Molecular and neural basis of contagious itch behavior in mice

Science. 2017 Mar 10;355(6329):1072-1076. doi: 10.1126/science.aak9748.


Socially contagious itch is ubiquitous in human society, but whether it exists in rodents is unclear. Using a behavioral paradigm that does not entail prior training or reward, we found that mice scratched after observing a conspecific scratching. Molecular mapping showed increased neuronal activity in the suprachiasmatic nucleus (SCN) of the hypothalamus of mice that displayed contagious scratching. Ablation of gastrin-releasing peptide receptor (GRPR) or GRPR neurons in the SCN abolished contagious scratching behavior, which was recapitulated by chemogenetic inhibition of SCN GRP neurons. Activation of SCN GRP/GRPR neurons evoked scratching behavior. These data demonstrate that GRP-GRPR signaling is necessary and sufficient for transmitting contagious itch information in the SCN. The findings may have implications for our understanding of neural circuits that control socially contagious behaviors.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Gastrin-Releasing Peptide / pharmacology
  • Gastrin-Releasing Peptide / physiology*
  • Imitative Behavior / physiology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neural Pathways
  • Neurons / drug effects
  • Neurons / physiology
  • Optogenetics
  • Receptors, Bombesin / genetics
  • Receptors, Bombesin / physiology*
  • Signal Transduction
  • Social Behavior*
  • Spinal Cord / physiology
  • Suprachiasmatic Nucleus / drug effects
  • Suprachiasmatic Nucleus / physiology*


  • Receptors, Bombesin
  • Gastrin-Releasing Peptide