{"id":20023,"date":"2026-03-24T17:01:33","date_gmt":"2026-03-24T17:01:33","guid":{"rendered":"https:\/\/ideainthebox.com\/index.php\/2026\/03\/24\/cryopreservation-brain-cryonics-organ-transplantation\/"},"modified":"2026-03-24T17:01:33","modified_gmt":"2026-03-24T17:01:33","slug":"cryopreservation-brain-cryonics-organ-transplantation","status":"publish","type":"post","link":"https:\/\/ideainthebox.com\/index.php\/2026\/03\/24\/cryopreservation-brain-cryonics-organ-transplantation\/","title":{"rendered":"This scientist rewarmed and studied pieces of his friend\u2019s cryopreserved brain"},"content":{"rendered":"
\n

L. Stephen Coles\u2019s brain sits cushioned in a vat at a storage facility in Arizona. It has been held there at a temperature of around \u2212146 degrees \u00b0C for over a decade, largely undisturbed.<\/p>\n

That is, apart from the time, a little over a year ago, when scientists slowly lifted the brain to take photos of it. Years before, the team had removed tiny pieces of it to send to Coles\u2019s friend. Coles, a researcher who studied aging, was interested in cryogenics\u2014the long-term storage of human bodies and brains in the hope that they might one day be brought back to life. Before he died, he asked cryobiologist Greg Fahy to study the effects of the preservation procedure on his brain. Coles was especially curious about whether his cooled brain would crack, says Fahy.<\/p>\n

Coles\u2019s brain was preserved shortly after he died in 2014, but Fahy has only recently got around to analyzing those samples. He says that Coles\u2019s brain is \u201castonishingly well preserved.\u201d<\/p>\n

\u201cWe can see every detail [in the structure of the brain biopsies],\u201d says Fahy, who is chief scientific officer at biotech companies Intervene Immune and 21st Century Medicine (where he is also executive director). He hopes this means that Coles\u2019s brain still stands a chance of reanimation at some point in the future.<\/p>\n

Other cryobiologists are less optimistic. \u201cThis brain is not alive,\u201d says John Bischof, who works on ways to cryopreserve human organs at the University of Minnesota.<\/p>\n

Still, Fahy\u2019s research could help provide a tool to neuroscientists looking for new ways to study the brain. And while human reanimation after cryopreservation may be the stuff of science fiction, using the technology to preserve organs for transplantation is within reach.<\/p>\n

Banking a brain<\/h3>\n

Coles, a gerontologist who spent the latter part of his career studying human longevity, opted to have his brain cryogenically preserved when he died of pancreatic cancer<\/a>.<\/p>\n

After he was declared dead, Coles\u2019s body was kept at a low temperature while he was transferred to Alcor, a cryonics facility in Arizona<\/a>. His head was removed from his body, and a team perfused his brain with \u201ccryoprotective\u201d chemicals that would prevent it from freezing. They then removed it from his skull and cooled it to \u2212146 \u00b0C.<\/p>\n

Coles had another request. As a scientist, he wanted his cryopreserved brain to be studied. Hundreds of people have opted to have their brains\u2014with or without the rest of their bodies\u2014stored at cryonic facilities (the remains of 259 individuals are currently stored as either whole bodies or heads at Alcor). But scientists know very little about what has happened to those brains, and there\u2019s no evidence to suggest they could be revived. Coles had met Fahy through their shared interest in longevity, and he asked him to investigate.<\/p>\n

\u201cHe thought that if he had himself cryopreserved, we could learn from his brain whether cracking was going to happen or not,\u201d says Fahy. That\u2019s what typically happens when organs are put into liquid nitrogen at \u2212196 \u00b0C, he says. The extreme cooling creates \u201ctension in the system,\u201d he says. \u201cIf you tap it, it\u2019ll just shatter.\u201d This cracking is less likely at the slightly warmer temperatures used for preservation.\u00a0<\/p>\n

Fahy was involved from the time the samples were taken.<\/p>\n

\u201cWe had Greg Fahy on the phone coordinating the whole thing, [including] where the biopsies were taken,\u201d says Nick Llewellyn, who oversees research at Alcor. (Llewellyn was not at Alcor at the time but has discussed the procedure with his colleagues.) The biopsied samples were stored in liquid nitrogen and earmarked for Fahy. The rest of the brain was cooled and kept in a temperature-controlled storage container at Alcor.<\/p>\n

Bouncing back<\/strong><\/h3>\n

It wasn\u2019t until years later that Fahy got around to studying those biopsies. He was interested in how the cryoprotectant\u2014which is toxic\u2014might have affected the brain cells. Previous research has shown that flooding tissues with cryoprotectant can distort the structure of cells, essentially squashing them.<\/p>\n

It\u2019s one of the many challenges facing cryobiologists interested in storing human tissues at very low temperatures. While the vitrification of eggs and embryos<\/a>\u2014which cools them to \u2212196 \u00b0C and essentially turns them to glass\u2014has become relatively routine (thanks in part to Fahy\u2019s own work on mouse embryos back in the 1980s<\/a>), preserving whole organs this way is much harder. It is difficult to cool bigger objects in a uniform way, and they are prone to damaging ice crystal formation, even when cryoprotectants are used, as well as cracking.<\/p>\n

Fahy found that when he rewarmed and rehydrated Coles\u2019s brain cells, their structure seemed to bounce back to some degree. Fahy demonstrated the effect over a Zoom call: \u201cIt looks like this,\u201d he said with his hands as if in prayer, \u201cand it goes back to this,\u201d he added, connecting his forefingers and thumbs to create a triangle shape.<\/p>\n

The structure of the tissue looks pretty intact, too, to him at least, though he admits a purist expecting a pristine structure would be disappointed. He and his colleagues have been able to see remarkable details in the cells and their component parts. \u201cThere\u2019s nothing we don\u2019t see,\u201d says Fahy, who has shared his results, which have not yet been peer reviewed, at the preprint server bioRxiv<\/a>. \u201cIt seems that [by taking the cryogenic approach] you can preserve everything.\u201d<\/p>\n

As for the cracking, \u201cfrom what I was told, no cracks were observed [by the team that initially preserved the brain],\u201d says Fahy. The team at Alcor took photographs of the brain when they took the biopsies, but the images were later lost due to a server malfunction, he says. In the more recent photos, the brain is covered in a layer of frost, which makes it impossible to see if there are any cracks, he adds. Attempts to remove the frost might damage the brain, so the team has decided to leave it alone, he says.<\/p>\n

Back to life?<\/strong><\/h3>\n

Fahy and his colleagues used chemicals to \u201cfix\u201d Coles\u2019s brain samples once they had been rewarmed. That process is typically used to stop fresh tissue samples from decaying, but it also effectively kills them.<\/p>\n

But he thinks his results suggest that it might be possible to cryopreserve small pieces of brain tissue and reanimate them to learn more about how they work. Functional recovery seems to be possible in mice\u2014a few weeks ago a team in Germany showed that they were able to revive brain slices that had been stored at \u2212196 <\/a>\u00b0C. Those brain samples showed electrical activity after being cooled and rewarmed.<\/p>\n

If cryobiologists can achieve the same feat with human brain samples, those samples could provide neuroscientists with new insights into how living brains work.<\/p>\n

Brain cryopreservation \u201ccan capture a little bit more of the complexities of the brain,\u201d says Shannon Tessier, a cryobiologist at Massachusetts General Hospital who is developing technologies to preserve hearts, livers, and kidneys for transplantation. \u201c[Being] able to use human brains from deceased individuals [could] add another layer to the research tool kit,\u201d she says.<\/p>\n

And Fahy\u2019s paper shows \u201cwhat happens when we try and vitrify a one-liter, dense, massive goop,\u201d says Matthew Powell-Palm, a cryobiologist at Texas A&M University. \u201cWe now have a strong indication that quite large [tissues and organs] can be vitrified by perfusion [without forming too much ice],\u201d he says.<\/p>\n

All of the scientists I spoke to, including Fahy, are also working on ways to cool and preserve organs for transplantation. These are in short supply partly because once an organ is removed from a donor, it usually must be transplanted into its recipient within a matter of hours.\u00a0<\/p>\n

Cryopreservation could buy enough time to make use of more organs, find better organ-donor matches, and potentially even prepare recipients\u2019 immune systems and save them from a lifetime of immunosuppressant drugs, says Bischof, who has also been developing new technologies for organ cryopreservation.<\/p>\n

Bischof, Fahy, and others have made huge strides in their attempts so far, and they have managed to remove, cryopreserve, and transplant organs in rabbits<\/a> and rats<\/a>, for example. \u201cWe\u2019re at the cusp of human-scale organ cryopreservation,\u201d says Bischof.<\/p>\n

But when it comes to preserving brains, donation isn\u2019t the aim. Coles had hoped to be reanimated\u2014a far more ambitious goal that hinges on the ability to restore brain function.<\/p>\n

Brain reanimation<\/strong><\/h3>\n

Fahy acknowledges that while the structure of Coles\u2019s brain samples did bounce back, there is no evidence to suggest the cells could be brought back to life and regain electrical activity and a functioning metabolism. \u201cRestoring it to function \u2026 that\u2019s a whole other story,\u201d he says.<\/p>\n

But he thinks that successful cryopreservation of the brain \u201cis the gateway to human suspended animation, which [could allow] us to get to the stars someday.\u201d Figuring out human preservation would also allow people to avoid death through what he calls \u201cmedical time travel\u201d\u2014journeying to an unspecified time in the future when science will have found a cure for whatever was due to kill that person. \u201cThat would be an ultimate goal to pursue,\u201d he says.<\/p>\n

\u201cI put the chances [of brain reanimation] at pretty low,\u201d says Alcor\u2019s own Llewellyn. \u201cThe kind of technology we need is practically unfathomable.\u201d<\/p>\n

The brains already in storage at Alcor and other facilities have been preserved in ways that \u201chave not been validated to work for reanimation,\u201d says Tessier. An expectation that they\u2019ll one day be brought back to life in some form is \u201cquite a jump of faith and hope that\u2019s not based on science,\u201d she says.<\/p>\n

As Powell-Palm puts it: \u201cThere are so many ways in which those neurons could be toast.\u201d<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

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