Relief of itch by scratching: state-dependent inhibition of primate spinothalamic tract neurons

Nat Neurosci. 2009 May;12(5):544-6. doi: 10.1038/nn.2292. Epub 2009 Apr 6.

Abstract

Itch is relieved by scratching, but the neural mechanisms that are responsible for this are unknown. Spinothalamic tract (STT) neurons respond to itch-producing agents and transmit pruritic information to the brain. We observed that scratching the cutaneous receptive field of primate STT neurons produced inhibition during histamine-evoked activity but not during spontaneous activity or activity evoked by a painful stimulus, suggesting that scratching inhibits the transmission of itch in the spinal cord in a state-dependent manner.

Publication types

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

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Afferent Pathways / drug effects
  • Afferent Pathways / physiology*
  • Animals
  • Haplorhini
  • Histamine
  • Histamine Agonists
  • Mechanoreceptors / physiology
  • Neural Inhibition / drug effects
  • Neural Inhibition / physiology*
  • Neurons / drug effects
  • Neurons / physiology*
  • Nociceptors / drug effects
  • Nociceptors / physiology
  • Physical Stimulation
  • Pruritus / chemically induced
  • Pruritus / physiopathology*
  • Sensory Receptor Cells / drug effects
  • Sensory Receptor Cells / physiology
  • Skin / innervation
  • Spinothalamic Tracts / physiology*
  • Touch / physiology

Substances

  • Histamine Agonists
  • Histamine