Regional brain and cerebrovasculature morphology during normative aging in male and female C57BL/6N mice

INTRODUCTION: Normative aging is the process of gradual physical, cognitive and biological changes that occur with advancing age. This contrasts to pathological processes, such as neurodegeneration where changes are accelerated and more pronounced. Brain morphology and its cerebrovasculature are known to progressively alter during normative human and rodent lifespan. METHODS: We assessed regional brain volumes (morphology) and cerebrovasculature characteristics across three lifespan epochs (6, 18, and 26 months of age) in male and female C57BL/6N mice, a widely used strain. The cerebrovasculature was assessed in mice using a vessel staining method we call vessel painting. High resolution magnetic resonance imaging (MRI) was acquired ex vivo to examine whole brain and regional volumes. RESULTS: While no overt changes in cortical vasculature were detected across age or sex, we observed age-related changes in total and regional brain volumes. Selected brain regions exhibited sex-specific alterations. CONCLUSION: Our study reports regional brain changes across the lifespan in an age- and sex-dependent manner in C57BL/6N mice.