1. Magnetic Resonance Center for Research in Metabolism and Physiology, Departments of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut 06510;
2. Magnetic Resonance Center for Research in Metabolism and Physiology, Departments of Biomedical Engineering, Yale University School of Medicine, New Haven, Connecticut 06510;
3. Magnetic Resonance Center for Research in Metabolism and Physiology, Departments of Psychiatry, Yale University School of Medicine, New Haven, Connecticut 06510;
4. Magnetic Resonance Center for Research in Metabolism and Physiology, Departments of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06510;
5. Magnetic Resonance Center for Research in Metabolism and Physiology, Departments of Section of Bioimaging Sciences, Yale University School of Medicine, New Haven, Connecticut 06510;