Effect of membrane tension on gap junctional conductance of supporting cells in Corti's organ

Hong Bo Zhao, J. Santos-Sacchi

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


The effects of turgor pressure-induced membrane tension on junctional coupling of Hensen cell isolates from the inner ear were evaluated by input capacitance or transjunctional conductance measurement techniques. Turgor pressure was altered by changing either pipette pressure or the osmolarities of extracellular solutions. Both positive pipette pressure and extracellular applications of hypotonic solutions, which caused cell size to concomitantly increase, uncoupled the cells as indicated by reduced input capacitance and transjunctional conductance. These changes were, in many cases, reversible and repeatable. Intracellular application of 50 μM H-7, a broad-based protein kinase inhibitor, and 10 mM BAPTA did not block the uncoupling effect of positive turgor pressure on inner ear gap junctions. The transjunctional conductance at a holding potential of -80 mV was 53.6 ± 5.8 nS (mean ± SEM, n = 9) and decreased ~40% at a turgor pressure of 1.41 ± 0.05 kPa. Considering the coincident kinetics of cell deformation and uncoupling, we speculate that mechanical forces work directly on gap junctions of the inner ear. These results suggest that pathologies that induce imbalances in cochlear osmotic pressure regulation may compromise normal cochlear homeostasis.

Original languageEnglish
Pages (from-to)447-455
Number of pages9
JournalJournal of General Physiology
Issue number4
StatePublished - Oct 1998


  • Cochlea
  • Gap junctions
  • Hensen cells
  • Membrane tension
  • Turgor pressure

ASJC Scopus subject areas

  • Physiology


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