Most people feel exhausted and disoriented after they travel quickly across several time zones. Not a problem for Giles Duffield’s special mice.
When the assistant professor of biological sciences subjected genetically engineered mice to the equivalent of a 10-hour flight from Athens to Los Angeles, they recovered twice as fast as regular mice.Duffield and his colleagues from Dartmouth Medical School and the Norris Cotton Cancer Center chemically knocked out the so-called “Inhibitor of DNA Binding 2” gene (Id2). When the researchers mimicked travel through several time zones by altering the rodents’ day/night light periods, they found the engineered mice were up and running normally within two days of their “trip.” Regular mice, in contrast, took five days to return to normal.
The researchers surmise that the Id2 gene plays a role in regulating the brain’s “bio-clock” response to light, synchronizing the body’s circadian rhythms with the outside world. In response to the day/night rhythm, the brain, through a structure in the hypothalamus known as the suprachiasmatic nucleus, sends signals to the body’s tissues to keep them in sync. When body and brain get out of phase, such as through rapid travel, the discomfort of jet lag results.
Duffield believes his work may provide a drug treatment target to alleviate the disorienting exhaustion of air travel. However, the ND assistant professor cautions that any drug therapy suppressing the jet-lag gene must be designed carefully, since the Id2 gene also is involved in early development.
John Monczunski is an associate editor of Notre Dame Magazine.