Blindness and auditory impairment caused by loss of the sodium bicarbonate cotransporter NBC3

Nat Genet. 2003 Jul;34(3):313-9. doi: 10.1038/ng1176.


Normal sensory transduction requires the efficient disposal of acid (H+) generated by neuronal and sensory receptor activity. Multiple highly sensitive transport mechanisms have evolved in prokaryotic and eukaryotic organisms to maintain acidity within strict limits. It is currently assumed that the multiplicity of these processes provides a biological robustness. Here we report that the visual and auditory systems have a specific requirement for H+ disposal mediated by the sodium bicarbonate cotransporter NBC3 (refs. 7,8). Mice lacking NBC3 develop blindness and auditory impairment because of degeneration of sensory receptors in the eye and inner ear as in Usher syndrome. Our results indicate that in certain sensory organs, in which the requirement to transduce specific environmental signals with speed, sensitivity and reliability is paramount, the choice of the H+ disposal mechanism used is limited.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Auditory Perceptual Disorders / etiology*
  • Auditory Perceptual Disorders / metabolism
  • Blindness / etiology*
  • Blindness / metabolism
  • Electroretinography
  • Evoked Potentials, Auditory, Brain Stem
  • Female
  • Fluorescein Angiography
  • Gene Targeting
  • Hair Cells, Auditory / metabolism
  • Hair Cells, Auditory / pathology
  • Immunoenzyme Techniques
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Photoreceptor Cells, Vertebrate / metabolism
  • Photoreceptor Cells, Vertebrate / pathology
  • Retinal Degeneration / etiology
  • Retinal Degeneration / metabolism
  • Retinal Degeneration / pathology
  • Sodium-Bicarbonate Symporters / deficiency*
  • Sodium-Bicarbonate Symporters / physiology


  • Slc4a7 protein, mouse
  • Sodium-Bicarbonate Symporters