In science fiction, space crews are usually spared the boredom and inconvenience of extended-distance space travel by getting placed into a state of suspended animation. Now this purpose might have come a step closer right after scientists showed that hibernation can be artificially triggered in rodents employing ultrasonic pulses.
The advance is observed as considerable for the reason that the strategy was helpful in rats – animals that do not naturally hibernate. This raises the prospect that humans might 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 developed 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 operate.
The group 1st identified a precise group of neurons in a deep brain area referred to as the hypothalamus preoptic location, which have been discovered to be involved in regulating physique temperature and metabolism through hibernation. They showed that, in mice, these neurons could be artificially activated employing 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 employing each carbohydrates and fat for power to only fat, a essential 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 technique that delivered an ultrasound pulse to maintain 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 technique 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 strategy in bigger animals.
In humans, inducing a torpor-like state has possible health-related applications, with some suggesting that slowing down metabolism could invest in vital time for treating life-threatening circumstances such as heart attack and stroke. “By extending the window for health-related intervention, this strategy delivers promising prospects for enhancing patients’ possibilities of survival,” mentioned Chen. “Additionally, the non-invasive nature of the strategy opens the possibility of building wearable ultrasound devices, such as helmets, for uncomplicated access in emergency conditions.”
Prof Martin Jastroch, of Stockholm University, who was not involved in the investigation, described the operate as a breakthrough. “Everything they see recapitulates what you see in nature,” he mentioned.
“They can also do this in rats, which is fairly thrilling,” he added, saying that “the possibility is fairly high” the similar strategy would, theoretically, operate in humans. “We could possibly have some residual skills there. Just before this paper no a single was even considering of how you could experiment with that in protected manner.”