5-HT1B receptor imaging and cognition: a positron emission tomography study in control subjects and Parkinson's disease patients.
BACKGROUND
The serotonin 5-HT1B receptor subtype is involved in the modulation of serotonin release and is a target of interest for neuroreceptor imaging. Previous studies have shown that the serotonin system is affected in Parkinson's disease (PD). Cognitive function, frequently impaired in PD, has been linked to the serotonin system. The aim of this study was to examine whether 5-HT1B receptor availability in the brain of healthy subjects and PD patients is associated with measures of cognitive function.


METHODS
Twelve control subjects and ten PD patients with normal mini-mental state examination scores were included in this study. Cognitive function was evaluated by assessment of semantic, episodic, and working memory, as well as fluency and visual attention. Creative ability, a measure of divergent thinking, was examined with the alternative uses of objects task. PET measurements were performed with the 5-HT1B receptor-radioligand [(11) C]AZ10419369 using the HRRT system.


RESULTS
PD patients showed statistically significant lower measures of semantic and episodic memory, as well as creative ability, compared with control subjects. Statistically significant positive correlations were found in control subjects between creative ability and average 5-HT1B receptor availability in grey matter, and in PD patients between scores of Beck Depression Inventory-II and creative ability.


CONCLUSIONS
Though creativity has been conventionally linked to dopamine function, our findings in control subjects suggest a link between 5-HT1B receptor availability and creative ability. In PD patients, creative ability was significantly associated with depressive symptoms but not with 5-HT1B receptor availability. This finding deserves further investigation in future studies.
Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm, Sweden.|Stockholm Brain Institute, Stockholm, Sweden.
Andrea
A
Varrone
Stockholm Brain Institute, Stockholm, Sweden.|Karolinska Institutet, Department of Clinical Neuroscience, Centre for Molecular Medicine, Stockholm, Sweden.
Per
P
Svenningsson
Stockholm Brain Institute, Stockholm, Sweden.|Department of Psychology, Stockholm University, Sweden.
Petter
P
Marklund
Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm, Sweden.
Helena
H
Fatouros-Bergman
Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm, Sweden.
Anton
A
Forsberg
Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm, Sweden.|Stockholm Brain Institute, Stockholm, Sweden.
Christer
C
Halldin
Stockholm Brain Institute, Stockholm, Sweden.|Department of Psychology, Stockholm University, Sweden.
Lars-Göran
LG
Nilsson
Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm, Sweden.|Stockholm Brain Institute, Stockholm, Sweden.|AstraZeneca Translational Science Center at Karolinska Institutet, Sweden.
Lars
L
Farde
D000368:Aged; D000704:Analysis of Variance; D001578:Benzopyrans / Q000493:pharmacokinetics; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000473:pathology; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009025:Morpholines / Q000493:pharmacokinetics; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology*; D010879:Piperazines / Q000493:pharmacokinetics; D049268:Positron-Emission Tomography; D011485:Protein Binding / Q000187:drug effects; D044302:Receptor, Serotonin, 5-HT1B / Q000378:metabolism*; D012720:Severity of Illness Index
C530629:5-methyl-8-(4-methyl-piperazin-1-yl)-4-oxo-4H-chromene-2-carboxylic acid (4-morpholin-4-yl-phenyl)amide; D001578:Benzopyrans; D009025:Morpholines; D010879:Piperazines; D044302:Receptor, Serotonin, 5-HT1B
PET; cognition; creativity; semantic memory; serotonin