We have seen it in dozens of movies, books and science fiction series (and in some news too). On our journey into deep space, while our ships travel the long routes that will connect us with other stars, human beings will need to hibernate.
The problem is that it is easier said than done. At least, until now.
In search of the mole. For years, scientists have been studying the ‘topor’. A physiological state in which mammals suppress metabolism, lower body temperature, and slow down other processes to conserve energy. And they have studied it not because of science fiction, but because slowing down the metabolism could be a fantastic tool in acute emergencies or serious illnesses.
Yet for all those years the torpor has been elusive. Mammals are very complex machines and, although researchers have been finding clues that allowed us to begin to understand how we can emulate other hibernators, reality has always shown us that it is a little more complex than our models anticipated.
An idea from decades ago that is finally possible today. Now, Nature Metabolism publishes a work in which it is shown that it is possible to “induce a reversible state of hibernation in mice and rats by means of directed ultrasound pulses” to a very specific area of the central nervous system: the preoptic area of the hypothalamus.
As Domenico Tupone of the University of Bologna explained at the Science Media Center, we have known for decades “the role of this area in the control of body temperature and its role in fever.” The interesting thing is that it turns out to be the first proposal that takes advantage of this knowledge in a non-invasive way and that opens up a huge number of possibilities.
But what exactly have they done? Hong Chen’s team has developed an ultrasound emitter that directs 10-second ultrasonic pulses into the preoptic area. Thanks to it, the researchers caused an immediate drop in body temperature of several degrees (an average of 3-3.5 °C), together with a reduction in the heart rate and oxygen consumption of the mice.
They were able to keep the animals in this state of torpor for 24 hours. Subsequently, they recovered with no signs of damage or discomfort. Not only that. The researchers tested the same system on rats (animals that do not hibernate naturally) and found a similar response.
Are we close to being able to ‘hibernate’ people? No, the truth is that not yet. As Tupone put it, “Mice are very small animals compared to humans. The preoptic area of the hypothalamus is a very deep region of the human brain, and it would be hard to imagine that an extracranial stimulus could be effective in such a deep region without interfering with the intermediate brain regions.
Of course, Tupone recognized that “an implantable microdevice, similar to deep brain stimulation electrodes, could probably be implanted directly in the area and this [la técnica de la que hablamos] would probably be applicable”. It is true that with some “side effects”.
At least right now, techniques for inducing torpor in humans lack precision and power. However, none of that is a problem to admit that we are on the right track.
In Xataka | Cryogenics is still science fiction, and there’s no guarantee it won’t stop.
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