Scientists are one step closer to preserving our brains forever.
They are one of the first to successfully thaw brain tissue that has been cryogenically frozen – without damaging it.
Also, after being frozen, their neurons could still send signals as normal.
This is a major challenge for science, as freezing the ultra-delicate medulla usually damages it, rendering it useless when thawed.
Not only is this a breakthrough for neuroscientists looking to study new drugs, but it could also fuel the sci-fi idea of bringing people back to life in the future.
The idea is that people can freeze their bodies, preserving them indefinitely, in the hope that in the future science will be advanced enough to bring them back to life, healthy.
Professor Jicheng Shao, a Harvard-trained neuroscientist who works at Fudan University in Shanghai, China, has developed a complex chemical mixture called MEDY that protects neurons from damage while they are frozen.
He doesn’t shy away from the idea that the research could be used for cryonics, which has been a fantasy among futurists for decades.
“MEDY can be used for cryopreservation of human brain tissue,” Dr. Shao said in his research, published in the journal Cell Reports Methods.
For a number of people with the future, such as Peter Thiel and Steve Aoki, who rely on keeping their bodies in ice after they die, this should be welcome news.
It’s just that, as Thiel admitted in a 2023 interview, we still don’t really know how to make cryopreservation work—for the body in general and the brain in particular.
This certainly hasn’t stopped businesses from profiting from advertising. Since the mid-20th century, we’ve been enjoying a cryorenaissance, with labs springing up in Michigan, Arizona, and Australia.
At Michigan-based Cryonics Lab, whole-body preservation starts at $28,000, and their clientele has tripled since 2006—now with more than 1,975 permanent residents.
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Each cryonics business has its own proper concoction that it believes preserves brains and bodies, but scientists have not concluded that there is one surefire way to protect the brain when it freezes.
Since 80 percent of our brain cells are made of water, when we freeze them, ice crystals sometimes form.
They can distort and damage all our cells, but especially the delicate brain cells – rendering them functionally useless when they thaw.
So Professor Shao and his team set out to find a different substance to submerge the brain tissue in that would keep it cold – stopping its aging – without running into problems with the crystals.
You could think of it as adding antifreeze to the water that circulates around your car’s engine – keeping it cool without freezing.
To do this, Professor Shao and his team grew small clumps of brain cells in petri dishes for three weeks – until they acquired the functions you’d see in a normal brain, just in miniature form.
They then soak these tiny brains, called organoids, in various mixtures including sugar, antifreeze and chemical solvents.
Once the samples were saturated, they were flash frozen with liquid nitrogen and then allowed to thaw over the next two weeks.
As the samples thawed, the scientists observed which samples recovered with the least amount of damage.
After some trial and error, they created a mixture they called MEDY—because of its four ingredients: methylcellulose, ethylene glycol, DMSO, and Y27632—that allowed them to freeze the tissue without any damage.
Not only did the brain tissue emerge unharmed, but it also returned to life, able to regain normal function.
In the future, if we want to learn how to do this with the whole body, we’ll need to be able to cure whatever killed a person in the first place and reverse aging, Dennis Kowalski, president of the Cryonics Institute, told Discover Magazine.
Dr. Kowalksi, a self-described optimist, admits that this is clearly “100 percent not possible today.”
Professor Shao’s mixture is not the first substance that has successfully protected the brain before it was frozen. Other freezing processes are promising but come with their own set of problems.
One popular method that has been extremely successful with pig brains involves pumping embalming fluid into the brain while one is still alive. This not only kills the subject, but makes it impossible to later revive the brain, neurologist Dr. Ken Hayworth of the Brain Preservation Foundation told CNET.
“It almost instantly glues together all the proteins in the brain,” Dr. Hayworth said.
In the near future, the MEDY technique will probably only be useful for the laboratory, Professor Shao wrote.
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But there are many things we can do with frozen brains in a lab.
Being able to freeze these tiny human brains means there will be more tissue on which researchers can test new drugs and therapies, Professor Shao wrote.
This could help us make breakthroughs in a number of stubborn areas of medicine, Dr. Takanori Takebe, a pediatrician at Cincinnati Children’s Hospital Medical Center, said in a 2018 paper.
“Organoids hold great promise to revolutionize 21st century healthcare by transforming drug development, precision medicine and ultimately transplant-based therapies for end-stage diseases,” said Dr. Takanori Takebe, a pediatrician at Children’s Medical Center Hospital in Cincinnati, in a 2018 paper.
In the more distant future, Professor Shao writes that MEDY has the potential to freeze the entire brain. But this comes with its own set of challenges, because going from freezing an organoid to a whole organ, such as the brain, is complicated for a number of reasons.
Studying organelles in general is a great way to understand how certain types of cells work.
But it’s not always effective at predicting how an entire organ will respond to new stimuli, because what’s in the dish is much less complex than what’s in our bodies, researchers at the Broad Center for Regenerative Medicine at Eli and Edith at the University of California wrote in 2023.
Furthermore, the University of California researchers write that these organelles simply “do not reflect the overall composition, organization, or function of the human brain.” So it’s hard to know if the way we freeze the organelle will translate to the whole brain.
Also, even if we can successfully freeze a brain without damaging it, there will be a whole new set of challenges to thawing it and reviving it because there is so little we currently understand about the brain, Dr. Ken Miller, a theoretical neuroscientist at Columbia University, told CNET.
“The most basic answer about how the brain works is that we don’t know. We know how many parts work … but we’re a long way from understanding the system,” Dr Miller said.
