The human brain occupies a unique position among the organs of the human body. With its 1010 nerve cells and the innumerable interconnections, it is the most complex living system we know. It is the prerequisite for all though~, feeling, and action and hence for the awareness of ourselves. In many religions and philosophies it was and is considered to be the seat of the immortal soul. For centuries some individuals looked upon the mentally ill with holy reverence, and others responded with shock and radical social ostracism. In the neurosciences, too, the brain is not just one organ among many. As with the genome, it is considered to be an information storage unit. But whereas the genetic information cannot be influenced by the individual carrier, the brain can learn, that is, it is capable of storing information from the life history of its carrier, and it can pass this information on. The neurosciences are an area of research that has cut across the boundaries of the classic disciplines and now includes a broad spectrum ranging from basic research to clinical medicine. These sciences have developed remarkable momentum since they have taken an interdisciplinary approach and made use of experimental techniques and concepts developed in the fields of physics, biochemistry, molecular biology, behavioral physiology, experimental psychology, and computer science.