Functional Alterations in Gray Matter Networks Mediated by White Matter During the Aging Process

Area of Science:

• Neuroscience
• Brain Imaging
• Aging Research

Background:

• Resting-state functional MRI (fMRI) extensively studies gray matter (GM) changes during aging.
• The impact of aging on functional connectivity (FC) between white matter (WM) and GM (WM-GM FC) is largely unknown.

Purpose of the Study:

• To propose a novel method for constructing functional networks integrating both WM and GM.
• To investigate age-related changes in WM-GM FC and network topology.

Main Methods:

• Developed a covariance-based approach for gray matter-white matter-gray matter (GM-WM-GM) mediated networks using data from 439 healthy adults.
• Quantified WM-GM FC using Pearson correlation coefficients and integrated WM atlas data with GM atlas data.
• Calculated topological properties and explored age effects on GM-WM-GM networks.

Main Results:

• Found a significant age-related decline in intranetwork connectivity and global network efficiency.
• Observed an inverted U-shaped pattern in internetwork connectivity, suggesting functional dedifferentiation.
• Noted decreased network modularity and stable local efficiency, indicating weakened long-range connections.

Conclusions:

• The study provides novel insights into age-associated brain network reorganization.
• Enhances understanding of the neural mechanisms underlying normal brain aging.