Using magnetic resonance imaging, researchers have discovered that the pathways in the top of the brain are all organized like woven sheets with the fibers running in two directions in the sheets and in a third direction perpendicular to the sheets. These sheets all stack together so that the entire connectivity of the brain follows three precisely defined directions. Credit: NSF and Harvard University

Have you ever wondered what your brain looks like or how it works for you?

It
was previously thought the inside of the brain resembled the assembly
of a bowl of spaghetti noodles. Researchers and scientists, funded by
the National Science Foundation, have now discovered that a more
uniformed grid-like pattern makes up the connections of the brain.

This
week’s issue of Science magazine details the finding in a paper titled,
“The Geometric Structure of the Brain Fiber Pathways: A Continuous
Orthogonal Grid.”

Scientists
from Harvard University, MIT’s Division of Health Sciences Technology,
Boston University, University Hospital Center & University of
Lausanne in Switzerland, Vanderbilt University and National Taiwan
University College of Medicine worked together using magnetic resonance
imaging (MRI) technology to map the three-dimensional, scaffold fiber
architecture of the brain. This technology, used for the first time in
this manner, determined that the pathways of the brain pass through
tissue that resembles a grid-like structure.

“By
looking at how the pathways fit in the brain, we anticipated the
connectivity to resemble that of a bowl of spaghetti, a very narrow and
discreet object,” said Van J.  Wedeen, associate professor of Radiology,
Massachusetts General Hospital, Harvard Medical School and Martinos
Center for Biomedical Imaging.

“We
discovered that the pathways in the top of the brain are all organized
like woven sheets with the fibers running in two directions in the
sheets and in a third direction perpendicular to the sheets. These
sheets all stack together so that the entire connectivity of the brain
follows three precisely defined directions.”

The
directions of the pathways were previously difficult to determine
because in embryological life the pathways run in simple directions but
become very bent and folded as the brain matures into an adult and more
information and skills are learned. The surface of the adult brain
appears more folded and the three directions become increasingly curved
and thus difficult to view definitively.

“This
is the first time it has ever been determined that the geometry of the
brain is described by a three-dimensional grid,” said Krastan Blagoev,
program director in the Mathematical & Physical Sciences Directorate
at the National Science Foundation. “We are so pleased with the outcome
of this important research and this significant development and look
forward to learning even more information regarding the connectivity and
pathways of the brain.

“The
research took MRI scanners and new mathematical algorithms to determine
a geometry to the relationship of nearby pathways in the brain so that
each pathway was part of a two-dimensional sheet of pathways that
together looked exactly like a woven sheet of fabric,” said Van Wedeen.

Each
pathway was part of a parallel series next to it crossed by a
perpendicular series at a right angle, together which formed a woven
grid. The structure was part of a three-dimensional scaffold connections
of the brain conformed to the extremely simple three-dimensional
structure, a single woven grid with fibers in only three axes.  By using
diffusion MRI and mapping the three-dimension motion of the water
molecules in the brain, the scientists ran the maps through mathematical
algorithms that inferred from the water motion pattern the fiber
architecture of the tissue of the brain.

By
comparing the human brain with those of primates, the researchers
determined clues regarding the aging and other conditions of the human
brain. This significant research and discovery opens the doors to a vast
array of further opportunities into the inter-working of our most vital
organ.

Source: National Science Foundation