A Neuroscientist Studying the Structure of Dog Brains (Published 2010) (2024)

At his Princeton laboratory, Samuel Wang is searching for basic information on how the brains of humans and dogs work. Dr. Wang, 42, an associate professor at the university, also spends time popularizing breakthroughs in his specialty — neuroscience. His book, “Welcome to Your Brain,” was named 2009 Young Adult Science Book of the Year by the American Association for the Advancement of Science. Next semester, he will offer a first for Princeton: an undergraduate course called “Neuroscience and Everyday Life.” Here is an edited version of a four-hour conversation.

Q. YOU’RE ALMOST EVANGELICAL ABOUT YOUR WORK. WHY DID YOU BECOME A NEUROSCIENTIST?

A. I was at Caltech in 1985, and I took a class in classical mechanics and another in introductory cell biology. And I remember asking this physics instructor about second order corrections in Lagrangian dynamics. He said, “Oh yes, that’s been thought of,” while spewing out a bunch of equations on the blackboard. I then asked my biology instructor a question about neurotransmission. He kind of smirked at me and said, “Nobody knows the answer to that.”

That felt great! It was great to ask a basic question and learn the answer wasn’t known. So neuroscience seemed like the way to go.

Q. AND NOW IS MORE KNOWN?

A. Much more. In the 1980s, we knew some things about how individual neurons, synapses and the brain — or at least regions of it — worked. Today, we have the means to see how they work as a system, together. What has changed is advances in molecular biology, genetics and also technology.

In the 1980s, the best tool for looking at neurocircuitry was to take a piece of removed tissue and look at single neurons. We now can see multiple neurons, and we can actually see how the cells talk to one another. Functional magnetic resonance imaging, F.M.R.I., lets you see what’s happening on the whole brain level. In the last three years, we’ve gotten connectomics, where people are taking a bit of tissue and mapping every connection in it. And there’s optogenetics — I’m doing a lot of that — where you express some fluorescent protein in some tissue that allows us to see individual cells and watch the change.

The other day, I went to a psychology lecture and I could see how I could turn what I’d just heard into an experiment. This colleague was working on decision-making and he’d theorized that it is guided, in part, by the release of dopamine. So I told him, “We can make dopamine go up very suddenly in the neurocircuitry — we can emulate that little release of chemicals in the dish.” So that means it’s possible to work out these theoretical ideas in the lab. People 30 years ago in neuroscience were smart, but they didn’t have the instrumentation to test their ideas. That’s only become possible in the last 10 years. And it’s a very different feeling.

Q. IS YOUR LAB DEVELOPING ANY OF THIS NEW TECHNOLOGY?

A. Yes. We are developing ways to look into brain tissue while it is thinking. The tools are optical, like the microscopes I build to observe and manipulate synapse function. In my lab, we can tickle different parts of a circuit tens of thousands of times a second. That’s close to emulating real brain function.

Q. YOU ARE STUDYING THE STRUCTURE OF DOG BRAINS. HOW DID THAT PROJECT BEGIN?

A. My wife and I took our pet pug for spinal surgery. At the vet’s office, there were all these M.R.I.’s sitting around, hundreds of them, and it struck me: “Hey, dogs aren’t covered by Hipaa! Their records aren’t confidential!”

It was like discovering a goldmine of data. We’ve since gotten all these veterinarians on Long Island and in Maryland to donate M.R.I.’s, and we have this huge database. We’re looking for relationships between dog brain size and dog breed characteristics. Australian sheep dogs and poodles can do fairly complex tasks. My pug, he’s very sweet, but he’s not the brightest.

There’s actually a lot of scientific literature on breed characteristics, intelligence and temperament. So we check all these M.R.I.’s against these studies, and we’re trying to find structural correlates. This is a huge opportunity to look at the relationship between brain structure and behavior. We’re asking, Do we find a larger cortex — the part of the brain that’s involved in problem solving and intelligence — in those breeds that are good in problem solving? Or, Could we find a larger amygdala, which is related to emotional responses, in dogs that are known to be high strung or nasty?

Q. ARE THERE IMPLICATIONS FOR HUMANS IN THIS?

A. That’s not clear yet. Dogs are much more variable than we are. Dogs can vary by a factor of 60 in body mass and a factor of 3 in brain size. This kind of variation is not something you commonly run across in humans. Compared with dogs, we’re all alike. There’s no striking difference between Einstein’s brain compared to that of non-Einsteins.

Q. YOU SAY THAT FUNCTIONAL MAGNETIC RESONANCE IMAGING HAS CHANGED BRAIN RESEARCH. DO YOU FIND THAT SOME RESEARCHERS ARE OVERINTERPRETING IT?

A. For some, it’s the new phrenology. There was a piece in one of the newspapers where someone was claiming that he could tell the difference between a liberal and conservative from F.M.R.I. It made me want to scream. The study was done on very small numbers of people and told us next to nothing about the mental process underlying how we form political opinions.

Q. WHEN YOU TELL PEOPLE YOU MEET AT PARTIES ABOUT YOUR WORK, WHAT DO THEY SAY?

A. They are very interested. There’s a lot of fascination with neuroscience because the brain determines who we are. The problem is that they’ve got all these myths. The most common one is we only use 10 percent of our brain. This began with Dale Carnegie, the father of the self-help movement, but it’s completely untrue. The proof is that if any one part of the brain is damaged, there’s usually a serious symptom. If you’d cut out 5 percent, it would be terrible. The second thing they want to know is if doing Sudoku will help them maintain mental fitness. I have to tell them, no, but doing physical exercise might. Then, they want to know if playing Mozart to babies makes them smarter. I tell them that babies are very good at learning from their environment, but Mozart appreciation comes later.

Q. GOING BACK TO YOUR YOUTHFUL DECISION TO ABANDON PHYSICS AND TAKE UP NEUROSCIENCE: ANY REGRETS?

A. Never. My parents, who were immigrants, didn’t understand it at the time. My father’s proud of me now. But my mother really wanted me to be an M.D. Even after I got a Ph.D., she still wanted that. She once sent me a brochure about a medical school in the Caribbean where I could become an M.D. in a year. My mother died a few years ago. I cannot remember ever being able to adequately explain to her what I do. That has a little to do with why I wrote, “Welcome to Your Brain.” I wanted to show how neuroscience speaks to everyday life.