Seasonal changes in brain serotonin transporter binding in short serotonin transporter linked polymorphic region-allele carriers but not in long-allele homozygotes.
BACKGROUND
A polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) has been associated with seasonality both in patients with seasonal affective disorder and in the general population.


METHODS
We used in vivo molecular imaging to measure cerebral serotonin transporter (5-HTT) binding in 57 healthy Scandinavians and related the outcome to season of the year and to the 5-HTTLPR carrier status.


RESULTS
We found that the number of daylight minutes at the time of scanning correlated negatively with 5-HTT binding in the putamen and the caudate, with a similar tendency in the thalamus, whereas this association was not observed for the midbrain. Furthermore, in the putamen, an anatomic region with relatively dense serotonin innervation, we found a significant gene x daylight effect, such that there was a negative correlation between 5-HTT binding and daylight minutes in carriers of the short 5-HTTLPR allele but not in homozygote carriers of the long allele.


CONCLUSIONS
Our findings are in line with S-carriers having an increased response in neural circuits involved in emotional processing to stressful environmental stimuli but here demonstrated as a endophenotype with dynamic changes in serotonin reuptake.
Kalbitzer
Jan
J
Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark. Jan.kalbitzer@charite.de
Erritzoe
David
D
Holst
Klaus K
KK
Nielsen
Finn A
FA
Marner
Lisbeth
L
Lehel
Szabolcs
S
Arentzen
Tine
T
Jernigan
Terry L
TL
Knudsen
Gitte M
GM
D000328:Adult; D000483:Alleles; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D001931:Brain Mapping; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D011110:Polymorphism, Genetic / Q000235:genetics; D011877:Radionuclide Imaging; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D044465:White People / Q000235:genetics
D050486:Serotonin Plasma Membrane Transport Proteins