Faecal bile acids are natural ligands of the mouse accessory olfactory system

Nat Commun. 2016 Jun 21:7:11936. doi: 10.1038/ncomms11936.


The accessory olfactory system (AOS) guides behaviours that are important for survival and reproduction, but understanding of AOS function is limited by a lack of identified natural ligands. Here we report that mouse faeces are a robust source of AOS chemosignals and identify bile acids as a class of natural AOS ligands. Single-unit electrophysiological recordings from accessory olfactory bulb neurons in ex vivo preparations show that AOS neurons are strongly and selectively activated by peripheral stimulation with mouse faecal extracts. Faecal extracts contain several unconjugated bile acids that cause concentration-dependent neuronal activity in the AOS. Many AOS neurons respond selectively to bile acids that are variably excreted in male and female mouse faeces, and others respond to bile acids absent in mouse faeces. These results identify faeces as a natural source of AOS information, and suggest that bile acids may be mammalian pheromones and kairomones.

MeSH terms

  • Action Potentials / drug effects*
  • Action Potentials / physiology
  • Animals
  • Bile Acids and Salts / chemistry
  • Bile Acids and Salts / isolation & purification
  • Bile Acids and Salts / pharmacology*
  • Feces / chemistry*
  • Female
  • Ligands
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Neurons / drug effects*
  • Neurons / physiology
  • Olfactory Bulb / drug effects*
  • Olfactory Bulb / physiology
  • Pheromones / pharmacology
  • Pheromones / urine*
  • Sex Factors
  • Single-Cell Analysis
  • Tissue Culture Techniques


  • Bile Acids and Salts
  • Ligands
  • Pheromones