The presence of KCNJ10 mRNA in stria vascularis of Slc26a4-/- mice supports the finding that intermediate cells are present. Expression of the KCNJ10 protein was assessed in young Slc26a4-/- mice by confocal immunocytochemistry. Interestingly, expression of the KCNJ10 protein was absent in stria vascularis but normal in spiral ganglia (Fig. 4). The absence of the KCNJ10 K+ channel in stria vascularis is sufficient to explain the loss of the endocochlear potential [17].