1. Center for Neural Circuits and Behavior; Departments of Neuroscience and Biology; University of California at San Diego; La Jolla CA 92093 USA
2. Netherlands Institute for Neuroscience; Royal Netherlands Academy of Arts and Sciences; Amsterdam The Netherlands
3. Departments of Neurology and Medicinal Chemistry; Biogen Idec Inc.; Weston MA USA
4. The Solomon H. Snyder Department of Neuroscience and Howard Hughes Medical Institute; The Johns Hopkins University School of Medicine; Baltimore MD USA