title: High opiate receptor binding potential in the human lateral pain system.
abstract: To determine how opiate receptor distribution is co-localized with the distribution of nociceptive areas in the human brain, eleven male healthy volunteers underwent one PET scan with the subtype-nonselective opioidergic radioligand [(18)F]fluoroethyl-diprenorphine under resting conditions. The binding potential (BP), a parameter for the regional cerebral opioid receptor availability, was computed using the occipital cortex as reference region. The following regions of interest (ROIs) were defined on individual MR images: thalamus, sensory motor strip (SI/MI area), frontal operculum, parietal operculum, anterior insular cortex, posterior insular cortex, anterior cingulate cortex (ACC; peri- and subgenual part of "classical ACC" only), midcingulate cortex (MCC, posterior part of "classical ACC"), putamen, caudate nucleus and the amygdala. BP for [(18)F]fluoroethyl-diprenorphine was lowest in the sensory motor strip (0.30). Highest BP was found in thalamus (1.36), basal ganglia (putamen 1.22, caudate 1.16) and amygdala (1.21). In the cingulate cortex, ACC (1.11) had higher BP than MCC (0.86). In the operculo-insular region, we found high BPs in all ROIs: anterior insula (1.16), posterior insula (1.05), frontal operculum (0.99) and parietal operculum (0.77). Factor analysis of interindividual variability of opiate receptor BP revealed four factors (95% explained variance): (1) operculo-insular areas, ACC, MCC and putamen, (2) amygdala and thalamus, (3) caudate and thalamus, (4) SI/MI and MCC. Nociceptive areas of the lateral pain system (frontoparietal operculum and insula) have opiate receptor BPs significantly higher than SI/MI, comparable to anterior and midcingulate areas of the medial pain system. These findings suggest that the cortical anti-nociceptive effects of opiates are not only mediated by ACC and MCC, but also by the operculo-insular cortex, if it can be assumed that opioid binding mediates anti-nociception in those structures.
authors.affiliation: Institute of Physiology and Pathophysiology, Johannes Gutenberg University, Saarstr. 21. D-55099 Mainz, Germany. baumgaer@uni-mainz.de
authors.forename: Ulf
authors.initials: U
authors.lastname: Baumgärtner
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Buchholz
authors.forename: Alexander
authors.initials: A
authors.lastname: Bellosevich
authors.forename: Walter
authors.initials: W
authors.lastname: Magerl
authors.forename: Thomas
authors.initials: T
authors.lastname: Siessmeier
authors.forename: Roman
authors.initials: R
authors.lastname: Rolke
authors.forename: Sabine
authors.initials: S
authors.lastname: Höhnemann
authors.forename: Markus
authors.initials: M
authors.lastname: Piel
authors.forename: Frank
authors.initials: F
authors.lastname: Rösch
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Wester
authors.forename: Gjermund
authors.initials: G
authors.lastname: Henriksen
authors.forename: Peter
authors.initials: P
authors.lastname: Stoeter
authors.forename: Peter
authors.initials: P
authors.lastname: Bartenstein
authors.forename: Rolf-Detlef
authors.initials: RD
authors.lastname: Treede
authors.forename: Mathias
authors.initials: M
authors.lastname: Schreckenberger
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D004174:Diprenorphine / Q000031:analogs & derivatives; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009619:Nociceptors / Q000502:physiology*; D010146:Pain / Q000503:physiopathology*; D049268:Positron-Emission Tomography; D011957:Receptors, Opioid / Q000502:physiology*
chemical_list: D011957:Receptors, Opioid; C063368:N-(3-fluoropropyl)-N-nordiprenorphine; D004174:Diprenorphine