For the second year in a row, groundbreaking research from the University of Virginia School of Medicine’s Department of Biochemistry and Molecular Genetics has made the list of the year’s top 10 discoveries and breakthroughs, as compiled by the director of the National Institute of Mental Health.
Under the heading “Brain Exceptionalism,” NIMH Director Thomas R. Insel, MD, highlights the discovery of an unexpected variation in the genetic makeup of nerve cells in the brain. “For me, 2013 will be the year when we began to realize how much the brain differs from other organs,” Insel writes, noting that the recent findings “really made the case for the human brain as not only the most mysterious but the most exceptional of organs.”
The discovery of the genetic “mosaic” in the brain’s neurons was the result of work at UVA by Mike McConnell, PhD, and Ira Hall, PhD, in collaboration with Fred H. Gage of the Salk Institute and a team of researchers. The work represented an important new application of single-cell sequencing, allowing scientists to look at the genetic makeup of individual cells. (The journal Nature Methods has named single-cell sequencing the “Method of the Year” in recognition of its transformative potential for genetic research. That article, out now, profiles the UVA mosaic research and other important applications.)
About the neuron mosaic
The UVA researchers found that up to 41 percent of the neurons they examined displayed at least one significant variation in DNA – a percentage far greater than anticipated. That variation could have enormous impact, potentially helping to explain schizophrenia, depression, bipolar disorder, autism and other such conditions thought to be genetically linked but not yet tied to a single gene. “The lesson,” Insel concludes, “is that we cannot use peripheral cells to know what is happening in the brain.”
Insel’s annual list can be found at the NIMH Director’s Blog.
In 2012’s listing, Insel highlighted a DNA discovery by a team led by UVA’s Anindya Dutta, MD, PhD, chairman of the Department of Biochemistry and Molecular Genetics. In establishing the existence of circular “microDNA” outside chromosomes, Dutta and his team upended the commonly accepted notion that mammalian DNA is wholly contained within chromosomes.