Serotonin transporter genotype modulates amygdala activity during mood regulation.
Recent studies have implicated the short allele of the serotonin transporter-linked polymorphic region (5-HTTLPR) in depression vulnerability, particularly in the context of stress. Several neuroimaging studies have shown that 5-HTTLPR genotype predicts amygdala reactivity to negatively valenced stimuli, suggesting a mechanism whereby the short allele confers depression risk. The current study investigated whether 5-HTTLPR genotype similarly affects neural activity during an induced sad mood and during recovery from sad mood. Participants were 15 homozygous short (S) and 15 homozygous long (L) individuals. Regional cerebral blood flow was measured with perfusion functional magnetic resonance imaging during four scanning blocks: baseline, sad mood, mood recovery and following return to baseline. Comparing mood recovery to baseline, both whole brain analyses and template-based region-of-interest analyses revealed greater amygdala activity for the S vs the L-group. There were no significant amygdala differences found during the induced sad mood. These results demonstrate the effect of the S allele on amygdala activity during intentional mood regulation and suggest that amygdala hyperactivity during recovery from a sad mood may be one mechanism by which the S allele confers depression risk.
Center for Cognitive Neuroscience, Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA. gillihan@mail.med.upenn.edu
Seth J
SJ
Gillihan
Hengyi
H
Rao
Jiongjiong
J
Wang
John A
JA
Detre
Jessica
J
Breland
Geena Mary V
GM
Sankoorikal
Edward S
ES
Brodkin
Martha J
MJ
Farah
D000328:Adult; D000339:Affect / Q000502:physiology*; D000483:Alleles; D000679:Amygdala / Q000502:physiology*; D000704:Analysis of Variance; D001931:Brain Mapping; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*
D050486:Serotonin Plasma Membrane Transport Proteins