Supraspinal TRPV1 modulates the emotional expression of abdominal pain

Pain. 2014 Oct;155(10):2153-60. doi: 10.1016/j.pain.2014.08.012. Epub 2014 Aug 17.

Abstract

The transient receptor potential vanilloid receptor type-1 (TRPV1) is critically involved in peripheral nociceptive processes of somatic and visceral pain. However, the role of the capsaicin receptor in the brain regarding visceral pain remains elusive. Here, we studied the contribution of TRPV1 to abdominal pain transmission at different nociceptive pathway levels using TRPV1 knock-out mice, resiniferatoxin-mediated deletion of TRPV1-positive primary sensory neurons, and intracerebral TRPV1 antagonism. We found that constitutive genetic TRPV1 deletion or peripheral TRPV1 deletion reduced acetic acid-evoked abdominal constrictions, without affecting referred abdominal hyperalgesia or allodynia in an acute pancreatitis model of visceral pain. Notably, intracerebral TRPV1 antagonism by SB 366791 significantly reduced chemical and inflammatory spontaneous abdominal nocifensive responses, as observed by reduced expressions of nociceptive facial grimacing, illustrating the affective component of pain. In addition to the established role of cerebral TRPV1 in anxiety, fear, or emotional stress, we demonstrate here for the first time that TRPV1 in the brain modulates visceral nociception by interfering with the affective component of abdominal pain.

Keywords: Pancreatitis; Resiniferatoxin; SB 366791; TRPV1; Visceral pain.

MeSH terms

  • Abdominal Pain / genetics
  • Abdominal Pain / metabolism*
  • Anilides / pharmacology
  • Animals
  • Behavior, Animal / drug effects
  • Behavior, Animal / physiology*
  • Cinnamates / pharmacology
  • Emotions / physiology*
  • Hyperalgesia / genetics
  • Hyperalgesia / metabolism*
  • Mice
  • Mice, Knockout
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / metabolism
  • Pain Measurement
  • Pain Threshold / drug effects
  • Pain Threshold / physiology
  • TRPV Cation Channels / antagonists & inhibitors
  • TRPV Cation Channels / genetics
  • TRPV Cation Channels / metabolism*

Substances

  • Anilides
  • Cinnamates
  • N-(3-methoxyphenyl)-4-chlorocinnamanilide
  • TRPV Cation Channels
  • TRPV1 protein, mouse