Expression of CLC-KB gene promoter in the mouse cochlea.

We have investigated the expression of chloride channels by examining the cochlea of mice harboring the enhanced green fluorescence protein (EGFP) gene driven by an 11 kbp human CLC-KB gene promoter. CLC-KB was seen not only on the stria vascularis but on spiral ligament and limbal fibrocytes, interdental cells and satellite cells of spiral ganglion neurons that are known to possess both Na,K-ATPase and the Na-K-Cl co-transporter (NKCC). These results suggest that some fibrocytes possessing both the CLC-KB and the NKCC may be involved in the regulation of cell volume, transport and recycling of Cl- such as is seen in the stria vascularis. Moreover, these fibrocytes may recycle Cl- through CLC that accompany Na+ and K+ into the cell via NKCC.