Hearts removed from dead rats started beating again after several days in a lab. No, it wasn't caused by that bright green serum from Re-Animator — it was real science at work, and it could mean heart transplants are about to get much, much easier. A completely "dead" heart can be coaxed into beating on its own within 8 days if treated correctly.

Reuters reports on an article published yesterday in Nature:

[Doris] Taylor and colleagues used a process called decellularization to wash away existing cells from the hearts of dead rats while leaving the basic collagen structure intact. They injected this gelatin-like scaffold with heart cells from newborn rats, fed them a nutrient-rich solution and left them in the lab to grow. Four days later, the hearts started to contract. The researchers used a pacemaker to coordinate the contractions. They hooked up the hearts to a pump so they were being filled with fluids and added a bit of pressure to simulate blood pressure. Eight days later, the hearts started to pump.

Scientists create beating hearts in lab [Reuters]