There’s nothing more fundamental to our very existence than the line between life and death. That’s the time we have on Earth, and it’s all we get. Things don’t get much more absolute than that, and it’s something we’ve known and grappled with for thousands of years.
So when some kind of scientific breakthrough comes along that seems to blur that line, well, it’s no surprise that everyone’s going to sit up and take notice.
Scientists at Yale University have blown their own minds by reviving some brain activity in pigs that had been dead for hours.
The Yale team is quick to point out that they didn’t fully revive the pigs’ brains — there wasn’t enough going on to call it consciousness or awareness, and the definition of death hasn’t changed — but even they were surprised by how much brain function they were able to restore.
You’d think that brain activity would stop pretty soon after blood stops flowing, but it turns out that’s not always the case.
Scientists have known for some time that brain cells can remain viable and be removed even hours after death, Yale neuroscientist Nenad Sestan told NPR . But those cells have to be studied in lab dishes, at which point “you are losing the 3D organization of the brain.”
So he and some of his Yale colleagues decided to see if they could study some brain cells in a fully intact brain.
However, to study brain cells in a complete, unsliced brain, they had to figure out how to supply it with oxygen and nutrients and the like.
All the stuff brains need to, well, live. It took the team six years and about 300 pig heads they got from a local slaughterhouse, but they did it.
“This really was a shot-in-the-dark project. We had no preconceived notion of whether or not this could work,” said team member Stefano Daniele.
The successful study involved 32 of those pig heads.
The work actually started at the slaughterhouse, where a couple of the researchers flushed the brains and cooled them off.
About four hours after they had left the slaughterhouse, the team hooked the brains’ blood vessels up to the system they had devised to keep the brains going, an experimental chamber they called BrainEx.
It wasn’t just blood running through the brains at that point.
The team concocted a special formula specifically for the occasion and pumped it through the brains for six hours.
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Compared to brains that had been left untreated, the BrainEx brains had retained some functions, like immune responses, and even after the BrainEx fluid was flushed out, some individual neurons still functioned.
Throughout the experiment, the team closely monitored the brains for signs of consciousness, just in case.
Consciousness was not the goal. As The Guardian reported, “had that appeared they would have lowered the temperature of the brain and used anaesthesia to stop that kind of activity,” said Dr. Stephen Latham, one of the study’s co-authors.
But they got closer than they expected to. “When we started this study we really never imagined we would get to this point,” Sestan said.
Even without a living, conscious brain, ethicists are still grappling with the results of the Yale study.
It’s an ethical hornet’s nest, really, with concerns about organ donation, what happens with dead tissue in the lab if it can be revived, protecting animal welfare in experiments, and of course, whether or not to apply this to humans.
However, this experiment does open up many avenues of study not involved with reviving the dead.
It’s especially useful for studying diseases of the brain like Alzheimer’s disease, which to this point have been studied with slices of brain or by growing colonies of brain cells in a Petri dish.
The BrainEx process might allow scientists to study such diseases in full 3D. Of course, it’s far too early to say for sure how this all might be applied down the road.
Although researchers are understandably excited about this study, many are pumping the brakes at the moment.
“This study is a long way from preserving human brain function after death as portrayed in the cartoon Futurama where heads were kept alive in a jar,” cautioned the University of Edinburgh’s Tara Spires-Jones.
The team’s research was published in the journal Nature .
h/t NPR , The Guardian
