Dr. Sonntag received his MD degree in 1993 and his PhD degree in virology in 1994 from University of Heidelberg, Germany. After an internship in internal medicine from 1993-1994, he worked as a research scientist at the Department of Virology at University of Heidelberg until 1995 when he became a research fellow in the Transplantation Biology Research Center, Massachusetts General Hospital, Boston. In 2000, he took a position as an assistant research stem cell biologist and instructor at the Center for Neuroregeneration, McLean Hospital, Belmont, MA. In 2004, he was promoted to associate stem cell biologist, and in 2005 to assistant professor in psychiatry (Neuroscience), Harvard Medical School. Dr. Sonntag is a molecular and cellular biologist and has extensive expertise in the fields of virology, immunology, stem cell biology, and neurobiology. He uses primary cells and the induced pluripotent stem cell paradigm and lentivirus vector systems to develop in vitro models of neuropsychiatric disorders and study mechanisms in aging and neurodegeneration on the molecular, cellular, and biochemical level with a current focus on understanding a role of bioenergetics and metabolism in Alzheimer's disease. In addition, he has extensive expertise in analyzing the gene expression networks in neurons isolated from postmortem brains. Dr. Sonntag has served as debuty or assistant editor on EJN, Brain Research, Stem Cells, and WJSC, and has been a member on the editorial boards of Brain and Behavior, ISRN Stem Cells, JTM, TMC,JoVE, Cells, and Frontiers in Aging Neuroscience.