Anxiety Dissociates Dorsal and Ventral Medial Prefrontal Cortex Functional Connectivity with the Amygdala at Rest

This study investigated whether individual differences in anxiety, which is often treated as a stable personality trait or a persistent psychological state, are reflected in the intrinsic functional connectivity of the brain at rest. While previous task-based neuroimaging research established that anxiety predicts amygdala and mPFC responses, the researchers aimed to determine if these connectivity patterns persist in the absence of external stimuli. Using resting-state functional magnetic resonance imaging (rs-fMRI), they analyzed 29 healthy volunteers, assessing the functional coupling between the amygdala (as a seed region) and the dorsal mPFC (dmPFC) and ventral mPFC (vmPFC).

Across all participants, the researchers observed a baseline pattern where amygdala activity was positively correlated with the vmPFC and negatively correlated with the dmPFC. Anxiety levels significantly moderated this connectivity. Specifically, in high-anxiety individuals, the expected positive connectivity between the amygdala and vmPFC was reversed into a negative correlation. Simultaneously, the typical negative connectivity between the amygdala and dmPFC disappeared, becoming uncorrelated. These results suggest that the neural circuitry involved in emotional regulation—typically involving the inhibitory control of the amygdala by the mPFC—is functionally altered or compromised even during resting conditions in more anxious individuals.

This research bridges the gap between task-based neuroimaging and resting-state physiology, demonstrating that individual differences in anxiety are encoded in the brain's spontaneous activity. The findings suggest that "resting" brain connectivity can act as an important baseline that predicts how an individual might respond to emotional tasks. Understanding these baseline dissociations between dorsal and ventral mPFC circuits provides a potential neurobiological marker for anxiety, which may help explain variability in clinical populations, such as those with posttraumatic stress disorder, where similar hyper- and hypo-active patterns are often observed.