title: Evidence for endogenous opioid release in the amygdala during positive emotion.
abstract: Endogenous opioid release has been linked to relief from aversive emotional memories, thereby promoting a euphoric state and subsequent interactions towards social stimuli resulting in the formation of social preferences. However, this theory remains controversial. Using positron emission tomography and [(11)C]diprenorphine (DPN) in healthy volunteers, we found significantly reduced DPN binding to opioid receptor in the hippocampus during positive mood induction compared to neutral mood. Furthermore, the magnitude of positive mood change correlated negatively with DPN binding in the amygdala bilaterally. Our finding of reduced DPN binding is consistent with increased release of endogenous opioids, providing direct evidence that localised release of endogenous opioids is involved in the regulation of positive emotion in humans.
authors.affiliation: Institute of Neurology, University College London, Queen Square, London WC1, UK. mkoepp@ion.ucl.ac.uk
authors.forename: M J
authors.initials: MJ
authors.lastname: Koepp
authors.forename: A
authors.initials: A
authors.lastname: Hammers
authors.forename: A D
authors.initials: AD
authors.lastname: Lawrence
authors.forename: M C
authors.initials: MC
authors.lastname: Asselin
authors.forename: P M
authors.initials: PM
authors.lastname: Grasby
authors.forename: C J
authors.initials: CJ
authors.lastname: Bench
mesh_terms: D000328:Adult; D000679:Amygdala / Q000502:physiology*; D001931:Brain Mapping; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D018847:Opioid Peptides / Q000378:metabolism*; D049268:Positron-Emission Tomography
chemical_list: D018847:Opioid Peptides