Emotion Regulation and Trait Anxiety Are Predicted by the Microstructure of Fibers between Amygdala and Prefrontal Cortex

Abstract

Diffusion tensor imaging revealed that trait anxiety predicts the microstructural properties of a prespecified fiber tract between the amygdala and the perigenual anterior cingulate cortex. Besides this particular pathway, it is likely that other pathways are also affected. We investigated white matter differences in persons featuring an anxious or a nonanxious personality, taking into account all potential pathway connections between amygdala and anxiety-related regions of the prefrontal cortex (PFC). Diffusion-weighted images, measures of trait anxiety and of reappraisal use (an effective emotion-regulation style), were collected in 48 females. With probabilistic tractography, pathways between the amygdala and the dorsolateral PFC, dorsomedial PFC, ventromedial PFC, and orbitofrontal cortex (OFC) were delineated. The resulting network showed a direct ventral connection between amygdala and PFC and a second limbic connection following the fornix and the anterior limb of the internal capsule. Reappraisal use predicted the microstructure of pathways to all calculated PFC regions in the left hemisphere, indicating stronger pathways for persons with high reappraisal use. Trait anxiety predicted the microstructure in pathways to the ventromedial PFC and OFC, indexing weaker connections in trait-anxious persons. These effects appeared in the right hemisphere, supporting lateralization and top-down inhibition theories of emotion processing. Whereas a specific microstructure is associated with an anxious personality, a different structure subserves emotion regulation. Both are part of a broad fiber tract network between amygdala and PFC.

The Inverse Relationship between the Microstructural Variability of Amygdala-Prefrontal Pathways and Trait Anxiety Is Moderated by Sex

“…Our data complement and expand previous findings from other groups that utilized dMRI to show an inverse relationship between frontotemporal white matter strength and trait anxiety/anxiety-related constructs (e.g., harm avoidance, neuroticism) in nonclinical populations (Kazlouski et al, 2011; Motzkin et al, 2011; Westlye et al, 2011; Taddei et al, 2012; Bjørnebekk et al, 2013; Mettler et al, 2013; Eden et al, 2015; Greening and Mitchell, 2015). Collectively, these findings support the notion that stronger connectivity between the amygdala and the vPFC reflects the capacity for efficient crosstalk between these brain regions that ultimately leads to beneficial outcomes in terms of anxiety (Kim et al, 2011b).…”

History of childhood maltreatment augments dorsolateral prefrontal processing of emotional valence in PTSD

“…Moreover, recent research suggests that different prefrontal regions modulate different aspects of bottom-up reactivity instantiated in the amygdala. Whereas the medial prefrontal cortex is involved with bottom-up appraisal of stimulus valence, the dorsolateral prefrontal cortex (dlPFC) serves to augment threat or valence-related attentional processes (Comte et al, 2014), which is consistent with the proposed role of the dlPFC in regulating amygdalar emotional reactivity (Delgado et al, 2008, Ray and Zald, 2012) and observations for indirect amygdalar-dlPFC connections (Eden et al, 2015). …”

Neural - hormonal responses to negative affective stimuli: Impact of dysphoric mood and sex

“…OFC and mPFC are important in the regulation of emotion (Amodio & Frith, 2006; Banks et al, 2007; Rive et al, 2013; Eden et al, 2015). They have a relatively high density of mineralocorticoid and glucocorticoid receptors, and are thus involved in stress-mediated HPA axis activity and potential neurotoxicity (De Kloet et al, 1998).…”