No film about interstellar travel is not complete without diving into a deep sleep. “Prometheus”, “Passengers”, everywhere we see the main characters Wake up in the cabins hibernation, restart your fragile physiology from the long stationary state of the fossils, often with the eruption of gastric fluids, i.e. simply by vomiting. This cruel process, apparently, makes sense. In the end, people do not go into hibernation in nature. But a small group of scientists trying to overcome nature and to immerse the person into an artificial hibernation. If successful, they can delay aging, to cure life-threatening illnesses and get us to Mars and beyond.
Last week, a group of experts gathered in New Orleans to explore the possibility of immersing people in “synthetic” hibernation, that is, artificial hibernation. Scientists learn from nature, attempting to understand the factors that lead to hibernation and re-awakening of the animals.
The mystery of hibernation
What could be better to overcome long segments of the life-threatening cold and lack of food, than dip into a deep unconsciousness? A large part of the animal world goes into winter hibernation: bears, squirrels, hedgehogs. Even our cousins of the primates, tolstolistyj lemurs, sharply reduce metabolic rate when food supplies are reduced.
What about us? Although we, unfortunately, do not go into hibernation, some of the “miracles” suggest that metabolic deep freeze can help to save our damaged body for the benefit of the future.
In 1999, the radiologist Anna Bagenholm fell through the ice while skiing in Norway. By the time of the rescue, she was under the ice for over 80 minutes. The General view was that she was clinically dead — no breathing, no pulse. Her body temperature dropped to an unprecedented 13.7 degrees Celsius.
However, when doctors gradually warmed her blood, the body slowly healed. The next day the heart was restarted. Twelve days later she opened her eyes. Eventually she fully recovered.
Case Bagenholm is just one of the tips to ensure that people have the ability to recover from a severely depressed metabolic state. For many years, doctors used therapeutic hypothermia, lowering the body temperature by several degrees within a few days to help patients cope with brain injury or epilepsy in the slow condition.
Rapid cooling helps to preserve the tissue, which was cut off from blood supply, so they require less oxygen to function. In China the experiments were stopping people in a frozen state for up to two weeks.
The promise of therapeutic hypothermia is so great that in 2014, NASA has partnered with SpaceWorks in Atlanta, and provided pre-financing to gubernatoru for space travel mission to Mars.
Although flight in space lasts only a few months, the space astronauts in the inactive state can greatly reduce the necessary amount of food and size of environment. Falling asleep can also prevent serious side effects from low gravity, such as changes in the current of the cerebrospinal fluid, affecting vision. Direct muscle stimulation, which kindly will implement the cradle of hibernation, can prevent muscle loss in zero gravity, and a deep state of unconsciousness can potentially minimize psychological problems such as boredom and loneliness.
The project moved to the second stage of funding, but it left a lot of questions. One of them is that prolonged hypothermia terrible impact on health: there may be blood clots, bleeding, infection, liver failure. In a space ship without sophisticated medical devices, these complications can be fatal.
Another problem is that we do not fully understand what is happening with the animal when it goes into hibernation. It has tried to solve at the conference in New Orleans.
Biological inspiration
Dr. Hannah Carey from the University of Wisconsin believes that the possibility of immersion of people in hibernation must be sought not in medicine, but in nature.
Cary is studying the hibernation habits of ground squirrels, small omnivorous rodent that roams the North American prairies. From late September until may ground squirrel hibernates in underground burrows, surviving the harsh winter.
“The fact that hibernation is possible in the lineage of primates, makes it possible for biomedical discovery, applicable to people,” she says.
One of the interesting observations made by Carey is that a low metabolic rate does not last all winter. Sleeping animals periodically come out of its stupor for half a day, increasing their body temperature to normal levels. However, the animals still would not eat or drink during these periods.
“Initially, sleep was considered a continuation of sleep, but physiologically it is different because your metabolism slows down completely, though, and remains,” says Oxford neuroscientist Dr. Vlad Vyazovskiy, speakers at the conference. “Torpor (daze), this extraordinary metabolic challenge, it seems, does something to the brain or body, combining sleep with recovery.”
Neuroscientists have been trying to collect a full list of benefits of sleep. For example, studies show that sleep helps the brain to clear toxic waste in the lymphatic system and allows you to “reboot” the brain synapses. If sleep by itself leads to a state of sleep deprivation, whether a periodic dip in sleep to help with that?
We don’t know yet. But Cary believes that the results of studies of animals show that in search of human hibernation study biology, natural gubernatorov will give better results than the use of medical practices on the basis of hypothermia, i.e. hypothermia.
Artificial falling asleep
While Cary and vyazovskaya investigate how hibernation helps animals stay healthy, Dr. Matteo serri from the University of Bologna in Italy has chosen a slightly different way: as an artificial way to induce torpor in animals that do not resort to hibernation?
The answer may be hiding in a small group of neurons in the brain region raphe pallidus. Since metabolism slows dramatically during hibernation, hormonal, and brain mechanisms, likely to start this process.
Even in 2013, his team of scientists was one of the first who put the rats into a state of hibernation. Usually these animals do not sleep in the winter. They injected a chemical into raphe pallidus to inhibit the activity of neurons. These neurons normally are involved in the “thermoregulatory protection from the cold,” says Surry, i.e. cause a biological response, opposing the decrease in body temperature.
Then, the rats were placed in a dark, cold room and were fed with a high fat content, as we know, reduces the speed of metabolism.
Off the protective neurons for six hours led to a sharp drop in temperature in the brain of rats. Their heart rhythms and blood pressure slowed and decreased. In the end, the pattern of brain waves began to resemble the pattern of waves of animals in condition of natural sleep.
The interesting thing was that when the researchers stopped the treatment, the rats recovered the following day they had no signs of abnormal behavior.
Previous attempts to call torpor in animals that do not hibernate failed, but in this study it was shown that inhibition of neurons in the raphe pallidus is important for the induction of corporatelogo state.
If these results are confirmed by the example of larger mammals, it then makes sense to go to dive into hibernation people. Serry and others are working on further analysis of the control of the brain over the daze and how to hack it to put the brain into hibernation.
What’s next?
The immersion of a person into a state of hibernation, hibernation, hibernation — call it what you want — is still far from reality. But the results of studies gradually reveal the molecular and neuronal factors that can in theory provide us a deep freeze.
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