We’ve always thought of death, especially brain death, as a hard line. Once it happens, that’s it, right? But some new, really interesting research is making scientists rethink that. They’ve been doing experiments with brains, and what they’ve found is pretty surprising. It turns out that even after a brain is considered dead, there might still be some stuff going on. This research is still pretty new, but it’s raising some big questions and could eventually change how we understand the brain and how we treat brain injuries and diseases.
Experiment restores key brain functions in ‘dead’ pig brain
Neuroscientist Zvonimir Vrselja, Ph.D., and his team at Yale School of Medicine stunned the medical world with a groundbreaking experiment about five years ago. They took a pig’s brain from a slaughterhouse, left it without oxygen at room temperature for four hours, and then attempted to revive it using a special machine.
This machine, called BrainEx, works like an artificial life-support system. Instead of blood, it pumped a special fluid, filled with protective chemicals and drugs into the brain. This mix helped prevent damage from oxygen loss, stabilized cell functions, and reduced the immune system’s attack on dying cells.
The results were astonishing: the brain’s outer layer turned pink again, brain cells started making proteins, and neurons showed signs of activity—just like in a living brain. However, the brain wasn’t conscious, and researchers never expected it to be. While it wasn’t truly “alive,” it also no longer looked completely dead.
“[This result] goes against everything we thought we knew about death,” said Dr. Lance Becker, a resuscitation and critical care expert, in an interview with New Scientist in November 2024. He added, “We’re at a real paradigm-shifting moment as we redefine what is life and what is death.”
Has the experiment been tested on human brains?
After doing the experiments on pigs, the scientists are now using donated human brains with their BrainEx machine. This is much trickier than working with pig brains, and it brings up some serious ethical questions. When they experimented on pigs, the researchers were very careful to make sure the brains didn’t show any signs of awareness or consciousness. They put sedatives in the special mix they pumped into the brains to prevent any electrical activity that might suggest consciousness, and they stopped the experiment after six hours. As Vrselja explained to New Scientist, “We had to develop new methods to make sure no electrical activity is occurring in an organized way that might reflect any kind of consciousness.”
With human brains, it’s even more important to prevent any chance of consciousness. Imagine if a person’s brain started to become aware during such an experiment – that would be a huge ethical problem. Hank Greely, a legal expert from Stanford, told New Scientist, “That’s very tricky ethically, legally, and scientifically.”
What are the scientists hoping to achieve with BrainEx?
They’re not trying to bring people back from the dead. Vrselja has said very clearly that they “have no intention of plugging anyone at the point of death into their BrainEx machine.” Instead, their work is more about understanding brain death itself. They’re showing that it might not be as irreversible as we previously believed. This raises the possibility of saving people who are close to death.
Right now, scientists are using BrainEx to keep brains “cellularly active for up to 24 hours.” This allows them to test new treatments for brain diseases like Alzheimer’s and Parkinson’s. They hope that this research will eventually lead to better ways to help people suffering from these devastating conditions.