Sour Sensing from the Tongue to the Brain

Cell. 2019 Oct 3;179(2):392-402.e15. doi: 10.1016/j.cell.2019.08.031. Epub 2019 Sep 19.


The ability to sense sour provides an important sensory signal to prevent the ingestion of unripe, spoiled, or fermented foods. Taste and somatosensory receptors in the oral cavity trigger aversive behaviors in response to acid stimuli. Here, we show that the ion channel Otopetrin-1, a proton-selective channel normally involved in the sensation of gravity in the vestibular system, is essential for sour sensing in the taste system. We demonstrate that knockout of Otop1 eliminates acid responses from sour-sensing taste receptor cells (TRCs). In addition, we show that mice engineered to express otopetrin-1 in sweet TRCs have sweet cells that also respond to sour stimuli. Next, we genetically identified the taste ganglion neurons mediating each of the five basic taste qualities and demonstrate that sour taste uses its own dedicated labeled line from TRCs in the tongue to finely tuned taste neurons in the brain to trigger aversive behaviors.

Keywords: brain circuits; innate behaviors; otopetrin; sensory coding; sour; taste.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acids / pharmacology
  • Afferent Pathways / cytology
  • Afferent Pathways / metabolism
  • Afferent Pathways / physiology
  • Animals
  • Brain / cytology
  • Brain / metabolism
  • Brain / physiology*
  • Female
  • Male
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Taste Buds / drug effects
  • Taste Buds / metabolism*
  • Taste Buds / physiology
  • Taste Perception
  • Taste*


  • Acids
  • Membrane Proteins
  • otopetrin 1 protein, mouse