Inducing Human Hibernation

"We see the science has advanced enough to put some of the science fiction into the realm of science reality."
"It doesn't mean we will have hibernating astronauts anytime soon, but we are learning from nature how to understand some of the things that happen to animals during hibernation, such as preventing bone loss or preventing muscle loss. This is already something that would be of great benefit for long-distance flight."
Leopold Summerer, head, advanced concepts team, European Space Agency

"We think that if we understand how they do it [hibernating animals], we can replicate it in humans."
"We don't know what the natural signal is for torpor. We don't know where the signal occurs in the brain -- it could be in the brain stem or the hypothalamus."
Kelly Drew, biochemist, University of Alaska, Fairbanks

"We don't know why it works, but we know it slows down metabolism and the inflammation] that epilepsy causes in the brain]."
"You actually lower the need for energy for the entire body [biological cooling]. So you give it time to catch up."
Romergryko Geocadin, professor of neurology and anesthesiology, John Hopkins University

SpaceWorks has looked at creating a habitat that would allow astronauts to travel to Mars while hibernating. Photo: Spaceworks

Professor Geocadin uses treatment known as therapeutic hypothermia in treatment of patients with severe epilepsy, or those patients suffering from brain trauma. The body has more of an opportunity to repair itself, if it is cooled and functions are slowed. With the use of ice packs, liquid-filled blankets, caps and cooling IV fluids, a patient's body temperature is reduced from normal by two or three degrees for up to three days.

This treatment has become a useful protocol for a small group of patients who have become comatose resulting from cardiac arrest, or who experience seizures or swelling of the brain. Any longer a cooling respite than that, says Professor Geocadin "and the whole house of cards starts to fall apart"; in other words the risk of precipitating blood clots, pneumonia or additional complications increases.

Kelly Drew, the biochemist at University of Alaska's Institute of Arctic Biology is studying the Arctic ground squirrel, trying to get a handle on how its metabolism can become so low, as a result of its being able to set its internal body temperature at 0 C -- freezing point -- during winter and survive. She thinks she has isolated the molecule responsible; the A1 adenosine receptor which, when stimulated, reduces the animal's body temperature to a depth that would destroy most animals' tissues.

Scientists are studying how the Arctic ground squirrel can get so cold without dying.

In attempts to reach a full understanding of the biological anomaly that leads to hibernation of this kind, biologists have busied themselves dissecting the neurological and biochemical transitways of the hibernating animals, including bears known to sleep in a hibernation state for six months at a time, and yet survive despite not having eaten anything for that period, nor exerted a muscle.

Scientists are hoping that full understanding of the natural process may aid them in devising medical therapies to be adapted for space travel. That therapeutic hypothermia which aids in the treatment of patients with traumatic brain injuries may lead eventually to trials useful enough to induce sleeplike states for very long periods of them, enabling them also to arouse the sleepers with no ill effects having been suffered.

To that end, a panel of European biomedical researchers, biologists and neuroscientists is preparing to announce recommendations for methodologies to be developed to result in human hibernation research and funding. A preliminary study funded by NASA viewed the proposal of placing astronauts in a state of torpor (hibernation) for weeks at a time. The benefits that might arise from that include less food and water required and a reduction in waste products.

Which would naturally lead to smaller living quarters, less space devoted to supplies, exercise and entertainment. If placing a crew in sleep mode is possible, it could conceivably minimize psychological challenges. The yearlong mission that U.S. astronaut Scott Kelly has begun at the International Space Station, combined with medical monitoring of his twin brother back on earth may provide clues relating to protecting humans who leave Earth's orbit for months or years at a time.

Meanwhile, in Italy scientists are set to begin a clinical trial lowering the body temperature of a pig through inhibiting a part of the hypothalamus that controls levels of energy, translated to inducing hypothermia. Should the experiment be successful, it would indicate that the pathway could be repeated in other animals that nature hasn't endowed with the biological traits of hibernation.