Association of striatal dopamine D2/D3 receptor binding potential with pain but not tactile sensitivity or placebo analgesia

Neurosci Lett. 2005 Mar 16;376(3):149-53. doi: 10.1016/j.neulet.2004.11.045. Epub 2004 Dec 9.

Abstract

Striatal dopamine D2/D3 receptors have been suggested to play a role in pain sensitivity and placebo effect. We studied whether the association of dopamine D2/D3 receptor binding potential (BP) with sensory thresholds is specific to the modality of pain, and whether striatal dopamine D2/D3 receptor BP predicts the magnitude of placebo analgesia. Pain and tactile thresholds, and placebo analgesia were assessed in eight healthy human male subjects who had previously participated in a dopamine D2/D3 receptor positron emission tomography study with [11C]raclopride. The results show that the cutaneous heat pain threshold was inversely correlated with dopamine D2/D3 receptor BP in the right putamen, but responses to tactile stimulation did not correlate with striatal dopamine D2/D3 receptor BP. Placebo-induced elevation of the heat pain threshold did not correlate with striatal dopamine D2/D3 receptor BP. These results suggest that the influence of striatal dopamine D2/D3 receptors on sensory thresholds is selective for the modality of pain. Moreover, striatal dopamine D2/D3 receptor BP appears not to predict individual's analgesic response to placebo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Analgesia / methods
  • Binding, Competitive / physiology
  • Corpus Striatum / metabolism*
  • Dopamine Antagonists / pharmacokinetics
  • Functional Laterality / physiology
  • Humans
  • Hyperalgesia / metabolism
  • Hyperalgesia / physiopathology
  • Male
  • Pain / metabolism*
  • Pain / physiopathology
  • Pain Threshold / physiology
  • Physical Stimulation
  • Placebo Effect
  • Putamen / metabolism
  • Raclopride / pharmacokinetics
  • Receptors, Dopamine D2 / metabolism*
  • Receptors, Dopamine D3
  • Sensory Thresholds / physiology*
  • Touch / physiology*

Substances

  • DRD3 protein, human
  • Dopamine Antagonists
  • Receptors, Dopamine D2
  • Receptors, Dopamine D3
  • Raclopride