Brain Wiring a No-Brainer?

The brain appears to be wired more like the checkerboard streets of New York City than the curvy lanes of Columbia, Md., suggests a new brain imaging study. The most detailed images, to date, reveal a pervasive 3D grid structure with no diagonals, say scientists funded by the National Institutes of Health.

“Far from being just a tangle of wires, the brain’s connections turn out to be more like ribbon cables -- folding 2D sheets of parallel neuronal fibers that cross paths at right angles, like the warp and weft of a fabric,” explained Van Wedeen, M.D., of Massachusetts General Hospital (MGH), A.A. Martinos Center for Biomedical Imaging and the Harvard Medical School. “This grid structure is continuous and consistent at all scales and across humans and other primate species.”

Wedeen and colleagues report new evidence of the brain’s elegant simplicity March 30, 2012 in the journal Science. The study was funded, in part, by the NIH’s National Institute of Mental Health (NIMH), the Human Connectome Project of the NIH Blueprint for Neuroscience Research, and other NIH components.

“Getting a high resolution wiring diagram of our brains is a landmark in human neuroanatomy,” said NIMH Director Thomas R. Insel, M.D. “This new technology may reveal individual differences in brain connections that could aid diagnosis and treatment of brain disorders.”

Knowledge gained from the study helped shape design specifications for the most powerful brain scanner of its kind, which was installed at MGH’s Martinos Center last fall. The new Connectom diffusion magnetic resonance imaging (MRI) scanner can visualize the networks of crisscrossing fibers – by which different parts of the brain communicate with each other – in 10-fold higher detail than conventional scanners, said Wedeen.

“This one-of-a-kind instrument is bringing into sharper focus an astonishingly simple architecture that makes sense in light of how the brain grows,” he explained. “The wiring of the mature brain appears to mirror three primal pathways established in embryonic development.”

As the brain gets wired up in early development, its connections form along perpendicular pathways, running horizontally, vertically and transversely. This grid structure appears to guide connectivity like lane markers on a highway, which would limit options for growing nerve fibers to change direction during development. If they can turn in just four directions: left, right, up or down, this may enforce a more efficient, orderly way for the fibers to find their proper connections – and for the structure to adapt through evolution, suggest the researchers.

Obtaining detailed images of these pathways in human brain has long eluded researchers, in part, because the human cortex, or outer mantle, develops many folds, nooks and crannies that obscure the structure of its connections. Although studies using chemical tracers in neural tracts of animal brains yielded hints of a grid structure, such invasive techniques could not be used in humans.

Wedeen’s team is part of a Human Connectome Project Harvard/MGH-UCLA consortium that is optimizing MRI technology to more accurately to image the pathways. In diffusion imaging, the scanner detects movement of water inside the fibers to reveal their locations. A high resolution technique called diffusion spectrum imaging (DSI) makes it possible to see the different orientations of multiple fibers that cross at a single location – the key to seeing the grid structure ceus for social workers

In the current study, researchers performed DSI scans on postmortem brains of four types of monkeys – rhesus, owl, marmoset and galago – and in living humans. They saw the same 2D sheet structure containing parallel fibers crossing paths everywhere in all of the brains – even in local path neighborhoods. The grid structure of cortex pathways was continuous with those of lower brain structures, including memory and emotion centers. The more complex human and rhesus brains showed more differentiation between pathways than simpler species.

Among immediate implications, the findings suggest a simplifying framework for understanding the brain’s structure, pathways and connectivity.

The technology used in the current study was able to see only about 25 percent of the grid structure in human brain. It was only apparent in large central circuitry, not in outlying areas where the folding obscures it. But lessons learned were incorporated into the design of the newly installed Connectom scanner, which can see 75 percent of it, according to Wedeen.

Much as a telescope with a larger mirror or lens provides a clearer image, the new scanner markedly boosts resolving power by magnifying magnetic fields with magnetically stronger copper coils, called gradients. Gradients make it possible to vary the magnetic field and get a precise fix on locations in the brain. The Connectom scanner’s gradients are seven times stronger than those of conventional scanners. Scans that would have previously taken hours – and, thus would have been impractical with living human subjects – can now be performed in minutes.

“Before, we had just driving directions. Now, we have a map showing how all the highways and byways are interconnected,” said Wedeen. “Brain wiring is not like the wiring in your basement, where it just needs to connect the right endpoints. Rather, the grid is the language of the brain and wiring and re-wiring work by modifying it.”


Detail from DSI scan shows fabric-like 3D grid structure of connections in monkey brain.

Source: Van Wedeen, M.D., Martinos Center and Dept. of Radiology, Massachusetts General Hospital and Harvard University Medical School


Curvature in this DSI image of a whole human brain turns out to be folding of 2D sheets of parallel neuronal fibers that cross paths at right angles. This picture came from the new Connectom scanner.
Source: Van Wedeen, M.D., Martinos Center and Dept. of Radiology, Massachusetts General Hospital and Harvard University Medical School

Reference

Wedeen VJ, Rosene DL, Ruopeng W, Guangping D, Mortazavi F, Hagmann P, Kass JH, Tseng W-YI. The Geometric Structure of the Brain Fiber Pathways: A Continuous Orthogonal Grid. March 30, 2012 Science.

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The mission of the NIMH is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery and cure. For more information, visit the NIMH website.

The NIH Blueprint for Neuroscience Research is a cooperative effort among the NIH Office of the Director and the 15 NIH Institutes and Centers that support research on the nervous system. By pooling resources and expertise, the Blueprint supports transformative neuroscience research, and the development of new tools, training opportunities, and other resources to assist neuroscientists.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit the NIH website.

School absenteeism, mental health problems linked

School absenteeism is a significant problem, and students who are frequently absent from school more often have symptoms of psychiatric disorders. A new longitudinal study of more than 17,000 youths has found that frequently missing school is associated with a higher prevalence of mental health problems later on in adolescence, and that mental health problems during one year also predict missing additional school days in the following year for students in middle and high school social worker continuing education

The study, published in the journal Child Development, was conducted by researchers at the University of California, Los Angeles (UCLA), the University of Florida, Boston University, the Child and Adolescent Services Research Center, the Oregon Social Learning Center, and Johns Hopkins University.

"We've long known that students who are frequently absent from school are more likely to have symptoms of psychiatric disorders, but less clear is the reason why," says Jeffrey Wood, associate professor of educational psychology and psychiatry at UCLA, who led the study. "These two aspects of youths' adjustment may at times exacerbate one another, leading over the course of time to more of each."

The study found that between grades 2 and 8, students who already had mental health symptoms (such as antisocial behavior or depression) missed more school days over the course of a year than they had in the previous year and than students with few or no mental health symptoms. Conversely, middle and high school students who were chronically absent in an earlier year of the study tended to have more depression and antisocial problems in subsequent years. For example, 8th graders who were absent more than 20 days were more likely to have higher levels of anxiety and depression in 10th grade than were 8th graders who were absent fewer than 20 days.

"The findings can help inform the development of programs to reduce school absenteeism," according to Wood. "School personnel in middle schools and high schools could benefit from knowing that mental health issues and school absenteeism each influence the other over time. Helping students address mental health issues may in turn help prevent the emergence of chronic absenteeism. At the same time, working to help students who are developing a pattern of chronic absenteeism come to school more consistently may help prevent psychiatric problems."

The researchers looked at more than 17,000 children in 1st through 12th grades using three datasets: the National Longitudinal Study of Adolescent Health, a longitudinal study of a nationally representative sample of adolescents in grades 7 to 12; the Johns Hopkins Prevention Intervention Research Center Study, a longitudinal study of classroom-based interventions involving children in grades 1 to 8; and the Linking the Interests of Families and Teachers trial, a longitudinal study of children in grades 1 through 12.

Researchers interviewed students and parents annually or biennially, and they gathered information from school attendance records. In addition, students, parents, and teachers filled out questionnaires.


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The study was funded by the National Institute of Mental Health and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, with cooperative funding from 17 other agencies.

PBS’s This Emotional Life: Documentary Launches a Campaign of Hope

PBS’s This Emotional Life: Documentary Launches a Campaign of Hope

Millions of Americans struggle to find more meaning in their lives every day.

To help, Vulcan Productions and NOVA/WGBH brought together a number of public and private organizations around a nationwide, multi-faceted project launched in conjunction with the recent PBS series, This Emotional Life.

The 2-year campaign aims to bring help and hope to those trying to improve their lives. The campaign includes SAMHSA, the National Alliance on Mental Illness, the Mayo Clinic, Blue Star Families, and other organizations.

"This is a unique opportunity to leverage the power of media to effect societal change — in this case, in the area of mental health and emotional well-being,&rquot; said A. Kathryn Power, M.Ed., Director of SAMHSA’s Center for Mental Health Services. "SAMHSA is working closely with the This Emotional Life team to make sure that the information, stories, and resources that make up this unprecedented project get to the people who need them most."

Documentary & Web Site
What do an uncontrollably angry teen and a misunderstood lottery winner have in common? Or how about a young husband misunderstood by his wife and an elderly woman on her way to a senior center? They were all interviewed for the PBS series This Emotional Life, which premiered in early January 2010.

This Emotional Life is a multi-platform endeavor that explores the science behind the human quest for emotional well-being, the barriers that stand in the way of this pursuit, and the importance of social relationships in surmounting life’s challenges and finding happiness.

"The TV series is the cornerstone of a broader project to help people form better, deeper, and more profound human connections," said Richard Hutton, Senior Executive Producer of Vulcan Productions.

This Emotional Life is complemented by a Web site, which provides vetted resources to build social support networks around topics highlighted in the series, such as the importance of early attachment, how to heal strained or damaged relationships, post-traumatic stress disorder (PTSD), stress, depression, grief, resilience and our pursuit of happiness.

Toolkits
Vulcan Productions is developing two toolkits, one that addresses early attachment for parents of infants and a second that addresses the emotional challenges faced by military service members and their families during the deployment cycle.

SAMHSA is distributing and assembling the "Early Moments Matter" toolkit designed to educate parents and caregivers of infants about what attachment is and why it's important.

The toolkit also provides parents concrete advice on ways to build attachment, a key to healthy social and emotional development. It will be distributed in high-birthrate hospitals, pediatric doctors' offices, and community-based clinics, as well as through partners who serve expecting and new parents.
mental health and social work continuing education ceu
"The Family Guide to Military Deployment," will provide tangible resources and tools to the families and friends of some of the 1.8 million servicemen and women who have been deployed, helping them face the emotional challenges typical of pre-deployment, deployment, and post-deployment.

For details about the documentary and campaign, visit the PBS Web site.