Scientists have taken another step towards permanently preserving our brains.
They are among the first to successfully thaw cryogenically frozen brain tissue without damaging it.
Additionally, after being frozen, their neurons were still able to send signals normally.
This poses a major challenge for science because freezing the ultra-delicate, squishy brain usually damages it, rendering it useless once thawed.
Not only is this a major breakthrough for neuroscientists looking to study new drugs, but it could also advance the science fiction idea of bringing people back to life in the future.
Many celebrities have said they hope to freeze their bodies when they die, in case they are able to resuscitate their brains in the future.
The Cryonics Institute’s longest-serving patient, Rhea Ettinger, has been there since 1977. The number of people housed at the Michigan facility has more than tripled since 2006.
The idea is that people could freeze their bodies, preserving them indefinitely, in the hope that in the future science will be advanced enough to bring them back to life and health.
Professor Zhicheng Shao, a Harvard-trained neuroscientist working at Fudan University in Shanghai, China, developed a complex chemical mixture dubbed MEDY that protects neurons from freezing damage.
He doesn’t hesitate to think that this research could be used for cryonics, a fantasy among futurists for decades.
“MEDY could be used for cryopreservation of human brain tissue,” Dr Shao said in his study published in the journal Cell Reports Methods.
For many forward-looking people, like Peter Thiel and Steve Aoki, who plan to preserve their bodies in ice after they die, this should be good news.
It’s just that, as Thiel acknowledged in a 2023 interview, we don’t yet really know how to make cryopreservation work – for the body in general and the brain in particular.
That certainly hasn’t stopped companies from cashing in on the hype. Since the mid-20th century, we have experienced a cryo-renaissance, with the creation of laboratories in Michigan, Arizona and Australia.
At Michigan-based Cryonics Lab, full-body preservation starts at $28,000, and its clientele has more than tripled since 2006 – now numbering more than 1,975 permanent residents.
Each cryogenics company has its own proprietary blend that it claims preserves the brain and body, but scientists have not concluded that there is a 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.
These can distort and damage all of our cells, but particularly delicate brain cells, rendering them functionally useless once thawed.
So Professor Shao and his team set out to find a different substance in which to immerse the brain tissue to keep it cold and prevent it from aging, without encountering any problems with the crystals.
It’s like adding antifreeze to the water circulating around your car’s engine, keeping it cool without freezing.
To do this, Professor Shao and his team grew small clusters of brain cells in petri dishes for three weeks, until they acquired the functions you would see in a normal brain, just in form. miniature.
Then they soaked these tiny brains, called organoids, in different mixtures, including sugar, antifreeze and chemical solvents.
Once the samples were saturated, they were frozen with liquid nitrogen and then thawed over the next two weeks.
As the samples thawed, the scientists observed which samples recovered with the least damage.
The tiny organoid – approximately the size of a lens – was made from connected human brain cells for a 2019 study.
A cryonics facility located next to Holbrook Cemetery, New South Wales, Australia. Locations in this freezer cost around $150,000.
Since the brain is 80% water, freezing it can cause ice crystals to form in the tissues, damaging the cells and rendering them inoperable when thawed.
After some trial and error, they concocted a mixture they call MEDY – for its four ingredients: methylcellulose, ethylene glycol, DMSO and Y27632 – that allows them to freeze tissue without any damage.
Not only did the brain tissue emerge intact, but it also came back to life, able to regain normal function.
In the future, if we want to learn how to do this with the whole body, we will have to be able to cure what killed a person in the first place and reverse aging, said Dennis Kowalski, president of the Cryonics Institute, » said Discover Magazine.
Dr. Kowalksi, a self-described optimist, acknowledged that this was clearly “100 percent impossible today.”
Professor Shao’s mixture is not the first substance to have successfully protected a brain before it is frozen. Other freezing processes have shown promise, but come with their own set of problems.
One popular method, which has seen great success in pig brains, is to pump embalming fluid into the brain while a person is still alive. This not only kills the subject, but also makes it impossible to resuscitate the brain later, neuroscientist Dr. Ken Hayworth, of the Brain Preservation Foundation, told CNET.
“It sticks together all the proteins in the brain almost instantly,” Dr. Hayworth said.
In the near future, Professor Shao wrote that the MEDY technique would probably be useful only for the laboratory, Professor Shao wrote.
But we can do a lot of things with frozen brains in the lab.
Being able to freeze these human mini-brains means more tissue will be available for researchers to test new drugs and therapies, Professor Shao wrote.
This could help us make breakthroughs in a number of difficult medical areas, Dr. Takanori Takebe, a pediatrician at Cincinnati Children’s Hospital Medical Center, said in a 2018 article.
“Organoids hold great promise for revolutionizing 21st century healthcare by transforming drug development, precision medicine, and ultimately transplantation-based therapies for terminal illnesses,” said Dr. Takanori Takebe, a pediatrician at Cincinnati Children’s Hospital Medical Center, in a 2018 article.
In the more distant future, Professor Shao wrote that MEDY had the potential to freeze the entire brain. But this comes with its share of challenges, because going from freezing an organoid to an entire organ, like the brain, is complicated for a number of reasons.
Organoid research, in general, is a great way to understand how certain cell types act.
But it’s not always effective at predicting how an entire organ would respond to new stimuli, because what’s in the dish is much less complex than what’s in our bodies, according to researchers at the center Eli and Edythe Broad of Regenerative Medicine from the University of California wrote in 2023.
What’s more, the University of California researchers wrote, these organoids “simply do not reflect the entire composition, organization, or function of the human brain.” So it’s unclear whether the way we freeze the organoid will carry over to the whole brain.
Additionally, even if we manage to freeze a brain without damaging it, there will be a whole new set of challenges thawing and resuscitating it because we currently know so little about the brain, theoretical neuroscientist Dr. Ken Miller at Columbia University. , told CNET.
“The most fundamental answer to how the brain works is that we don’t know. We know how many things work…but we’re a long way from understanding the system,” Dr. Miller said.
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