How do you build a brain? According to nature, you start with a curved, three-dimensional grid that’s simple and orderly, say HMS researchers at the Martinos Center for Biomedical Imaging at Massachusetts General Hospital.
In the March 30 issue of Science, lead author Van Wedeen, an HMS associate professor of radiology and a member of the faculty of Harvard–MIT Health Sciences and Technology, reports his team’s discovery of a remarkably simple organizational structure in the brains of humans and other primates. Employing sophisticated mathematical analyses of advanced imaging data, they found that the pathways carrying neural signals through the brain are built from parallel and perpendicular fibers that cross each other in an orderly fashion. The finding, says Wedeen, was completely unexpected.
“Although our findings could be described as a new longitude and latitude for the brain,” he adds, “they’re also leading us to an entirely new understanding of how and why the brain is organized the way it is. A simple grid structure makes both evolutionary and developmental sense. It’s easier for a simple structure to change and adapt, whether we’re talking about changes from evolution or from changes that can occur during an individual’s lifetime—both the normal neuroplasticity associated with development and learning or the damage that results from injury or disease.”