Resting-State Functional and Structural Connectivity Within an Insula–Amygdala Route Specifically Index State and Trait Anxiety

• Published in: Biological psychiatry (1969) Vol. 73; no. 1; pp. 85 - 92
• Main Authors: Baur, Volker, Hänggi, Jürgen, Langer, Nicolas, Jäncke, Lutz
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 2013; Elsevier
• Subjects: Adult; Amygdala; Amygdala - pathology; Amygdala - physiopathology; Anxiety - pathology; Anxiety - physiopathology; Biological and medical sciences; Cerebral Cortex - pathology; Cerebral Cortex - physiopathology; Diffusion Tensor Imaging - methods; Diffusion Tensor Imaging - psychology; Functional Neuroimaging - methods; Functional Neuroimaging - psychology; Humans; insula; Magnetic Resonance Imaging - methods; Magnetic Resonance Imaging - psychology; Medical sciences; Neural Pathways - physiology; Neural Pathways - physiopathology; Personality Inventory - statistics & numerical data; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; resting-state functional connectivity; state anxiety; structural connectivity; trait anxiety; state anxiety; resting-state functional connectivity; structural connectivity; Amygdala; insula; trait anxiety; Affect affectivity; Central nervous system; Basal ganglion; Personality; Encephalon; Rest; Anxiety; Insular cortex; Amygdaloid nucleus
• DOI: 10.1016/j.biopsych.2012.06.003
• ISSN: 0006-3223

Background Conjoint activity of the insula and amygdala has frequently been reported during emotional stimulation in general and in anxiety-related contexts in particular. However, direct connectivity between the insula and amygdala in this framework has received little attention so far. Studying whether inter-individual differences in anxiety reflect variation in insula–amygdala connectivity is a way to push forward the understanding of network-related aspects underlying anxious behavior. Methods To investigate functional and structural connectivity, we applied resting-state functional magnetic resonance imaging and diffusion tensor imaging in a group of 32 healthy subjects. Specific measures of connectivity between subregions of the insula and amygdala were related to subjects' anxiety levels. Results Resting-state functional connectivity between the anterior insula and the basolateral amygdala was strongly related to state anxiety, explaining 40% of behavioral variance across subjects. This was substantiated by applying tractography, yielding a relationship between trait anxiety and axial diffusivity for a direct pathway between anterior insula and basolateral amygdala. Conclusions Our results indicate that anterior insula and basolateral amygdala constitute a network part that is prominently linked to anxiety. Within this route, state and trait behavioral impacts seem to be specifically linked to dynamic functional and more static structural neural aspects, respectively. Insula–amygdala resting-state functional connectivity can be assessed in an easy and straightforward way and has high potential to serve as a biomarker for anxiety.