The brain is one of the most complex systems of all and a fascinating subject of research. At the Cécile and Oskar Vogt Institute of Brain Research, we are concerned with the question of the basic organizational principles and functions of the human brain, in particular the cerebral cortex and its dependence on various internal and external influences. Here we work very closely with the Research Center Jülich (Institute of Neuroscience and Medicine, INM-1). We are investigating the architecture of connections in the human brain using PLI (Polarized Light Imaging) with unprecedented micrometer resolution. We are creating an atlas of the human brain based on architectural and functional criteria and making the maps freely available to the scientific community (Julich-Brain Cytoarchitectonic Atlas, SPM Toolbox). The three-dimensional brain model "BigBrain" makes it possible for the first time to see and understand the complicated structure of the brain on a microscopic level in all three levels of space (BigBrain). Together with Research Center Jülich, we are involved in the Human Brain Project, one of the flagship projects of the EU's FET Initiative (http://www.humanbrainproject.eu).