A Sensor for Low Environmental Oxygen in the Mouse Main Olfactory Epithelium

Neuron. 2016 Dec 21;92(6):1196-1203. doi: 10.1016/j.neuron.2016.11.001. Epub 2016 Dec 1.


Sensing the level of oxygen in the external and internal environments is essential for survival. Organisms have evolved multiple mechanisms to sense oxygen. No function in oxygen sensing has been attributed to any mammalian olfactory system. Here, we demonstrate that low environmental oxygen directly activates a subpopulation of sensory neurons in the mouse main olfactory epithelium. These neurons express the soluble guanylate cyclase Gucy1b2 and the cation channel Trpc2. Low oxygen induces calcium influx in these neurons, and Gucy1b2 and Trpc2 are required for these responses. In vivo exposure of a mouse to low environmental oxygen causes Gucy1b2-dependent activation of olfactory bulb neurons in the vicinity of the glomeruli formed by axons of Gucy1b2+ sensory neurons. Low environmental oxygen also induces conditioned place aversion, for which Gucy1b2 and Trpc2 are required. We propose that this chemosensory function enables a mouse to rapidly assess the oxygen level in the external environment.

MeSH terms

  • Animals
  • Chemoreceptor Cells / metabolism*
  • Mice
  • Mice, Knockout
  • Mutation
  • Olfactory Mucosa / cytology
  • Olfactory Mucosa / metabolism*
  • Oxygen / metabolism*
  • Soluble Guanylyl Cyclase / genetics*
  • Soluble Guanylyl Cyclase / metabolism
  • TRPC Cation Channels / genetics*
  • TRPC Cation Channels / metabolism


  • Gucy1b2 protein, mouse
  • TRPC Cation Channels
  • Trpc2 protein, mouse
  • Soluble Guanylyl Cyclase
  • Oxygen