In science fiction, space crews are typically spared the boredom and inconvenience of extended-distance space travel by getting placed into a state of suspended animation. Now this aim may possibly have come a step closer immediately after scientists showed that hibernation can be artificially triggered in rodents utilizing ultrasonic pulses.
The advance is noticed as considerable mainly because the method was productive in rats – animals that do not naturally hibernate. This raises the prospect that humans may possibly also retain a vestigial hibernation circuit in the brain that could be artificially reactivated.
“If this proves feasible in humans, we could envision astronauts wearing a helmet-like device made to target the hypothalamus area for inducing a hypothermia and hypometabolism state,” mentioned Hong Chen, an associate professor at Washington University in St Louis, who led the function.
The group very first identified a distinct group of neurons in a deep brain area named the hypothalamus preoptic region, which have been discovered to be involved in regulating physique temperature and metabolism in the course of hibernation. They showed that, in mice, these neurons could be artificially activated utilizing ultrasound, delivered non-invasively by means of a helmet.
When stimulated, the mice showed a drop in physique temperature of about 3C for about a single hour. The mice’s metabolism also shifted from utilizing each carbohydrates and fat for power to only fat, a crucial function of torpor, and their heart prices fell by about 47%, all whilst at space temperature.
The scientists also created an automatic closed-loop feedback program that delivered an ultrasound pulse to retain the mice in the induced torpor if they showed indicators of warming up. This permitted the mice to be kept at 33C in the hibernation-like state for 24 hours. When the ultrasound program was switched off, they woke up once again.
The experiments, described in the journal Nature Metabolism, showed that the similar device worked in rats, which had a 1C drop in core physique temperature when the similar brain area was targeted. Chen mentioned the outcome was “surprising and fascinating” and the group planned to test the method in bigger animals.
In humans, inducing a torpor-like state has possible healthcare applications, with some suggesting that slowing down metabolism could get vital time for treating life-threatening circumstances such as heart attack and stroke. “By extending the window for healthcare intervention, this method gives promising prospects for enhancing patients’ probabilities of survival,” mentioned Chen. “Additionally, the non-invasive nature of the method opens the possibility of creating wearable ultrasound devices, such as helmets, for quick access in emergency conditions.”
Prof Martin Jastroch, of Stockholm University, who was not involved in the analysis, described the function as a breakthrough. “Everything they see recapitulates what you see in nature,” he mentioned.
“They can also do this in rats, which is pretty fascinating,” he added, saying that “the likelihood is pretty high” the similar method would, theoretically, function in humans. “We may possibly have some residual skills there. Just before this paper no a single was even considering of how you could experiment with that in secure manner.”