System-level reconfiguration of the aging brain: Linking dynamics, morphology and micro-architectures

Area of Science:

• Neuroscience
• Aging Research
• Brain Dynamics

Background:

• Healthy aging involves structural and functional brain changes.
• Resting-state functional magnetic resonance imaging (rs-fMRI) shows static connectivity changes with age.
• Whole-brain functional dynamics and their link to structural atrophy in aging are poorly understood.

Purpose of the Study:

• To investigate whole-brain functional dynamics in aging using advanced data-driven methods.
• To explore the association between functional brain dynamics and structural atrophy.
• To understand the structure-dynamics coupling in the aging brain.

Main Methods:

• Utilized rs-fMRI data from 252 participants (young and older adults).
• Applied normalized Shannon entropy, phase synchronization, and temporal asymmetry analyses.
• Integrated morphometric analyses and partial least squares (PLS) for structure-dynamics coupling.

Main Results:

• Older adults exhibited reduced spatiotemporal complexity (Shannon entropy).
• Enhanced global integration and metastability were observed in older adults, particularly in attention and frontoparietal networks.
• Significant covariance was found between structural atrophy and dynamic functional metrics, indicating tight structure-dynamics coupling.

Conclusions:

• Aging is characterized by reduced neural complexity and altered functional dynamics.
• A significant interplay exists between structural atrophy and dynamic functional reorganization in the aging brain.
• Findings provide a multiscale perspective on neural decline, highlighting structure-dynamics coupling.