Inner hair cell response patterns: Implications for low-frequency hearing

2001 ◽  
Vol 110 (4) ◽  
pp. 2034-2044 ◽  
Author(s):  
M. A. Cheatham ◽  
P. Dallos
Keyword(s):  
Hair Cell ◽  
Cell Response ◽  
Low Frequency ◽  
Response Patterns ◽  
Inner Hair Cell

scholarly journals Inner hair cell dysfunction in Klhl18 mutant mice leads to low frequency progressive hearing loss

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258158
Author(s):  
Neil J. Ingham ◽  
Navid Banafshe ◽  
Clarisse Panganiban ◽  
Julia L. Crunden ◽  
Jing Chen ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Hair Cell ◽  
Cell Function ◽  
Low Frequency ◽  
Mutant Mice ◽  
Auditory Brainstem Responses ◽  
Distortion Product Otoacoustic Emission ◽  
Inner Hair Cell ◽  
Distortion Product ◽  
Age Related

Age-related hearing loss in humans (presbycusis) typically involves impairment of high frequency sensitivity before becoming progressively more severe at lower frequencies. Pathologies initially affecting lower frequency regions of hearing are less common. Here we describe a progressive, predominantly low-frequency recessive hearing impairment in two mutant mouse lines carrying different mutant alleles of the Klhl18 gene: a spontaneous missense mutation (Klhl18lowf) and a targeted mutation (Klhl18tm1a(KOMP)Wtsi). Both males and females were studied, and the two mutant lines showed similar phenotypes. Threshold for auditory brainstem responses (ABR; a measure of auditory nerve and brainstem neural activity) were normal at 3 weeks old but showed progressive increases from 4 weeks onwards. In contrast, distortion product otoacoustic emission (DPOAE) sensitivity and amplitudes (a reflection of cochlear outer hair cell function) remained normal in mutants. Electrophysiological recordings from the round window of Klhl18lowf mutants at 6 weeks old revealed 1) raised compound action potential thresholds that were similar to ABR thresholds, 2) cochlear microphonic potentials that were normal compared with wildtype and heterozygous control mice and 3) summating potentials that were reduced in amplitude compared to control mice. Scanning electron microscopy showed that Klhl18lowf mutant mice had abnormally tapering of the tips of inner hair cell stereocilia in the apical half of the cochlea while their synapses appeared normal. These results suggest that Klhl18 is necessary to maintain inner hair cell stereocilia and normal inner hair cell function at low frequencies.

scholarly journals Inner hair cell dysfunction in Klhl18 mutant mice leads to low frequency progressive hearing loss

2021 ◽  
Author(s):  
Neil J Ingham ◽  
Navid Banafshe ◽  
Clarisse Panganiban ◽  
Julia L Crunden ◽  
Jing Chen ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Hair Cell ◽  
Outer Hair Cell ◽  
Cell Function ◽  
Low Frequency ◽  
Auditory Brainstem ◽  
Auditory Neuropathy ◽  
Mutant Mice ◽  
Inner Hair Cell ◽  
Apical Half

ABSTRACTAge-related hearing loss in humans (presbycusis) typically involves impairment of high frequency sensitivity before becoming progressively more severe at lower frequencies. Pathologies initially affecting lower frequency regions of hearing are less common. Here we describe a progressive, predominantly low-frequency hearing impairment in two mutant mouse lines, carrying different mutant alleles of the Klhl18 gene: a spontaneous missense mutation (Klhl18lowf) and a targeted mutation (Klhl18tm1a(KOMP)Wtsi). Both males and females were studied, and the two mutant lines showed similar phenotypes. Auditory brainstem response (ABR) thresholds (a measure of auditory nerve and brainstem neural activity) were normal at 3 weeks old but showed progressive increases from 4 weeks onwards. In contrast, distortion product otoacoustic emission (DPOAE) sensitivity and amplitudes (a reflection of cochlear outer hair cell function) remained normal in mutants. Electrophysiological recordings from the round window of Klhl18lowf mutants at 6 weeks old revealed 1) raised compound action potential thresholds that were similar to ABR thresholds, 2) cochlear microphonic potentials that were normal compared with wildtype and heterozygous control mice and 3) summating potentials that were reduced in amplitude compared to control mice. Scanning electron microscopy showed that Klhl18lowf mutant mice had abnormally tapering inner hair cell stereocilia in the apical half of the cochlea while their synapses appeared normal. These results suggest that Klhl18 is necessary to maintain inner hair cell stereocilia and normal inner hair cell function at low frequencies. Klhl18 mutant mice exhibit an uncommon low frequency hearing impairment with physiological features consistent with Auditory Neuropathy Spectrum Disorder (ANSD).SIGNIFICANCE STATEMENTWe describe a novel progressive hearing loss in Klhl18 mutant mice that affects the lower frequencies of its’ hearing range. Investigation of two mutant alleles of this gene revealed primary inner hair cell defects affecting the neural output of the cochlea while outer hair cell function appeared normal. The tallest stereocilia of inner hair cells showed an abnormal tapering shape, especially notable in the apical half of the cochlear duct corresponding to the low frequency hearing loss. Our finding of a primary inner hair cell defect associated with raised thresholds for auditory brainstem responses combined with normal outer hair cell function suggests that Klhl18 deficiency and inner hair cell pathology may contribute to Auditory Neuropathy Spectrum Disorder in humans.

scholarly journals Inner hair cell stereocilia are embedded in the tectorial membrane

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pierre Hakizimana ◽  
Anders Fridberger
Keyword(s):  
Electron Microscopy ◽  
Hair Cell ◽  
Mechanical Stimulation ◽  
Hair Cells ◽  
Viscous Drag ◽  
Tectorial Membrane ◽  
Inner Hair Cell ◽  
Inner Hair Cells ◽  
Inward Currents

AbstractMammalian hearing depends on sound-evoked displacements of the stereocilia of inner hair cells (IHCs), which cause the endogenous mechanoelectrical transducer channels to conduct inward currents of cations including Ca2+. Due to their presumed lack of contacts with the overlaying tectorial membrane (TM), the putative stimulation mechanism for these stereocilia is by means of the viscous drag of the surrounding endolymph. However, despite numerous efforts to characterize the TM by electron microscopy and other techniques, the exact IHC stereocilia-TM relationship remains elusive. Here we show that Ca2+-rich filamentous structures, that we call Ca2+ ducts, connect the TM to the IHC stereocilia to enable mechanical stimulation by the TM while also ensuring the stereocilia access to TM Ca2+. Our results call for a reassessment of the stimulation mechanism for the IHC stereocilia and the TM role in hearing.

Free radical scavenger protects against inner hair cell loss after cochlear ischemia

Neuroreport ◽  
2003 ◽  
Vol 14 (14) ◽  
pp. 1881-1884 ◽  
Author(s):  
Toshiki Maetani ◽  
Nobuhiro Hakuba ◽  
Masafumi Taniguchi ◽  
Jun Hyodo ◽  
Yoshitaka Shimizu ◽  
...  
Keyword(s):  
Free Radical ◽  
Hair Cell ◽  
Cell Loss ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Hair Cell Loss ◽  
Inner Hair Cell

scholarly journals A Complex of RIM2alpha and RIM-Binding Protein 2 Stabilizes Slow Voltage-Dependent Inactivation of Cochlear Inner Hair Cell Cav1.3 L-Type Ca2+ Channels

2018 ◽  
Vol 114 (3) ◽  
pp. 637a-638a
Author(s):  
Nadine J. Ortner ◽  
Alexandra Pinggera ◽  
Anita Siller ◽  
Nadja Hofer ◽  
Niels Brandt ◽  
...  
Keyword(s):  
Hair Cell ◽  
Binding Protein ◽  
Inner Hair Cell ◽  
Dependent Inactivation ◽  
Voltage Dependent ◽  
Ca2 Channels
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