David DiGregorio is conducting his PhD research in neuroscience in a laboratory that does not explicitly study neurons. His adviser and mentor, Dr. Julio Vergara, is a biophysicist whose primary research is in muscle physiology. What the two had in common was calcium.

David had become interested in calcium during a post-college year working at Genentech, the biotechnology firm in South San Francisco. There, he had helped measure calcium inside lymphocyte cells. He learned that calcium is so essential to the body's functions that the body will actually deconstruct the skeleton to get what it needs. "They say taking calcium is for your bones, but in reality, it's necessary for many other cellular process in your body," he says.

Dr. Vergara, in the course of studying changes in the amount of calcium inside muscle cells, had developed a new way to do the measuring that was fast enough to suit the millisecond time scale of the synaptic transmitters that carry messages between cells. He suggested that David might apply those measuring techniques to communications between nerve cells and muscle cells. The resulting work was the first in the world to measure calcium changes so quickly and at the level of the single nerve cell.

Facilitating this combination of interests and resources was the fact the David's chosen field, neuroscience, is an Interdepartmental Program (IDP) at UCLA, a degree-granting structure that makes more than 150 faculty across campus available as mentors for graduate research. Like other graduate students, David began with a year of course work and exposure to a number of labs in rotation. During that process, he met Dr. Francisco Bezanilla, another biophysicist, who introduced him to Dr. Vergara, a fellow Chilean.

Besides their interest in calcium, Dr. Vergara and David also shared a preference for using the methods of physics and engineering to examine questions that involve biology. During his undergraduate work at Stanford University, David had proceeded from mechanical engineering to chemical engineering to biology. By his senior year, he knew that he wanted to do biophysics.

In his dissertation research, David worked with frog nerve and muscle cells isolated in a laboratory dish. Using a glass pipette, he was able to introduce into the cell molecules that give off light when they bind to calcium, allowing him to measure its presence during different cell activities. The calcium gives a signal to releases neurotransmitters, which initiate an electrical signal to a muscle cell or another nerve cell.

David's measurement technique attracted the attention of Dr. Angus Silver, who does synaptic physiology at the University College of London. As a result, David will work there as a postdoctoral fellow, applying his knowledge to the study of calcium in the brain's cerebellum, the part that is responsible for integrating movement. "It's going to be a nice stepping stone," says David, who is considering that this aspect of brain research might be built into a career.

The first stepping stone in David's career path was one of his teachers at Silver Creek High School in San Jose. Mr. Okuda's advanced placement biology class was "the best course I took in high school," David says. Mr. Okuda was "inspiring yet very accurate and knowledgeable in his approach to teaching biology, and for whatever reason, I just latched onto it."

It seemed that people were always assuming David would become a medical doctor. In fact, he came to UCLA in the Medical Scientist Training Program that would have resulted in an MD as well as a PhD. However, he'd been drawn to UCLA by the excellence of the neuroscience program, and eventually, he decided to focus on the science alone. Still, he has completed two years of classroom work toward an MD, and thus, he hopes to be "a more medicine-sensitive scientist." Eventually, he hopes to find a position within the research/teaching faculty at a medical school.

His outlook should be bright. This year, David was one of two students both from neuroscience who were honored by the UCLA Alumi Association as Outstanding Graduate Students. The awards were presented at a black-tie gala, David says: " It was a lot of fuss for a scientist. I'm not used to that kind of attention."

Published in Fall 1999, Graduate Quarterly