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Human Brain Mapping

Cytoarchitectonic probability maps

Neuroscientist Prof. Dr. Katrin Amunts and her team go on a unique research expedition: They create a three-dimensional atlas of the brain

At first glance, the “route” is limited. The human brain contains about 1,500 cm³ of brain tissue, and the terrain is quite something. The goal “is to develop a realistic, three-dimensional computer brain model based on structural, cytoarchitectonic, genetic, and molecular characteristics.” As part of this project, scientists at INM-1 are examining many thousands of histological brain sections. The sections are analyzed using modern scanning microscopes and image analysis methods. Then the cellular architecture is statistically analyzed and digitally reconstructed in 3-D. With her colleague, Prof. Dr. Karl Zilles, and a large team of medical doctors, physicists, biologists, mathematicians and graduate students, Prof. Dr. Katrin Amunts is developing a unique brain atlas that will gradually replace Brodmann’s map from 1909. “The psychiatrist and anatomist Korbinian Brodmann mapped the cerebral cortex and divided it into about 50 areas. He not only created a cytoarchitectonic map, but also provided the basis for later comparative neuroanatomical investigations. Brodmann was convinced that each brain area is responsible for a specific function, an assumption that could only be proven for a small fraction of the areas with the resources available at that time,” [Prof. Dr. Katrin Amunts, director of the Institute of Neuroscience and Medicine, INM-1 (Structural and functional organization of the brain) as well as director of the C. & O. Vogt Institute of Brain Research at Heinrich Heine University Düsseldorf].

Brodmann KarteSeitliche Ansicht der 1909 von Korbinian Brodmann veröffentlichten Gehirnkarte.
Copyright: Brodmann, K. (1909). Vergleichende Lokalisationslehre der Großhirnrinde in ihren Prinzipien dargestellt auf Grund des Zellenbaues. Leipzig, Verlag von Johann Ambrosius Barth.

Lateral view of the brain map published by Korbinian Brodmann in 1909.
Copyright: Brodmann, K. (1909). Vergleichende Lokalisationslehre der Großhirnrinde in ihren Prinzipien dargestellt auf Grund des Zellenbaues. Leipzig, published by Johann Ambrosius Barth.
Although Brodmann’s discovery was groundbreaking, the hundredyear- old map is merely a schematic drawing, not the three-dimensional record that is needed today as a basis for comparison in modern imaging studies to assign patient data to the microscopic structures of the brain. “We need to understand the ‘healthy’ brain before we can take the next step and distinguish differences in people suffering from neurological or psychiatric disorders,” explains Katrin Amunts. Although only about 70 percent of the brain is mapped, the 3-D brain model from Jülich is in many ways already more complex than the Brodmann map. There are several reasons for this: Katrin Amunts and her interdisciplinary team consider that brain structures differ from each other, thus taking their interindividual variability into account. Furthermore, they not only map the cerebral cortex, but also nuclei deep in the brain. “The areas of the cortex do not operate in isolation like islands. Rather, they form networks and cooperate with the subcortical nuclei,” she explains. The 3-D brain model continues to develop with each newly defined area. The procedure is very time-consuming, as a scientist needs about one year to analyze and map a new area.

About 70 percent of the brain has now been mapped. For this purpose, thousands of histological brain sections have been, and are being, investigated at Forschungszentrum Jülich. The tissue samples are scanned using microscopes and advanced image analysis techniques. They are then statistically analyzed and reconstructed on a computer in 3-D.

3D Hirnatlas

Additional Information

Combining probabilistic cytoarchitectonic maps and functional imaging data

Brain collection