Frontal-limbic white matter pathway associations with the serotonin transporter gene promoter region (5-HTTLPR) polymorphism.
Variation in the serotonin transporter gene-linked polymorphic region (5-HTTLPR) has been associated with heightened neural activity in limbic and prefrontal regions in response to emotional stimuli. The current study examined whether the 5-HTTLPR polymorphism is also associated with alterations in microstructure of frontal-limbic white matter (WM) tracts. Thirty-seven (mean age, 20.51 years; range, 13-28) female participants were genotyped for the 5-HTTLPR polymorphism. Diffusion MRI was collected and a probabilistically defined tract of the uncinate fasciculus (UF), a WM pathway connecting the amygdala to medial and orbital prefrontal cortex, was used to generate fractional anisotropy (FA) values for participants. Regression analyses indicated a significant inverse association between number of low-expressing 5-HTTLPR alleles and FA values for the left frontal UF region, beta = - 0.42, p = 0.005. Furthermore, there was a positive association between age and FA values for bilateral frontal regions of the UF; these effects explained 39 and 20% of the variance in FA values for left and right frontal regions, respectively. 5-HTTLPR genotype and age appear to independently influence the WM microstructure of the UF. The observed reduction in FA values among low-expressing 5-HTTLPR allele carriers may contribute to biased regulation of emotional stimuli.
Department of Psychology, The University of Texas at Austin, Austin, Texas 78712, USA. jpacheco@mail.utexas.edu
Jennifer
J
Pacheco
Christopher G
CG
Beevers
Cristina
C
Benavides
John
J
McGeary
Eric
E
Stice
David M
DM
Schnyer
D000293:Adolescent; D000328:Adult; D000375:Aging; D000483:Alleles; D000679:Amygdala / Q000033:anatomy & histology* / Q000502:physiology; D016880:Anisotropy; D038524:Diffusion Magnetic Resonance Imaging; D005006:Ethnicity / Q000235:genetics; D005260:Female; D007839:Functional Laterality / Q000235:genetics / Q000502:physiology; D005838:Genotype; D006801:Humans; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D020641:Polymorphism, Single Nucleotide; D017397:Prefrontal Cortex / Q000033:anatomy & histology* / Q000502:physiology; D011401:Promoter Regions, Genetic; D044469:Racial Groups / Q000235:genetics; D012044:Regression Analysis; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D055815:Young Adult
C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins