The study, published online in the July 13 issue of PloS (Public Library of Science) Biology, found that a group of sparrows studied in the laboratory dramatically reduced how long they slept during the time they would ordinarily be migrating. But they were nonetheless able to function and perform normally despite their sleep deprivation. During times when the birds were not migrating, however, sleep deprivation appeared to impair their performance - similar to what happens to sleep-deprived humans.
If researchers ascertain how the birds do so well on so little sleep during migration, the finding could benefit people who need to stay awake and function at a high level for long periods of time, as well as those who suffer from sleep disorders of various kinds. In addition, sleep in the migrating birds was similar to sleep changes that typically occur in humans with depression or bipolar disorder.
"We already know from human studies that people with severe depression and mania show characteristic changes in their sleep patterns, such as having insomnia and entering REM sleep (the dream stage) too quickly after falling asleep," says Ruth Benca, professor of psychiatry at UW Medical School and principal investigator of the study. "Finding this same pattern in the birds offers us an intriguing model for studying mechanisms for seasonal mood disorders, such as bipolar illness."
Benca and her colleagues studied captive white-crowned sparrows, songbirds that normally migrate at night between Alaska and Southern California twice a year. When in captivity in laboratory cages during perio
Contact: Lisa Brunette
University of Wisconsin-Madison