Brain Food: Spring-Loaded Muscles

Jan 16, 2014

A Northern Arizona University regents’ biology professor is studying how the speed with which frogs catch insects can improve the mechanics of artificial limbs for humans. Kiisa Nishikawa has discovered the connection is a protein called titin. It essentially enables muscles to “think,” reacting in milliseconds, rather than waiting for a signal from the brain.

Regents' Professor Kiisa Nishikawa with her former post-doc Ted Uyeno, now a professor at Valdosta State University.
Credit Danielle Borth, NAU Office of Public Affairs

“So, the interesting thing about frogs is that they extend their tongues to catch bugs, and they do this extremely rapidly,” Nishikawa says. “And so what happens in the example of the frog is a nice one that shows the interplay between brain control movement and muscle control of movement, which is sometimes called a preflex, in contrast to a reflex because it occurs earlier in time.”

Nishikawa says this reaction spring-loads muscles for quick response time. In her lab at NAU, engineers have built a model that mimics the titin-like properties of muscle. Nishikawa explains this discovery holds great promise in the field of neuroscience and in the development of smarter prosthetics.

“It seems intuitive, I think, to say that if we could make a prosthesis that would work more like a muscle, our brain would expect it to function like a muscle that this would be more comfortable and potentially more maneuverable, it wouldn’t lead to osteoarthritis and some of the other problems that day after day, year after year use of current prosthetic devices does,” Nishikawa says.

Nishikawa hopes this new understanding of muscle function will inspire a new generation of biomedical devices that could power prosthetics or even stimulate paralyzed muscles.