It is no news that one of the greatest ambitions of human space exploration for the foreseeable future is to get astronauts to Mars. However, this is a challenging goal in several respects, especially with regard to food, resistance to low temperatures, exposure to radiation, among other factors that directly affect the health of individuals.
In science fiction films, space crews are often spared the inconvenience of long-distance travel by being put into a state of “suspended animation” – somewhat similar to hibernation, the natural process of metabolic depression inherent in some animals.
And it is quite possible that this leaves the field of fantasy to come true. An article published on Thursday (25) in the magazine Metabolism of nature describes research conducted by a team of scientists from several US institutions demonstrating that hibernation can be artificially triggered using ultrasonic pulses.
Experiments on mice – animals that do not hibernate naturally – were applied in the study and obtained very satisfactory results, raising the prospect that humans too may retain a residual hibernation circuit in the brain with artificial activation and reactivation.
“If this proves feasible in humans, we can imagine astronauts wearing a helmet-like device designed to target the hypothalamus region to induce a state of hypothermia and hypometabolism,” said Hong Chen, an associate professor at Washington University. of St. Louis, lead author of the study, to the journal The Guardian.
First, the team identified a specific group of neurons in a deep brain region called the preoptic area of the hypothalamus, which may be involved in regulating body temperature and metabolism during hibernation.
They showed that, in mice, these neurons could be artificially activated using ultrasonic currents delivered noninvasively through a kind of helmet.
When stimulated, the mice showed a drop of about 3°C in body temperature for about an hour. Even the animals’ metabolism stopped using carbohydrates and fats in the production of energy, starting to use only fats, a fundamental characteristic of torpor (state of prostration). Additionally, their heart rates decreased by about 47%, all at room temperature.
The scientists also developed a closed-loop automatic feedback system that generated an ultrasonic pulse to keep the mice in induced torpor if they showed signs of warming up. This allowed the animals to be kept at 33ºC in hibernation for 24 hours. When the ultrasound was turned off, they woke up again.
Then the same device was used on rats (which weigh 10 times mice), which experienced a 1°C drop in core body temperature when the same brain region was targeted. According to Chen, the result was “surprising and fascinating,” and the team plans to test the technique on even larger animals.
In addition to potential use in long-distance space travel, such as future manned missions to Mars (something already being considered by space agencies), inducing a torpor-like state in humans has potential medical applications. Slowing down your metabolism could, for example, buy you critical time to treat potentially life-threatening conditions like heart attack and stroke.
“By extending the window for medical intervention, this technique offers promising prospects for improving patients’ chances of survival,” said Chen. “Furthermore, the noninvasive nature of the technique opens up the possibility of developing wearable ultrasound devices, such as helmets, for easy access in emergency situations.”
Since NASA has announced that it intends to get people to Mars by 2040, we still have quite a few years before the technique proves safe for humans. Until then, the procedure remains a movie thing, at least for now.
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Source: Olhar Digital