Correlation Between Functional Connectivity in the Default Mode Network (DMN) and Plasma Biomarker Concentrations in Patients with Mild Cognitive Impairment
Bibliographic record
Abstract
BACKGROUND: Disruptions in brain network connectivity are strongly associated with the progression of cognitive decline in the Alzheimer's disease (AD) continuum, including mild cognitive impairment (MCI). This study aimed to investigate the relationship between alterations in functional brain connectivity within the default mode network (DMN) in patients with MCI and plasma biomarker levels typically altered in AD (Aβ40, Aβ42, Tau, pTau-181, Aβ42/Aβ40, Aβ42/pTau, Aβ42/tTau, pTau/tTau). METHODS: Eighteen patients (mean age = 65 years) diagnosed with MCI according to the 2018 NIA-AA and Alzheimer's Association criteria, based on medical and neuropsychological evaluation at the Hospital das Clínicas, University of Campinas (HC-UNICAMP), Brazil, were selected for blood collection and subsequent functional magnetic resonance imaging (fMRI) scans. Plasma samples were stored and analyzed using the automated SIMOA HD-X immunoassay system (Quanterix, Billerica, MA). Resting-state fMRI (RS-fMRI) data were acquired using a 3T Achieva-Intera PHILIPS® scanner. Both imaging data and correlation analyses were processed using the UF2C toolbox within MATLAB and SPM12, with results corrected for false discovery rate (FDR). RESULTS: Two notable negative correlations were found between the right hippocampus and right precuneus and the Aβ42/Aβ40 ratio (Spearman's correlation: r = -0.76, p = 0.033). No significant correlations were observed for other plasma biomarkers after FDR correction. CONCLUSION: Since network reorganization is a characteristic feature of MCI and AD, with regions exhibiting increased or decreased activity, the observed inverse relationship between Aβ42/Aβ40 and functional connectivity between the right hippocampus and right precuneus (indicating that an increase in Aβ42/Aβ40 is associated with decreased functional connectivity, and vice versa) supports the disease's underlying pathophysiology. This finding provides a potential avenue for research and diagnostic monitoring. Further studies are needed to explore the functional impact of these alterations and their relevance to disease progression.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".