Excessive brain iron negatively affects working memory and related processes but the impact of cortical iron on task-relevant, cortical brain networks is unknown. We hypothesized that high cortical iron concentration may disrupt functional circuitry within cortical networks supporting working memory performance. Fifty-five healthy older adults completed an N-Back working memory paradigm while functional magnetic resonance imaging (fMRI) was performed. Participants also underwent quantitative susceptibility mapping (QSM) imaging for assessment of non-heme brain iron concentration. Additionally, pseudo continuous arterial spin labeling scans were obtained to control for potential contributions of cerebral blood volume and structural brain images were used to control for contributions of brain volume. Task performance was positively correlated with strength of task-based functional connectivity (tFC) between brain regions of the frontoparietal working memory network. However, higher cortical iron concentration was associated with lower tFC within this frontoparietal network and with poorer working memory performance after controlling for both cerebral blood flow and brain volume. Our results suggest that high cortical iron concentration disrupts communication within frontoparietal networks supporting working memory and is associated with reduced working memory performance in older adults.
|State||Published - Dec 2020|
Bibliographical noteFunding Information:
This work was supported by the National Institutes of Health (grant numbers NIA R01AG055449 , NIA P30 AG028383 and NIGMS S10 OD023573 ). The content is solely the responsibility of the authors and does not necessarily represent the official views of these granting agencies. The authors declare no competing financial interests. The authors thank Shoshana Bardach for help with participant recruitment and Beverly Meacham and Eric Foreman for assisting/conducting the MRI scans. We also thank Drs. Anders Anderson and Pascal Spincemaille and Yi Wang for helpful discussions.
- Working memory
ASJC Scopus subject areas
- Cognitive Neuroscience