Extended-amygdala intrinsic functional connectivity networks: A population study.

Area of Science:

• Neuroscience
• Human Neuroimaging
• Functional Connectivity

Background:

• The extended amygdala (ExtA), comprising the bed nucleus of the stria terminalis (BST) and central nucleus of the amygdala (CeA), is implicated in negative emotional states, stress, and substance use.
• The functional integration of individual ExtA structures remains debated.

Purpose of the Study:

• To compare intrinsic functional connectivity networks (ICNs) of the BST and CeA in a large human sample.
• To investigate if inter-individual differences in BST-CeA ICNs relate to negative disposition and alcohol use.
• To assess the heritability of BST-CeA intrinsic functional connectivity (iFC) and its co-heritability with these psychological components.

Main Methods:

• Utilized task-free functional magnetic resonance imaging (fMRI) data from over 1,000 healthy young adults in the Human Connectome Project.
• Compared ICNs of the BST and CeA.
• Assessed heritability of iFC and correlations with principal components of negative disposition and alcohol use.

Main Results:

• Demonstrated discrete yet overlapping ICNs for the BST and CeA, consistent with prior research.
• Found no evidence for heritability of within BST-CeA iFC.
• Post hoc analyses revealed significant heritability for BST iFC with superficial and centromedial amygdala regions.
• No significant correlations or co-heritability were found between BST-CeA iFC and the assessed psychological components.

Conclusions:

• The BST and CeA exhibit distinct but interconnected functional networks.
• Within-network BST-CeA functional connectivity is not heritable in young adults.
• Specific BST-amygdala connectivity shows heritability, but this does not directly link to dispositional negative affect or alcohol use in this cohort.
• Future research should explore task-based and clinical fMRI, and causal paradigms to understand ExtA network function.