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One on one with… Ed Callaway

Ed Callaway

Ed Callaway can't resist a puzzle. Whether it's perfecting his golf swing, playing poker or trying to unravel the most complicated conundrum in existence—the human brain—Callaway finds bliss in those moments when he's completely immersed in solving a problem. And when it comes to studying the brain, his penchant for puzzles has paid off.

Callaway, a professor in Salk's Systems Neurobiology Laboratories and holder of the Audrey Geisel Chair in Biomedical Science, focuses on deciphering circuits in the cerebral cortex, the brain's outer layer, that process visual information. In one major breakthrough, he developed a way to use a modified rabies virus to trace single connections between neurons. This method and others are used by labs all around the world to map connections related to numerous nervous system functions and diseases such as schizophrenia, autism, Parkinson's and Huntington's.

Inside Salk sat down with Callaway to discuss his work and family, why he retired his putter, and the time he won a big poker pot without even trying.

Your father was an engineer. Did that have anything to do with your career choice?

My father was an electrical engineer and designed the infrared radiometers used on one of NASA's Pioneer spacecraft to explore the solar system. We helped him wrap wire coils around metal rods to make electromagnets for one of his projects. It taught me you could build your own technologies, which is really important for science, because the tools you need to really push the edge often don't exist. We also always had lots of animals in the house when I was a kid: lizards, snakes, hamsters. A hamster once snuck into my sock drawer and had a litter of pups. It was eye opening.

When I was an undergraduate in college learning about the brain and neurons, it struck me that it's really a lot like electrical engineering, that our brains are electrochemical devices. But this living device makes our experience of life possible. I thought, 'Wow. I want to study that.'

You and your wife, Amy Freeman, have three children (Jackson, 25; Perri, 21; and Marin, 19). Did you push them to go into science?

I tried not to bring the work home with me. Perri is studying biology at Barnard, focusing on infectious disease, and she worked in Greg Lemke's lab at Salk when she was home from college last summer. Jackson studied computer science at the University of California, San Diego and now works in San Francisco, and Marin is studying international relations at Stanford. I'm sure I've had some influence, but really they've all chosen their own path. I didn't bring the science home for my own benefit as well. You need to take a break from it. I find that when I take my conscious mind off my research by doing something completely different, my unconscious mind seems to do its best work. That's when I get ideas that are less controlled and more creative.

How do you get your mind off your research?

I took up golf a few years ago and got obsessed with it. It's really hard— kind of like science—so it took all my concentration to learn and improve. I grew up with three brothers, so I've always been very competitive. Golf appealed to me. At one point, though, I realized I'd plateaued at golf and was getting frustrated and the time commitment to get past it was just too much. It was either golf or time spent with my family and in the lab. So one day, I just quit cold turkey. I was a long distance runner and scholarship athlete in college, so after I quit playing golf, I started running again. It's another good way to rest the mind. I also play poker occasionally. There, the challenge is really reading your opponents, which is another kind of puzzle. Once, I was playing with Florian Engert from Harvard and Mike Ehlers who's now at Pfizer and I had a straight flush. I knew there was no hand that could beat me and I told them so. They kept raising me, and I told them, 'Really guys, you don't want to raise me.' But they thought I was bluffing and they just kept going. I won a lot that night.

Science is also very competitive. Does that appeal to you?

Ed Callaway developed a technique for tracing connections between brain cells using a modified virus. The glowing green neurons in these images are connected to each other.
Courtesy of Euiseok Kim

I wouldn't say that it necessarily appeals to me, but it sometimes influences the work. I think it did more so earlier in my career. I'm still competitive, but now it's more about solving the problems I see in front of me. I like a challenge and meeting the challenge often requires a team working together rather than in competition. For example, there's the challenge of running a lab, which means solving the puzzle of funding the lab and really understanding the people I'm working with. If you want to do the best science, you've got to hire the best people. And everybody has their strengths and weaknesses, so figuring out what projects are best for a certain person or who they should work with is really important. Ultimately, if you hire great people, the best thing you can do is get out of their way. For instance, one of my former grad students, Ian Wickersham, played a big part in the viral tracing methods we've developed.

What's most exciting in neuroscience now?

The brain is so complicated, but suddenly we got these incredible tools. The viral tracing technology we developed is helping us map neural circuits at a level of detail that was unthinkable just a few years ago. Optogenetic tools that let us control neural activity with light are another huge advance. The combination of the ability to trace connections between types of neurons and the ability to control them is really powerful. We can now decode how these networks of neurons guide the vast array of very distinct brain functions, as well as determine how dysfunctions in various parts of these networks can lead to different neurological conditions. If we can pinpoint distinct network disruptions in distinct types of diseases, we can significantly improve our understanding of the underlying molecular mechanisms of these diseases— and get even closer to developing solutions for them.