Stria vascularis (SV) as well as other inner ear tissue components are rich in ion and water channel/transporter proteins.In the SV they are essential for maintaining endo-cochlear chemical composition and potential (EP) critical for hair cell function and hearing.By using immunohistochemistry combined with confocal and super-resolution microscopy (SIM), we analyzed directly fixed * human cochleae for proteins related to transportation of ions (ion transporters and ion channels) such as Kir4.1 (KCNJ10) and voltage-gated potassium channel proteins Kv7.1 (KCNQ1/KCNE1) in SV.Furthermore, we examined the expression of connexin 30/26 (Cx30/Cx26), ion transporters NKCC1 and Na+-K+-ATPase.Water channel proteins aquaporin2/4/5 and tight junction protein claudin and occluding 11 in human cochlea were also investigated.Human SV was margined apically and basally by tight junctions (TJ) containing occludin and claudin 11.TJs encompass the enclave, assumingly maintaining a high intra-strial K+-concentration and electro-chemical gradient; TJs also constitute an integral part of the blood-labyrinth barrier.The K+ channel KCNJ10 (Kir 4.1), which generates the K+ equilibrium EP, was expressed both in the intermediate and basal cells and partly co-localized with Cx26.NKCC1 encodes the furosemide-sensitive Na+/K+/2Cl co-transporter and was found in the marginal cells.The KCNQ1 gene, which encodes the voltage-gated potassium channel Kv7.1 (KvLQT1) was expressed in the apical cell membrane of the marginal cells.The Cx26 and Cx30 protein expression using super-resolution structured illumination microscopy (SIM) showed closely associated homomeric GJ plaques.The association of Cx26 with the potassium channel KCNJ10 could explain the vulnerability to GJB2 gene disruption.