1. The McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
2. Center for Neural Science, New York University, New York, NY 10003, USA.
3. Institute for Behavioral Genetics, Department of Integrated Physiology, University of Colorado, Boulder, CO 80303, USA.
4. Division of Infectious Diseases and Immunology and Program in Innate Immunity, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
5. The Kimmel Center for Biology and Medicine of the Skirball Institute, New York University School of Medicine, New York, NY 10016, USA.
6. Howard Hughes Medical Institute, New York, NY 10016, USA.