We present a consistent second-order expansion of nonlinear constitutive theories for outer hair cells. For a particular theory, we will test the validity of such a model for small variations in voltage and strain about the resting state of outer hair cells. An analysis of the various terms in the simplified nonlinear model and their relevance to outer hair cell mechanics are presented. Results show that the second-order expansion is adequate for modeling outer hair cell mechanics in a global model of the cochlea. Model predictions agree with the notion that voltage nonlinearities are the dominant ones at low sound levels in vivo.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1121/1.1871753 | DOI Listing |
Hear Res
January 2025
Columbia University Irving Medical Center, Department of Otolaryngology, Head and Neck Surgery, 180 Fort Washington Ave, New York, 10032, NY, USA; Columbia University, Department of Biomedical Engineering, 1210 Amsterdam Ave, New York, 10027, NY, USA.
Sound-evoked displacement responses at the outer hair cell-Deiters' cell junction (OHC-DC) are of significant interest in cochlear mechanics, as OHCs are believed to be in part responsible for active tuning enhancement and amplification. Motion in the cochlea is three-dimensional, and the architecture of the organ of Corti complex (OCC) suggests the presence and mechanical importance of all three components of motion. Optical coherence tomography (OCT) displacement measurements of OHC-DC motion from different experimental preparations often show disparate results, potentially due to OCT measuring only the motion component along the beam axis.
View Article and Find Full Text PDFAdv Healthc Mater
January 2025
Department of Otorhinolaryngology-Head and Neck Surgery, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221002, P. R. China.
Noise-induced hearing loss (NIHL) results from prolonged exposure to intense noise, causing damage to sensory outer hair cells (OHCs) and spiral ganglion neurons (SGNs). The blood labyrinth barrier (BLB) hinders systemic drug delivery to the inner ear. This study applied a retro-auricular round window membrane (RWM) method to bypass the BLB, enabling the transport of macromolecular proteins into the inner ear.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
January 2025
Department of Otolaryngology, Head and Neck Surgery, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, 330006 Nanchang, Jiangxi, China.
Background: It has been reported the therapeutic effects of mesenchymal stem cells (MSCs) on hearing loss. This study explored the therapeutic effects of growth differentiation factor 6 (GDF6) overexpression-induced MSCs (MSCs-GDF6) on age-related hearing loss (ARHL) and its underlying mechanisms.
Methods: Reverse transcription-quantitative PCR and western blotting were used to evaluate gene expression.
Hear Res
December 2024
Bionics Institute, East Melbourne, Victoria 3002, Australia; Department of Medical Bionics, The University of Melbourne, Fitzroy, Victoria 3065, Australia; Department of Surgery (Otolaryngology), University of Melbourne, The Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria 3002, Australia. Electronic address:
In the adult mammalian cochlea, hair cell loss is irreversible and causes deafness. The basic helix-loop transcription factor Atoh1 is essential for normal hair cell development in the embryonic ear. Over-expression of Atoh1 in the adult cochlea by gene therapy can convert supporting cells (cells that underlie hair cells) into a hair cell lineage.
View Article and Find Full Text PDFDev Dyn
January 2025
Department of Human Anatomy, College of Basic Medical Sciences, Jilin University, Changchun, China.
Background: Previous studies with Gfi1-mutated lines have shown that Gfi1 is essential for hair cell maturation and survival.
Results: We analyzed the phenotype of another Gfi1-mutated line Gfi1 in the inner ears of neonates at P5-7 and found that the cochlea phenotypically differed from the vestibule in the Gfi1 mouse. Specifically, there was a marked reduction in hair cells in the cochlea, which was characterized by greater reductions in the outer hair cells but far less reductions (mainly in the basal turn) in the inner hair cells, whereas the vestibular hair cells remained unaffected.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!