We thank the study participants for their important contributions to this study. This work was supported by the Max Planck Society, the Max Planck Förderstiftung, and the DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain, as well as by the Niedersachsen-Research Network on Neuroinfectiology of the Ministry of Science and Culture of Lower Saxony. The computations were performed at the Vital-IT (http://www.vital-it.ch) center for high-performance computing of the SIB Swiss Institute of Bioinformatics. This work was also supported by a Young Investigator Grant from the Brain & Behavior Research Foundation, as well as a postdoctoral scholarship from the Daimler and Benz Foundation, both awarded to C.H. J.F. is supported by a professorship grant from the Swiss National Science Foundation (PP00P3_133703).