A second class of chemosensory receptors in the olfactory epithelium

Nature. 2006 Aug 10;442(7103):645-50. doi: 10.1038/nature05066. Epub 2006 Jul 30.


The mammalian olfactory system detects chemicals sensed as odours as well as social cues that stimulate innate responses. Odorants are detected in the nasal olfactory epithelium by the odorant receptor family, whose approximately 1,000 members allow the discrimination of a myriad of odorants. Here we report the discovery of a second family of receptors in the mouse olfactory epithelium. Genes encoding these receptors, called 'trace amine-associated receptors' (TAARs), are present in human, mouse and fish. Like odorant receptors, individual mouse TAARs are expressed in unique subsets of neurons dispersed in the epithelium. Notably, at least three mouse TAARs recognize volatile amines found in urine: one detects a compound linked to stress, whereas the other two detect compounds enriched in male versus female urine-one of which is reportedly a pheromone. The evolutionary conservation of the TAAR family suggests a chemosensory function distinct from odorant receptors. Ligands identified for TAARs thus far suggest a function associated with the detection of social cues.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amines / analysis
  • Amines / metabolism
  • Animals
  • Cues
  • Female
  • Gene Expression Profiling
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neurons / classification
  • Neurons / metabolism
  • Odorants / analysis
  • Olfactory Mucosa / cytology
  • Olfactory Mucosa / metabolism*
  • Organ Specificity
  • Pheromones / metabolism
  • Receptors, G-Protein-Coupled / classification*
  • Receptors, G-Protein-Coupled / genetics
  • Receptors, G-Protein-Coupled / metabolism*
  • Sexual Maturation
  • Stress, Physiological / metabolism
  • Substrate Specificity
  • Urine / chemistry
  • Volatilization


  • Amines
  • Pheromones
  • Receptors, G-Protein-Coupled
  • Trace amine-associated receptor 1