|Sung Nyun Kim1,3;Do-Hyung Kang1,4;Je-Yeon Yun1,4;Tae Young Lee4;Wi Hoon Jung3;Joon Hwan Jang1,4; and Jun Soo Kwon1,2,3,4;
1Department of Psychiatry, Seoul National University College of Medicine, Seoul,
2;Department of Brain and Cognitive Sciences - World Class University Program, Seoul National University College of Natural Sciences, Seoul,
3;Institute of Human Behavioral Medicine, SNU-MRC, Seoul,
4;Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
Genetic imaging is used to investigate the mechanism by which genetic variants influence brain structure. In a previous study, a structural change of the dorsolateral prefrontal cortex was associated with symptom modulation in post-traumatic stress disorder patients. This study examined the effect of a polymorphism in the gene encoding brain-derived neurotrophic factor (BDNF) on regional gray matter (GM) volumes and the correlations between the dorsolateral prefrontal GM volume and the stress level in healthy volunteers.
Methods : Sixty-one volunteers underwent genotyping for the BDNF Val66Met single nucleotide polymorphism (SNP) and completed the Stress Response Inventory (SRI). Magnetic resonance images were also acquired, and the effect of each
subject's BDNF genotype and SRI subscore on his or her dorsolateral prefrontal GM volume was evaluated.
Results : The Val/Val homozygotes had significantly larger GM volumes in the prefrontal cortex and the precuneus, the uncus, and the superior temporal and occipital cortices than Met carriers. The Met homozygotes demonstrated a higher stress response in depression domain than Val/Val and Val/Met groups. A negative correlation between the middle frontal cortex GM volume and the SRI depression subscore was found.
Conclusion : These findings indicate an interaction between genes and brain structure, and they suggest that differences in dorsolateral prefrontal GM volume related to the BDNF Val66Met SNP are associated with resilience to stressful life events, particularly in the dimension of emotion.
Brain-derived neurotrophic factor;Val66Met;Genetic polymorphism;Magnetic resonance imaging;Stress;Dorsolateral prefrontal cortex.