Alzheimer's About.com

The normal cerebral cortex

This is an image of the normal adult brain. In Alzheimer's the cerebral cortex atrophies. That means that this area of the brain shrinks and this shrinkage is dramatically different from the cerebral cortex of a normal brain. The cerebral cortex is the outer surface of the brain. It is responsible for all intellectual functioning. There are two major changes that can be observed in the brain at autopsy; the amount of brain substance in the folds of the brain (the gyri) is decreased; the spaces in the folds of the brain (the sulci) are grossly enlarged.