Thirteen-lined ground squirrelCOURTESY OF THE GRACHEVA LABFor animals to hibernate, they must somehow avoid typical responses to cold temperatures, such as shivering and moving to warm up. According to a study published today (December 19) in Cell Reports, two hibernating mammals, Syrian hamsters (Mesocricetus auratus) and thirteen-lined ground squirrels (Ictidomys tridecemlineatus), have evolved changes in a cold-activated ion channel that makes it—and thus the rodents—less sensitive to cold than its counterpart in mice and rats, which do not hibernate.
This study “goes a long way to explain how [animals] can accommodate living in extremes,” says Mark Hoon, a neuroscientist at the National Institutes of Health who was not involved in the work. “They’ve basically switched off noxious responses to the cold that most mammals have.”
Syrian hamsters are native to northern Syria and thirteen-lined ground squirrels to Wisconsin, both chilly climates. “We’re trying to understand the molecular strategies that these animals employ in order to survive harsh environments during prolonged periods of cold exposure,” coauthor Elena Gracheva of Yale University tells The Scientist.
Gracheva and colleagues tested the animals’ temperature preference by putting them in an arena where the floor was made of two temperature-controlled plates, one warm and one cooler. While mice always ...
