You’re Not Dead Until You’re Warm and Dead: Reanimating the Frozen 

Science’s long-standing goal of resuscitating a frozen body has made intriguing progress recently, with frozen brain tissue successfully being restored to a functional state for the first time. Researchers’ samples resumed electrical cellular activity in apparently undamaged slices of mouse brain which had been, for six hours, kept at a temperature of negative 320.8 Fahrenheit. 

History

Such research is ongoing. There have long been proponents of freezing one’s remains after death, hoping to be revived in the future, ideally when medicine has conquered mortality. A number of partially successful cryogenic experiments have been attempted to this end since the 1950’s, but none with the degree of reliabiity necessary to preserve all of  body’s cells and structures with itegrity intact, especially the brain’s fragile syapses. 

Until now, each experiment has resulted in tissue damage, making function impossible.  In  one case, though, limited activity resumed in a feline brain sample following storage for several years at -20 Celsius.

How?

The recent successful mouse brain experiment refined a process called vitrification. Since the human body is mostly water, freezing remains has been challenging because of the catastrophic destruction to cells caused by expanding ice crystals. Vitrification replaces the water in tissues with an anti-freeze type agent (a cryoprotectant) that prevents freezing, water expansion, and ice crystal formation.

Awakening from Cryostasis?

There’s a long way to go, but modest evidence suggests that the polarizing theory may actually be a viable one; the prospect survives mainly because of a few relevant successes.

One of the most amazing to date is that of Anna Bagenholm, a 29-year old skier in Norway who in 1999 broke through the ice of a frozen stream and was trapped beneath it, her body submerged in frigid water, head in an air pocket just under the ice, for more than eighty minutes. She had no heartbeat and wasn’t breathing upon rescue. It was 2.5 hours before she was in a hospital, at which time her core temperature was 56.7 degrees Fahrenheit. 

It took 9 hours and shifts of over a hundred doctors working nonstop to restore her heartbeat, but they did it. Today (20 years later), Bagenholm works as a radiologist at the hospital that saved her, with minimal nerve damage. It took years of physical therapy for her to recover, but recover she has.

Her survival has been attributed partly to the circumstances of frigid immerion, which delayed cell death. The low temperatures slowed her metabolism so much that her cells required a fraction of their typical oxygen requirement. 

Considered with the other successes of freezing eggs, sperm, and entire human embryos alongside the revival of less complex frozen life forms after literally thousands of years, adherents to the possibility of cheating death by deep-freeze see proof enough for hope of greater achievements to come. 

The big challenges

Vitrification could offer a crucial partial solution by eliminating ice expansion and crystals within tissues, but other obstacles remain.

For one thing, will it become ethically acceptable in America to freeze a living brain, thereby killing the patient? It is clearly preferable to preserve a functioning brain and that presents problems here in America, though various national standards already exist. 

Also, however quickly action may follow death, the replacement of the body’s water with cryoprotectant is nowhere near instantaneous. Time is function when it comes to oxygen deprivation in the brain, and hypoxic changes could lead to permanent damage should the patient ever be resuscitated. 

Yet another complication in an already sticky web of them, but the recent results are a  significant step forward.