Better Aging through Brain Chemistry: Serotonin and Dopamine Accompany Worms' Life Span Extension

Article excerpt

It's no eternal youth, but worms on a very low-calorie diet produce high levels of certain neural chemicals even as they age. These chemicals may be key to longer, healthy lives, a new study suggests.

Unlike their normal counterparts, worms with a genetic mutation that makes them eat less maintain high levels of serotonin and dopamine as they get older, scientists report in the March 12 Journal of Neuroscience. But calorie restriction wasn't necessary to get some benefits: Extra serotonin on its own seemed to provide behavioral improvements and a modest life span boost.

It's too early to say whether the results hold true for other animals, but there are hints that some aspects of the brain's serotonin and dopamine machinery go awry in people as the years advance.

The worm results may help clarify which physiological changes can actually influence the aging process and which are just along for the ride, says geneticist Michael Petrascheck of the Scripps Research Institute in La Jolla, Calif. "The question is, 'Which ones really do matter?'" The new study suggests that in some cases, these brain chemicals maybe important, he says.

Researchers led by Shi-Qing Cai of the Chinese Academy of Sciences in Shanghai noticed that in the roundworm Caenorhabditis elegans, old age came with diminished levels of serotonin and dopamine. These neurotransmitters help neurons send signals, some of which involve mood, pleasure, movement and eating. But a similar decline wasn't present in the worms that carried a mutation making them inefficient eaters. (The mutation, in the eat-2 gene, extended worm life span by about 50 percent in previous experiments. …