1 Institute of Neuroscience and Medicine (INM-6) and Institute for Advanced Simulation (IAS-6), Jülich Research Center and JARA, 52425 Jülich, Germany, Bernstein Center Freiburg and Faculty of Biology, Albert-Ludwig University of Freiburg, 79104 Freiburg im Breisgau, Germany, and Institute of Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh EH8 9LE, United Kingdom r.duarte@fz-juelich.de.