Suspended animation is a classic science fiction trope. In many stories, travelers on long space trips are put into sealed pods where they sleep away their journey -- and, often, stop aging. Sometimes the suspended animation was explained to be an advanced freezing technique, sometimes as elaborate technobabble, and occasionally directly compared to hibernation. It was science fiction verging on fantasy, and nobody thought it would be available any time soon.
Well, get your pajamas ready.
Researchers at the Fred Hutchinson Cancer Research Center in Seattle have discovered a remarkably simple way to induce an extreme hibernation state in mice (which do not normally hibernate). The mice were exposed to air containing 80 parts per million of hydrogen sulphide -- a gas characteristic of rotten eggs -- resulting in a suspended condition. The state was readily reversed by exposure to normal air, with no ill effects.
While hibernating, their metabolic rates plummeted by about 90% as their cells dropped their usual demand for oxygen. Core body temperatures dropped from the normal 37°C to 15°C.
“Once down to around 15°C, instead of 150 breaths per minute, they were down to just a couple of really shallow breaths a minute,” says Roth.
The researchers are still investigating precisely how the hydrogen sulphide induces this state. Although no human tests are in the works, medical scientists are excited by the prospect of functional, reversible suspended animation. Such a state would be enormously useful in the case of heart attacks and strokes, preventing tissue damage while the patient is transported to a hospital, and for preserving transplantable organs.
Any use in space travel would be far off, of course. The furthest any human has gone so far has been to the Moon and back, and even a trip to Mars -- the most likely voyage over the next few decades -- would be short enough to handle without hibernation. Still, it's nice to see a widely-recognized bit of science fiction leap into the realm of the possible.
Sadly, any age-stopping benefits remain purely speculative.