Bears and squirrels hibernate to survive harsh conditions; why not humans? If we want to travel deep into space or combat deadly diseases, physiologist Matteo Cerri says hibernation might be the key.

Transcript

MANOUSH ZOMORODI, HOST:

On the show today, rest. And one of the truest, deepest forms of rest comes to some animals every winter.

MATTEO CERRI: When we talk about hibernation, what we really mean is to do what squirrels or bears or hamster, bats - that all these animals do in winter when they don't have enough resources, enough food or water.

ZOMORODI: Matteo Cerri is a professor at the University of Bologna, where he studies hibernation.

CERRI: They change what they need from the environment by entering this very, very special state. So it's a bit more like a standby on a TV screen or on a computer.

ZOMORODI: And to put their body on standby, Matteo says that animals first have to find the right spot.

CERRI: So what you're looking for is a place where you could be safe from predators, potentially invisible to the rest of the environment - where you can just wait, a place where you can be cozy and safe.

ZOMORODI: Then the body, heart, lungs, brain slow down to a creep. And there's a word for it.

CERRI: Yes. We call that torpor.

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CERRI: So torpor is the technical word that refers to a low metabolic state. And sometime I say to my students, it's like a metabolic austerity. You don't spend anything more than what is strictly needed to exist. You could think of hibernation - or torpor, more correctly, as the natural state that may be the closer to death without actually, you know, going over.

ZOMORODI: OK. So those are the basics of hibernation. But here's the thing about Matteo.

CERRI: I'm actually working on - try to replicate or simulate hibernation for human use.

ZOMORODI: Yeah, human hibernation. Matteo is studying whether it would be possible to put people into this extreme state of torpor.

CERRI: I will say, there is a clear path to try to reach this goal.

ZOMORODI: OK. Matteo, I understand why animals would hibernate. But you think that there are reasons why humans would want to hibernate?

CERRI: That's absolutely what we're thinking is a basket full of resources for medicine, for space travel. And it could really exploit a different state of the body, a different physiology that we are starting now to unraveling and understanding in deeper detail, and could lead to, potentially, disruptive application. I know disruptive is a hype word.

ZOMORODI: (Laughter).

CERRI: And maybe it's counterproductive to say it. But I really think it will be disruptive.

ZOMORODI: Well, yeah, it definitely sounds disruptive. But - OK, so let's start with space travel. You are working with the European Space Agency on this problem, figuring out how astronauts could travel years - even decades - into deep space, which would be really hard on the human body.

CERRI: Yeah. Having a trip that lasts, let's say, a decade in space, you have to imagine yourself - you are in a very confined space, night and day, every time, every minute, every hour. So that is pretty stressful. And then there are other problem. Your strength, the structure of your body - some muscle will become weak because of the lack of gravity, and as well for your bone. If they will not be able to keep you standing against the gravity of another planet, how are you going to stand or walk? Then there is the problem of radiation. So the amount of radiation you would get for this kind of trip, there's just too much, unless we find some way to reduce this damage or protect ourselves from the damage.

ZOMORODI: OK. So that's a lot of problems. But you think hibernation could do that, could work as protection?

CERRI: That's absolutely right. First thing, obviously, you don't need that much food and water and resources when you're hibernating. And you don't produce much biological waste as well. So all of that is cleaner. Your muscle and your bone will probably preserve much of their structure and their strength. And finally, hibernation gives cell an interesting defense against radiation. It doesn't reduce, apparently, the damage radiation do to tissues. But he help tissue repair those damage in a much better way than if we were not hibernating.

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ZOMORODI: Wow. That is fascinating. But I don't think that many of us have plans to travel to Mars anytime soon.

CERRI: (Laughter).

ZOMORODI: I will say, though, you are making me fantasize about going into hibernation for my next long-haul flight. Is that possible? Could we, maybe, one day, put ourselves into a state of hibernation and wake up in a different time zone feeling pretty good?

CERRI: That would be great. That would be fantastic. I hate long flights. So - I had a friend. He's, like, a trader in the stock market. He was asking me, could we go into torpor when the market goes down...

ZOMORODI: (Laughter).

CERRI: ...And wake up when the market goes up? So it will all depend on how easy and risky the technology would be. But why put a limit to our hope?

ZOMORODI: When we come back, we get a little more grounded - how hibernation could be used more immediately in medical treatments. On the show today, rest. I'm Manoush Zomorodi. And you're listening to the TED Radio Hour from NPR. Stay with us.

It's the TED Radio Hour from NPR. I'm Manoush Zomorodi, and we were just talking to hibernation expert Matteo Cerri. Matteo says there are a few intriguing stories that make researchers believe humans can hibernate or be put into a state of torpor, including a story published in 1800 about an entire village in Russia that would sleep through the winter.

CERRI: There is a Russian term for this winter sleep. It's called lotska. I don't know if I pronounce it correctly. And apparently, those peasants and villagers were gathering together in this large house in the center of the town to sleep the winter off together - just sleeping there, waiting for spring to come.

ZOMORODI: I mean, that's - whether it's true or not, that is a beautiful story. It's like a fairy tale. But there is a famous story from the neurologist Oliver Sacks about a man that he called Uncle Toby, right?

CERRI: Yes, definitely. Oliver Sacks - he was visiting a family for - you know, on-site for some other question. And he noticed this person, like - he said, like, icy frozen - still alive though - with temperature - body temperature of 69 Fahrenheit. So about 20 Celsius.

ZOMORODI: Yikes. Cold.

CERRI: Yes - and ask what happen to him. And they say, well, this is Uncle Toby. And seven years ago, he just stopped. He lives with us. We take care of him. We feed him, we shave him, we dress him, but he just stands there. So he suspected hyperthyroidism as a possible cause of this strange behavior and proposed to treat him with thyroid hormone - at the time was available. And the family agree, and Uncle Toby actually - he woke up. So he was given a drug and he wake up, and he doesn't remember the seven years that were passed. But then - and that would be a good ending story. But the story actually is not - it's sad in its end, because Uncle Toby had cancer - small cell lung cancer - and the cancer woke up with him. And then it killed him in a few months.

ZOMORODI: So does that mean that when Uncle Toby was in this sort of stupor that maybe - not only did he go to sleep, but maybe the cancer went to sleep during that time?

CERRI: Yes, that is exactly the point. The idea is that the cancer in Uncle Toby had found a way to leave both. So a provocative hypothesis would be that the cancer actually produced something that unlocked the ability of the brain to enter torpor. And then therefore the body entered torpor, and therefore the cancer stopped growing because that what happened in torpor. The cancer usually stopped growing. And they both stay that way. And once we awake Uncle Toby, we also wake the cancer, and the story ends.

ZOMORODI: So when we hear that story, does it tell us something about the way that putting humans into hibernation or torpor might be used when it comes to treating something as aggressive and active as mutations in cells, cancer?

CERRI: It could be. It could be used for this kind of clinical condition. Even more pressing would be for someone waiting for an organ transplant. There are about 50 people pretty much every day between the - within Europe and the United States die because of lack of organ. So if you could suspend them, you know, slowing their down metabolism down, then you increase their chances to potentially find an organ. But in the case of Uncle Toby's story, the important part for us is that there seems to be a way in which the brain can be made - induce hibernation, can be reactivating this old state, even in humans. And so it would be feasible. That's what we hope for.

ZOMORODI: I mean, do you imagine wings of hospitals filled with patients who are resting in a state of torpor, waiting for their cancer treatment or waiting for an organ transplant? Is that something that might happen?

CERRI: Yes. Yes, that's what I envision.

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ZOMORODI: So how would we do this? Whether, you know, it is for space travel or for medicine or any number of purposes, like, how would you put people into this state of hibernation?

CERRI: So, so far, the greatest results were to induce into a state that very much resemble hibernation animal that are not able to enter hibernation or torpor. And we call - I call, personally - this state synthetic torpor.

ZOMORODI: Oh, so you induce this in animals in the lab.

CERRI: Yes. And we were able to do it by silencing the activity of a little group of neurons in the very old part of our brain. In the past 10 years, there have been amazing discovery in the field. We have now a better idea of the brain network that control torpor. We have uncover other hotspot that could be target for inducing torpor. So a lot of exciting thing happen in the - really, in the last 10 years.

ZOMORODI: So can we talk about waking up? What it - I had the pleasure of having a routine procedure earlier this week where I was put under general anesthesia, and it is just the weirdest thing coming out of it. You're like, wait, where was I for (laughter) the last half hour? What would waking up from this state of torpor hibernation be like?

CERRI: It's the most dangerous part, I would say, of hibernation. And...

ZOMORODI: Oh.

CERRI: ...And there is really little that we know about how this animal wakes up. The Arctic ground squirrel, his brain is at minus 1 Celsius. How is this brain able to bring the body back to normal? And that's still quite unknown. But what we see is definitely for, especially for the brain, is the most plastic state I've ever seen as a neurophysiologist. So synapses get form and reform is a neuro storm (ph) of molecules, of active brain molecules. So it could be something about, like, dreaming or it could provide you sensation of dreamlike state, my guess. Maybe is even pleasurable - we don't know - or maybe not. But after you wake up, I would say you will also be very, very sleepy.

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CERRI: You need to sleep after hibernation. The reason why - still mystery. Like, the entire time you spent in torpor was sleep deprivation.

ZOMORODI: So you need to rest after your big rest.

CERRI: Oh, yeah. It's hard to tell that hibernation is rest. It's suspension. You are retiring from the game of life for a little bit of time.

ZOMORODI: That's neurophysiologist and hibernation researcher Matteo Cerri. If you speak Italian, you can watch his TED Talk at ted.com. Transcript provided by NPR, Copyright NPR.