Explanation of cochlear active acoustic amplification mechanism has been an unsolved medical problem. This is closely related to the motion stereocilia at top outer hair cells in cochlea. The regulated by tip-link tension and fluid force lymph fluid. Therefore, studying during important part explanation cochlea's sensory sound mechanism. Most previous studies regarded as rigid bodies, ignored i...

Recessive splice site and nonsense mutations of PCDH15, encoding protocadherin 15, are known to cause deafness and retinitis pigmentosa in Usher syndrome type 1F (USH1F). Here we report that non-syndromic recessive hearing loss (DFNB23) is caused by missense mutations of PCDH15. This suggests a genotype-phenotype correlation in which hypomorphic alleles cause non-syndromic hearing loss, while m...

Based on surface morphology, 6 hair cell types have been identified on the sensory epithelia of the bullfrog otolithic and auditory organs. One of these types apparently is the morphogenetic precursor of vibrational and auditory hair cells. Another type, with a kinocilium several times as long as the longest stereocilia, apparently mediates gravistatic sensitivity. A third type, with a bulbed k...

Modern weapon systems produce very high levels of impulse and/or continuous noise. Exposure to intense noise induces mechanical and/or metabolic damage to the inner ear. At the hearing threshold the amplitude of the displacements of the sensory structures of the inner ear (stereocilia) is about 10 m (1/100 the diameter of the hydrogen atom). At 120 dB this amplitude reaches 1 micrometer (corres...

The hair bundle--the sensory organelle of inner-ear hair cells of vertebrates--exemplifies the ability of a cell to assemble complex, elegant structures. Proper construction of the bundle is required for proper mechanotransduction in response to external forces and to transmit information about sound and movement. Bundles contain tightly controlled numbers of actin-filled stereocilia, which are...

We investigated whether amiloride-blockable proton-gated cation channels ASIC1a (acid-sensing ion channel-1a) and ASIC1b are expressed in the stereocilia of mouse cochlear hair cells. In-situ hybridization studies showed that ASIC1b transcripts, but not ASIC1a transcripts, were expressed in the inner and outer hair cells. Fluorescent immunohistochemical and immunogold electron microscopic analy...

The luminal surface of the initial segment of the epididymal duct in the Japanese monkey was observed under a field emission type scanning electron microscope. The long, slender stereocilia projecting from the apical surface of the columnar cells were found to be closely arranged in a funnel-like form opening to the lumen. The funnels formed by stereocilia were also confirmed by observation of ...

To understand how cells differentially use the dozens of myosin isozymes present in each genome, we examined the distribution of four unconventional myosin isozymes in the inner ear, a tissue that is particularly reliant on actin-rich structures and unconventional myosin isozymes. Of the four isozymes, each from a different class, three are expressed in the hair cells of amphibia and mammals. I...

Reactive oxygen species (ROS) have been suggested to play a major role in aminoglycoside-induced hair cell (HC) loss, but are difficult to detect. Moreover, ROS can occur normally in cells where they have roles in metabolism, cell signaling and other processes. Two new probes, aminophenyl fluorescein (APF) and hydroxyphenyl fluorescein (HPF) are dyes which selectively detect highly-reactive oxy...