Imaging Study Shows Brain Maturing - Article
Article: Imaging Study Shows Brain Maturing
The brain's center of reasoning and problem solving is among the last to mature, a new study graphically reveals. The decade-long magnetic resonance imaging (MRI) study of normal brain development, from ages 4 to 21, by researchers at NIH's National Institute of Mental Health (NIMH) and University of California Los Angeles (UCLA) shows that such "higher-order" brain centers, such as the prefrontal cortex, don't fully develop until young adulthood.
A time-lapse 3-D movie that compresses 15 years of human brain maturation, ages 5 to 20, into seconds shows gray matter the working tissue of the brain's cortex diminishing in a back-to-front wave, likely reflecting the pruning of unused neuronal connections during the teen years. Cortex areas can be seen maturing at ages in which relevant cognitive and functional developmental milestones occur. The sequence of maturation also roughly parallels the evolution of the mammalian brain, suggest Drs. Nitin Gogtay, Judith Rapoport, NIMH, and Paul Thompson, Arthur Toga, UCLA, and colleagues, whose study is published online during the week of May 17, 2004 in The Proceedings of the National Academy of Sciences.
"To interpret brain changes we were seeing in neurodevelopmental disorders like schizophrenia (
The researchers scanned the same 13 healthy children and teens every two years as they grew up, for 10 years. After co-registering the scans with each other, using an intricate set brain anatomical landmarks, they visualized the ebb and flow of gray matter - neurons and their branch-like extensions in maps that, together, form the movie showing brain maturation from ages 5 to 20.
It was long believed that a spurt of overproduction of gray matter during the first 18 months of life was followed by a steady decline as unused circuitry is discarded. Then, in the late l990s, NIMH's Dr. Jay Giedd, a co-author of the current study, and colleagues, discovered a second wave of overproduction of gray matter (
The new study found that the first areas to mature (e.g., extreme front and back of the brain) are those with the most basic functions, such as processing the senses and movement. Areas involved in spatial orientation and language (parietal lobes) follow. Areas with more advanced functions integrating information from the senses, reasoning and other "executive" functions (prefrontal cortex) mature last.
In a related study published a few years ago, Rapoport and colleagues discovered an exaggerated wave of gray matter loss (
Also participating in the new study were: Leslie Lusk, Cathy Vaituzis, Tom Nugent, David Herman, Drs. Deanna Greenstein, Liv Clasen, NIMH; Kiralee Hayashi, UCLA.
The graphic "Time-Lapse Imaging Tracks Brain Maturation from ages 5 to 20" is available at
A Time-lapse Imaging movie is available at
NIMH is part of the National Institutes of Health (NIH), the Federal Government's primary agency for biomedical and behavioral research. NIH is a component of the U.S. Department of Health and Human Services.
Source: National Institutes of Health
Cache Date: December 16, 2004