In science fiction, space crews are frequently spared the boredom and inconvenience of lengthy-distance space travel by becoming placed into a state of suspended animation. Now this purpose may perhaps have come a step closer immediately after scientists showed that hibernation can be artificially triggered in rodents working with ultrasonic pulses.

The advance is noticed as considerable since the strategy was successful in rats – animals that do not naturally hibernate. This raises the prospect that humans may perhaps 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 perform.

The group initially identified a particular group of neurons in a deep brain area named the hypothalamus preoptic location, which have been located to be involved in regulating physique temperature and metabolism for the duration of hibernation. They showed that, in mice, these neurons could be artificially activated working with ultrasound, delivered non-invasively by way of a helmet.

When stimulated, the mice showed a drop in physique temperature of about 3C for about 1 hour. The mice’s metabolism also shifted from working with each carbohydrates and fat for power to only fat, a crucial function of torpor, and their heart prices fell by about 47%, all even though at space temperature.

The scientists also created an automatic closed-loop feedback method 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 method was switched off, they woke up once again.

The experiments, described in the journal Nature Metabolism, showed that the exact same device worked in rats, which had a 1C drop in core physique temperature when the exact same 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 acquire crucial time for treating life-threatening situations such as heart attack and stroke. “By extending the window for health-related intervention, this strategy presents promising prospects for enhancing patients’ probabilities of survival,” mentioned Chen. “Additionally, the non-invasive nature of the strategy opens the possibility of establishing wearable ultrasound devices, such as helmets, for straightforward access in emergency scenarios.”

Prof Martin Jastroch, of Stockholm University, who was not involved in the analysis, described the perform as a breakthrough. “Everything they see recapitulates what you see in nature,” he mentioned.

“They can also do this in rats, which is really thrilling,” he added, saying that “the likelihood is really high” the exact same strategy would, theoretically, perform in humans. “We may well have some residual skills there. Prior to this paper no 1 was even considering of how you could experiment with that in protected manner.”