Elevated Cytosolic Cl- Concentrations in Dendritic Knobs of Mouse Vomeronasal Sensory Neurons

Chem Senses. 2016 Oct;41(8):669-76. doi: 10.1093/chemse/bjw077. Epub 2016 Jul 4.


In rodents, the vomeronasal system controls social and sexual behavior. However, several mechanistic aspects of sensory signaling in the vomeronasal organ remain unclear. Here, we investigate the biophysical basis of a recently proposed vomeronasal signal transduction component-a Ca(2+)-activated Cl(-) current. As the physiological role of such a current is a direct function of the Cl(-) equilibrium potential, we determined the intracellular Cl(-) concentration in dendritic knobs of vomeronasal neurons. Quantitative fluorescence lifetime imaging of a Cl(-)-sensitive dye at the apical surface of the intact vomeronasal neuroepithelium revealed increased cytosolic Cl(-) levels in dendritic knobs, a substantially lower Cl(-) concentration in vomeronasal sustentacular cells, and an apparent Cl(-) gradient in vomeronasal neurons along their dendritic apicobasal axis. Together, our data provide a biophysical basis for sensory signal amplification in vomeronasal neuron microvilli by opening Ca(2+)-activated Cl(-) channels.

Keywords: accessory olfactory system; cytosolic chloride concentration; fluorescence lifetime imaging; signal transduction; vomeronasal organ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism
  • Chloride Channels / metabolism
  • Chlorides / analysis*
  • Cytosol / chemistry*
  • Cytosol / metabolism
  • Dendrites / chemistry*
  • Dendrites / metabolism
  • Mice
  • Sensory Receptor Cells / chemistry*
  • Sensory Receptor Cells / metabolism
  • Vomeronasal Organ / chemistry*
  • Vomeronasal Organ / metabolism


  • Chloride Channels
  • Chlorides
  • Calcium