Hibernating black bears suggest new paths for tissue preservation

Some mammals have an attractive solution for coping with long winters—sleep through them. Black bears (Ursus americanus) for example can hibernate for five to seven months of the year, going without food and water or the light of day.

Fat loss and perhaps a little grogginess aside, when they emerge from their dens in the springtime, the bears seem no worse for the wear. The secrets to their successful hibernation, in which bone and muscle mass remain intact despite long periods of nonuse, have eluded scientists, who had trouble consistently monitoring the large animals in naturalistic conditions.

A new study offers insights into this metabolic limbo that might eventually prove medically useful in preserving human tissue after trauma or during long periods of inactivity (by decreasing energy and oxygen demands) if scientists can find the genetic pathways responsible for these shifts. "We simply need to learn how to turn things on and off to induce state that take advantage of the different levels of hibernation," Øivind Tøien, of the Institute of Arctic Biology at the University of Alaska Fairbanks and co-author of the new study, said in a prepared statement.