Researchers at Ohio State University and their colleagues found that the hamsters had higher levels of certain immune cells in their bloodstream during the short days of winter. In addition, during acute stress, hamsters kept in winter-like conditions launched a more vigorous immune response in preparation for potential injury or infection.
Hamsters take a cue from the decreasing length of days as winter approaches as a signal to boost their immune function, according to the study, which will be published in the March 19 edition of the Proceedings of the National Academy of Sciences.
"Our results suggest that Siberian hamsters are prepared to mount a greater and more rapid immune response during short days compared to long days because that may be a more efficient strategy for survival," said Firdaus Dhabhar, co-author of the study and assistant professor of oral biology and molecular virology, immunology and medical genetics at Ohio State University.
The results also suggest that
short periods of stress may
actually enhance immune
responses, Dhabhar said, even
Contact: Firdaus Dhabhar
Ohio State University