Hibernation in mice: Are humans next?

June 12, 2020

Tsukuba Japan -- In Sci-Fi movies, astronauts often enter an inactive state in "hibernation chambers" to cross the vastness of space. This could cut down on the required amount of food and oxygen and to prevent serious side effects from low gravity, such as muscle wasting in zero-G condition. A state of unconsciousness could also potentially minimize psychological challenges in space. Could humans hibernate in the future?

Why do some animals hibernate while others do not? Do all animals have the potential to hibernate even if they never do so in nature? Researchers from the University of Tsukuba in Japan opened the door to answering these questions by finding specific cells in the mouse brain that can trigger a hibernation-like state when activated. The study was published in the scientific journal Nature.

Animals usually enter hibernation when food becomes scarce in the winter. Their metabolism slows down, and their body temperature drops to a new set-point. This is like lowering the temperature on your thermostat in the winter--it reduces the amount of energy needed to maintain the body. Along with a slower metabolism and a new set-point comes slower heart rate, weaker breathing, and less brain activity. Importantly, when animals come out of hibernation, their body and organs are healthy, even if they have lost a little weight.

Even though mice do not hibernate, researchers led by Takeshi Sakurai at the University of Tsukuba and Genshiro Sunagawa at the RIKEN Center for Biosystems Dynamics Research show that activating a specific type of cell in the mouse brain--dubbed Q neurons--caused them to enter a hibernation-like state for several days. "The mice exhibited distinctive qualities that met the criteria for hibernation," notes Sakurai. "In particular, the body temperature set-point lowered from about 96.8°F [36°C] to about 81°F [27°C], and the body functioned normally to maintain a lower body temperature around 22°C, even when the surrounding ambient temperature was dramatically reduced." The mice also showed all the signs of a reduced metabolism that are common during hibernation, including reduced heart rate, oxygen consumption, and respiration.

Being able to send mice into a hibernation-like state for days simply by artificially exciting Q neurons was somewhat unexpected. "Even more surprising," says first author Tohru Takahashi, "is that we were able to induce a similar hypometabolic state in rats, a species that neither hibernates nor has daily torpor." Although we do not know the answer yet, the possibility that humans also have Q neurons that can be used to induce a similar state is tantalizing.

"People might not want to hibernate for the same reasons as animals," explains Sunagawa. "But there are medical reasons for wanting to place people in suspended animation, such as during emergency transport or critically ill conditions as in severe pneumonia, when the demand for oxygen cannot meet the supply."

Sparing oxygen is not only for medicine. "In the future," Sakurai added, "we may put human in a hibernation-like state for missions to Mars and beyond."
-end-


University of Tsukuba

Related Hibernation Articles from Brightsurf:

Generational shifts help migratory bats keep pace with global warming
An international team of scientists led by the Leibniz Institute for Zoo and Wildlife Research demonstrated that in the common noctule bat, one of the largest European bat species, the colonization of hibernacula progresses from lower to higher latitudes over successive generations of young animals - especially first-year males.

Evidence of hibernation-like state in Antarctic animal
Among the many winter survival strategies in the animal world, hibernation is one of the most common.

Fossil evidence of 'hibernation-like' state in 250-million-year-old Antarctic animal
University of Washington scientists report evidence of a hibernation-like state in Lystrosaurus, an animal that lived in Antarctica during the Early Triassic, some 250 million years ago.

Hibernation in mice: Are humans next?
University of Tsukuba and RIKEN researchers identified cells in the brain that can induce a hibernation-like state in mice or rats, species that do not naturally hibernate.

Neuroscientists discover neural circuits that control hibernation-like behaviors in mice
Harvard Medical School neuroscientists have discovered a population of neurons in the hypothalamus that controls hibernation-like behavior, or torpor, in mice, revealing for the first time the neural circuits that regulate this state.

First genetic evidence of resistance in some bats to white-nose syndrome, a devastating fungal disease
A new study from University of Michigan biologists presents the first genetic evidence of resistance in some bats to white-nose syndrome, a deadly fungal disease that has decimated some North American bat populations.

Learning from the bears
Grizzly bears spend many months in hibernation, but their muscles do not suffer from the lack of movement.

Solution of the high-resolution crystal structure of stress proteins from Staphylococcus
One of the main factors favoring a microorganism's survival in extreme conditions is preserving ribosomes -- a macromolecular complex comprising RNA and proteins

WSU grizzly research reveals remarkable genetic regulation during hibernation
New RNA sequencing-based genetic research conducted at Washington State University's Bear Research, Education, and Conservation Center shows grizzlies express a larger number of genes in preparation for, and during hibernation to cope with such stressors, than do any other species studied.

Beware of sleeping queens underfoot this spring
Scientists at Queen Mary University of London have discovered a never before reported behaviour of queen bumblebees.

Read More: Hibernation News and Hibernation Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.