Three recent papers on aging explore the neuropathology behind a little-understood brain disease, hippocampal sclerosis (known to scientists and clinicians as HS-AGING). HS-AGING, much like Alzheimer's disease, causes symptoms of dementia -- cognitive decline and impaired memory -- in aged persons. Although Alzheimer's disease is probably the most recognized cause of dementia, HS-AGING also causes serious cognitive impairment in older adults.