Reindeer shed light on sleep disorders

Tis the season...

Fatigue and health problems suffered by astronauts and shift workers could be better understood with the help of reindeer that live near the North Pole, scientists report today.

A Norwegian team has found that, unlike people, these reindeer have a weak body clock that is almost insensitive to the 24-hour cycle of darkness and light.

Living in the far north, the animals must cope with continuous daylight in the summer and darkness in the winter, so they must resort to other cues if they are to rely on their body clocks.

Prof Karl-Arne Stokkan, of the University of Tromso, and colleagues found by studying two sub-species of reindeer for a year that animals that undergo extremes of darkness and light "clock off".

link to full article...