Identification of Vascular Gap Junction Protein Expression in the Cochlear Microvessels

Abstract

Using the immunohistochemistry combined with confocal microscopy technique and western blot analysis, we found that pericytes on the vessels of the spiral ligament have Connexin 40 (Cx 40) and Connexin 37 (Cx 37) in both guinea pigs and mice. In particular, Cx 40 was abundantly expressedin both endothelial cells and pericytes of the spiral ligament vessels. Also Cx 40 was intensively expressed in the intermediate‐like cells of the stria vascualris in the guinea pigs but not obviously in the mouse stria vascularis. There was no Cx 37 and Cx 40 signal in the endothelial cells and the pericytes of the stria vascularis vasculature. Also no detectable Connexin (Cx 43) was found in both the vessels of the spiral ligament and the stria vascularis. Our results are different from studies that assessed Connexin expression in the retinal or brain pericytes which do expressCx 43. The variation of Connexin expression in the different vasculatures may have important consequences for the difference of coordination and propagation of vascular signals and responses. The regional and animal species difference in expression heterogeneity of Cx 40 & Cx 37 indicates a possible functional and structural heterogeneity of pericytes in the vessels of the spiral ligament and the stria vascualris. Supported by NIH NIDCD R03 DC008888‐01A1 & NIH NIDCD DC 00105, DC 005983.