Local and Global Structural Architecture Supports Functional Organization in the Aging Brain

Neuroscience research suggests that local and global functional interactions throughout the human brain are modulated by the underlying anatomical architecture. Age-related changes of anatomical tracts suggest a potential for concomitant changes in structure-function coupling. We compared functional connectivity inferred from spontaneous BOLD fMRI with structural connectivity inferred from DTI in a sample of 47 adults ranging from 18 to 82 years of age. We noted that the strength of structural and functional connectivity decreased in most regions as subjects aged. Local regionwise structure-function correspondence varied across the age spectrum. We also found that the structural architecture upholds the functional modular organization at a global level, such that regions are more densely connected within their functionally defined module, and that this varies with age. Tracts from structural hubs may actually strengthen within functional modules with age, such that the structural core increasingly supports functional organization throughout the aging process.M.A