You’ve likely seen humans being put under a state of stasis in the movies or TV series like ‘The 100’. It’s that sci-fi scene where people are in high-tech tanks in suspended animation to remain preserved and un-aging for decades or centuries to reach a far-off planet. And as unrealistic as it may seem, there may be a way to do it, and researchers are coming close to figuring it out already.
A team of Harvard Medical School (HMS) neuroscientists identified neurons in mice that control hibernation-like behaviors. When it’s too cold, and food is scarce, mice experience bouts of inactivity – which isn’t hibernation, but it’s similar. What the scientists did was locate what switches on this mechanism, after which they were able to control it and put the mice under a state of dormancy and take them out of it.
When animals like bears, hummingbirds, and frogs enter into biological stasis (hibernation), their heart rate, metabolism, and breathing slow to almost nothing, and body temperatures drop dramatically.
Co-lead author Senmiao Sun, who is a graduate student in the Harvard Program in Neuroscience, explained:
In warm-blooded animals, body temperature is tightly regulated. A drop of a couple of degrees in humans, for example, leads to hypothermia and can be fatal. However, torpor circumvents this regulation and allows body temperatures to fall dramatically. Studying torpor in mice helps us understand how this fascinating feature of warm-blooded animals might be manipulated through neural processes.
The possibilities that arise from people being able to hibernate, as these animals can, are vast – from medical applications like preventing brain injury during a stroke and enabling new treatments for metabolic diseases to helping NASA send humans to Mars and eventually onward to another star.
Another co-lead author, Sinisa Hrvatin, who is an instructor in neurobiology in the Blavatnik Institute at HMS, said:
The imagination runs wild when we think about the potential of hibernation-like states in humans. Could we really extend lifespan? Is this the way to send people to Mars? To answer these questions, we must first study the fundamental biology of torpor and hibernation in animals. We and others are doing this — it is not science fiction.
There are still many questions about the state of suspended animation and its effects on the mammalian brain, but this study has brought about some significant insights.
Senior author Michael Greenberg, who is a professor and chair of Harvard’s Department of Neurobiology, said:
It’s far too soon to say whether we could induce this type of state in a human, but it is a goal that could be worthwhile. It could potentially lead to an understanding of suspended animation, metabolic control, and possibly extended lifespan. Suspended animation in particular is a common theme in science fiction, and perhaps our ability to traverse the stars will someday depend on it.
Now we know it is possible to induce torpor by stimulating neurons by adding a chemical compound to specific regions of the brain. This knowledge opens the door to many more new studies to come!
Hrvatin said:
Our findings open the door to a new understanding of what torpor and hibernation are, and how they affect cells, the brain, and the body. We can now rigorously study how animals enter and exit these states, identify the underlying biology, and think about applications in humans. This study represents one of the key steps of this journey.
The team is now experimenting with long-term torpor and its effects on mice while continuing their research on the underlying mechanisms and pathways that allow the neurons to regulate torpor and the roles of other populations of neurons.
If ever realized, the implications of humans being able to hibernate are profound. Astronauts could travel in smaller spacecraft because they wouldn’t need to move around and wouldn’t need to bring as much food and water with them. It would dramatically reduce the cost of space travel and make the whole ordeal more efficient.
