Reach Out
and Touch
Some Worm

It is 1 millimeter long. It lives in dirt. It eats bacteria. And, it just might help Drs. Miriam B. Goodman and Beth Pruitt gather insight on how the sense of touch works. “It” is the roundworm, C. elegans.

C. elegans is a primitive organism commonly used to study sensation. Its nervous system consists of only 302 neurons (compared to the billions of neurons in humans). Despite their simplicity, these tiny creatures can sense their environment by taste, smell, temperature, and touch. In fact, Goodman’s research group recently demonstrated that touch alone can lead to a response of electrical changes in specific C. elegans nerve cells. Viewed on a larger scale, the animal reacts to the force of touch by changing directions. To understand exactly how this happens, Goodman and Pruitt are planning to watch and measure the worms in action. But, before getting started, the interdisciplinary research team needed to develop equipment to precisely “poke” their experimental subjects in a consistent, measurable way. This begs the question, how do you reliably apply force to a squishy, wiggly worm that is practically microscopic?

The answer was to customize a sensitive cantilever system typically used for material science-grade measurements (shown “poking” C. elegans above). Now that an OTL Research Incentive Grant has helped fund the development of this necessary tool, the system can be used to ask and answer even more questions. A few examples are: How is the signal sent from the surface of the animal to the neuron hundreds of microns away? How does the touch response change when certain C. elegans genes are altered or knocked out? What electrical and mechanical changes occur in the worm’s nerve cells during the time it is being poked?

If these questions are answered, the results could be relevant to creatures much more complicated than roundworms. Some of the proteins implicated in the C. elegans touch response have already been identified. There are similar proteins (known as homologs) found in the cells that line the human cardiovascular system. Eventually, the knowledge gained by this research might be applied to help design drugs to treat high blood pressure or diabetes.

Miriam Goodman
Assistant Professor of Molecular & Cellular Physiology
Beth Pruitt
Assistant Professor of Mechanical Engineering
“Biomechanics of Sensory Mechanotransduction” (2003)