Exploring the Anxious Brain at Rest: Increased Subcortico-Frontal Coupling Associated with an Anxious State

Thursday, October 11, 2012 — Poster Session IV
2:00 p.m. – 4:00 p.m.	Natcher Conference Center, Building 45	NIMH	NEURO/BEHAV/SENSYS-25

* FARE Award Winner

Authors

• K. E. Vytal
• C. Overstreet
• O. J. Robinson
• C. Grillon

Abstract

Neuroimaging research has traditionally explored fear and anxiety with discrete threat cues, such as those in fear conditioning paradigms. However, a more relevant approach to understanding clinical anxiety comes from paradigms that elicit sustained anticipatory anxiety. Here we implement a translational method of anxiety-induction (unpredictable threat of shock) that serves as a robust model of anxiety disorders. We use resting-state fMRI to probe how anticipatory anxiety alters amygdala-prefrontal cortical (PFC) connectivity. Twenty healthy participants (13m) were scanned under threat of shock and safe conditions. Subjects viewed a single word (THREAT or SAFE) during two 6-minute scans. Results suggest anticipatory anxiety increases connectivity between amygdala and regions involved in threat appraisal (medial PFC), as well as autonomic nervous system control (thalamus), indicating this network may facilitate preparatory behaviors (e.g., vigilance, avoidance). In contrast, safety was associated with increased connectivity between amygdala and regions implicated in fear reduction (vmPFC) and introspection (precuneus). These results are underscored by similar findings in anxiety patients, suggesting that pathological and induced anxiety both create a specific preparatory context that is distinct from the default mode network. Future research may use this preparatory context to identify biomarkers of anxious pathology and target these circuits for therapeutic intervention.

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