K(+) cycling and its regulation in the cochlea and the vestibular labyrinth.
Potassium (K(+)) plays a very important role in the cochlea. K(+) is the major cation in endolymph and the charge carrier for sensory transduction and the generation of the endocochlear potential. The importance of K(+) handling in the cochlea is marked by the discovery of several forms of hereditary deafness that are due to mutations of K(+) channels. Deafness results from mutations of KCNQ4, a K(+) channel in the sensory hair cells, as well as from mutations of the gap junction proteins GJB2, GJB3 and GJB6 that may facilitate cell-to-cell movements of K(+). Deafness results also from mutations of KCNQ1 or KCNE1, subunits of a K(+) channel that carries K(+) from strial marginal cells and vestibular dark cells into endolymph. Further, deafness results from mutations of KCNJ10, a K(+) channel that generates the endocochlear potential in conjunction with the high K(+) concentration in strial intermediate cells and the low K(+) concentration in the intrastrial fluid spaces. This review details recent advances in the understanding of K(+) transport and its regulation in the cochlea and the vestibular labyrinth.
Wangemann
Philine
P
Cell Physiology Laboratory, Anatomy and Physiology Department, Kansas State University, Manhattan, Kans 66506, USA. wange@vet.ksu.edu
D003051:Cochlea / Q000378:metabolism*; D000072259:Connexin 26; D017630:Connexins; D007758:Ear, Inner / Q000378:metabolism*; D006801:Humans; D015221:Potassium Channels / Q000378:metabolism*; D015854:Up-Regulation; D014722:Vestibule, Labyrinth / Q000378:metabolism*
D017630:Connexins; C000607042:GJB2 protein, human; D015221:Potassium Channels; D000072259:Connexin 26