or /pa/ syllables. As in natural speech, visual motion onset preceded the acoustic signal by 150 msec. Control conditions included visual and acoustic nonspeech signals as well as visual-only and acoustic-only stimuli. (a) Both speech and nonspeech motion yielded a consistent attenuation of the auditory M50 field, suggesting a visually induced “preparatory baseline shift” at the level of the auditory cortex. (b) Within the temporal domain of the auditory M100 field, visual speech and nonspeech motion gave rise to different response patterns (nonspeech: M100 attenuation; visual /pa/: left-hemisphere M100 enhancement; /ta/: no effect). (c) These interactions could be further decomposed using a six-dipole model. One of these three pairs of dipoles (V270) was fitted to motion-induced activity at a latency of 270 msec after motion onset, that is, the time domain of the auditory M100 field, and could be attributed to the posterior insula. This dipole source responded to nonspeech motion and visual /pa/, but was found suppressed in the case of visual /ta/. Such a nonlinear interaction might reflect the operation of a binary distinction between the marked phonological feature “labial” versus its underspecified competitor “coronal.” Thus, visual processing seems to be shaped by linguistic data structures even prior to its fusion with auditory information channel.

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Treatment of (Central) Auditory Processing Disorder: Bridging the Gap Between the Audiologist and the Speech-Language Pathologist

Perspectives on Hearing and Hearing Disorders in Childhood ◽

10.1044/hhdc22.2.46 ◽

2012 ◽

Vol 22 (2) ◽

pp. 46-56

Author(s):

Velvet Buehler

Keyword(s):

Auditory Processing ◽

Temporal Discrimination ◽

Temporal Integration ◽

Acoustic Signals ◽

Auditory Processing Disorder ◽

Academic Learning ◽

Auditory Information ◽

Central Auditory Processing ◽

Related Factors ◽

Auditory Performance

There is a history of debate and controversy about the assessment and intervention of children diagnosed with auditory processing disorder (APD). Professionals in communication sciences and disorders view APD from different perspectives. Speech-language pathologists (SLPs) tend to view APD from the language and literacy perspective, or a top-down model, whereas audiologists tend to view APD from an auditory perception perspective, or a bottom-up model. Professionals who assess and treat children with APD need to bridge the gap and merge their different perspectives to plan effective intervention for children with APD. A panel of audiologists who demonstrated expertise in the area of Central Auditory Processing Disorders (CAPDs) developed The American Speech-Language-Hearing Association's (ASHA's) technical report on APDs (ASHA, 2005). This report was approved by ASHA's Executive board in 2005. In this report, central auditory processing refers to the efficiency and effectiveness by which the central nervous system uses auditory information. Central auditory processing includes the auditory mechanisms underlying the skills of sound localization and lateralization; auditory discrimination; auditory pattern recognition; temporal aspects of audition, including temporal integration, temporal discrimination, temporal ordering, and temporal masking; auditory performance in competing acoustic signals; and auditory performance with degraded acoustic signals (ASHA, 1996; Bellis, 2003; Chermak & Musiek, 1997; Jerger, 2009). A CAPD is a deficit in processing auditory input that is not due to higher-order language, cognitive, or related factors (Musiek, Bellis, & Chermak, 2005; Musiek & Chermak, 2007). However, children diagnosed with CAPD may experience difficulties in academic learning, speech, language, social skills, and literacy (e.g., encoding, decoding, reading comprehension, reading fluency, and written language).

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Histological evaluation of cochlear hair cell damage from noise-induced hearing loss in chinchillas

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159217 ◽

1990 ◽

Vol 48 (3) ◽

pp. 332-333

Author(s):

R.V. Harrison ◽

R.J. Mount ◽

P. White ◽

N. Fukushima

Keyword(s):

Hair Cell ◽

Evoked Potential ◽

Cell Damage ◽

Acoustic Trauma ◽

Histological Evaluation ◽

Cell Integrity ◽

Functional Changes ◽

Cochlear Hair Cell ◽

Left And Right ◽

Contralateral Ear

In studies which attempt to define the influence of various factors on recovery of hair cell integrity after acoustic trauma, an experimental and a control ear which initially have equal degrees of damage are required. With in a group of animals receiving an identical level of acoustic trauma there is more symmetry between the ears of each individual, in respect to function, than between animals. Figure 1 illustrates this, left and right cochlear evoked potential (CAP) audiograms are shown for two chinchillas receiving identical trauma. For this reason the contralateral ear is used as control.To compliment such functional evaluations we have devised a scoring system, based on the condition of hair cell stereocilia as revealed by scanning electron microscopy, which permits total stereociliar damage to be expressed numerically. This quantification permits correlation of the degree of structural pathology with functional changes. In this paper wereport experiments to verify the symmetry of stereociliar integrity between two ears, both for normal (non-exposed) animals and chinchillas in which each ear has received identical noise trauma.

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