CMU Neuroscientist receives NSF grant for possible schizophrenia research

The National Institute of Mental Health (NIMH) and the National Science Foundation (NSF) recently awarded Carnegie Mellon biology professor Nathan Urban a $979,000 grant for his research in neuron synchronization.

Urban, who has been at Carnegie Mellon since 2002, teaches Biology of the Brain (03-360) and Neural Plasticity in Sensory and Motor Systems (03-761).

Urban collaborated with G. Bard Ermentrout, a professor in the University of Pittsburgh’s mathematics department.

NIMH and NSF provided the grant so that Urban and Ermentrout could further their research, which may help to determine the causes of certain brain disorders, including schizophrenia.

The University has played a role in Urban’s research. “Carnegie Mellon made a decision a few years ago to become heavily invested in the area of neuroscience,” said Urban. “I usually have a couple of undergraduates in my lab.”

A variety of majors are applicable to the study of neuroscience; Urban has worked with students studying biology, physics, electrical engineering, and computer science from both Carnegie Mellon and the University of Pittsburgh.
The studies of a neuroscientist might seem complicated, but Urban’s work with neuron synchronization can be simplified through the use of two simple analogies.

“You can think about synchronization in clocks,” said Urban. Dating back to 1657, early experiments in synchronization dealt with the observation of pendulums.

Another way to think of synchronization is to consider a clapping audience.

During his lectures on synchronization, Urban often asks his audience to clap with a steady rhythm. Working towards this goal, the audience members don’t all follow the same person.

They listen for two things: the time period between claps (the frequency) and what they need to do. Certain audience members have to accelerate their clapping, while others have to slow down.

An audience synchronizing itself is an example of stochastic synchrony. Urban’s work resembles the example with gamma neurons, which conduct slow motor impulses, in place of people.

Like the members of an audience, neurons can become synchronized in two ways. Directly connected neurons can collectively respond to a particular signal, the same way an audience would react to a pacemaker. This kind of activity is said to be connectivity-induced.

Stochastic synchrony is a noise-induced reaction, one that is caused by many random inputs, such as an entire audience initially clapping arythmically. “By increasing the amount of noise, you can increase the amount of structure,” Urban said.

Urban and Ermentrout studied stochastic synchrony both experimentally and computationally. Working in one of the Mellon Institute’s three neuroscience labs, Urban was primarily involved in experimental research.

Using mice, he studied the olfactory bulb, a part of the brain responsible for processing odors. A mouse has to be able to recognize tens of thousands of smells: those of food, predators, and prey. Portions of the olfactory bulb will work in sync to communicate information about a single odor to the brain.

Ermentrout works on the computational side of things. In place of neurons, Ermentrout uses simplified equations.
By modifying the equations, he can determine the essential factors of stochastic synchrony. This is helpful in determining which other systems in the brain might also function through the use of noise-induced synchronization.

That’s the objective of Urban’s work: He’s trying to establish a causal relationship between problems with neuronal synchronization and disorders of the brain, including schizophrenia.

Gamma neurons, which have high frequencies, are thought to send messages to the brain via stochastic synchrony. These are the same neurons involved in processes like perception, consciousness, and memory.
“This sort of synchronization is disrupted in certain patient populations,” said Urban.

It has been suggested that this kind of disruption could be the root of schizophrenia. Current treatments for schizophrenia are not related to its cause, only its symptoms, which include delusions and hallucinations, as well as many of the problems associated with depression, such as low energy.

“Trying to find the exact causes of the illness is where things are really headed at this point,” said Kevin Eklund, a clinical specialist at the Western Psychiatric Institute & Clinic, part of the University of Pittsburgh Medical Center.

Finding the cause of schizophrenia could lead to advancements in treatment. Medication and psychotherapy are the most common methods of treatment. Figuring out more about how the disease starts could be considered a breakthrough.

Neuroscience is a significant area of study at both Carnegie Mellon and the University of Pittsburgh. Because Carnegie Mellon lacks a medical school, the most effective kind of research for its professors and students is acutely focused. This kind of thinking has allowed scientists such as Urban to delve deeply into cognitive neuroscience.

The University of Pittsburgh is a useful neighbor because Carnegie Mellon researchers can take advantage of its medical school for broader study. “There’s a really good synthesis between the two universities,” said Urban.