Age-related memory decline is associated with vascular and microglial degeneration in aged rats

► Memory impairment with age associated with microglial and vascular degeneration. ► Reduced VEGF expression with age impaired vascular remodeling and memory. ► Glial and vessel degeneration may represent pathology of MCI, but not dementia. The hippocampus processes memory is an early target of aging-related biological and structural lesions, leading to memory decline. With absent neurodegeneration in the hippocampus, which identified in rodent model of normal aging the pathology underlying age-related memory impairment is not complete. The effective glial–vascular networks are the key for maintaining neuronal functions. The changes of glial cells and cerebral capillaries with age may contribute to memory decline. Thus we examined age associated changes in neurons, glial phenotypes and microvasculature in the hippocampus of aged rats with memory decline. Young adult (6 months) and aged (35 months) male rats (Fisher/Norway-Brown) were used. To evaluate memory, four days of acquisition phase of Morris water maze tasks were carried out in both age groups and followed by a probe trial 2h after the acquisition. The brains were then collected for analysis using immunochemistry. The aged rats showed a delayed latency (p