KCNK5 channels mostly expressed in cochlear outer sulcus cells are indispensable for hearing

Nat Commun. 2015 Nov 9;6:8780. doi: 10.1038/ncomms9780.

Abstract

In the cochlea, K(+) is essential for mechano-electrical transduction. Here, we explore cochlear structure and function in mice lacking K(+) channels of the two-pore domain family. A profound deafness associated with a decrease in endocochlear potential is found in adult Kcnk5(-/-) mice. Hearing occurs around postnatal day 19 (P19), and completely disappears 2 days later. At P19, Kcnk5(-/-) mice have a normal endolymphatic [K(+)] but a partly lowered endocochlear potential. Using Lac-Z as a gene reporter, KCNK5 is mainly found in outer sulcus Claudius', Boettcher's and root cells. Low levels of expression are also seen in the spiral ganglion, Reissner's membrane and stria vascularis. Essential channels (KCNJ10 and KCNQ1) contributing to K(+) secretion in stria vascularis have normal expression in Kcnk5(-/-) mice. Thus, KCNK5 channels are indispensable for the maintenance of hearing. Among several plausible mechanisms, we emphasize their role in K(+) recycling along the outer sulcus lateral route.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cochlea / metabolism*
  • Cochlea / pathology
  • Cochlea / physiology
  • Deafness / genetics*
  • Deafness / physiopathology
  • Endolymph / chemistry
  • Evoked Potentials, Auditory, Brain Stem
  • Hearing / genetics*
  • Hearing / physiology
  • Immunohistochemistry
  • KCNQ1 Potassium Channel / metabolism
  • Membrane Potentials / genetics
  • Mice
  • Mice, Knockout
  • Mutation
  • Nerve Tissue Proteins / genetics
  • Potassium
  • Potassium Channels / genetics
  • Potassium Channels, Inwardly Rectifying / metabolism
  • Potassium Channels, Tandem Pore Domain / genetics*
  • Round Window, Ear / physiopathology
  • Spiral Ganglion / cytology
  • Spiral Ganglion / pathology
  • Stria Vascularis / metabolism
  • Vestibular Function Tests

Substances

  • KCNQ1 Potassium Channel
  • Kcnj10 (channel)
  • Kcnk5 protein, mouse
  • Kcnq1 protein, mouse
  • Nerve Tissue Proteins
  • Potassium Channels
  • Potassium Channels, Inwardly Rectifying
  • Potassium Channels, Tandem Pore Domain
  • TASK3 protein, mouse
  • potassium channel subfamily K member 3
  • Potassium