Throughout time, people have been fascinated by periodic cicadas. With the longest lifecycle (some up to 17 years) and loudest mating call in the insect world, a vast population in the billions and appetite for fruit and ornamental trees, these pesky but captivating creatures pose some challenging problems in natural history and development. But for scientists at the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), the periodic cicada also offer clues about how high-speed and high- performance muscles work, and how this knowledge might someday make human muscle work better.
NIAMS' Laboratory of Muscle Biology and its Muscle Proteomics and Nanotechnology Section, headed by Kuan Wang, Ph.D., conducts basic research on many aspects of normal and diseased muscles. One of their interests is how superfast muscles in nature can work more than 50 times faster than human muscles. That, says Dr. Wang, is where the cicada comes in. "These periodic cicadas spend 17 years underground and then billions of them come out at the same time to mate and pass their lives to the next generation. The insatiable males attract females and fend off competitors by their mating calls. The fast and furious sound is produced by the rattling of a pair of membranes near their wings with superfast muscles, in much the same way rattlesnakes shake their tails."
When the Magicicada cassini emerged by the billions two summers ago on the East Coast, the researchers took advantage of the rare opportunity. "This was a perfect summer project for 2004. Cicadas were abundantly available near our labs, and our team members are great at dissection, video and audio documentation, and imaging by magnetic resonance and electron microscopy. Everyone was motivated and fascinated by the drama unfolding around us," says Dr.Wang. "Besides documenting the insects' life cycle with some really gorgeous photographs and videos, we found that the tymbal muscle has a special design that allows the muscle to shorten a lot without damaging the motors that drive the muscle."
"To really understand muscle performance, it is important for scientists to look way beyond humans and rodents for sophisticated designs," says Dr. Wang. "These superfast muscles in cicada and elsewhere are the 'Maseratis' of muscle. The question is, 'how do they manage to outperform us?' Can we somehow and someday engineer these features into 'designer muscles' that work faster and stronger and last longer? Can we use this engineered muscle to restore and enhance normal muscle function to people with degenerative muscle diseases?"
These lofty goals, admits Dr. Wang, are many years away. But, he says, "It is time to dream, to plan and to act."
Photo caption: Superfast tymbal muscles of male periodic cicadas (in yellow) generate rapid contractions (up to 50 times per second) that rattle a pair of stiffened tymbal membranes (in red) to emit high-pitch mating calls to attract females.
The mission of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the Department of Health and Human Services' National Institutes of Health, is to support research into the causes, treatment and prevention of arthritis and musculoskeletal and skin diseases; the training of basic and clinical scientists to carry out this research; and the dissemination of information on research progress in these diseases. For more information about NIAMS, call the information clearinghouse at (301) 495-4484 or (877) 22-NIAMS (free call) or visit the NIAMS Web site at http://www.niams.nih.gov
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Nahirney PC et al . What the buzz was all about: superfast song muscles rattle the tymbals of male periodical cicadas. FASEB J. 2006;20:2117-2026.