Examination of Compensatory Network in Healthy Aging Adults with Graph Theory

Abstract

The human brain, especially the prefrontal cortex (PFC), is reorganized functionally and anatomically in order to adapt to neuronal challenges in aging. This study employed structural MRI, resting-state fMRI (rs-fMRI), and high angular diffusion resolution imaging (HARDI), and examined the functional and structural reorganization of PFC in aging using the Chinese sample of 174 subjects aged from 21 years and above. We found age-related increases in the functional and/or structural connectivity between PFC and the posterior brain. Such findings were partially mediated by age-related increases in the functional and/or structural connectivity of the occipital lobe with the rest of posterior brain. Our results suggest that the PFC reorganization in aging could be partly due to the adaptation to age-related changes in the functional and structural reorganization of the posterior brain. This thus supports the idea derived from task-based fMRI that the PFC reorganization in aging may be adapted to the need of compensations for resolving less distinctive stimulus information from the posterior brain regions. Finally, we showed that the structural connectivity of PFC with the temporal lobe was fully mediated by the temporal cortical thickness, suggesting that the brain morphology plays an important role in the functional and structural reorganization with aging.