Geneticists at the Salk Institute have found a new way to study brain cells in the elderly, and it could mean a renewed understanding of Alzheimer's.

Historically, if a geneticist wanted to study an older person's cells (whether brain cells, skin cells or any other cell), they had to remove age markers, basically restoring the cell to its baby state. However, that wasn't much use, because without those age markers, it was pretty hard to study age-related diseases like Alzheimer's.

Now, for the first time, scientists can use skin samples from older folks to create brain cells that still have those age markers, and so are A-OK for accurately studying age-related illness and aging itself.

"Wait, what?" you say. "They turn skin cells into brain cells?" Yes, they do, by first reverting the skin cell into a stem cell (which can basically become any part of the body), then reassigning it a new identity as a brain cell. However, in the process of reverting the skin cell into a brain cell, they would lose all of the cell's age and information. As any grampa will tell you, the older a cell, the more it knows.

Now, they can just turn an old man's hand cell into an old man's brain cell, without having to revert to a stem cell. That means all of the age-related information won't be lost, and the resulting cell will be easier to use to study elderly brains.

"This lets us keep age-related signatures in the cells so that we can more easily study the effects of aging on the brain," says Rusty Gage, a professor in the Salk Institute's Laboratory of Genetics and senior author of the paper.

The technique may also be used in the future to study other organs that are affected by age, such as the liver and heart. With cells that more closely reflect those of an older person, scientists can tailor treatments to the exact needs of an older patient.

The study was published Oct. 8 in the redundantly titled journal, Cell Stem Cell.