Association of striatal dopamine D2/D3 receptor binding potential with pain but not tactile sensitivity or placebo analgesia.
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.
Martikainen
Ilkka K
IK
Department of Physiology, University of Turku, Turku, Finland.
Hagelberg
Nora
N
Mansikka
Heikki
H
Hietala
Jarmo
J
Någren
Kjell
K
Scheinin
Harry
H
Pertovaara
Antti
A
D000328:Adult; D000698:Analgesia / Q000379:methods; D001667:Binding, Competitive / Q000502:physiology; D003342:Corpus Striatum / Q000378:metabolism*; D018492:Dopamine Antagonists / Q000493:pharmacokinetics; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D006930:Hyperalgesia / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D010146:Pain / Q000378:metabolism* / Q000503:physiopathology; D017288:Pain Threshold / Q000502:physiology; D010812:Physical Stimulation; D015990:Placebo Effect; D011699:Putamen / Q000378:metabolism; D020891:Raclopride / Q000493:pharmacokinetics; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3; D012684:Sensory Thresholds / Q000502:physiology*; D014110:Touch / Q000502:physiology*
C493593:DRD3 protein, human; D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D020891:Raclopride