Altered regional brain activity and functional connectivity in relation to blood lead levels
Bibliographic record
Abstract
Lead is a prevalent heavy metal pollutant in the environment, and chronic lead exposure in occupational settings has been linked to cognitive decline. Our objective was to delineate lead-induced changes in brain functional activity through the assessment of regional homogeneity (ReHo), degree centrality (DC) and seed-based functional connectivity (FC) using resting-state functional magnetic resonance imaging (rs-fMRI). In this cross-sectional study, we recruited 76 participants from a smelting company. Based on their blood lead levels, 26 participants were assigned to the lead exposure group (≥ 300 μg/L), whereas 23 were assigned to the control group (≤ 100 μg/L). Neuropsychological assessments included the Montreal Cognitive Assessment, Mini-Mental State Examination, Self-rating Anxiety Scale, and Self-rating Depression Scale. Participants underwent rs-fMRI for ReHo, DC, and FC analyses. Brain regions demonstrating significant differences in ReHo and DC were identified as regions of interest for subsequent FC analysis. We also examined the relationships between lead levels, FC values, and neuropsychological scores. Compared to the control group, individuals with high lead exposure exhibited increased ReHo in the bilateral insula and vermis and elevated DC in the left olfactory cortex. Notably, the left insula demonstrated reduced FC with the right cerebellar crus I, left fusiform gyrus, left superior frontal gyrus, and left middle frontal gyrus. The right insula also displayed reduced FC with the right middle frontal gyrus but increased FC between the left olfactory cortex and right insula. Furthermore, negative correlations were observed between lead levels and FC of the left insula with the left fusiform gyrus ( r = − 0.586), left superior frontal gyrus ( r = − 0.556), and left middle frontal gyrus ( r = − 0.626), as well as between FC of the right insula and the right middle frontal gyrus ( r = − 0.587). Conversely, there was a positive association between FC of the left olfactory cortex with the right insula and lead levels ( r = 0.609), whereas an inverse relationship was noted with neurocognitive assessments. The disruption in insula coordination may significantly impair long-range FC and contribute to cognitive deficits resulting from lead exposure. The insula appears to be a pivotal region in lead-associated neurocognitive impairment.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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".