Researchers will gather today to discuss the potential for hibernation and the related process, torpor, to aid human health in spaceflight at the American Physiological Society (APS) Comparative Physiology: Complexity and Integration conference in New Orleans.

Astronauts Benefits

Humans do not naturally undergo torpor, but scientists are interested in the idea of producing states of "synthetic" torpor in certain situations, including spaceflight. The symposium will explore how synthetic torpor might be induced by the brain, its similarities, and differences to sleep, and how it could benefit astronauts

Studying hibernation in mammals-how are they able to safely lower their body temperature and metabolism for extended periods of time may also aid treatment of people experiencing traumatic medical events, such as stroke, cardiac arrest, and severe blood loss.

How the nervous system reduces metabolic activity during torpor is unknown. However, many of the organs that regulate metabolism are controlled by nerve cells (neurons) located in the raphe pallidus, an area of the brainstem that controls the production of heat in mammals.

For an animal to enter torpor, the neurons within the raphe pallidus have to be inhibited. If a function in these cells is not suppressed, "their activity would counteract the hypothermia induced by torpor.

Neuronal Connections

Cerri will present preliminary results identifying neurons projecting to the raphe pallidus and involved in the torpor-related activity. Defining the relationship between sleep and torpor has been fraught with controversy, but the two states appear to be intimately linked Because of the neuronal connections they share.

Research suggests that a lack of available food sources may cause mammals to conserve energy and lower their body temperature, two hallmark characteristics of torpor.

 However, "less is known about the specific fasting-related signals which initiate entry into torpor.  He will discuss the connection between sleep and torpor and why more research is needed to determine how torpor affects brain function in animals.

Some of the physiological adaptations that animals exhibit-such as the low-oxygen environments that seals and penguins experience with deep diving or that birds experience at a high-altitude flight-are impossible for humans. Understanding how animals adapted to extreme conditions may positive play a role in human medical science, especially in the "extreme environment of space.

The increasingly real possibility of traveling to Mars-once just a science fiction story emphasizes the need to resolve factors that have hampered the feasibility of long-duration spaceflight, including having an ample supply of food, water, and breathable air.

Finding a way to induce torpor in humans could help eliminate limiting factors as well as protect astronauts from harmful radiation. Meir '  human spaceflight