scholarly journals Gαi Proteins are Indispensable for Hearing

2018 ◽  
Vol 47 (4) ◽  
pp. 1509-1532 ◽  
Author(s):  
Sandra Beer-Hammer ◽  
Sze Chim Lee ◽  
Stephanie A. Mauriac ◽  
Veronika Leiss ◽  
Isabel A. M. Groh ◽  
...  
Keyword(s):  
Auditory Processing ◽  
High Frequency ◽  
Hearing Threshold ◽  
Cell Polarization ◽  
Hair Bundle ◽  
Inner Hair Cell ◽  
Mouse Mutants ◽  
Protein Functions ◽  
Morphological Defects ◽  
Central Auditory Neurons

Background/Aims: From invertebrates to mammals, Gαi proteins act together with their common binding partner Gpsm2 to govern cell polarization and planar organization in virtually any polarized cell. Recently, we demonstrated that Gαi3-deficiency in pre-hearing murine cochleae pointed to a role of Gαi3 for asymmetric migration of the kinocilium as well as the orientation and shape of the stereociliary (“hair”) bundle, a requirement for the progression of mature hearing. We found that the lack of Gαi3 impairs stereociliary elongation and hair bundle shape in high-frequency cochlear regions, linked to elevated hearing thresholds for high-frequency sound. How these morphological defects translate into hearing phenotypes is not clear. Methods: Here, we studied global and conditional Gnai3 and Gnai2 mouse mutants deficient for either one or both Gαi proteins. Comparative analyses of global versus Foxg1-driven conditional mutants that mainly delete in the inner ear and telencephalon in combination with functional tests were applied to dissect essential and redundant functions of different Gαi isoforms and to assign specific defects to outer or inner hair cells, the auditory nerve, satellite cells or central auditory neurons. Results: Here we report that lack of Gαi3 but not of the ubiquitously expressed Gαi2 elevates hearing threshold, accompanied by impaired hair bundle elongation and shape in high-frequency cochlear regions. During the crucial reprogramming of the immature inner hair cell (IHC) synapse into a functional sensory synapse of the mature IHC deficiency for Gαi2 or Gαi3 had no impact. In contrast, double-deficiency for Gαi2 and Gαi3 isoforms results in abnormalities along the entire tonotopic axis including profound deafness associated with stereocilia defects. In these mice, postnatal IHC synapse maturation is also impaired. In addition, the analysis of conditional versus global Gαi3-deficient mice revealed that the amplitude of ABR wave IV was disproportionally elevated in comparison to ABR wave I indicating that Gαi3 is selectively involved in generation of neural gain during auditory processing. Conclusion: We propose a so far unrecognized complexity of isoform-specific and overlapping Gαi protein functions particular during final differentiation processes.

scholarly journals Audiometric notch and extended high-frequency hearing threshold shift in relation to total leisure noise exposure: An exploratory analysis

2017 ◽  
Vol 19 (91) ◽  
pp. 263 ◽  
Author(s):  
Veronika Weilnhammer ◽  
Wenjia Wei ◽  
Stefanie Heinze ◽  
DorisG Gerstner ◽  
SandraM Walser ◽  
...  
Keyword(s):  
High Frequency ◽  
Noise Exposure ◽  
Hearing Threshold ◽  
Exploratory Analysis ◽  
Threshold Shift

scholarly journals Hearing Thresholds Changes after MRI 1.5T of Head and Neck

2019 ◽  
Vol 2019 ◽  
pp. 1-4 ◽  
Author(s):  
Maryam Bahaloo ◽  
Mohammad Hossein Davari ◽  
Mohammad Sobhan ◽  
Seyyed Jalil Mirmohammadi ◽  
Mohammad Taghi Jalalian ◽  
...  
Keyword(s):  
Head And Neck ◽  
High Frequency ◽  
Repeated Measures ◽  
Hearing Threshold ◽  
Significant Shift ◽  
Auditory Thresholds ◽  
Hearing Thresholds ◽  
High Frequency Audiometry ◽  
Significant Difference ◽  
Before And After

Introduction. Exposure to high intensity noise produced by MRI is a cause for concern. This study was conducted to determine the temporary and permanent effects of exposure to noise created by performing MRI on the hearing threshold of the subjects using conventional and extended high frequency audiometry. Methods. This semiexperimental study was performed on 35 patients referred to Shahid Rahnemoun Hospital for head and neck MRI due to different clinical conditions. The hearing threshold of patients was measured before, immediately after, and 24 hours after performing 1.5 Tesla MRI using conventional and extended high frequency audiometry. SPSS version 18 was used to compare the mean hearing thresholds before and after MRI using paired T test and repeated measures analysis. Results. Comparison of auditory thresholds in conventional and extended high frequencies before and immediately after MRI showed a significant shift at 4 KHz (P = 0.008 and P = 0.08 for right and left ears), 6 KHz (P = 0.03 and P = 0.01 for right and left ears), and 14 KHz (P =0.03 and P = 0.31 for right and left ears). However, there was no significant difference between audiometric thresholds before and 24 hours after MRI. Conclusion. Noise due to 1.5 Tesla MRI can only cause transient threshold shift.

scholarly journals Hearing threshold levels and hearing loss among people in Zhejiang, China: a population-based cross-sectional study

BMJ Open ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. e027152 ◽  
Author(s):  
Dahui Wang ◽  
Huai Zhang ◽  
Haiyan Ma ◽  
Long Zhang ◽  
Lei Yang ◽  
...  
Keyword(s):  
Hearing Loss ◽  
High Frequency ◽  
Age Groups ◽  
Hearing Threshold ◽  
Population Based ◽  
Cross Sectional Study ◽  
Zhejiang Province ◽  
Sectional Study ◽  
Cross Sectional ◽  
High Frequency Hearing Loss

Hearing loss (≥26 dB threshold in the better ear), as a common chronic condition in humans, is increasingly gaining attention. Relevant research in China is relatively scarce, so we conduct a population-based study to investigate the prevalence of hearing loss among age groups, genders and ears in Zhejiang province, China, from September 2016 to June 2018.Study designPopulation-based cross-sectional studyParticipantsA total of 3754 participants aged 18–98 years and living in Zhejiang province, China.Outcome measuresPure-tone audiometric thresholds were measured at frequencies of 0.125–8 kHz for each subject. All participants were asked to complete a structured questionnaire, in the presence of a healthcare official.ResultsThe prevalence of speech-frequency and high-frequency hearing loss was 27.9% and 42.9%, respectively, in Zhejiang. There were significant differences in auditory thresholds at most frequencies among the age groups, genders (male vs female: 31.6%vs24.1% at speech frequency; 48.9% vs 36.8% at high frequency) and ears. In addition to the common factors affecting both types of hearing loss, a significant correlation was found between personal income and speech-frequency hearing loss (OR=0.69, 95% CI 0.52 to 0.92), and between hyperlipidaemia and high-frequency hearing loss (OR=1.45, 95% CI 1.02 to 2.07).ConclusionThe prevalence of hearing loss was high among people living in Zhejiang, particularly males, and in the left ear. Moreover, hearing thresholds increased with age. Several lifestyle and environment factors, which can be influenced by awareness and education, were significantly associated with hearing loss.

scholarly journals Effects of Various Extents of High-Frequency Hearing Loss on Speech Recognition and Gap Detection at Low Frequencies in Patients with Sensorineural Hearing Loss

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Bei Li ◽  
Yang Guo ◽  
Guang Yang ◽  
Yanmei Feng ◽  
Shankai Yin
Keyword(s):  
Hearing Loss ◽  
Speech Recognition ◽  
Sensorineural Hearing Loss ◽  
High Frequency ◽  
Hearing Threshold ◽  
Sensorineural Hearing ◽  
Gap Detection ◽  
Detection Thresholds ◽  
Low Frequencies ◽  
Compressed Speech

This study explored whether the time-compressed speech perception varied with the degree of hearing loss in high-frequency sensorineural hearing loss (HF SNHL) individuals. 65 HF SNHL individuals with different cutoff frequencies were recruited and further divided into mildly, moderately, and/or severely affected subgroups in terms of the averaged thresholds of all frequencies exhibiting hearing loss. Time-compressed speech recognition scores under both quiet and noisy conditions and gap detection thresholds within low frequencies that had normal thresholds were obtained from all patients and compared with data from 11 age-matched individuals with normal hearing threshold at all frequencies. Correlations of the time-compressed speech recognition scores with the extents of HF SNHL and with the 1 kHz gap detection thresholds were studied across all participants. We found that the time-compressed speech recognition scores were significantly affected by and correlated with the extents of HF SNHL. The time-compressed speech recognition scores also correlated with the 1 kHz gap detection thresholds except when the compression ratio of speech was 0.8 under quiet condition. Above all, the extents of HF SNHL were significantly correlated with the 1 kHz gap thresholds.

scholarly journals Loss of Cochlear Ribbon Synapse Is a Critical Contributor to Chronic Salicylate Sodium Treatment-Induced Tinnitus without Change Hearing Threshold

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Wei Zhang ◽  
Zhe Peng ◽  
ShuKui Yu ◽  
Qing-Ling Song ◽  
Teng-Fei Qu ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Acoustic Startle ◽  
Acoustic Startle Response ◽  
Hearing Threshold ◽  
Significant Loss ◽  
Acoustic Startle Reflex ◽  
Ribbon Synapse ◽  
Inner Hair Cell ◽  
Adult Rats ◽  
Ribbon Synapses

Tinnitus is a common auditory disease worldwide; it is estimated that more than 10% of all individuals experience this hearing disorder during their lifetime. Tinnitus is sometimes accompanied by hearing loss. However, hearing loss is not acquired in some other tinnitus generations. In this study, we injected adult rats with salicylate sodium (SS) (200 mg/kg/day for 10 days) and found no significant hearing threshold changes at 2, 4, 8, 12, 14, 16, 20, or 24 kHz (all p>0.05). Tinnitus was confirmed in the treated rats via Behaviour Testing of Acoustic Startle Response (ASR) and Gap Prepulse Inhibition Test of Acoustic Startle Reflex (GPIAS). A immunostaining study showed that there is significant loss of anti-CtBP2 puncta (a marker of cochlear inner hair cell (HC) ribbon synapses) in treated animals in apical, middle, and basal turns (all p<0.05). The ABR wave I amplitudes were significantly reduced at 4, 8, 12, 14, 16, and 20 kHz (all p<0.05). No significant losses of outer HCs, inner HCs, or HC cilia were observed (all p>0.05). Thus, our study suggests that loss of cochlear inner HC ribbon synapse after SS exposure is a contributor to the development of tinnitus without changing hearing threshold.

Assessment of cortical auditory evoked potentials in children with specific language impairment

2018 ◽  
Vol 72 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Elżbieta Włodarczyk ◽  
Agata Szkiełkowska ◽  
Adam Pilka ◽  
Henryk Skarżyński
Keyword(s):  
Early Diagnosis ◽  
Language Impairment ◽  
Specific Language Impairment ◽  
Auditory Processing ◽  
Personal Development ◽  
Auditory Evoked Potentials ◽  
Hearing Threshold ◽  
Speech Development ◽  
Therapeutic Success ◽  
Specific Language

The proper course of speech development heavily influences the cognitive and personal development of children. It is a condition for achieving preschool and school successes – it facilitates socializing and expressing feelings and needs. Impairment of language and its development in children represents a major diagnostic and therapeutic challenge for physicians and therapists. Early diagnosis of coexisting deficits and starting the therapy influence the therapeutic success. One of the basic diagnostic tests for children suffering from specific language impairment (SLI) is audiometry, thus far referred to as a hearing test. Auditory processing is just as important as a proper hearing threshold. Therefore, diagnosis of central auditory disorder may be a valuable supplementation of diagnosis of language impairment. Early diagnosis and implementation of appropriate treatment may contribute to an effective language therapy.

scholarly journals Investigation of Tinnitus Patients in Italy: Clinical and Audiological Characteristics

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Francesco Martines ◽  
Daniela Bentivegna ◽  
Fabiola Di Piazza ◽  
Enrico Martines ◽  
Vincenzo Sciacca ◽  
...  
Keyword(s):  
Hearing Loss ◽  
High Frequency ◽  
Pure Tone ◽  
Hearing Threshold ◽  
Related Factors ◽  
High Frequencies ◽  
Tinnitus Severity ◽  
Hearing Status ◽  
Neural Connection ◽  
The Impact

Objective. 312 tinnitus sufferers were studied in order to analyze: the clinical characteristics of tinnitus; the presence of tinnitus-age correlation and tinnitus-hearing loss correlation; the impact of tinnitus on subjects' life and where possible the etiological/predisposing factors of tinnitus.Results. There is a slight predominance of males. The highest percentage of tinnitus results in the decades 61–70. Of the tinnitus sufferers, 197 (63.14%) have a hearing deficit (light hearing loss in 37.18% of cases). The hearing impairment results of sensorineural type in 74.62% and limited to the high frequencies in 58.50%. The tinnitus is referred as unilateral in 59.93%, a pure tone in 66.99% and 10 dB above the hearing threshold in 37.7%. It is limited to high frequencies in 72.10% of the patients with sensorineural hearing loss (SNHL) while the 88.37% of the patients with high-frequency SNHL have a high-pitched tinnitus ( ).Conclusion. Hearing status and age represent the principal tinnitus related factors; there is a statistically significant association between high-pitched tinnitus and high-frequency SNHL. There is no significant correlation between tinnitus severity and tinnitus loudness confirming the possibility that neural connection involved in evoking tinnitus-related negative reactions are governed by conditioned reflexes.

scholarly journals Environmental Factors in Susceptibility to Noise-induced Hearing Loss in Student Musicians

2008 ◽  
Vol 23 (1) ◽  
pp. 20-28
Author(s):  
Susan L Phillips ◽  
Julie Shoemaker ◽  
Sandra T Mace ◽  
Donald A Hodges
Keyword(s):  
Risk Factor ◽  
High Frequency ◽  
Hearing Threshold ◽  
Music Students ◽  
First Year ◽  
The Third ◽  
School Of Music ◽  
The Right ◽  
Susceptibility To Noise ◽  
Determining Factor

Hearing threshold and survey data collected over 3 years in a university school of music indicate that 52% of undergraduate music students show declines in high-frequency hearing at 6000 Hz consistent with acoustic overexposure. Declines at 4000 Hz have grown in number over the 3 years, from 2% the first year to 30% in the third year. These “noise notches” are seen in all instrument groups, including voice, and are seen more in the right ear than the left ear in all groups. Exposure to outside noise does not appear to be a determining factor in who develops these declines. It is concluded that genetic predisposition is a likely risk factor.

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