It could be possible to live forever, but you may have to die to do it.

Scientists have developed a new technique for brain preservation that could be the first step - of many - to be revived after biological death. It's a technique that its inventor has called "100% fatal," which raises enormous ethical issues that might be dwarfed only by the practical problems of making this dream of immortality a reality.

The journey back to life

The new technique is called "aldehyde stabilized cryopreservation" or ASC, and it's aimed at preserving human brains at the molecular level. This, advocates suggest, might allow the possibility in the future of extracting the information from preserved brains, and uploading it into a computer or synthetic body for digital immortality.

Images of ASC-preserved pig brain dissection. (The Brain Preservation Foundation)

The fantasy of somehow being revived after death by medical science reaches back at least to the 1960s with the dawn of "cryonic preservation." Since then, a few hundred people have been frozen and stored in liquid nitrogen in order to preserve their bodies and brains in the hope that medical science will someday develop a way to cure their ailments, repair them, and bring them back to life.

Scientists generally are hugely skeptical that this kind of preservation works. Dr. Ken Hayworth, a neuroscientist at the Howard Hughes medical Institute in Virginia, was an early enthusiast for cryonics, and had arranged to be frozen on his death. His research, however, led him to suspect that the cryonic freezing process damaged brains so badly that revival was impossible.

Dr. Ken Hayworth is a neuroscientist at the Howard Hughes medical Institute in Virginia (The Brain Preservation Foundation)

"You need to know how well your brain is going to be preserved by any of these companies," he says, "I think a lot of these companies, what they're selling is false hope." This led him to abandon his cryonics contract.

But he was still very much interested in the idea that cryonics represented. To stimulate research in this area, Dr. Hayworth founded the Brain Preservation Foundation, and raised funds for prizes meant to drive development of the technology. To win the prize, according to Dr. Hayworth, the entrant had to demonstrate that "the synaptic connectivity of an entire large mammal brain can be preserved."

A different vision for brain preservation

Earlier this year, the $80,000 prize was awarded for a technique that essentially glues all of what scientists currently think are the important biological structures in the brain in place. The winner was a group led by Dr. Robert McIntyre, an AI researcher-turned-neurobiologist, who developed a technique to flood the brain of a pig with a chemical called gluteraldehyde.

Dr. Robert McIntyre is the CEO of Nectome Inc. (Nectome)

Gluteraldehyde bonds to the proteins in the brain, fixing the neurons, synapses and most of the large proteins and important molecules in the brain in place. These are, as far as neuroscientists know, all of the important molecules and structures that encode our memory and personality. If they're preserved, then, at least in theory, all of the information that was encoded in the living brain could also be retained. The brain could then be frozen without damage for long term storage.

Canadian neurobiologist Dr. Michael Hendricks, a researcher at McGill University, admits that the technique can likely preserve all the information in a brain, but it's not going to be possible to bring a brain preserved this way back to biological life. "The major downside of these chemical fixatives is that the tissue is by definition dead."

"Preserving a brain is not that difficult. Having said that, the revival part is incredibly difficult, just insanely, insanely difficult." - Dr. Ken Hayworth

Dr. Hayworth agrees, but has a different vision for brain preservation. Because these preserved brains may retain all of the information in a mind, then it could be possible to retrieve that information. The brains could be scanned in 3-D, using something like an electron microscope. This could, in theory, allow all the information in a mind encoded in the biology of the brain to be extracted, and uploaded into a computer.

He admits it's hard to overstate how big a job this would be. "Preserving a brain is not that difficult. Having said that, the revival part is incredibly difficult, just insanely, insanely difficult."

It seems ever more likely that we're approaching "the singularity": the point where machine intelligence exceeds human intelligence. (Wikipedia)

The sheer amount of information is overwhelming. A brain scanned at the molecular level is likely to take up at least a trilllion, trillion pixels. Then that information somehow needs to be "run" as a computer program in a brain or robot.

At the moment, we have no idea of what technology might be necessary to do that. Dr. Hayworth compares the scale of the effort that he expects would be required to that of the Apollo moon landings, and doesn't think it would be technically feasible for at least half a century or more.

Nectome's "100% fatal" procedure

Preserving a brain this way is also likely to be enormously controversial, acknowledges Dr. Hayworth, because, ideally, it would be done when the patient is still alive. "One of the best ways to get a really well preserved brain is to make sure you start that procedure before your biological brain decays to mush. And so the brain preservation procedure, in an optimal sense, should be developed as a medical procedure that could be applied before death." In order to minimize the controversy, Dr. Hayworth wants to proceed with studying this slowly, through the conventional and cautious scientific and medical investigation.

What we have done is something that would be incomprehensible and terrifying to [the ancient Egyptian mummies]. So I think it's safe to say whatever some imagined far future society might find interesting to do with our brains might be equally incomprehensible and terrifying. - Dr. Michael Hendricks

However the leader of the team who won the Brain Preservation Prize seems to be courting, rather than avoiding controversy. Robert McIntyre, through his Silicon Valley start-up Nectome, has been promoting his "100% fatal" brain preservation procedure, taking $10,000 deposits from potential customers, and according to reports in MIT's Technology Review, consulting with lawyers about the legality of performing brain preservation on living patients under California's assisted suicide laws.

This certainly attracted headlines, but also led the Massachusetts Institute of Technology, which had a research agreement with Nectome to pursue basic neuroscience work, to sever ties with the company.

Robert McIntyre taking a rabbit brain out of a -135 degrees Celsius freezer unit after overnight storage. The brain is completely solid. (The Brain Preservation Foundation)

Dr. Hayworth, for one, is concerned that this kind of controversy could lead to government regulation that would ban the procedure, dashing his hopes of effective brain preservation.

Dr. Michael Hendricks, however, thinks that those hopes are slim in any case. He thinks Dr. Hayworth, if anything, underestimates the difficulty of reviving a preserved brain, and wonders why a future society would want this. But beyond that, he wonders if those who wake up in a future society would necessarily be happy with their new life.

"The assumption here is that whatever society does this is going to be benign with us or comprehensible with respect to us." A good analogy, he suggests, is the Egyptian mummies who preserved themselves for immortality. Today, of course, they're museum specimens.

"What we have done," he says, "is something that would be be incomprehensible and terrifying to them. So I think it's safe to say whatever some imagined far future society might find interesting to do with our brains might be equally incomprehensible and terrifying."





