Scientists bring pigs’ brains back from dead
The experiment has blurred the line between life and death, and provoked excitement and horror in equal measure. Does this mean we will one day be able to reverse death? Should we want to?
Thirty-two pigs heads were laid on a slab in a laboratory.
The pigs had been slaughtered four hours earlier. Then their heads were severed from their bodies. They were, without question, dead.
But not for long. When the scientists pumped the heads with artificial blood, some brain cells started functioning again. In fact, certain regions of the brain were behaving as if they had never died.
However, the scientists were unable to restore brain-wide electrical firing, which means the brains did not regain consciousness.
“They could not think. They could not feel,” explains science writer Mark Ritter. “But within them, you could see the signs of activity.”
The findings, which have now been published in the journal Nature, are forcing doctors to re-think the boundary between life and death. It even raises the possibility that we could reverse death entirely.
Until the 1950s, a person was considered dead when their body had lost one of three key functions: their heart stopped beating; they stopped breathing, or their brain showed no signs of activity.
But then came CPR and ventilators, which could revive the heart and keep the lungs breathing. That left only brain death as the last concrete, irreversible symptom of death. Until now.
Could we, one day, reverse brain death in humans?
Neuroscientist Nenad Sestan, who led the experiment, believes it would work on the brains of primates, a group which includes humans. He also thinks it could be possible to restore consciousness, perhaps indefinitely.
But assuming your body was damaged beyond repair by age, disease or injury, what kind of life would it be?
A living hell, according to ethics professor Benjamin Curtis.
“You would have to spend the foreseeable future as a disembodied brain in a bucket, locked away inside your own mind without access to the senses that allow us to experience and interact with the world,” he argued in a piece for The Conversation.
Even an new, healthy body might not help. Curtis says that, attached to a new body, the brain would be overwhelmed with unfamiliar chemical and electrical signals.
“It could send [it] mad,” writes Curtis.
Rest in peace?
Why are we so concerned with reversing death? Death isn’t evil, it’s natural. Immortal life would eventually make you despondent and bored, having done and seen everything on offer. Life is precious and poignant because we know it isn’t forever.
But if we could preserve our bodies and minds in perfect health, how long would you want to live for? A few hundred years? A few thousand? It would mean more time with our families; time to travel the world; time to write a book or learn a language. Doesn’t that sound like heaven?
- Do you want to live forever?
- Is it unethical to experiment on dead brains like this?
- Write down five questions you would like to ask the scientists who carried out the experiment.
- Write a short story, no more than two A4 pages, from the perspective of a 1,000-year-old person. What have they seen over their long life? How do they feel about the world now?
Some People Say...
“The fear of death follows from the fear of life. A man who lives fully is prepared to die at any time.”Mark Twain
What do you think?
Q & A
- What do we know?
- The brains of 32 pigs were partially revived four hours after their death, after researchers at Yale University attached them to a machine that pumps artificial blood. The researchers hope the experiment could help them to understand brain diseases like Alzheimer’s. To prevent the pigs from becoming conscious during the experiment, the scientists gave them a drug to limit brain function.
- What do we not know?
- If we will ever succeed in resurrecting a conscious brain, and what kind of quality of life — if it can be termed life — that brain would have. We don’t know how long these experiments will be continued. Ethicists are calling for new regulations on similar experiments because the animals could end up in a “grey area: not alive, but not completely dead”.
- Electrical firing
- Your brain works by firing electrical currents through billions of nerve cells, which are arranged in patterns to carry out different functions.
- The state of being aware. How consciousness works, and what exactly it is, is the subjects of centuries of philosophical argument.
- Cardiopulmonary resuscitation. When you push down on someone’s chest and breathe into their mouth, in the hope of reviving them. It is only successful about 40% of the time when performed in a hospital.
- A machine that breathes for a person when they are unable to.
- Brain death
- When a person has no brain activity at all. It is also called brain-stem death.
- A group of mammals that includes apes, humans, lemurs and bushbabies among others.