Photo by John Abbott
To understand the workings of an enormously complex brain, it’s sometimes best to look at a simpler one. Rudy Behnia, whose research centers on vision, studies fruit flies for just that reason.
“The human brain is very complicated, it has about 86 billion neurons and a large portion of them are active at any given moment,” said Behnia, an assistant professor of neuroscience and a principal investigator at Columbia’s Mortimer B. Zuckerman Mind Brain Behavior Institute. “The fly has between 100,000 and 150,000 neurons, an order of magnitude that is more manageable to try to fully understand.”
Her research is aimed at exploring how brains process and interpret information from the eyes. She is most interested in motion and color perception, and tries to tease out how the brain interprets whether something is moving and what color it is.
Sixty to 70 percent of a fruit fly’s neurons are devoted to vision. Using powerful genetic tools available in flies, it’s possible to identify, mark, activate and deactivate specific neurons to see what happens in the neural circuit and to the flies’ behavior. Despite obvious differences between fruit flies and humans, there are enough similarities in their visual systems to provide insight into how the human brain operates and what it is capable of.
“Learning how the fly does it is going to give us insight into how we do it,” Behnia said. Behnia, who was born in France and earned her undergraduate and master’s degrees in Paris, came to Columbia in 2015 with a Ph.D. from the University of Cambridge in the U.K. and a post-doc spent at New York University. “The Zuckerman Mind Brain Behavior Institute was a big draw,” she said. “The people who built this have a vision of what neuroscience research can and should be.”
Behnia never planned to be a neuroscientist. Her Ph.D. is in cell and molecular biology, based on work with yeast, a single-cell organism. But as she was completing her doctorate she became fascinated by the technological advances in neuroscience, such as the ability to look under a microscope at the activity of neurons in a living animal.
As she read more about neuroscience, she came across a paper by Columbia University Professor Richard Axel, whose groundbreaking research on the olfactory system won him the Nobel Prize in Physiology and Medicine in 2004. That deepened her interest in the study of sensory perception.
“Whether we work on smell, on taste or on vision, the fundamental principles are shared,” she said. Axel is now one of three co-directors of the Zuckerman Institute. “I wanted a change, I wanted to learn new things,” Behnia recalled. “Brain science was a field that was booming.”
At NYU, she worked with Professor Claude Desplan, whose research is focused on how neurons develop in the brain, and how they form the visual system. She wanted to go further, to understand how, after these neurons are developed, an animal uses information from the eye to be able to see things relevant to its life.
Fruit flies can see ultra-violet light, for example, but humans can’t. “Presumably this is because seeing in the UV spectrum is useful to flies and not to us,” Behnia said. Indeed, the boundaries of an animal’s sensory perceptions depend on the evolutionary advantages they provide. Bees also see UV light, which helps them to see patterns in flowers and to find food. Similarly, bats can hear very high-frequency sounds, which they use for echolocation; some snakes can sense heat, helping them detect prey in the dark.
Behnia, whose current office and lab are in the Northwest Corner Building on the Morningside campus, will move into the Jerome L. Greene Science Center on the new Manhattanville campus, alongside colleagues in a diversity of fields ranging from chemistry and biomedical engineering to theoretical neuroscience. She appreciates that colleagues working in different disciplines in the same building may encourage her to explore something she wouldn’t otherwise have considered. She is already in touch with teams building microscopes and other instrumentation that she uses in her research.
“It’s not just good for me, it will be great for my students,” she said. “They are going to benefit from being around all these talented and creative people. The Zuckerman Institute is really a place to train the next generation of scientists.”
—By Georgette Jasen