Age-related ultrastructural neurovascular changes in the female mouse cortex and hippocampus

Blood-brain barrier (BBB) breakdown occurs in aging and neurodegenerative diseases. Although age-associated alterations have previously been described, most studies focused male brains; hence, little is known about BBB females. This study measured ultrastructural features the female using transmission electron microscopy 3-dimensional reconstruction of cortical hippocampal capillaries from 6- 24-month-old C57BL/6J mice. Aged showed more changes than capillaries. Specifically, aged cortex thicker basement membrane, higher number volume endothelial pseudopods, decreased mitochondrial number, larger pericyte mitochondria, pericyte–endothelial cell contact, increased tight junction tortuosity compared with young animals. Only membrane thickness were observed hippocampus. Regional comparison revealed significant differences pseudopods junctions between hippocampus Therefore, shows region-specific that may lead to oxidative stress abnormal capillary blood flow stability, potentially contributing cerebrovascular diseases, particularly postmenopausal women. • Aging associated blood-brain are prominent prefrontal The luminal surface brain cells due a greater pseudopodal projections Pericyte significantly increased, occasionally forming tubular networks, both Tight tortuosity, but not complexity, when Pericyte–endothelial contact capillaries, whereas astrocyte–basement changed or vessels age.