Age differences in the intrinsic functional connectivity of default network subsystems.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Aging Research

Background:

• The default mode network (DMN) comprises core regions like the ventromedial prefrontal cortex and posterior cingulate cortex (PCC), with distinct subsystems.
• These subsystems include the medial temporal lobe (MTL) for memory/future projection and dorsomedial prefrontal cortex (dmPFC) for self-reference.
• The PCC is further divided into ventral (vPCC) and dorsal (dPCC) regions, differentially connected to DMN and cognitive control networks.

Purpose of the Study:

• To investigate age-related differences in resting-state functional connectivity within DMN subsystems.
• To compare connectivity patterns between young and older adults in MTL, dmPFC, vPCC, and dPCC subsystems.

Main Methods:

• Utilized resting-state functional connectivity analysis.
• Employed a multivariate technique to identify common and unique connectivity patterns.
• Applied rigorous motion correction procedures to ensure data quality.

Main Results:

• All analyzed DMN regions exhibited robust connectivity within the network and distinct patterns across age groups.
• Young and older adults showed similar functional connectivity in the MTL subsystem.
• Older adults displayed reduced connectivity in vPCC and dmPFC subsystems but enhanced connectivity in the dPCC subsystem, associated with cognitive control.

Conclusions:

• Distinct DMN subsystems are maintained with age, though connectivity strength varies.
• Age-related decline is evident in DMN connectivity, particularly in subsystems linked to memory and self-reference.
• Connectivity within cognitive control-associated regions (dDCC) appears relatively preserved or enhanced in older adults.