1. Neurobiology Research, Veterans Affairs Medical Center, Sepulveda, CA 91343 and and Department of Psychiatry and Brain Research Institute, UCLA School of Medicine, Los Angeles, CA 90024.
2. Department of Psychiatry, San Diego Veterans Affairs Medical Center, and University of California, La Jolla, CA 92093.
3. Department of Psychiatry, Stanford University School of Medicine, Palo Alto, CA 94305.