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Scent Sensations: Pitt Alum Nathan Urban Makes Headlines with Revealing Olfactory Research

Photo of Nathan Urban

You’re approaching your house, and a smell hits you before you even open the front door—dinner’s cooking. A second later, you’re in the entry, and the smell is stronger here. In another moment, you realize what it is. Fried chicken is on the menu tonight, and it smells tasty.

All of this has taken place in the space of a few seconds; a few seconds during which the neurons in an area of the brain called the olfactory bulb are firing rapidly. According to research by Pitt alum and Carnegie Mellon Associate Professor Nathan Urban, the brain makes short work of the incoming signals from these wildly firing neurons through a mechanism called dynamic connectivity.

Urban and a team of other researchers from the Center for the Neural Basis of Cognition (CNBC)—an innovative joint Pitt-CMU collaboration—have identified dynamic connectivity as a process where neuronal circuits are rewired on the fly in order to allow stimuli to be more accurately sensed. This was big news in their field; scientists had previously thought connections made by olfactory neurons were dictated by anatomy and changed slowly. The insights made by the CNBC team were published in the January 2008 issue of Nature Neuroscience.

“If you think of the brain like a computer, then the connections between neurons are like the software that the brain is running,” explains Urban. “Our work shows that this biological software is changed rapidly as a function of the kind of input that the system receives.”

Choosing a Path Less Traveled

When Nathan Urban first entered Pitt as a freshman, he planned to be an engineer. But he got the idea that he’d like to take a neuroscience class. The only problem? It wasn’t a course intended for freshmen. Not deterred, Urban sought out the class professor and got permission to register.

“I was very excited by that course. It was a career-altering event,” recalls Urban. “It became very clear that this was a relatively new, emerging field—and one in which the most fundamental questions were still unanswered. In a physics or math course, to get to the point to ask the pressing research questions of the day, you’d have to be a senior. In neuroscience, which is a young field, we were talking about active research questions in that first course.”

Urban switched his major and, in 1991, earned a Bachelor of Science degree in both neuroscience and mathematics and philosophy from the University of Pittsburgh. After graduation, he secured one of the coveted few Rhodes Scholarships, which allowed him to study mathematics and philosophy with some of the field’s great scholars at Oxford University in England. Two years and a Bachelor of Arts in mathematics and philosophy later, he returned to the United States, and Pittsburgh—this time to pursue his PhD in neuroscience.

From 1993 to 1998, Urban studied under advisor and Pitt professor Germán Barrionuevo. After completing his doctorate, Urban did what most newly minted PhDs do—he sought out a fellowship. Again, determined to work with the best, he secured a post-doc with 1991 Nobel Prize in Medicine winner Bert Sakmann at the prestigious Max-Planck Institute for Medical Research in Heidelberg, Germany.

“The diversity of the backgrounds and interests of people in the lab made a compelling case for me. It was an environment where I could learn a lot from the people there,” Urban says. “It was a great experience, both professionally and culturally.”

Coming Full Circle

When Urban returned from Germany, he joined the faculty in Carnegie Mellon’s Department of Biological Sciences. He’s maintained an active neuroscience research lab in addition to teaching both undergrad and graduate neuroscience courses. Urban has also kept his ties to Pitt strong, with an adjunct associate professor appointment through the CNBC, as well as ongoing joint research endeavors with multiple Pitt departments.

Now that Urban himself is a professor and advisor, he’s recently seen his career come full circle. “This spring, I graduated my first doctorate student—a Pitt student. There was one person on his committee that was on my PhD committee,” Urban says. “The department that trained me is now seeing the results of that training.”

Though Urban is too modest to speculate on what his former professors think of their protégé-turned-colleague, there’s no doubt he’s turned some heads. In addition to a CV with dozens of published articles in his research areas of neurophysiology, computational neuroscience, olfaction, and the neurobiology of attention and decision making, he recently had an NIH grant worth nearly $1.5 million renewed. This funding initially allowed Urban and his peers to reveal the phenomena of dynamic connectivity; the extension will help the team uncover the mechanisms that allow single neurons to behave as “clocks,” allowing them to fire precisely at particular times relative to a stimulus.

Urban also has another NIH grant under his belt (for $977,000), in combination with the mathematics department at Pitt, to study synchronous activity in neuron groups. The research has implications for helping the psychiatric community better understand—and perhaps more effectively treat—certain mental disorders such as schizophrenia.

On the horizon for Urban is a joint grant, submitted with researchers nationwide, that proposes groundbreaking research into artificial sensing systems. “There are a variety of applications,” says Urban, “from military to medical to homeland security.”

All these varied research endeavors—across disciplines, universities, and even state lines—aptly illustrate Urban’s freshman-year revelation that neuroscience is fresh, relevant, and truly interdisciplinary: “It’s a real fertile ground for bringing people together.”

For more information on Urban’s research, visit his lab page at www.andrew.cmu.edu/user/nurban/Lab_pages/

To learn more about the CNBC, check out www.cnbc.cmu.edu/

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