Enhanced resting-state functional connectivity between core memory-task activation peaks is associated with memory...

Area of Science:

• Neuroscience
• Cognitive Neurology
• Medical Imaging

Background:

• Resting-state functional connectivity (FC) alterations are observed in Alzheimer's disease (AD), but their precise role in predicting episodic memory deficits remains unclear.
• Understanding these neural network changes is crucial for early detection and intervention in cognitive decline.

Purpose of the Study:

• To investigate alterations in resting-state FC within memory-related brain regions in individuals with AD and amnestic mild cognitive impairment (aMCI).
• To determine if these FC changes predict episodic memory performance in aMCI and AD patients.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was used to compute FC between 18 brain regions identified through memory-task meta-analysis.
• Participants included cognitively healthy controls (HC), aMCI subjects, and AD dementia patients.

Main Results:

• Higher FC between the parahippocampus, parietal cortex, and middle frontal gyrus was found in both aMCI and AD groups compared to HC.
• Increased parahippocampal-prefrontal FC significantly correlated with reduced episodic memory performance in aMCI, independent of amyloid-beta and APOE ε4 status.

Conclusions:

• Elevated parahippocampal-prefrontal FC is a potential predictive biomarker for episodic memory impairment in aMCI.
• This suggests a dysfunctional neural network reorganization within memory-related circuits in the early stages of Alzheimer's disease.