A molecular timekeeper called vasopressin steadies the rhythm of the body’s daily cycles and may hamper acclimatization to new time zones. Mice rapidly recover from a laboratory form of jet lag when researchers block the hormone in the brain, a new study shows.
Fluctuations in physiology and behavior move to the beat of the circadian clock. Crossing time zones or working night shifts throws the body out of sync, leading to sleep and digestive problems, says neuroscientist Hitoshi Okamura of Kyoto University, who led the study. “When we face this situation,” he says, “we are forced to suffer.”