A photochemical reaction between intravenous rose bengal and xenon light was used to induce a selective thrombus in the rat anterior inferior cerebellar artery (AICA). Compound action potentials (CAPs) were recorded by electrocochleography and cochlear blood flow (CBF) was monitored by laser Doppler flowmetry. Photothrombotic occlusion of the AICA caused inner ear ischemia to various degrees with or without alterations of the CAP. With use of this model we investigated the critical range of the CBF for preserving cochlear function, represented by the CAPs induced with 8 kHz half-wave of sinusoid at 100 dB SPL. Results then showed that a CBF range between 26.7% and 42.9% of baseline was somewhat critical for maintenance of cochlear function in an acute phase of ischemia. Pretreatment with heparin significantly delayed thrombotic occlusion of the AICA in a dose-dependent manner. Further use of our model for inner ear ischemia may be useful for studying pathophysiology and pharmacological therapy of cochlear disturbances subsequent to circulatory disorders.
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PLoS One
January 2025
Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Objective: This multicenter, randomized, double-blind, placebo-controlled, crossover trial aimed to evaluate whether prolonged noisy galvanic vestibular stimulation improves body balance in patients with vestibulopathy.
Materials And Methods: This trial was registered in the Japan Pharmaceutical Information Center Clinical Trials Information registry (jRCT1080224083). Subjects were 20- to 85-year-old patients who had been unsteady for more than one year and whose symptoms had persisted despite more than six months of rehabilitation.
Proc Natl Acad Sci U S A
January 2025
Department of Neurobiology, Harvard Medical School, Boston, MA 02115.
The sense of hearing originates in the cochlea, which detects sounds across dynamic sensory environments. Like other peripheral organs, the cochlea is subjected to environmental insults, including loud, damage-inducing sounds. In response to internal and external stimuli, the central nervous system directly modulates cochlear function through olivocochlear neurons (OCNs), which are located in the brainstem and innervate the cochlear sensory epithelium.
View Article and Find Full Text PDFCureus
December 2024
Geriatrics and Long-Term Care, Rumailah Hospital - Hamad Medical Corporation, Doha, QAT.
Background and objective Viral infections caused by cytomegalovirus, lymphocytic choriomeningitis virus, varicella-zoster virus, herpes simplex type 1 and type 2, rubella, measles, rubeola, HIV, West Nile virus, Lassa virus, and mumps are known to be associated with hearing loss. There have been reports of inner ear involvement in coronavirus disease 2019 (COVID-19) patients but the extent and variations in cochlear involvement of symptomatic and asymptomatic patients has not been adequately described. This study aimed to evaluate the hearing status among symptomatic and asymptomatic COVID-19 patients to address the prospects for routine screening for hearing loss in COVID-19 patients.
View Article and Find Full Text PDFHear 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 PDFNat Commun
January 2025
Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA.
Assembly of actin-based stereocilia is critical for cochlear hair cells to detect sound. To tune their mechanosensivity, stereocilia form bundles composed of graded rows of ascending height, necessitating the precise control of actin polymerization. Myosin 15 (MYO15A) drives hair bundle development by delivering critical proteins to growing stereocilia that regulate actin polymerization via an unknown mechanism.
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