RT Journal Article SR Electronic T1 An ATP-Dependent Inwardly Rectifying Potassium Channel, KAB-2 (Kir4.1), in Cochlear Stria Vascularis of Inner Ear: Its Specific Subcellular Localization and Correlation with the Formation of Endocochlear Potential JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 4711 OP 4721 DO 10.1523/JNEUROSCI.17-12-04711.1997 VO 17 IS 12 A1 Hiroshi Hibino A1 Yoshiyuki Horio A1 Atsushi Inanobe A1 Katsumi Doi A1 Minoru Ito A1 Mitsuhiko Yamada A1 Takahiro Gotow A1 Yasuo Uchiyama A1 Masaru Kawamura A1 Takeshi Kubo A1 Yoshihisa Kurachi YR 1997 UL http://www.jneurosci.org/content/17/12/4711.abstract AB Cochlear endolymph has a highly positive potential of approximately +80 mV. This so-called endocochlear potential (EP) is essential for hearing. Although pivotal roles of K+ channels in the formation of EP have been suggested, the types and distribution of K+ channels in cochlea have not been characterized. Because EP was depressed by vascular perfusion of Ba2+, an inhibitor of inwardly rectifying K+ (Kir) channels, but not by either 4-aminopyridine or tetraethylammonium, we examined the expression of Kir channel subunits in cochlear stria vascularis, the tissue that is supposed to play the central role in the generation of positive EP. Of 11 members of the Kir channel family examined with reverse transcription-PCR, we could detect only expression of KAB-2 (Kir4.1) mRNA in stria vascularis. KAB-2 immunoreactivity was specifically localized at the basolateral membrane of marginal cells but not in either basal or intermediate cells. Developmental expression of KAB-2 in marginal cells paralleled formation of EP. Furthermore, deaf mutant mice (viable dominant spotting; WV/WV) expressed no KAB-2 in their marginal cells. These results suggest that KAB-2 in marginal cells may be critically involved in the generation of positive EP.