Humans Could Potentially Put on a Helmet and Hibernate

Rats, like humans, don't naturally hibernate. But scientists have figured out a way to induce a torpor-like state in the rodents which, as the Guardian reports, raises the prospect that the same thing can happen in humans, with a host of hard-to-imagine ramifications in fields ranging from space travel to health care. Scientists keyed in on a group of neurons in the hypothalamus preoptic area of the brain involved in regulating body temperature and metabolism during hibernation. They then activated the neurons in mice, using helmets that delivered ultrasonic pulses. The result: body temperature dropped 3 degrees Celsius, heart rates fell by nearly half, and the body began using fat for energy, rather than fat and carbohydrates. After 24 hours, the system was shut off and the mice woke up.

The same system also worked on rats, which don't naturally hibernate—a "surprising and fascinating" result, according to Hong Chen of Washington University, lead author of a study on the findings published Thursday in Nature Metabolism. (Hibernation has also been triggered in rats through the injection of drugs that act on the hypothalamus.) "If this proves feasible in humans, we could envision astronauts wearing a helmet-like device designed to target the hypothalamus region for inducing a hypothermia and hypometabolism state," Chen tells the Guardian. The BBC digs into what a torpor-like state in humans would mean for space travel, including the prevention of muscle loss for astronauts and huge reductions in the size of spacecraft needed for long journeys, as the amount of food cargo could be reduced by 75%.

But a torpor-like state could also "buy critical time for treating life-threatening conditions," per the Guardian. Therapeutic hypothermia, involving the lowering of body temperature, is already used to reduce damage in cases of cardiac arrest or traumatic brain injury. Per the BBC, "cooling the body down ... reduces the body's demand for energy and oxygen." The study also "opens the possibility of developing wearable ultrasound devices, such as helmets, for easy access in emergency situations," says Chen. Far-fetched as it may seem, "as far as we know, there is nothing unique about homo sapiens that would prevent our species from hibernating," Vladyslav Vyazovski, a professor of sleep physiology at Oxford, tells the BBC. Interested in learning more? Check out Vyazovski's TED Talk. (More hibernation stories.)