scholarly journals Striatin is required for hearing and affects inner hair cells and ribbon synapses

2020 ◽  
Author(s):  
Prathamesh Thangaraj Nadar Ponniah ◽  
Shahar Taiber ◽  
Michal Caspi ◽  
Tal Koffler-Brill ◽  
Amiel A. Dror ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Hair Cells ◽  
High Frequency ◽  
Cell Junctions ◽  
Scanning Electron Micrographs ◽  
High Frequency Hearing Loss ◽  
Inner Hair Cells ◽  
Brainstem Response ◽  
Deficient Mice ◽  
Cell Cell

AbstractStriatin, a subunit of the serine/threonine phosphatase PP2A, is a core member of the conserved striatin-interacting phosphatase and kinase (STRIPAK) complexes. The protein is expressed in the cell junctions between epithelial cells, which play a role in maintaining cell-cell junctional integrity. Since adhesion is crucial for the function of the mammalian inner ear, we examined the localization and function of striatin in the mouse cochlea. Our results show that in neonatal mice, striatin is specifically expressed in the cell-cell junctions of the inner hair cells, the receptor cells in the mammalian cochlea. Auditory brainstem response measurements of striatin-deficient mice indicated a progressive, high-frequency hearing loss, suggesting that striatin is essential for normal hearing. Moreover, scanning electron micrographs of the organ of Corti revealed a moderate degeneration of the outer hair cells in the middle and basal regions, concordant with the high-frequency hearing loss. Importantly, striatin-deficient mice show aberrant ribbon synapse maturation that may lead to the observed auditory impairment. Together, these results suggest a novel function for striatin in the mammalian auditory system.

scholarly journals N-acetyl-cysteine prevents age-related hearing loss and the progressive loss of inner hair cells in γ-glutamyl transferase 1 deficient mice

Aging ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 730-750 ◽  
Author(s):  
Dalian Ding ◽  
Haiyan Jiang ◽  
Guang-Di Chen ◽  
Chantal Longo-Guess ◽  
Vijaya Prakash Krishnan Muthaiah ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Hair Cells ◽  
Inner Hair Cells ◽  
Progressive Loss ◽  
Age Related ◽  
Acetyl Cysteine ◽  
Glutamyl Transferase ◽  
Age Related Hearing Loss ◽  
Deficient Mice

scholarly journals Noise Exposure Potentiates Exocytosis From Cochlear Inner Hair Cells

2021 ◽  
Vol 13 ◽  
Author(s):  
Luis E. Boero ◽  
Shelby Payne ◽  
Maria Eugenia Gómez-Casati ◽  
Mark A. Rutherford ◽  
Juan D. Goutman
Keyword(s):  
Hearing Loss ◽  
Hair Cells ◽  
Synaptic Vesicles ◽  
Noise Exposure ◽  
Synaptic Function ◽  
Inner Hair Cells ◽  
Distortion Product ◽  
Brainstem Response ◽  
Ganglion Neurons ◽  
Bell Shaped Curve

Noise-induced hearing loss has gained relevance as one of the most common forms of hearing impairment. The anatomical correlates of hearing loss, principally cell damage and/or death, are relatively well-understood histologically. However, much less is known about the physiological aspects of damaged, surviving cells. Here we addressed the functional consequences of noise exposure on the capacity of inner hair cells (IHCs) to release synaptic vesicles at synapses with spiral ganglion neurons (SGNs). Mice of either sex at postnatal day (P) 15–16 were exposed to 1–12 kHz noise at 120 dB sound pressure level (SPL), for 1 h. Exocytosis was measured by tracking changes in membrane capacitance (ΔCm) from IHCs of the apical cochlea. Upon IHC depolarization to different membrane potentials, ΔCm showed the typical bell-shaped curve that mirrors the voltage dependence of Ca2+ influx, in both exposed and unexposed cells. Surprisingly, from IHCs at 1-day after exposure (d.a.e.), we found potentiation of exocytosis at the peak of the bell-shaped curve. The increase in exocytosis was not accompanied by changes in whole-cell Ca2+ influx, suggesting a modification in coupling between Ca2+ channels and synaptic vesicles. Consistent with this notion, noise exposure also changed the Ca2+-dependence of exocytosis from linear to supralinear. Noise exposure did not cause loss of IHCs, but did result in a small reduction in the number of IHC-SGN synapses at 1-d.a.e. which recovered by 14-d.a.e. In contrast, a strong reduction in auditory brainstem response wave-I amplitude (representing synchronous firing of SGNs) and distortion product otoacoustic emissions (reflecting outer hair cell function) indicated a profound hearing loss at 1- and 14-d.a.e. To determine the role of glutamate release in the noise-induced potentiation of exocytosis, we evaluated vesicular glutamate transporter-3 (Vglut3) knock-out (KO) mice. Unlike WT, IHCs from Vglut3KO mice showed a noise-induced reduction in ΔCm and Ca2+ influx with no change in the Ca2+-dependence of exocytosis. Together, these results indicate that traumatic noise exposure triggers changes of IHC synaptic function including a Vglut3-dependent potentiation of exocytosis.

Letter to the Editor

PEDIATRICS ◽  
1994 ◽  
Vol 94 (6) ◽  
pp. 950-952
Author(s):  
Michael J. M. Raffin ◽  
Gregory J. Matz
Keyword(s):  
Hearing Loss ◽  
Auditory Brainstem Response ◽  
High Frequency ◽  
Auditory Brainstem ◽  
Hearing Screening ◽  
Newborn Hearing Screening ◽  
High Frequency Hearing Loss ◽  
Universal Newborn Hearing Screening ◽  
Newborn Hearing ◽  
Brainstem Response

We thank Bess and Paradise, (1994)1 for bringing attention to some relevant issues related to universal newborn hearing screening. We note that their assertion that the effects of mild or moderate temporary hearing loss are "entirely speculative and perhaps nonexistent" may be somewhat overstated (see, for example, Teele, Klein, Chase, Menyuk, Rosner and associates, 1990).2 The assertion that click-evoked auditory brainstem response (ABR) may be used "... primarily to detect high-frequency hearing loss" is not warranted and misleading.

scholarly journals A study of cisplatin chemotherapy and hearing loss

2018 ◽  
Vol 4 (5) ◽  
pp. 1297 ◽  
Author(s):  
L. Sivasankari ◽  
Lalitha Subramanian
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Hair Cells ◽  
High Frequency ◽  
Chemotherapeutic Agents ◽  
Sensorineural Hearing ◽  
Cochlear Hair Cells ◽  
High Frequency Hearing Loss ◽  
Auditory Monitoring

<p class="abstract"><strong>Background:</strong> Various medications have been associated with ototoxicity. Platinum containing chemotherapeutic agents are associated with cochleotoxicity, characterized by high frequency hearing loss. Cisplatin and related agents are absorbed by the cochlear hair cells, resulting in ototoxicity through the production of reactive oxygen species.</p><p class="abstract"><strong>Methods:</strong> About 67 patients, irrespective of the type of cancer, fit to undergo chemotherapy were considered for study after meticulous examination. Audiograms were taken prior to chemotherapy, at the end of each cycle of chemotherapy, and follow-up audiograms at 3 months and 6 months after completion of chemotherapy.  </p><p class="abstract"><strong>Results:</strong> Among 37% of the patients with normal hearing, 10% of the patients developed sensorineural hearing loss after treatment. Among 63% of the patients with prior mild sensorineural hearing loss, 11.8% developed worsening of hearing after completion of treatment.</p><p class="abstract"><strong>Conclusions:</strong> Audiologic monitoring is important in patients undergoing cisplatin chemotherapy and post- chemotherapy auditory monitoring is essential to rehabilitate the patients with Sensorineural hearing loss.</p>

Modified Earpieces and CROS for High Frequency Hearing Losses

1968 ◽  
Vol 11 (1) ◽  
pp. 204-218 ◽  
Author(s):  
Elizabeth Dodds ◽  
Earl Harford
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
High Frequency ◽  
Hearing Aid ◽  
Sound Field ◽  
Intensity Level ◽  
Test Results ◽  
High Frequency Hearing Loss ◽  
Increased Sensitivity ◽  
Difficult Cases

Persons with a high frequency hearing loss are difficult cases for whom to find suitable amplification. We have experienced some success with this problem in our Hearing Clinics using a specially designed earmold with a hearing aid. Thirty-five cases with high frequency hearing losses were selected from our clinical files for analysis of test results using standard, vented, and open earpieces. A statistical analysis of test results revealed that PB scores in sound field, using an average conversational intensity level (70 dB SPL), were enhanced when utilizing any one of the three earmolds. This result was due undoubtedly to increased sensitivity provided by the hearing aid. Only the open earmold used with a CROS hearing aid resulted in a significant improvement in discrimination when compared with the group’s unaided PB score under earphones or when comparing inter-earmold scores. These findings suggest that the inclusion of the open earmold with a CROS aid in the audiologist’s armamentarium should increase his flexibility in selecting hearing aids for persons with a high frequency hearing loss.

scholarly journals Evaluating the Effectiveness of Earplugs in Preventing Noise-Induced Hearing Loss in an Auto Parts Factory in China

2021 ◽  
Vol 18 (13) ◽  
pp. 7190
Author(s):  
Wei Gong ◽  
Liangliang Zhao ◽  
Ling Li ◽  
Thais C. Morata ◽  
Wei Qiu ◽  
...  
Keyword(s):  
Hearing Loss ◽  
High Frequency ◽  
Health And Safety ◽  
Health Department ◽  
Detectable Effect ◽  
High Frequency Hearing Loss ◽  
Mandatory Requirement ◽  
Exposed Workers ◽  
Fit Testing ◽  
Auto Parts

A survey was administered to 385 noise-exposed workers from an auto parts factory and 1268 non-noise-exposed health department employees in China. Individual 8 h A-weighted equivalent sound levels (LAeq,8h), earplug personal attenuation ratings (PARs), and pure-tone audiometric tests were performed. The average LAeq,8h of noise-exposed workers was 87 dB (A) with a mean PAR of 7 dB. The prevalence of high-frequency hearing loss was 65% for noise-exposed workers and 33% for the non-noise-exposed employees. The use of earplugs had no observable effect on the prevalence of high-frequency hearing loss of the study participants (OR 0.964, 95% CI 0.925–1.005, p = 0.085). No significant relationship between the effectiveness offered by earplug use and high-frequency hearing thresholds at 3, 4, and 6 kHz was found (t = −1.54, p = 0.125). The mandatory requirement of earplug use without individualized training on how to wear HPDs correctly had no detectable effect on the prevention of hearing loss at the auto parts factory. The hearing conservation program at the surveyed factory was not effective. Periodic hearing tests, earplug fit testing, expanding the offer of different types of hearing protection, and employee education about the importance of protecting their hearing were recommended to the occupational health and safety program.

scholarly journals Chronic Oral Selegiline Treatment Mitigates Age-Related Hearing Loss in BALB/c Mice

2021 ◽  
Vol 22 (6) ◽  
pp. 2853
Author(s):  
Judit Szepesy ◽  
Viktória Humli ◽  
János Farkas ◽  
Ildikó Miklya ◽  
Júlia Tímár ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Dose Range ◽  
Auditory Brainstem ◽  
High Frequency Hearing Loss ◽  
Age Related ◽  
Hearing Function ◽  
Brainstem Response ◽  
Aging Societies ◽  
Age Related Hearing Loss

Age-related hearing loss (ARHL), a sensorineural hearing loss of multifactorial origin, increases its prevalence in aging societies. Besides hearing aids and cochlear implants, there is no FDA approved efficient pharmacotherapy to either cure or prevent ARHL. We hypothesized that selegiline, an antiparkinsonian drug, could be a promising candidate for the treatment due to its complex neuroprotective, antioxidant, antiapoptotic, and dopaminergic neurotransmission enhancing effects. We monitored by repeated Auditory Brainstem Response (ABR) measurements the effect of chronic per os selegiline administration on the hearing function in BALB/c and DBA/2J mice, which strains exhibit moderate and rapid progressive high frequency hearing loss, respectively. The treatments were started at 1 month of age and lasted until almost a year and 5 months of age, respectively. In BALB/c mice, 4 mg/kg selegiline significantly mitigated the progression of ARHL at higher frequencies. Used in a wide dose range (0.15–45 mg/kg), selegiline had no effect in DBA/2J mice. Our results suggest that selegiline can partially preserve the hearing in certain forms of ARHL by alleviating its development. It might also be otoprotective in other mammals or humans.

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