It is known that increased circulating glucocorticoids in the wake of excessive, chronic,
repetitive stress increases anxiety and impairs Brain-Derived Neurotrophic Factor (BDNF)
signaling. Recent studies of BDNF gene methylation in relation to maternal care have linked
high BDNF methylation levels in the blood of adults to lower quality of received maternal
care measured via self-report. Yet the specific mechanisms by which these phenomena
occur remain to be established. The present study examines the link between methylation
of the BDNF gene promoter region and patterns of neural activity that are associated with
maternal response to stressful versus non-stressful child stimuli within a sample that
includes mothers with interpersonal violence-related PTSD (IPV-PTSD). 46 mothers underwent fMRI. The contrast of neural activity when watching children—including their own—
was then correlated to BDNF methylation. Consistent with the existing literature, the present
study found that maternal BDNF methylation was associated with higher levels of maternal
anxiety and greater childhood exposure to domestic violence. fMRI results showed a positive correlation of BDNF methylation with maternal brain activity in the anterior cingulate
(ACC), and ventromedial prefrontal cortex (vmPFC), regions generally credited with a regulatory function toward brain areas that are generating emotions. Furthermore we found a
negative correlation of BDNF methylation with the activity of the right hippocampus. Since
our stimuli focus on stressful parenting conditions, these data suggest that the correlation
between vmPFC/ACC activity and BDNF methylation may be linked to mothers who are at
a disadvantage with respect to emotion regulation when facing stressful parenting situations. Overall, this study provides evidence that epigenetic signatures of stress-related
genes can be linked to functional brain regions regulating parenting stress, thus advancing
our understanding of mothers at risk for stress-related psychopathology.