title: Expression of gap junction protein connexin43 in the adult rat cochlea: comparison with connexin26.
abstract: To elucidate whether the two different gap junction proteins connexin43 (Cx43) and connexin26 (Cx26) are expressed and localized in a similar manner in the adult rat cochlea, we performed three-dimensional confocal microscopy using cryosections and surface preparations. In the cochlear lateral wall, Cx43-positive spots were localized mainly in the stria vascularis and only a few spots were present in the spiral ligament, whereas Cx26-positive spots were detected in both the stria vascularis and the spiral ligament. In the spiral limbus, Cx43 was widely distributed, whereas Cx26 was more concentrated on the side facing the scala vestibuli and in the basal portion. In the organ of Corti, Cx43-positive spots were present between the supporting cells but they were fewer and much smaller than those of Cx26. These data demonstrated distinct differences between Cx43 and Cx26 in expression and localization in the cochlea. In addition, the area of overlap of zonula occludens-1 (ZO-1) immunolabeling with Cx43-positive spots was small, whereas it was fairly large with Cx26-positive spots in the cochlear lateral wall, suggesting that the differences are not associated with the structural difference between carboxyl terminals, i.e., those of Cx43 possess sequences for binding to ZO-1, whereas those of Cx26 lack these binding sequences.
authors.affiliation: Department of Otolaryngology, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Takamatsu
authors.forename: Masahito
authors.initials: M
authors.lastname: Oyamada
mesh_terms: D000818:Animals; D003051:Cochlea / Q000033:anatomy & histology / Q000378:metabolism*; D000072259:Connexin 26; D018031:Connexin 43 / Q000378:metabolism*; D017630:Connexins / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D018613:Microscopy, Confocal; D009925:Organ of Corti / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013137:Spiral Lamina / Q000378:metabolism; D062826:Zonula Occludens-1 Protein
chemical_list: D018031:Connexin 43; D017630:Connexins; C000607044:Gjb2 protein, rat; D008565:Membrane Proteins; D010750:Phosphoproteins; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; D000072259:Connexin 26