Mapping the brain to discover who’s at risk
Press Release, Israel Ministry of Foreign Affairs, 21 Oct 2010
Early intervention for those at risk of autism and schizophrenia may be possible with a new ‘brain atlas’ being produced with the help of scientists in Israel.
Researchers from Tel Aviv University are developing a new atlas of the brain (Photo courtesy of Wikipedia)
By Sue Galant
By investigating connections within the brain, researchers gain new understanding of disorders of the mind, such as autism and schizophrenia, which affect multiple brain areas.
New research from Tel Aviv University (TAU) is helping to produce an ‘atlas of the brain,’ by mapping the connections that comprise the human brain. It is expected that these ‘maps’ will lead to a new understanding of brain disorders as well as new treatments for them.
Dr. Yaniv Assaf of the university’s Department of Neurobiology is collaborating with an international team of scientists to learn how different parts of the human brain ‘connect.’ This information will be compiled in brain ‘maps,’ in the form of an ‘atlas’. Assaf predicts that "Once we assemble this atlas, we’ll be able to determine who’s at risk of disorders like schizophrenia, so that an early intervention therapy can be applied."
To uncover these secrets of the brain, an intense network of collaborative research is required. The scientists are building on a tool, the AxCaliber that was co-developed in Assaf’s laboratory and described in a recent issue of the journal Brain.
Abnormal brain connections
Brain researchers already know that autism and schizophrenia are not localized disorders, in that there is no one place in the brain where they can be found. That’s why a brain atlas will be an invaluable resource for understanding how parts of our brain connect to other parts within, leading to a deeper understanding of these diseases.
"It’s currently impossible for clinicians to ‘see’ subtle disorders in the brain that might cause a life-threatening, devastating disability," explains Assaf, whose most recent research was conducted in collaboration with the US National Institutes of Health.
Developmental disorders like autism are believed to be a function of abnormal connections among different regions within the brain – like wires between telephone poles. Assaf is examining clusters of brain wiring, or axons, to help scientists produce a better working map of the brain for future research.
Axons connect brain cells. About one micron (one millionth of a meter) in diameter, the tiny axons transfer information to each other and to different parts of the brain. To date there has been no non-invasive imaging technique that allows scientists to ‘see’ such features in the brain in a living person. This is partly because the axons are so small, and partly due to the delicate nature of the brain.
AxCaliber cuts through the mystery
Assaf’s tool, AxCaliber, which he has been working on since 2004, can look at larger groups of multiple axons and collect data from the group itself, which measure the velocity and flow of information within the brain.
Using a standard MRI available in most major hospitals, the AxCaliber provides a way to recognize groups of abnormal axon clusters. Systematically arranged into an atlas, these groups could serve as biomarkers for the early diagnosis, treatment and monitoring of brain disorders.
"Abnormal white matter will exhibit a different distribution of axon diameters," Assaf explains. "The diameter of the axon controls the flow of information. In a normal brain, per region, per functional demand, there is a certain distribution of axonal diameters. In diseases or under abnormal conditions, this distribution may change," he continues, adding that these differences were measured, in several diseases such as autism and ALS. "We expect that with AxCaliber it will be possible to monitor these changes in-vivo, in humans," he states.
"Currently, we can map the healthy human brain past the age of puberty. But once we will assemble this atlas, we could do this scan before puberty – and maybe even in utero – to determine who’s at risk for disorders like schizophrenia, so that an early intervention therapy can be applied," Assaf relates.
Really using his head
He’s working on the brain atlas with a pan-European consortium of brain scientists through a 12-laboratory network called CONNECT. The consortium, funded by the European Union, includes Assaf, his TAU colleague Prof. Yoram Cohen, and partners in the UK, France, Germany, Denmark, Italy and Switzerland. Each of the teams in the consortium offers its individual expertise to gain a deeper understanding of connections in the brain and how they change over time. Their goal is to be better able to predict the onset of brain-related diseases and to treat them more effectively.
In the short term, Assaf says that the researchers hope "to incorporate frameworks such as AxCaliber into connectivity analysis of the brain to achieve a more comprehensive and accurate estimation of brain connections. In the long run, they hope to shift this method to routine work that will be the basis for advanced mapping of the brain when some abnormality is suspected."
In response to a question Assaf offers assurances that MRI is a safe and non-invasive imaging technique, which can be used for research purposes on a regular basis in healthy subjects, with no fear of harming them in any way.
Confirming that he has offered up his own brain, willingly inserting his head into a TAU-owned MRI at a local hospital to help to map the anatomy of a healthy brain’s connections for the study, he notes that he was happy to volunteer. "I found that my brain is normal, which is good to know. Nothing exceptional for better or for worse," he smiles.