scholarly journals Erratum to “Liproxstatin-1 Protects Hair Cell-Like HEI-OC1 Cells and Cochlear Hair Cells against Neomycin Ototoxicity”

2021 ◽  
Vol 2021 ◽  
pp. 1-2
Author(s):  
Zhiwei Zheng ◽  
Dongmei Tang ◽  
Liping Zhao ◽  
Wen Li ◽  
Jinghong Han ◽  
...  
Keyword(s):  
Hair Cell ◽  
Hair Cells ◽  
Cochlear Hair Cells

scholarly journals Effects of cochlear hair cell ablation on spatial learning/memory

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Z. Jason Qian ◽  
Anthony J. Ricci
Keyword(s):  
Hearing Loss ◽  
Hair Cell ◽  
Spatial Learning ◽  
Hair Cells ◽  
Noise Exposure ◽  
Memory Errors ◽  
Cochlear Hair Cells ◽  
Cochlear Hair Cell ◽  
Cell Ablation ◽  
Spatial Learning Memory

AbstractCurrent clinical interest lies in the relationship between hearing loss and cognitive impairment. Previous work demonstrated that noise exposure, a common cause of sensorineural hearing loss (SNHL), leads to cognitive impairments in mice. However, in noise-induced models, it is difficult to distinguish the effects of noise trauma from subsequent SNHL on central processes. Here, we use cochlear hair cell ablation to isolate the effects of SNHL. Cochlear hair cells were conditionally and selectively ablated in mature, transgenic mice where the human diphtheria toxin (DT) receptor was expressed behind the hair-cell specific Pou4f3 promoter. Due to higher Pou4f3 expression in cochlear hair cells than vestibular hair cells, administration of a low dose of DT caused profound SNHL without vestibular dysfunction and had no effect on wild-type (WT) littermates. Spatial learning/memory was assayed using an automated radial 8-arm maze (RAM), where mice were trained to find food rewards over a 14-day period. The number of working memory errors (WME) and reference memory errors (RME) per training day were recorded. All animals were injected with DT during P30–60 and underwent the RAM assay during P90–120. SNHL animals committed more WME and RME than WT animals, demonstrating that isolated SNHL affected cognitive function. Duration of SNHL (60 versus 90 days post DT injection) had no effect on RAM performance. However, younger age of acquired SNHL (DT on P30 versus P60) was associated with fewer WME. This describes the previously undocumented effect of isolated SNHL on cognitive processes that do not directly rely on auditory sensory input.

Shaker-1 mutations reveal roles for myosin VIIA in both development and function of cochlear hair cells

Development ◽  
1998 ◽  
Vol 125 (4) ◽  
pp. 557-566 ◽  
Author(s):  
T. Self ◽  
M. Mahony ◽  
J. Fleming ◽  
J. Walsh ◽  
S.D. Brown ◽  
...  
Keyword(s):  
Hair Cell ◽  
Hair Cells ◽  
Usher Syndrome ◽  
Orthologous Gene ◽  
Cell Development ◽  
Cochlear Hair Cells ◽  
Cochlear Hair Cell ◽  
Show Evidence ◽  
Myosin Viia ◽  
And Function

The mouse shaker-1 locus, Myo7a, encodes myosin VIIA and mutations in the orthologous gene in humans cause Usher syndrome type 1B or non-syndromic deafness. Myo7a is expressed very early in sensory hair cell development in the inner ear. We describe the effects of three mutations on cochlear hair cell development and function. In the Myo7a816SB and Myo7a6J mutants, stereocilia grow and form rows of graded heights as normal, but the bundles become progressively more disorganised. Most of these mutants show no gross electrophysiological responses, but some did show evidence of hair cell depolarisation despite the disorganisation of their bundles. In contrast, the original shaker-1 mutants, Myo7ash1, had normal early development of stereocilia bundles, but still showed abnormal cochlear responses. These findings suggest that myosin VIIA is required for normal stereocilia bundle organisation and has a role in the function of cochlear hair cells.

scholarly journals LIN28B/let-7control the ability of neonatal murine auditory supporting cells to generate hair cells through mTOR signaling

2020 ◽  
Vol 117 (36) ◽  
pp. 22225-22236
Author(s):  
Xiao-Jun Li ◽  
Angelika Doetzlhofer
Keyword(s):  
Hair Cell ◽  
Hair Cells ◽  
Rna Binding ◽  
Mammalian Target Of Rapamycin ◽  
Cell Loss ◽  
Supporting Cell ◽  
Dependent Manner ◽  
Cell Plasticity ◽  
Supporting Cells ◽  
Cochlear Hair Cells

Mechano-sensory hair cells within the inner ear cochlea are essential for the detection of sound. In mammals, cochlear hair cells are only produced during development and their loss, due to disease or trauma, is a leading cause of deafness. In the immature cochlea, prior to the onset of hearing, hair cell loss stimulates neighboring supporting cells to act as hair cell progenitors and produce new hair cells. However, for reasons unknown, such regenerative capacity (plasticity) is lost once supporting cells undergo maturation. Here, we demonstrate that the RNA binding protein LIN28B plays an important role in the production of hair cells by supporting cells and provide evidence that the developmental drop in supporting cell plasticity in the mammalian cochlea is, at least in part, a product of declining LIN28B-mammalian target of rapamycin (mTOR) activity. Employing murine cochlear organoid and explant cultures to model mitotic and nonmitotic mechanisms of hair cell generation, we show that loss of LIN28B function, due to its conditional deletion, or due to overexpression of the antagonistic miRNAlet-7g, suppressed Akt-mTOR complex 1 (mTORC1) activity and renders young, immature supporting cells incapable of generating hair cells. Conversely, we found that LIN28B overexpression increased Akt-mTORC1 activity and allowed supporting cells that were undergoing maturation to de-differentiate into progenitor-like cells and to produce hair cells via mitotic and nonmitotic mechanisms. Finally, using the mTORC1 inhibitor rapamycin, we demonstrate that LIN28B promotes supporting cell plasticity in an mTORC1-dependent manner.

The coding of sound pressure and frequency in cochlear hair cells of the terrapin

1978 ◽  
Vol 203 (1151) ◽  
pp. 209-218 ◽  
Keyword(s):  
Hair Cell ◽  
Hair Cells ◽  
Characteristic Frequency ◽  
Voltage Response ◽  
Recording Electrode ◽  
Small Current ◽  
Cochlear Hair Cells ◽  
Damped Oscillations ◽  
Current Steps ◽  
Two Stages

Intracellular recordings have been made from single hair cells in the cochlea of the terrapin, and the site of recording has been verified by injection of a fluorescent dye through the recording electrode. A hair cell gives periodic voltage responses graded with the intensity and frequency of the sound stimulus, and produces the largest response at its characteristic frequency. When small current steps are injected through the recording electrode, the voltage response of the cell exhibits damped oscillations at its characteristic frequency. The results are consistent with the idea that the cochlear frequency selectivity arises in two stages and it is suggested that the second stage resides within the hair cell itself.

Polybrene: Observations on cochlear hair cell necrosis and minimal lentiviral transduction of cochlear hair cells

2015 ◽  
Vol 600 ◽  
pp. 164-170 ◽  
Author(s):  
Miaomiao Han ◽  
Dongzhen Yu ◽  
Qiang Song ◽  
Jiping Wang ◽  
Pin Dong ◽  
...  
Keyword(s):  
Hair Cell ◽  
Hair Cells ◽  
Cell Necrosis ◽  
Cochlear Hair Cells ◽  
Lentiviral Transduction ◽  
Cochlear Hair Cell

scholarly journals Disruption of Hars2 in Cochlear Hair Cells Causes Progressive Mitochondrial Dysfunction and Hearing Loss in Mice

2021 ◽  
Vol 15 ◽  
Author(s):  
Pengcheng Xu ◽  
Longhao Wang ◽  
Hu Peng ◽  
Huihui Liu ◽  
Hongchao Liu ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Hair Cell ◽  
Mitochondrial Dysfunction ◽  
Hair Cells ◽  
Cell Loss ◽  
Outer Hair Cells ◽  
Hair Cell Loss ◽  
Progressive Hearing Loss ◽  
Cochlear Hair Cells ◽  
Inner Hair Cells

Mutations in a number of genes encoding mitochondrial aminoacyl-tRNA synthetases lead to non-syndromic and/or syndromic sensorineural hearing loss in humans, while their cellular and physiological pathology in cochlea has rarely been investigated in vivo. In this study, we showed that histidyl-tRNA synthetase HARS2, whose deficiency is associated with Perrault syndrome 2 (PRLTS2), is robustly expressed in postnatal mouse cochlea including the outer and inner hair cells. Targeted knockout of Hars2 in mouse hair cells resulted in delayed onset (P30), rapidly progressive hearing loss similar to the PRLTS2 hearing phenotype. Significant hair cell loss was observed starting from P45 following elevated reactive oxygen species (ROS) level and activated mitochondrial apoptotic pathway. Despite of normal ribbon synapse formation, whole-cell patch clamp of the inner hair cells revealed reduced calcium influx and compromised sustained synaptic exocytosis prior to the hair cell loss at P30, consistent with the decreased supra-threshold wave I amplitudes of the auditory brainstem response. Starting from P14, increasing proportion of morphologically abnormal mitochondria was observed by transmission electron microscope, exhibiting swelling, deformation, loss of cristae and emergence of large intrinsic vacuoles that are associated with mitochondrial dysfunction. Though the mitochondrial abnormalities are more prominent in inner hair cells, it is the outer hair cells suffering more severe cell loss. Taken together, our results suggest that conditional knockout of Hars2 in mouse cochlear hair cells leads to accumulating mitochondrial dysfunction and ROS stress, triggers progressive hearing loss highlighted by hair cell synaptopathy and apoptosis, and is differentially perceived by inner and outer hair cells.

scholarly journals Suppression of Inflammation Delays Hair Cell Regeneration and Functional Recovery Following Lateral Line Damage in Zebrafish Larvae

2020 ◽  
Author(s):  
Ru Zhang ◽  
Xiao-Peng Liu ◽  
Ya-Juan Li ◽  
Ming Wang ◽  
Lin Chen ◽  
...  
Keyword(s):  
Hair Cell ◽  
Functional Recovery ◽  
Lateral Line ◽  
Hair Cells ◽  
Calcium Imaging ◽  
Inflammatory Responses ◽  
Early Stage ◽  
Cell Regeneration ◽  
Hair Cell Regeneration ◽  
Cochlear Hair Cells

AbstractBackgroundHuman cochlear hair cells cannot spontaneously regenerate after loss. In contrast, those in fish and amphibians have a remarkable ability to regenerate after damaged. Previous studies focus on signaling mechanisms of hair cell regeneration, such as Wnt and Notch signals but seldom on the fact that the beginning of regeneration is accompanied by a large number of inflammatory responses. The detailed role of this inflammation in hair cell regeneration is still unknown. In addition, there is no appropriate behavioral method to quantitatively evaluate the functional recovery of lateral line hair cells after regeneration.ResultsIn this study, we found that when inflammation was suppressed, the regeneration of lateral line hair cells and the recovery of the rheotaxis of the larvae were significantly delayed. Calcium imaging showed that the function of the neuromasts in the inflammation-inhibited group was weaker than that in the non-inflammation-inhibited group at the Early Stage of regeneration, and returned to normal at the Late Stage. Calcium imaging also revealed the cause of the mismatch between the function and quantity during regeneration.ConclusionsOur results, meanwhile, suggest that suppressing inflammation delays hair cell regeneration and functional recovery when hair cells are damaged. This study may provide a new knowledge for how to promote hair cell regeneration and functional recovery in adult mammals.

Large Releasable Pool of Synaptic Vesicles in Chick Cochlear Hair Cells

2004 ◽  
Vol 91 (6) ◽  
pp. 2422-2428 ◽  
Author(s):  
Marc D. Eisen ◽  
Maria Spassova ◽  
Thomas D. Parsons
Keyword(s):  
Hair Cell ◽  
Hair Cells ◽  
Neurotransmitter Release ◽  
Metabotropic Glutamate Receptors ◽  
Cochlear Hair Cells ◽  
Metabotropic Glutamate ◽  
Cochlear Hair Cell ◽  
Cytoplasmic Vesicles ◽  
Vesicle Pool ◽  
Cell Synapse

Hearing requires the hair cell synapse to maintain notable temporal fidelity (≤1 ms) while sustaining neurotransmitter release for prolonged periods of time (minutes). Here we probed the properties and possible anatomical substrate of prolonged neurotransmitter release by using electrical measures of cell surface area as a proxy for neurotransmitter release to study hair cell exocytosis evoked by repetitive stimuli. We observed marked depression of exocytosis by chick tall hair cells. This exocytic depression cannot be explained by calcium current inactivation, presynaptic autoinhibition by metabotropic glutamate receptors, or postsynaptic receptor desensitization. Rather, cochlear hair cell exocytic depression resulted from the exhaustion of a functional vesicle pool. This releasable vesicle pool is large, totaling approximately 8,000 vesicles, and is nearly 10 times greater than the number of vesicles tethered to synaptic ribbons. Such a large functional pool suggests the recruitment of cytoplasmic vesicles to sustain exocytosis, important for maintaining prolonged, high rates of neural activity needed to encode sound.

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