Aging-Related Modular Architectural Reorganization of the Metabolic Brain Network.

Background: Modules in brain network represent groups of brain regions that are collectively involved in one or more cognitive domains. Exploring aging-related reorganization of the brain modular architecture using metabolic brain network could further our understanding about aging-related neuromechanism and neurodegenerations. Materials and Methods: In this study, 432 subjects who performed 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) were enrolled and divided into young and old adult groups, as well as female and male groups. The modular architecture was detected, and the connector and hub nodes were identified to explore the topological role of the brain regions based on the metabolic brain network. Results: This study revealed that human metabolic brain network was modular and could be clustered into three modules. The modular architecture was reorganized from young to old ages with regions related to sensorimotor function clustered into the same module; and the number of connector nodes was reduced and most connector nodes were localized in temporo-occipital areas related to visual and auditory functions in old ages. The major gender difference is that the metabolic brain network was delineated into four modules in old female group with the nodes related to sensorimotor function split into two modules. Discussion: Those findings suggest aging is associated with reorganized brain modular architecture. Clinical Trial Registration number: ChiCTR2000036842. Impact statement Distinguishing the basic biology underlying aging from that underlying disease is critical for the prevention, diagnosis, and treatment of the aging-related brain disorders. In this study, we tried to uncover aging-related brain modular reorganization by using metabolic brain network. We found the modular architecture was slightly reorganized from young to old ages with regions related to sensorimotor function more converged. The number of connector nodes was reduced and most connector nodes were localized into the temporo-occipital regions. The major gender difference was that metabolic brain network was delineated into four modules in the old female group with the sensorimotor functions split into two modules.