A Genetics-Based Map of the Brain

By Sathya Achia Abraham

A national team of researchers has developed a new tool to study and explain how the brain works – the first map of the surface of the brain based on the basis of genetic information.

Although there are several established maps of the brain that show the different regions, they have been developed based on the general structure of lobes and folds, or on the basis of apparent function of different regions. This new map is the first to be based on genetic information.

The team was led by researchers at the University of California, San Diego, and included scientists from Virginia Commonwealth University, Boston University, Harvard Medical School and Massachusetts General Hospital. William S. Kremen, Ph.D., professor of psychiatry, and Anders M. Dale, Ph.D., professor of radiology, neurosciences, and psychiatry, both at the University of California, San Diego, led the efforts of this work.

In the study, published in the March 30 issue of the journal Science, the team reported the development of a genetic map of the brain that may allow researchers to better identify relationships between brain regions and abilities, or more easily find specific genes that influence brain growth and development.

“In this study we developed a new map of the brain by estimating genetic correlations between different regions and identifying clusters within them,” said study contributor and co-author, Michael Neale, Ph.D., professor of psychiatry and human genetics in the VCU School of Medicine.

Neale developed the Mx software used to model the data. He served as the principal investigator of a sub-contract to the UCSD and Harvard-based project.

“This new map shows that there are 12 regions in each half of the brain. Across the two halves, the corresponding regions are highly genetically correlated, so there is a good deal of left-right hemisphere symmetry in cortical areas,” he said.

For this software application, Neale wrote a specialized script to maximize the speed with which the very large number of bivariate genetic models could be fitted to the data.  He also contributed to the authorship of the manuscript.

According to Neale, the surface area of the brain has been shown to be an important marker of aging.  Different regions are also related to different mental abilities - verbal and visual-spatial abilities “map” to different regions of the brain.

Neale said that although cortical thickness seems more related to Alzheimer’s disease than cortical area, the relationship of aging to cortical area is important. 

“Possibly, differences in area in specific regions will relate to changes in different aspects of aging,” said Neale. For example, reduction in certain regions might relate to confusion or others to loss of balance. 

“The better we understand the structure, development and maturation of the brain, the better we may be able to select therapies to counteract the effects of aging,” said Neale.

For nearly 30 years, Neale, an internationally-known expert in statistical methodology, has developed and applied statistical models in genetic studies, primarily of twins and their relatives, with the goal of better understanding the brain and behavior.

The work was supported in part by grants from the National Institute on Aging, National Institute of Drug Abuse, National Institute of Neurological Disorders and Stroke, National Center for Research Resources, National Institute for Biomedical Imaging and Bioengineering, National Center for Alternative Medicine, National Institute for Neurological, Disorders and Stroke, and the Ellison Medical Foundation.