Evidence for Increased Thermogenesis of Mice in Space

Mice have been widely adopted as a model organism for research to study the effects of simulated microgravity on the body. Dr. Russell Turner of Oregon State University is conducting studies to characterize the adaptive responses of mice to sub-thermoneutral housing. In a newly-published paper, Dr. Turner examined the brown (BAT) and white (WAT) adipose tissue of female mice from a 37-day ISS mission and compared them to ground controls. 

Results from analysis of the spaceflight samples provides direct evidence for elevated non-shivering thermogenesis of mice while on the ISS, in spite of comparable housing temperatures between space and ground controls.  

Unlike humans, mice can experience dramatic reductions in core temperature when exposed to temperatures below what is considered to be thermoneutral for them – about 29° -31°C. This is important because increased thermogenesis may exaggerate (e.g., bone loss) or alter (e.g., response to ionizing radiation) physiological responses to spaceflight in mice. 

Because of species specific differences in thermoregulation, this could impact the translatability of the animal studies to astronauts. The article is available online here.