MRI-based system could help identify neurological and psychiatric diseases early and improve treatment.
By JUDY SIEGEL-ITZKOVICHCONNECT project’s new ‘atlas’ 370(photo credit: Tel Aviv University)
The healthy brains of 120 living people – not members of the Knesset, but other Israelis and some Europeans – have been scanned with a magnetic resonance instrument (MRI) to build the world’s first “atlas” of the microstructure of white matter.Led by Prof. Yaniv Assaf of Tel Aviv University’s neurobiology department and the Sagol School of Neuroscience, the CONNECT project could eventually help identify the first signs of neurological and psychiatric diseases at an early stage in life so they could be treated early on.“Healthy people at age 30 could already have a brain microstructure with less plasticity and thus be at risk for disease decades later. They could take medications early to prevent deterioration,” he said. “But that is still far away.”White matter is one of the two major parts of the central nervous system and consists mostly of glial cells and myelinated axons, which transmit signals from one area of the cerebrum to another and between the cerebrum and lower brain centers. Appearing pinkish-white to the naked eye, the myelin tissue is composed largely of lipid (fat) tissue veined with capillaries; when preserved in formaldehyde for storage, it looks white. It has a different function than the brain’s “gray matter,” which is composed of neurons (nerve cells).While gray matter is involved mostly in cognition and processing, white matter is actively involved in how the brain learns and coordinates communication among different brain regions.The three-year CONNECT project’s final results have the potential to change the face of neuroscience and medicine over the coming decade, according to the European Union consortium of 12 research groups in the project, which will be disclosed at a meeting of the researchers in Paris.Assaf told The Jerusalem Post on Tuesday that a new tool called a “diffusion MRI” looked at the movement of water molecules.By measuring that movement, he said, it showed all the anatomical microstructures of the white matter.Funding the CONNECT project, which cost 2.4 million euros, was the EU’s future and emerging technologies program (FET/ICT). The participants came not only from Israel, but from the United Kingdom, Germany, France, Denmark, Switzerland and Italy.Until now, biomedical research teams in the field of neurobiology have depended on a “brain atlas” produced by painstaking and destructive histological examination of the brains of a few people who died and donated their bodies to science.
But, said Assaf, the new whole-brain atlas is based on three-dimensional MRI scans of healthy brains from living people, which were combined. The advanced MRI technology provides unprecedented detail and accuracy, making an atlas similar to what we might obtain by examining every square millimeter of brain tissue (around 100 million) with a microscope. The automated methods turn this arduous process into a much more manageable task and leaves the brain intact.The microscopic features mapped in the atlas included average nerve cell size, diameter and density within the white matter, and will serve as the reference standard of future brain studies in medicine as well as basic neuroscience.The average came from calculating the f i g u r e s scanned in all 120 healthy subjects, between the ages of 25 and 35.Assaf noted that the results “provide new depth and accuracy in our understanding of the human brain in health and disease.”Historically, he explained, most neuroscience research has focused on understanding and studying gray matter and neurons, while white matter has largely been ignored because of the lack of good research tools to study it, even though white matter comprises half of the brain’s volume.The TAU neuroscientist suggested that the results could be used in the future to characterize and understand micro-structural changes caused by different neurodegenerative diseases, such as Alzheimer’s, amyotrophic lateral sclerosis (ALS) or schizophrenia, and to develop better diagnostic procedures for these and other devastating conditions.Assaf said the CONNECT project had no connection to the “Blue Brain Project” coordinated in Switzerland, whose Israeli participant is Prof. Idan Segev of the Hebrew University. The Swiss project is an attempt to reverse-engineer the human brain and recreate it at the cellular level inside a computer simulation, using slices of living brain tissue to build biologically realistic models of neurons and networks of neurons in the cerebral cortex.Researchers use this data to create simulations on the Blue Gene supercomputer, which IBM built.Assaf said that while the two projects are very different, “in future, they may be able to complement each other and produce better understanding of how the brain works and how brain disease occurs.”
