Resting-State Network Dynamics in Asthma: Interplay Between Depressive Symptoms and Airway Inflammation

Area of Science:

• Neuroscience
• Psychiatry
• Immunology

Background:

• Asthma and depression frequently co-occur, potentially exacerbating each other.
• The salience network (SN) is implicated, but the roles of the default mode network (DMN) and frontoparietal network (FPN) in this connection are unclear.
• Triple network theory provides a framework for understanding these interactions.

Purpose of the Study:

• To investigate longitudinal changes in brain network graph-theory metrics in individuals with asthma.
• To examine how these network changes relate to depressive symptoms following allergen challenge.
• To clarify the roles of the SN, DMN, and FPN in the asthma-depression link.

Main Methods:

• Twenty-four individuals with asthma underwent functional magnetic resonance imaging (fMRI) scans before and after segmental allergen challenge.
• Depressive symptoms were assessed using the Beck Depression Inventory.
• Region-of-interest (ROI)-to-ROI analyses were employed to analyze changes in graph-theory metrics, controlling for sex.

Main Results:

• Allergen challenge induced significant alterations in brain network properties.
• Reduced degree and betweenness centrality in the posterior cingulate cortex (DMN) and reduced degree centrality in the anterior cingulate cortex (SN) correlated with depressive symptoms.
• Altered SN-DMN and SN-FPN interactions, specifically in parietal regions, were also linked to depressive symptoms.

Conclusions:

• Segmental allergen challenge alters brain network graph-theory metrics within and between resting-state networks.
• These network changes are associated with depressive symptoms in individuals with asthma.
• Findings underscore the salience network's crucial role in network switching and its susceptibility to inflammation in the context of the asthma-depression connection.