High-Resolution Resting-State Functional Connectivity of the Extended Amygdala

Area of Science:

• Neuroscience
• Neuroimaging
• Psychiatry

Background:

• The extended amygdala, comprising the central (CeA) and basolateral (BLA) amygdala nuclei and the bed nucleus of the stria terminalis (BNST), is crucial for anxiety.
• Human neurocircuitry of the extended amygdala remains less understood compared to animal models due to its small size.

Purpose of the Study:

• To define, compare, and contrast the functional connectivity (FC) of extended amygdala nuclei in humans.
• To investigate the relationship between FC and self-reported anxiety and intolerance of uncertainty.

Main Methods:

• Utilized high-resolution 7-Tesla magnetic resonance imaging (MRI) in 57 healthy adults.
• Analyzed resting-state functional connectivity (FC) of the CeA, BLA, and BNST.
• Correlated FC with trait anxiety and intolerance of uncertainty scores.

Main Results:

• FC patterns largely replicated previous findings.
• Extended amygdala nuclei shared FC with hippocampal, cingulate, medial prefrontal, and subgenual cortices.
• CeA and BLA showed stronger coupling with parahippocampal, temporal, fusiform, and occipital gyri compared to BNST.
• BNST exhibited stronger coupling with the anterior caudate and anterior cingulate cortex than CeA and BLA.
• No robust relationship was found between trait anxiety, intolerance of uncertainty, and resting-state FC of the extended amygdala.

Conclusions:

• This study provides a detailed map of resting-state FC within the human extended amygdala.
• Distinct connectivity profiles exist for CeA, BLA, and BNST.
• Resting-state FC of the extended amygdala was not strongly associated with individual differences in anxiety or intolerance of uncertainty in this cohort.