Scar formation after drug-induced cochlear insult

Hear Res. 1991 Feb;51(2):173-83. doi: 10.1016/0378-5955(91)90034-7.


Structural and molecular changes in the guinea pig organ of Corti were studied using histochemistry and electron microscopy in the course of drug-induced hair cell degeneration. Actin filaments disappear from the cuticular plate and the stereocilia. An actin-rich bridge appears in the apical region of dying hair cells. Two supporting cells form a scar for a given hair cell. The supporting cells expand and invade the spaces of Nuel and then the region previously occupied by the hair cell. The scar region becomes cytokeratin-labeled. In this study, the apical domain of the hair cell is the last part of the cell to degenerate. Hair cell degeneration coincides temporally with scar formation. We define the resulting scar as a 'type I' scar. The results provide preliminary information about the molecular composition of the type I scar and suggest a structural basis for the dynamics of scar formation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actin Cytoskeleton / drug effects
  • Actin Cytoskeleton / metabolism
  • Actin Cytoskeleton / pathology
  • Actins / metabolism
  • Animals
  • Cicatrix / metabolism
  • Cicatrix / pathology*
  • Cochlea / drug effects
  • Cochlea / metabolism
  • Cochlea / pathology*
  • Ethacrynic Acid / toxicity
  • Guinea Pigs
  • Hair Cells, Auditory / drug effects
  • Hair Cells, Auditory / metabolism
  • Hair Cells, Auditory / pathology
  • Histocytochemistry
  • Kanamycin / toxicity
  • Keratins / metabolism
  • Microscopy, Electron
  • Organ of Corti / drug effects
  • Organ of Corti / metabolism
  • Organ of Corti / pathology


  • Actins
  • Kanamycin
  • Keratins
  • Ethacrynic Acid