Fornix Microstructure and Memory Performance Is Associated with Altered Neural Connectivity during Episodic...

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Aging Research

Background:

• White matter microstructure declines with age, potentially affecting cognitive functions like episodic recognition.
• Understanding the link between structural integrity and neural network function is crucial for aging cognition.

Purpose of the Study:

• To investigate the association between age-related white matter microstructure changes and altered task-related connectivity in episodic recognition.
• To explore how white matter integrity, specifically fractional anisotropy (FA), relates to functional connectivity within the recognition network.

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) in 282 healthy middle-to-late aged adults.
• Examined fractional anisotropy (FA) in age-vulnerable white matter regions and its relationship with recognition network connectivity.
• Employed psychophysiological interaction (PPI) analyses to assess task-related functional connectivity.

Main Results:

• A positive correlation was found between fornix FA and memory performance, both decreasing with age.
• Higher fornix FA was linked to increased task-related connectivity among key brain regions including the hippocampus, caudate, and frontal cortex.
• Enhanced task performance correlated with stronger connectivity between the posterior cingulate cortex, frontal cortex, and hippocampus.

Conclusions:

• Aging negatively affects white matter microstructure and memory, though fornix microstructure did not fully mediate this relationship.
• Dynamic functional connectivity emerged as a significant correlate of better memory performance.
• Alterations in fornix microstructure partially explain connectivity patterns within the recognition memory network, highlighting the interplay between structure, function, and cognition.