In vivo measurements of brain trapping of C-labelled alpha-methyl-L-tryptophan during acute changes in mood states.
BACKGROUND
Little is known about the specific contribution of serotonin (5-HT) to the neurobiology of emotion and mood in healthy people. In an exploratory study, we sought to investigate the effect of rapid and sustained changes of emotional state on the trapping of 11C-labelled alpha-methyl-L-tryptophan (11C-alphaMtrp) used as a proxy of 5-HT synthesis, using positron emission tomography (PET).


METHODS
In a within-subject repeated-measure design, participants recalled autobiographical memories to self-induce sadness, happiness and a neutral emotional state during scanning to measure brain trapping of 11C-alphaMtrp. Three separate scan acquisitions, counterbalanced for order across subjects, took place at the McConnell Brain Imaging Center, Montréal.


RESULTS
Whole brain analysis revealed positive and negative correlations between experienced levels of emotions and 11C-alphaMtrp trapping in the right anterior cingulate cortex.


CONCLUSIONS
These findings point to a mechanism whereby state-related changes in a proxy of 5-HT synthesis underscore aspects of the self-regulation of normal mood.
Perreau-Linck, Beauregard, Paquette-Department of Psychology, University of Montréal, Que.
Elisabeth
E
Perreau-Linck
Mario
M
Beauregard
Paul
P
Gravel
Vincent
V
Paquette
Jean-Paul
JP
Soucy
Mirko
M
Diksic
Chawki
C
Benkelfat
D000328:Adult; D000339:Affect / Q000502:physiology*; D001921:Brain / Q000378:metabolism*; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography; D012701:Serotonin / Q000096:biosynthesis; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000378:metabolism
C020774:alpha-methyltryptophan; D012701:Serotonin; D014364:Tryptophan