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Access Type

WSU Access

Date of Award

January 2011

Degree Type


Degree Name




First Advisor

Naftali Raz


Increase in non-heme iron in the brain has been theorized as molecular mechanism underlying neural and cognitive differences in normal and pathological aging. However, due to limitations of in vivo estimation methods, non-heme iron has not been broadly studied in healthy aging samples with cognitive assessment. The few extant human studies have found a significant correlation between increased brain iron estimates and cognitive decline. However, the current study is the first to investigate the possible indirect effect of age on cognitive decline mediated through non-heme iron accumulation and cardiovascular risk. Non-heme iron was uniquely measured from susceptibility weighted images (SWI) as ∆öAverage Iron (LQ) and ∆R2*. Non-heme iron estimates significantly increased in the basal ganglia. Regional non-heme iron concentration increase in the corpus callosum and insula cortex were exacerbated by increased cardiovascular risk. Whereas elevated cardiovascular risk associated with increased brain iron estimates in the hippocampus absent of age effects. Age-related decline in spatial navigation was significantly mediated solely by non-heme iron estimates in the basal ganglia. The current study offers new insight into mediating hematic factors on cognitive decline in normal aging.

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