NEW YORK, Mar 08 (Reuters Health) -- Secrets of brain development and growth
continue to emerge, thanks to the possibilities generated by new technologies.
The latest advance comes from a joint US-Canadian group of researchers who used
sophisticated imaging techniques to visualize changes in brain structure during
childhood.
Led by Dr. Arthur W. Toga of the University of California, Los Angeles,
School of Medicine, the team described their work as "the creation of spatially
complex, four-dimensional quantitative maps of growth patterns in the developing
human brain." Their report is published in the March 9th issue of the journal
Nature.
Using magnetic resonance imaging (MRI), the researchers were able to perform
a never-before-accomplished feat -- that of mapping, in detail, the changes
occurring in children's brains over a period of years. Among the group's
observations was the notable growth of the corpus callosum, a structure that
serves to connect the two hemispheres of the brain and which contains hundreds
of millions of nerve fibers.
According to Toga and his colleagues, a particular area of the callosum
called the isthmus was found to be a "focus of extreme growth... (which) was
detected consistently in all subjects tracked between 6 and 15 years (of age)."
This callosal area, associated with language and certain thinking skills,
"grew more rapidly than surrounding regions across time spans before and during
puberty (6-13 years), with growth attenuated shortly afterwards (11-15 years),"
the team writes.
This growth pattern supports what is known about language acquisition, the
researchers point out. "The ability to learn new languages declines rapidly over
the age of 12 years, as does the ability to recover language function if
linguistic areas in one brain hemisphere are surgically (removed)," Toga and
colleagues explain.
Another possible application of this MRI technique is being suggested by the
researchers, who "recently found that (a particular group of nerve fibers)
crossing at the callosal isthmus, degenerates fastest in early Alzheimer's
disease." They believe that their form of dynamic mapping "may... offer
advantages in tracking fine-scale effects of therapeutic interventions in
dementia (and other diseases)."
