library_add_check Quiz: The Body

Could drinking blood make you younger?

Using a technique called heterochronic parabiosis, experimenters [1] hooked up the circulation of blood in one mouse with that of another mouse, then measured their brains several weeks later. One-third of the surgically joined mice were young mice. Another third of the surgically joined mice were old mice, while the last third were a combination of one old mouse and one young mouse.

What happened to the brain of the young mouse when connected with an old mouse (compared to a young mouse connected with a young mouse)?