Ratio of dopamine synthesis capacity to D2 receptor availability in ventral striatum correlates with central processing of affective stimuli.
OBJECTIVE
Dopaminergic neurotransmission in the ventral striatum may interact with limbic processing of affective stimuli, whereas dorsal striatal dopaminergic neurotransmission can affect habitual processing of emotionally salient stimuli in the pre-frontal cortex. We investigated the dopaminergic neurotransmission in the ventral and dorsal striatum with respect to central processing of affective stimuli in healthy subjects.


METHODS
Subjects were investigated with positron emission tomography and [(18)F]DOPA for measurements of dopamine synthesis capacity and [(18)F]DMFP for estimation of dopamine D2 receptor binding potential. Functional magnetic resonance imaging was used to assess the blood-oxygen-level-dependent (BOLD) response to affective pictures, which was correlated with the ratio of [(18)F]DOPA net influx constant K(app)(in)/[(18)F]DMFP-binding potential (BP_ND) in the ventral and dorsal striatum.


RESULTS
The magnitude of the ratio in the ventral striatum was positively correlated with BOLD signal increases elicited by negative versus neutral pictures in the right medial frontal gyrus (BA10), right inferior parietal lobe and left post-central gyrus. In the dorsal striatum, the ratio was positively correlated with BOLD signal activation elicited by negative versus neutral stimuli in the left post-central gyrus. The BOLD signal elicited by positive versus neutral stimuli in the superior parietal gyrus was positively correlated with the dorsal and ventral striatal ratio.


CONCLUSIONS
The correlations of the ratio in the ventral and dorsal striatum with processing of affective stimuli in the named cortical regions support the hypothesis that dopamine transmission in functional divisions of the striatum modulates processing of affective stimuli in specific cortical areas.
Kienast
Thorsten
T
Department of Psychiatry and Psychotherapy of the Charité University Medical Center, Charité Campus Mitte, Charitéplatz 1, 10117, Berlin, Germany.
Siessmeier
Thomas
T
Wrase
Jana
J
Braus
Dieter F
DF
Smolka
Michael N
MN
Buchholz
Hans Georg
HG
Rapp
Michael
M
Schreckenberger
Mathias
M
Rösch
Frank
F
Cumming
Paul
P
Gruender
Gerhard
G
Mann
Karl
K
Bartenstein
Peter
P
Heinz
Andreas
A
D000328:Adult; D000339:Affect / Q000502:physiology*; D001479:Basal Ganglia / Q000000981:diagnostic imaging / Q000378:metabolism*; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D017448:Receptors, Dopamine D2 / Q000378:metabolism*
D017448:Receptors, Dopamine D2; D004298:Dopamine