1. Neuroimaging Research Branch; National Institute on Drug Abuse; National Institutes of Health; Baltimore MD USA
2. Departments of Psychiatry, Radiology, and Bioengineering; University of Illinois at Chicago; Chicago IL USA
3. Division of Clinical Research; National Institute of Allergy and Infectious Diseases; National Institutes of Health; Frederick MD USA
4. Preclinical Pharmacology Section; National Institute on Drug Abuse; National Institutes of Health; Baltimore MD USA