Zombie pigs? Scientists restore partial function in hours-dead animal brains

Dead pigs’ brains have been partially revived in a study that upends established wisdom about what happens when we die, raising serious ethical questions even though researchers claim the brains never regained consciousness.

Disembodied pig brains subjected to an experimental preservative procedure showed some restored cellular and molecular function and even some synaptic activity, researchers discovered, observing these “signs of life” ten hours after the animals had been killed. The brains of ordinary pigs, taken from a slaughterhouse, were cleansed and cooled, then pumped full of a chemical cocktail designed to slow their deterioration, and the results – published Wednesday in the journal Nature – are striking.

“This is not a living brain, but it is a cellularly active brain,” Yale University neuroscientist Nenad Sestan told NPR, adding that the researchers were able to preserve tissue and cell structure and reduce cell death in addition to restoring vital neurochemical functions like glucose and oxygen uptake.

Researchers burned through hundreds of dead pig heads over a six-year period working to develop a technique – which they’ve christened BrainEX – to keep the brains supplied with oxygen, nutrients and other chemicals intended to halt their deterioration, because they were determined to study the organs in their original form. Previous experiments had already shown viable cells could be removed from brains hours after their owners were pronounced dead, but “once you do that, you are losing the 3D organization of the brain,” Sestan pointed out.

Despite researchers’ claim that the reanimated pig brains showed none of the electrochemical signals associated with consciousness, they deliberately made an effort to avoid “waking up” the brains. “It was something the researchers were actively worried about,” bioethicist Stephen Latham said, explaining the researchers had a plan of action in place to shut down the experiment immediately with “anesthesia and cooling” should the pig brains get too excited.

Specifically, a drug that dampens or blocks neuronal activity was included in the preservative solution because researchers thought the cells would be better preserved if their activity was minimized. But individual cells, cleansed of the solution and tested for electrochemical responses, appeared to be quite active, and even in their pharmacologically-dulled state, the preserved brains showed “spontaneous synaptic activity.” Researcher Stefano Daniele admits “we cannot speak with any scientific certainty” as to whether consciousness could be restored to the brains without the blocker, since “we did not run those experiments.”

Even without answering the consciousness question, the Yale experiment turns current science about “brain death” on its head, placing the practice of extracting organs for transplant from brain-dead patients in question – as well as current protocols regarding the handling of (possibly revivable) dead tissue from humans and animals alike.

Like this story? Share it with a friend!