
Alzheimer s Research & Therapy, Journal Year: 2025, Volume and Issue: 17(1)
Published: April 25, 2025
Abstract Background Both aging and Alzheimer's disease (AD) affect brain networks, with early disruptions occurring in regions involved episodic memory. Few studies have, however, focused on distinguishing region-specific effects of AD-biomarker negative “normal” amyloid- tau pathology functional connectivity. Further, longitudinal combining imaging, biomarkers, cognition are rare. Methods We assessed resting-state connectivity (rsFC) strength graph measures the memory network including medial temporal lobe (MTL), posteromedial cortex (PMC), prefrontal alongside over two years. For this preregistered study, we included 100 older adults who were tau-negative using CSF PET measurements to investigate aging, 70 had data available changes related AD pathology. All participants cognitively unimpaired from PREVENT-AD cohort. used region interest (ROI)-to-ROI bivariate correlations, analysis, multiple regression models. Results In sample, rsFC within PMC, between parahippocampal inferomedial precuneus, posterior hippocampus precuneus decreased time. Additionally, observed a decrease global efficiency. there was steeper efficiency higher baseline age particularly parahippocampal-gyrus regions. lower PMC associated poorer performance. sample data, increase anterior superior Higher MTL-PMC differentially trajectories depending APOE4 genotype. Conclusions Our findings suggest differential Hypoconnectivity cognitive decline. hyperconnectivity decline carriers. Future should more diverse samples, nonetheless, our approach allowed us identify pathology, enhancing cross-sectional research. Hyperconnectivity has been proposed as mechanism before, now contribute specific connections focus future Graphical A ) “Normal aging” tau- biomarker status characterized by strength. B Cognitively Alzheimer’s at (measured via cerebrospinal fluid) exhibited
Language: Английский