Overturning Old Age

HAVE SCIENTISTS DISCOVERED THE FOUNTAIN OF YOUTH?

- Natasha Yim

The experiments sound like something out of a horror movie. Sew two mice together so that they share blood in a single circulatory system. Gross as it may seem, this procedure has led to new discoveries in the study of aging. Studies using the procedure, called parabiosis (pa-ra-byoh-sis), suggest that pumping blood from young mice into old mice can make the old mice act young again. Wow! Reversing the aging process is an exciting goal. But scientists are still testing “young blood” and debating whether it really holds the secret to turning back time.

Getting a Tune Up

Our bodies are made up of billions of cells containing biological information. Some cells group together to form tissues, which perform specific functions like digesting food or fighting disease. As we get older, tissues and cells don’t work as well, or they may stop working altogether. Over time, we may forget things, huff and puff after a short walk, or experience aches and pains.

In parabiosis experiments, blood from young mice appeared to revive tissues and cells in older mice. Scientists wondered if young blood might give older people a “tune up”— kind of like an oil change for a car. The fresh oil doesn’t make the car brand new, but it makes the engine run better.

In the 2000s, Thomas Rando, a neurologist at Stanford University in California, conducted an experiment using parabiosis. He joined young and old mice together for five weeks. He found that the young mouse blood caused certain cells in older mice to help repair damaged muscles. But the blood from old mice also affected young mice in negative ways. It made their muscles heal a lot more slowly. Rando’s experiment also hinted at some growth of new brain cells. This really interested Tony Wyss-Coray, a neuroscientist at Stanford University.