The basal ganglia are clusters of nerve cells responsible for initiatiting and integrating movements. The basal ganglia become bright with age due to iron accumulation. No health problems are associated with this change.

The subarachnoid space is the space around the outside of the brain. As the brain becomes smaller as a result of the gradual, life-long loss of brain cells, this area increases in size to fill the space.

The hippocampus is the memory center of the brain. There is some cell loss associated with healthy aging, but this by itself does not indicate significant memory loss.

The ventricles are hollow spaces filled with cerebrospinal fluid. Like the subarachnoid space, these spaces increase in size as the brain becomes smaller with age.

The white matter is a communication channel for the brain's information processing gray matter. White matter changes in appearance with aging. The reason for these changes is unclear, but it may be related to the normal slowing of information processing in the brain with age.