WILL HUMAN HIBERNATION EVER HAPPEN?

Is long-term suspended animation possible? Humans may soon be held at death’s door for a few hours (see main story), but what about more lengthy “human hibernation”? Clues could be found in our genes. The fat-tailed dwarf lemur (see picture) is the only primate known to hibernate. Its brain might hold clues to the genetic mechanisms behind such metabolic flexibility. Kathrin Dausmann at the University of Hamburg, Germany, who made the discovery with her colleagues in 2004, reckons that humans may have the genes to hibernate, but we just don’t  switch them on (New Scientist, 21 January 2006, p 28). Chemicals could also help slow metabolism. Mark Roth at the Fred Hutchinson Cancer Research Center in Seattle, Washington, and his colleagues have used hydrogen sulphide to put mice into suspended animation for 6 hours. The gas slows the metabolism by limiting oxygen uptake by cells. They are now studying a metabolism-decreasing chemical found naturally in the body. It may all be down to economics, says Peter Rhee at the University of Arizona. “When I was in medical school, 5 minutes of brain death and you were dead. Now we can increase that to hours. With the time and money, maybe we could start to think about extending [suspended animation] to months and years".