Dissociation Between Neural Functional Connectivity and Brain Volume Loss with Age: Insights from Resting-State...

Area of Science:

• Neuroscience
• Aging Research
• Brain Imaging

Background:

• Age-related brain volume loss is a known phenomenon.
• Neural functional connectivity (FC) changes with aging, but its relationship with structural decline requires further investigation.

Purpose of the Study:

• To examine the correlation between age-related brain volume reduction and alterations in neural functional connectivity.
• To identify if specific brain regions with significant volume loss exhibit corresponding functional connectivity changes.

Main Methods:

• Utilized resting-state magnetoencephalography (MEG) and MRI in 75 healthy adults (20-86 years).
• Calculated whole brain volume and neural functional connectivity using amplitude envelope correlation (AEC) in the alpha frequency band.
• Analyzed correlations between age, brain volume, mean AEC, and standard deviation (SD) of AEC across 66 functional parcellations.

Main Results:

• Whole brain volume significantly decreased with age (r=-0.322, p=0.00480), with pronounced loss in individuals over 75.
• Mean neural connectivity (AEC) declined with age (r=-0.359, p=0.00153), showing significant differences between younger (<45) and older (>75) groups.
• The standard deviation of AEC also decreased across the brain with aging (r=-0.326, p=0.0043).
• Seven regions with significant age-related volume loss did not consistently show altered AEC or its SD compared to other regions.

Conclusions:

• Both brain volume and neural functional connectivity exhibit age-related declines.
• Reduced variability in functional connectivity is observed with aging.
• Localized functional adaptations may compensate for age-related structural decline in specific brain regions.