Tags

Type your tag names separated by a space and hit enter

The endocochlear potential depends on two K+ diffusion potentials and an electrical barrier in the stria vascularis of the inner ear.
Proc Natl Acad Sci U S A. 2008 Feb 05; 105(5):1751-6.PN

Abstract

An endocochlear potential (EP) of +80 mV is essential for audition. Although the regulation of K(+) concentration ([K(+)]) in various compartments of the cochlear stria vascularis seems crucial for the formation of the EP, the mechanism remains uncertain. We have used multibarreled electrodes to measure the potential, [K(+)], and input resistance in each compartment of the stria vascularis. The stria faces two fluids, perilymph and endolymph, and contains an extracelluar compartment, the intrastrial space (IS), surrounded by two epithelial layers, the marginal cell (MC) layer and that composed of intermediate and basal cells. Fluid in the IS exhibits a low [K(+)] and a positive potential, called the intrastrial potential (ISP). We found that the input resistance of the IS was high, indicating this space is electrically isolated from the neighboring extracellular fluids. This arrangement is indispensable for maintaining positive ISP. Inhibiting the K(+) transporters of the stria by anoxia, ouabain, or bumetanide caused the [K(+)] of the IS to increase and the intracellular [K(+)] of MCs to decrease, reducing both the ISP and the EP. Calculations indicate that the ISP represents the K(+) diffusion potential across the apical membranes of intermediate cells through Ba(2+)-sensitive K(+) channels. The K(+) diffusion potential across the apical membranes of MCs also contributes to the EP. Because the EP depends on two K(+) diffusion potentials and an electrical barrier in the stria vascularis, interference with any of these elements can interrupt hearing.

Authors+Show Affiliations

Division of Molecular and Cellular Pharmacology, Department of Pharmacology, and Department of Otolaryngology, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18218777

Citation

Nin, Fumiaki, et al. "The Endocochlear Potential Depends On Two K+ Diffusion Potentials and an Electrical Barrier in the Stria Vascularis of the Inner Ear." Proceedings of the National Academy of Sciences of the United States of America, vol. 105, no. 5, 2008, pp. 1751-6.
Nin F, Hibino H, Doi K, et al. The endocochlear potential depends on two K+ diffusion potentials and an electrical barrier in the stria vascularis of the inner ear. Proc Natl Acad Sci USA. 2008;105(5):1751-6.
Nin, F., Hibino, H., Doi, K., Suzuki, T., Hisa, Y., & Kurachi, Y. (2008). The endocochlear potential depends on two K+ diffusion potentials and an electrical barrier in the stria vascularis of the inner ear. Proceedings of the National Academy of Sciences of the United States of America, 105(5), 1751-6. https://doi.org/10.1073/pnas.0711463105
Nin F, et al. The Endocochlear Potential Depends On Two K+ Diffusion Potentials and an Electrical Barrier in the Stria Vascularis of the Inner Ear. Proc Natl Acad Sci USA. 2008 Feb 5;105(5):1751-6. PubMed PMID: 18218777.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The endocochlear potential depends on two K+ diffusion potentials and an electrical barrier in the stria vascularis of the inner ear. AU - Nin,Fumiaki, AU - Hibino,Hiroshi, AU - Doi,Katsumi, AU - Suzuki,Toshihiro, AU - Hisa,Yasuo, AU - Kurachi,Yoshihisa, Y1 - 2008/01/24/ PY - 2008/1/26/pubmed PY - 2008/3/8/medline PY - 2008/1/26/entrez SP - 1751 EP - 6 JF - Proceedings of the National Academy of Sciences of the United States of America JO - Proc. Natl. Acad. Sci. U.S.A. VL - 105 IS - 5 N2 - An endocochlear potential (EP) of +80 mV is essential for audition. Although the regulation of K(+) concentration ([K(+)]) in various compartments of the cochlear stria vascularis seems crucial for the formation of the EP, the mechanism remains uncertain. We have used multibarreled electrodes to measure the potential, [K(+)], and input resistance in each compartment of the stria vascularis. The stria faces two fluids, perilymph and endolymph, and contains an extracelluar compartment, the intrastrial space (IS), surrounded by two epithelial layers, the marginal cell (MC) layer and that composed of intermediate and basal cells. Fluid in the IS exhibits a low [K(+)] and a positive potential, called the intrastrial potential (ISP). We found that the input resistance of the IS was high, indicating this space is electrically isolated from the neighboring extracellular fluids. This arrangement is indispensable for maintaining positive ISP. Inhibiting the K(+) transporters of the stria by anoxia, ouabain, or bumetanide caused the [K(+)] of the IS to increase and the intracellular [K(+)] of MCs to decrease, reducing both the ISP and the EP. Calculations indicate that the ISP represents the K(+) diffusion potential across the apical membranes of intermediate cells through Ba(2+)-sensitive K(+) channels. The K(+) diffusion potential across the apical membranes of MCs also contributes to the EP. Because the EP depends on two K(+) diffusion potentials and an electrical barrier in the stria vascularis, interference with any of these elements can interrupt hearing. SN - 1091-6490 UR - https://www.unboundmedicine.com/medline/citation/18218777/The_endocochlear_potential_depends_on_two_K+_diffusion_potentials_and_an_electrical_barrier_in_the_stria_vascularis_of_the_inner_ear_ L2 - http://www.pnas.org/cgi/pmidlookup?view=long&pmid=18218777 DB - PRIME DP - Unbound Medicine ER -