1Departments of Neuroscience and Cell Biology and Pediatrics (Neurology), Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08854, 2University of Michigan Autism and Communication Disorders Center, Departments of Psychology and Psychiatry, University of Michigan, Ann Arbor, MI 48109-2054, 3Department of Pediatrics, McMaster University, Hamilton, Ontario, L8N 3Z5, Canada, 4Department of Neurosciences, University of California, San Diego, La Jolla, California 92093, 5Center for Autism Research, Children’s Hospital Research Center, San Diego, California 92123, 6Departments of Radiology, Psychiatry, and Bioengineering, University of Washington School of Medicine, Seattle, Washington 98105, 7Department of Psychiatry and Neuropsychology, Division of Cellular Neuroscience, Maastricht University, 6200 MD Maastricht, The Netherlands, 8Yale Child Study Center and Diagnostic Radiology, Yale University, New Haven, Connecticut 06520, 9Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute of Mental Health, Bethesda, Maryland 20892-3730, and 10Center for Behavioral Neuroscience and Department of Psychiatry, Yerkes National Primate Research Center, Emory University School of Medicine, Atlanta, Georgia 30329