By Greg Miller, Science Now, March 30, 2011
Credit: M. D. Van Wedeen, Martinos Center and Dept. of Radiology/Massachusetts General Hospital/Harvard U. Medical School
To the unaided eye, the most striking feature of the human brain
is its squiggly pattern of bumps and grooves. But within those curves is a latticework of nerve fibers that cross each other at roughly
right angles (above), according to a study published in tomorrow's issue of Science.
The researchers used a recently-developed method called diffusion spectrum
imaging to infer the position of nerve fibers in the living human brain from the
way water flows through and around them. These scans revealed an orderly weave
of fibers—a much simpler organization than many scientists would have
suspected. Scans in four monkey species found a similar pattern. The
researchers suggest that this grid-like organization may be advantageous during
brain development, providing the equivalent of highway lane markers to help
growing nerve fibers find their way to the appropriate destination.
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