In a massive story in the New York Times this Sunday, journalist Amy Harmon documented the journey of a dying 23-year-old woman who decided to freeze her brain.
The woman, Kim Suozzi, had terminal brain cancer, and wanted to preserve her brain with the hope that it could one day be revived.
Suozzi isn't alone, either. More than 100 people have undergone cryonics (freezing their body for reviving later) or neuropreservation (freezing of just the head and brain) since the first case in the 1960s, according to the Alcor Life Extension Foundation, which performs both procedures.
Alcor requires patients to sign over to them their life insurance policies of $80,000 for neuropreservation and $200,000 for cryonics, according to their website.
Medical professionals and researchers have gotten quite good at freezing and reviving human parts — everything from organs for transplantation to embryos and eggs for reproduction. But the human brain is a whole other story.
The truth is, no one has ever been revived after death and freezing. Experts, including Winfried Denk, a brain mapping expert at the Max Planck Institute of Neurobiology in Germany, who Harmon quoted in her story, think the ability to revive someone who has undergone cryopreservation is at least 40 years away. By then, hopefully, we'd also have developed cures to whatever killed the patient in the first place.
The problem is, when the body dies, cells immediately start releasing toxic substances and decomposing. It's extremely difficult to prevent this natural process from happening, but a few organizations, including Alcor, which Suozzi used, are giving cryonics a try with the hope that one day they will be able to bring their frozen patients back to life.
Here's how Alcor does it:
- Within minutes of the patient's heart stopping and being medically pronounced dead, the cryonics team places him/her in an ice water bath to start the cooling and preservation process.
- Life support is administered to artificially keep the heart beating, the blood pumping, and to increase blood oxygen levels to those experienced in airplanes. This keeps the brain healthy during the cryopreservation process.
- An external heart-lung machine takes over for the patient's organs, and the patient is cooled to a temperature a few degrees above the freezing point of water, where oxygen is no longer necessary.
- Blood is replaced with a cryoprotectant antifreeze solution over the course of a few hours. The cryoprotectant chemicals used are similar to those used for transporting organs for transplant. This antifreeze is crucial for keeping ice crystals from forming, since ice expands and can form spiky crystals that damage brain cells.
- The patient is slowly cooled (in a few more hours) via nitrogen gas circulation to -193 degrees Fahrenheit. At this temperature, their cells vitrify, and turn into a solid. They technically don't "freeze" since the process is ice-free, and molecules instead move slower and slower until all chemistry stops.
- Over the next two weeks, the patient is cooled to about -320 degrees Fahrenheit, and the cryopreserved brain and/or body is stored under liquid nitrogen for long term care.
But how would freezing a brain work to bring a human back to life? We really don't know yet.
Billions of cells make up the human brain, and the most important thing in preserving it is keeping their connections intact. If those connections are frozen intact, the hope is that future scientists would be able to read them from a frozen brain and recreate that person from those connections — either implanted into a synthetic, or "lab-grown," brain and body, or potentially into a computer.
What's hard is that researchers aren't even sure they fully understand how these connections work to create memories and personality. The Human Connectome Project aims to learn more about this network, but significant progress will take decades and hundreds of millions of dollars.
While people are having their heads and bodies preserved now, it will take a long time before they can be revived. What that will look like, however, is a whole other story.
