Cutting-edge imaging research may provide new applications in treatment of Down syndrome and other genetic disorders.
For two years, neuroscientists from the University of Utah (Salt Lake City; USA) examined the brains of 15 individuals with Down syndrome and compared their functional magnetic resonance imaging (fMRI) brain images with the brains of 15 healthy control individuals. They found significant differences in the brain images of individuals with Down syndrome—data that could change the way the disorder is treated in the future, according to Julie R. Korenberg, MD, PhD, lead investigator for the Down syndrome study and director of the University of Utah’s USTAR Center for Integrated Neurosciences and Human Behavior.
“It opens up a whole new world of possibilities for accelerating therapeutics with Down syndrome and for other developmental disorders,” Dr. Korenberg stated about the study. “Up until now, there was no functional imaging of Down syndrome and we knew we needed it. To have this team of people that are taking fundamental neuroscience and applying it to imaging—it is unprecedented.”
The research idea in itself was innovative, according to Jeff Anderson, MD, PhD, first author of the study, which was published June 2013 in the online journal NeuroImage: Clinical
. “It turns out that Down syndrome, in spite of being an incredibly common disorder, has been almost completely ignored by the scientific community in terms of brain imaging,” said Dr. Anderson. “We set out to do a project where we recorded the brain function of people with Down syndrome. What we found were some pretty striking abnormalities. It looks like there is massive overconnectivity in the brains of individuals with Down syndrome. These are larger differences by an order of magnitude than we’re seeing in autism or in other disorders. In addition, we’re also seeing that there are some places in the brain that are underconnected—areas that are far apart and are part of networks in the brain where regions in a healthy brain work together to perform tasks.”
Dr. Anderson described the new findings as creating a “wiring diagram” of the Down syndrome brain. The brain consists of cells, most of which are on the brain’s surface and are networked together in different ways like a circuit. Areas on the surface of the brain are where all the action is and most of the middle of the brain is where all the wires between the cells exist. What researchers have developed with brain imaging allows them to measure quantitatively how strong “wiring” is between any two points in the brain, according to Dr. Anderson.
Researchers for the first time will now have a way to gauge how and if a specific type of therapy is having positive results for a Down syndrome patient. “One of the troubles in getting therapies to work in a disorder like Down syndrome is we don’t have a good way of testing to see if they’re working. If you can measure quantitatively what is abnormal in the brain of someone with Down syndrome, if you have a medication you think might work, you can give them a medication and after a short period of time you can, using brain imaging, see if it’s changing the abnormality,” Dr. Anderson said. “Like a lot of problems in science, the real problem is just getting something you can measure. It’s like taking a thread from a tapestry that you can hold onto and pull. Once you have the foothold, you can keep pulling and pulling and the whole picture has unraveled and you can understand what’s going on.”
The new study is part of a larger study taking place at the University of Utah. The broader study is now in its second year and funded by the US National Institute of Child Health and Developmental Disabilities. Dr. Korenberg oversaw the study, which is part of a larger mission that she leads at the Brain Institute to research the molecular genetics of mental retardation.
In the new study on Down syndrome brain imaging, researchers also compared Down syndrome patients with brain images from those diagnosed with autism and other genetic disorders. The research will clear the way for further study into the brain and genetics.
“What we can now say is that those genes on chromosome 21 alter the development and function of the brain in particular ways,” Dr. Korenberg said. “We’re beginning to not just sort through, but to unravel the mysteries of how the brain develops and how the brain functions and what the genetic basis of that function is. And that’s very exciting.”
University of Utah