Precise toxigenic ablation of intermediate cells abolishes the "battery" of the cochlear duct

J Neurosci. 2013 Sep 4;33(36):14601-6. doi: 10.1523/JNEUROSCI.2147-13.2013.

Abstract

The extracellular potential of excitable and nonexcitable cells with respect to ground is ∼0 mV. One of the known exceptions in mammals is the cochlear duct, where the potential is ∼80-100 mV, called the endocochlear potential (EP). The EP serves as the "battery" for transduction of sound, contributing toward the sensitivity of the auditory system. The stria vascularis (StV) of the cochlear duct is the station where the EP is generated, but the cell-specific roles in the StV are ill defined. Using the intermediate cell (IC)-specific tyrosinase promoter, under the control of diphtheria toxin (DT), we eliminated and/or halted differentiation of neural crest melanocytes after migration to the StV. The ensuing adult transgenic mice are profoundly deaf. Additionally, the EP was abolished. Expression of melanocyte early marker and Kir4.1 in ICs precedes the onset of pigment synthesis. Activation of DT leads to loss of ICs. Finally, in accord with the distinct embryology of retinal pigmented cells, transgenic mice with toxigenic ablation of neural crest-derived melanocytes have intact visual responses. We assert that the tyrosinase promoter is the distinct target for genetic manipulation of IC-specific genes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Action Potentials
  • Animals
  • Cell Differentiation
  • Deafness / genetics*
  • Diphtheria Toxin / genetics*
  • Diphtheria Toxin / metabolism
  • Melanocytes / cytology
  • Melanocytes / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Monophenol Monooxygenase / genetics
  • Neural Crest / cytology
  • Neural Crest / metabolism
  • Potassium Channels, Inwardly Rectifying / genetics
  • Potassium Channels, Inwardly Rectifying / metabolism
  • Promoter Regions, Genetic
  • Retinal Pigment Epithelium / cytology
  • Retinal Pigment Epithelium / metabolism
  • Stria Vascularis / cytology*
  • Stria Vascularis / metabolism
  • Stria Vascularis / physiology
  • Transgenes / genetics*
  • Vision, Ocular / genetics

Substances

  • Diphtheria Toxin
  • Kcnj10 (channel)
  • Potassium Channels, Inwardly Rectifying
  • Monophenol Monooxygenase