Narrator: This is Science Today. Those who have experienced jet lag know the symptoms, including fatigue and forgetfulness. While travelers usually recover from this disruption of their internal clock fairly quickly, researchers have found that the symptoms persist in those who are chronically exposed, such as pilots and night-shift workers. Psychology professor Lance Kriegsfeld of the University of California, Berkeley, says their studies in the lab indicate that the brain structure actually changes from chronic jet lag.
Kriegsfeld: We don't know what the mechanism that leads from jet lag to changes in neurogensis. There's a couple of hypotheses that we're exploring, one being that we know that neurons within the hippocampus have their own circadian clocks and it's thought that when you disrupt the whole body clock that you also disrupt the cellular clock in these neurons that are developing. And that's important for cellular metabolism and growth and we think that disrupting the clock in these individual cells as they're maturing and growing and being incorporated into the adult brain is disrupted by jet lag.
Narrator: For Science Today, I'm Larissa Branin.