July 9, 2004

Vanderbilt to acquire specialized imaging device

Featured Image

Calum Avison, Ph.D., sits in front of an image of a brain of a non-human primate which was scanned using a fMRI scanner. Vanderbilt will acquire the same kind of high-powered scanner in 2006, thanks to a $2 million grant. Photo by Anne Rayner

Vanderbilt to acquire specialized imaging device

A $2 million grant from the National Center for Research Resources (NCRR), a component of the National Institutes of Health, is bringing Vanderbilt closer to its goal of being one of the top imaging research centers in the world.

The funding is one of the NCRR’s Major Research Instrumentation grants, and will allow Vanderbilt to procure a functional magnetic resonance imaging (fMRI) scanner dedicated to imaging non-human primates. The custom-made device is expected to be installed on campus in early 2006.

“This [scanner] will be a unique addition that will support work at the forefront of neuroscience,” said John Gore, Ph.D., director of the Vanderbilt Institute of Imaging Science. “It builds and relies on the technical expertise of the faculty and staff within the Institute in MR imaging and other areas, and it will open up new programs and opportunities to apply imaging to understand higher brain function.”

According to Calum Avison, Ph.D., the principal investigator for this project, the scanner will be one of no more than a half dozen such devices in the world.

“It’s the strength of the research, those in Wilson Hall [Psychology department] and the Medical Center who do vision research and those in the Imaging Center, that has brought this about. It’s having that critical mass of people that can persuade the NIH that this is a good place to put one of these very rare systems,” said Avison, professor of Radiology and Radiological Sciences and Pharmacology.

“There’s something pretty magical about Vanderbilt right now. As an institution it seems to have mastered the art of pulling people together from what may have first seemed diverse and disparate areas, and realizing that if you put them together, good things happen,” he said.

Functional magnetic resonance imaging measures changes in the magnetic properties of blood as it transports oxygen to brain tissue in response to increased neuronal activity. The relatively new technology offers a non-invasive way to image neuronal activity in the brain, and thus study how the brain functions, “sees” and learns.

The new fMRI scanner is specially designed to accommodate non-human primates. Unlike human scanners, which are positioned horizontally, the scanner for non-human primates is vertical. The animal will sit on a chair and be raised up on an elevator-like platform into the scanner.

To date, very little fMRI data have been collected from non-human primates, in part because the design of human scanners can make research more difficult. Non-human primates must be trained to crouch in an uncomfortable, sphinx-like position to use the horizontal scanners. The vertical scanner will allow the non-human primates to sit in a way they’ve historically been trained to sit when doing tests, which Avison said is more comfortable for the animals.

The new scanning capabilities will have a significant impact not only on the Imaging Center, but also those who study non-human primates. Anna Roe, Ph.D., associate professor of Psychology, said the new imaging tool will allow her to take her research one step further.

Roe studies the fundamental modules — or groupings of neurons — involved in cortical function. Focusing mainly on understanding vision, Roe works to uncover which modules in the brain are responsible for understanding what one sees. To date, Roe has been unable to see how different areas in the brain work together to produce the understanding.

“My own personal intrigue is being able to link up multiple levels of study — looking at the whole brain with fMRI, looking at a local patch of cortex with optical imaging, and then being able to look at single neurons with electrophysiological methods,” she said. “If you can correlate these three levels of investigation, you’ll have a very powerful and well-developed view of brain function, and it will also serve to link up three very different bodies of literature.”

Roe said using fMRI in non-human primates will also build a bridge between human and animal studies, and will make animal studies even more relevant to humans.

Avison explained, “The non-human primates have brain architecture and brain functions that are really the closest we’re going to come to those of human beings. We’ll learn a lot not only from the ways in which they are the same, but also in the ways they are different.”

One advantage, according to the researchers, is that the brain activity of the non-human primates can be monitored in the same non-invasive manner as humans are monitored — and they can be monitored doing the same tasks.

“With the fMRI, we can set up the same exact paradigm and have the non-human primate do a behavior, and have a human do that same thing in a human fMRI, and see which brain areas are active. Presumably the areas that are activated should be functionally analogous,” Roe said.

“We know how human and non-human primate brains compare anatomically, but with fMRI, we will be able to see how much they are alike regarding functionality,” said Andrew Rossi, Ph.D., assistant professor of Psychology, who specializes in electrophysiology research in non-human primates. Once the functional likeness is known, and the two bodies of knowledge can be bridged, Rossi said researchers will be closer to the end goal of understanding the human brain.

“We’re a long way from figuring out how the system normally works,” he said. “But once we are able to do this, we can better understand what to do when the system fails. For example, by learning the brain circuitry responsible for attention, we can find ways to treat those with ADHD or autism — where the ability to pay attention is hindered. And finding solutions and therapies is what we’re all ultimately working toward.”