Solving a long-standing scientific mystery, a team of Tufts scientists figured out how fireflies trigger their flashes

Medford/Somerville, Mass. [07.02.01] -- While researchers had figured out the basics of the firefly's "light bulb," the way the bugs switched it on and off so precisely left scientists in the dark for decades. But new research from a team of Tufts scientists has finally solved the mystery, shedding new light on the chemical trigger that controls the firefly's flash.

   "We knew about the chemistry that makes fireflies light up," Tufts' Barry Trimmer said in a report on the British Broadcasting Corporation. "But we now have the missing piece of the puzzle that explains how they are able to throw the switch on and off."

   The key is nitric oxide, reported the Tufts team in a study published in the June 29th edition of the journal Science.

   Trimmer told CNN that nitric oxide prevents the fireflies from using oxygen, which fuels their cells.

   "The nitric oxide works by throwing a biological switch that keeps oxygen from escaping from the cells inside the lantern. The result is sort of like what happens when you blow air on a dying fire," reported the international news network.

   "Amazingly enough," Trimmer said in an MSNBC article, "it's a temporary cut in the power supply that probably triggers the firefly flash." The nitric oxide, he explained on National Public Radio's All Things Considered, acts as a messenger to the mitochondria found in the fireflies' abdomen.

   While other creatures such as jellyfish and bacteria have the ability to produce light, fireflies are very unique.

   "The firefly's talent for producing precisely timed, rapid bursts of light is quite rare," Tufts' Sara Lewis told the BBC.

   Lewis, a biology professor and an expert on fireflies told the Chicago Tribune, "The fireflies that we study in our work we chose particularly because the have a very precise control of the timing of their flashes and it's very important in their ecology."

   Over 200 species of the insects exist, each one with a distinct flash pattern.

   "The ability to control the timing of the flash is key to their successful courtship," Lewis explained to the Dallas Morning News. "Without it, they'd be lost."

   The short bursts of nitric oxide gas allow the fireflies to control the flicker of their lights -- the key to attracting a mate from the correct species.

   The Tufts findings quickly spread around the world, as newspapers and broadcast news networks from London to India to Chicago and New York reported the work of the Tufts team -- which included Trimmer, Lewis, biologist June Aprille, and Thomas Michel, a cardiologist at Brigham and Women's Hospital.

   "This is a question people have been asking for a long time," Trimmer told the Boston Globe.

   The team's findings are already leading to more questions in the scientific community.

   "Trimmer said the discovery adds to the legend of nitric oxide, a dissolved gas that researchers only in recent years have recognized as an important chemical in the body," reported an article in The New York Times.

   Scientists believe the gas plays a key role in everything from the circulatory system to the heart to the brain.

   "Nitric oxide seems to be turning up in a lot of different places, and this is one of the most unusual places," Lewis told the Dallas Morning News. "It's really a novel finding."

   And the research helps explain more than just fireflies.

   "The Tufts researchers say their new findings may prove important to human medicine," CNN reported. "After all, they say, the nervous system of insects and mammals really aren't that different."

   While they may be tiny insects, Trimmer said, fireflies may hold a key to some of the most complex parts of the human body.

   "When we look for things in insect brains, they are helping to tell us about the way things work in human brains as well," he told CNN.

   And it's always fun to find the answer to a question that had stumped scientists for over 40 years.

   "It was a nice mystery to solve," Trimmer told the Dallas Morning News.