A. V. Apkarian
Apkar Vania Apkarian is a professor of neuroscience at Northwestern University. He has been a pioneer in the use of Magnetic resonance spectroscopy to study the neurochemistry of the brain. Dr.Apkarian has a master's degree in electrical engineering from the University of Southern California and earned a Ph.D. in neuroscience from the State University of New York Upstate Medical University in Syracuse, New York. He is the brother of V. A. Apkarian, a noted laser spectroscopist.
Dr. Apkarian has studied pain for two decades, both in animal models and fMRI studies in humans. His current interests include cortical dynamics of pain as well as brain plasticity. His overall goal is the uncovering of brain mechanisms underlying pain qualia. This process should hopefully traverse through the alleviation of clinical pain conditions, as well as a more profound theoretical and mechanistic understanding of the brain.
"A. Vania Apkarian and his colleagues at Northwestern University have found a series of abnormalities in the brains of chronic pain sufferers: the part of the prefrontal cortex linked to decision making appears to have shrunk in chronic pain patients. And another part of the prefrontal cortex linked to emotion is hyperactive. In fact, a unique study assessing background pain in chronic back-pain patients suggests that the constant pain these people experience is linked to activity almost entirely in emotion-regulating parts of the brain." 
Selected media coverage
Washington Post June 21, 2007 "'Memory Traces' May Help Spur Chronic Pain"
NY Times November 23, 2004 "Patterns: Pain and the Downsized Brain"
BBC November 23, 2004 "Pain link to permanent brain loss "
NY Times August 10, 1999 "Peering into the Brain To See Pain at Work"
Medical News: Pain Management February 6, 2008 "Chronic Pain Disrupts Resting Brain Dynamics"
Technology Review November 11, 2007 "The Brain in Chronic Pain"
Chicago Tribune July 3, 2007 "Sometimes physical pain can be traced to memory"
LA Times November 29, 2004 "Back pain linked to premature aging"
New Scientist November 27, 2004 "Does Back Pain Shrink Your Brain?"
Wissenchaft November 26, 2004 "Dauerhafte Rückenschmerzen lassen das Gehirn schrumpfen"