Development of functional and structural connectivity within the default mode network in young children

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Brain Imaging

Background:

• Brain development involves the maturation of functional and structural networks.
• The default-mode network (DMN) is crucial for cognitive functions and includes key regions like the posterior cingulate cortex (PCC) and medial prefrontal cortex (mPFC).
• Limited understanding exists regarding the developmental trajectory of DMN connectivity from childhood to adulthood.

Purpose of the Study:

• To investigate developmental changes in DMN functional and structural connectivity.
• To identify specific DMN connections that mature significantly from childhood to adulthood.
• To explore the relationship between structural and functional connectivity maturation within the DMN.

Main Methods:

• Utilized a multimodal imaging approach combining resting-state fMRI, voxel-based morphometry, and diffusion tensor imaging-based tractography.
• Analyzed functional connectivity patterns within the DMN across different age groups.
• Assessed structural connectivity and gray matter volume differences in DMN regions and connecting white matter tracts.

Main Results:

• The DMN exhibits significant developmental changes in both functional and structural connectivity, varying across DMN nodes.
• PCC-mPFC connectivity, along the cingulum bundle, demonstrates the least mature structural and functional connectivity in children.
• Children can exhibit adult-like functional connectivity between PCC and MTL despite weak or absent structural connections, indicating a dissociation between structural and functional maturation.

Conclusions:

• Maturation of PCC-mPFC structural connectivity is vital for adolescent development of self-related and social-cognitive functions.
• Functional brain connectivity can reach adult levels in children even with underlying immature structural connections.
• Multimodal analysis is essential for characterizing the heterogeneous development and maturation of complex brain networks.