Subregional differences in intrinsic amygdala hyperconnectivity and hypoconnectivity in autism spectrum disorder

Area of Science:

• Neuroscience
• Psychiatry
• Developmental Neuroscience

Background:

• The amygdala, crucial for emotion processing, has distinct subregions.
• The laterobasal (LB) amygdala's role in autism spectrum disorder (ASD) symptoms is under-investigated.
• Subregional amygdala dysfunction may underlie ASD pathophysiology.

Purpose of the Study:

• To investigate the relationship between amygdalar subregion intrinsic connectivity and autism symptom severity.
• To explore the association between amygdalar connectivity, anxiety, and depressive symptoms in ASD.
• To differentiate functional connectivity patterns in ASD versus typically developing (TD) individuals.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) data collected from adolescents and adults with ASD and TD controls.
• Functional connectivity analyses focused on three amygdalar subregions: centromedial (CM), laterobasal (LB), and superficial (SF).
• Correlations between functional connectivity and behavioral measures (autism symptoms, depression, anxiety) were assessed.

Main Results:

• ASD participants exhibited decreased LB subregion connectivity and increased CM and SF subregion connectivity compared to TD controls.
• Under-connectivity from the LB subregion was associated with social symptoms in ASD.
• Over- and under-connectivity in CM, SF, and LB subregions related to comorbid depression and anxiety in ASD.

Conclusions:

• Findings reveal functional subregional differences in amygdala connectivity in ASD.
• Specific patterns of amygdalar connectivity are linked to social deficits and comorbid mood disorders in ASD.
• This research provides novel insights into the neural underpinnings of ASD heterogeneity.