Many animals live longer when raised on low calorie diets. But now researchers at Washington University School of Medicine in St. Louis have shown that they can extend the life spans of roundworms even when the worms are well fed it just takes a chemical that blocks their sense of smell.
Three years ago, the researchers, led by Kerry Kornfeld, M.D., Ph.D., reported they found that a class of anticonvulsant medications made the roundworm Caenorhabditis elegans live longer. But until now, they didn't quite know what the drugs did to give the worms their longevity. They report their latest findings in the Oct. 24 issue of the Public Library of Science Genetics.
"We've learned that the drugs inhibit neurons in the worm's head that sense chemicals in their surroundings the neurons are like the worm's nose," says Kornfeld, professor of developmental biology. "Like roundworms that are grown in a food-scarce environment, the worms exposed to the anticonvulsant ethosuximide lived longer. But these worms ate plenty of food. That suggests that the worms' sensation of food is critical to controlling their metabolism and life span."
If roundworms sense that food is abundant, their metabolism adjusts accordingly. Their bodies respond to promote rapid ingestion, rapid growth and rapid aging, Kornfeld explains. In contrast, when the worms sense a shortage of food, they make "metabolic decisions" to delay growth, delay energy use and extend lifespan.
In the long term, Kornfeld's goal is to identify compounds that could potentially delay human aging. The research group for this project also included James Collins, Ph.D., Kim Evason, M.D., Ph.D., Chris Pickett, Ph.D., and Daniel Schneider.
Kornfeld's lab studies C. elegans because they live only about two to three weeks, so experimental results can be obtained quickly. In addition, the worms' genome has been sequenced and extensively studied.
|Contact: Gwen Ericson|
Washington University School of Medicine