NASA wants to send humans to Mars within the next decade, and to keep them healthy during the trip, the agency will have a lot to learn from bats. New discoveries may have taken the first step.
People can’t hibernate for a few reasons. Above all, our body cannot store enough fat without harming yourself, functioning with such low levels of energy and brain activity, or surviving a massive drop in body temperature, explains .
There are several species of animals that hibernate, but bats are easy to study because they are small (at least when we compare them to bears, for example), as pointed out Gerald Kerth, zoologist at the University of Greifswald, Germany.
When it’s cold, bat cells change drastically, allowing the animal’s body to optimize oxygen and survive the weather. For a trip to Mars, it would be ideal if humans could do it too.
It was with this motivation in mind that Kerth and his team carried out a publication published in October in Proceedings of the National Academy of Sciences.
In the forests near the University of Greifswald laboratory, scientists captured 35 wild greater tree bats, that hibernate in large colonies. Before releasing them again, they picked the animals’ blood in the laboratory.
They also collected blood from Egyptian fruit bats who live at the Friedrich Loeffler Institute, an animal disease research center. Finally, they obtained blood from a registry of human blood. In total, the study authors gathered more than half a million red blood cells between the three species.
They then placed white blood cells from the three species in contact with different temperatures. As the cold increased, both bats’ and humans’ red blood cells became thicker and more rigid, but only the bats’ red blood cells became significantly thicker in relation to its rigidity.
“As far as I know, there has never been such a detailed comparison between human and bat red blood cells,” says Kerth.
Contrary to what happened with bat globules, the ratio of thickness to stiffness of human red blood cells remained.
The study authors now hypothesize that these more resistant bat cells provide a great benefit: by remaining in the lung capillaries and muscles for longer at low temperatures, the modified cells can increase the absorption and distribution of oxygen throughout the body.
These discoveries constitute “one of many pieces of the puzzle on the path to torpor in humans”, says the molecular biologist who researches space medicine Marcus Kruger, but “many important questions remain unanswered, notably how to induce hibernation in humans. Is this something we can do through fat accumulation, food deprivation, pharmacological support?”
There are other obstacles that need to be overcome to get to Mars, such as supplies: around 70 shuttles would be needed to transport the necessary food and fuel to keep people alive on the trip to Mars and back.
Despite all this, Mikkael A. Sekeresa hematologist at the University of Miami, says this study takes a big step forward in terms of possibility of human hibernation.
He says the research “has implications for the fact that humans can enter a state of torpor for prolonged periods — with the hope of a better outcome than that of the hapless astronauts in the Alien film series.”
