The primary mission of the Pain Focus Group is to stimulate the study and management of chronic or persistent pain conditions of cutaneous and deep tissue origin. The program is diverse and spans the basic and clinicial sciences from molecular studies to clinical trial studies. A secondary mission is to transfer the research findings to health professionals and the public via outreach and demonstration projects in the community.
Our working model is that research on pain has reached a level of understanding that facilitates the transfer of basic knowledge to the study of persistent pain in humans and, ultimately, to new methods of diagnosing and treating these conditions in the general population. Further advances will require multidisciplinary collaborations among basic and clinical scientists and clinicians. A multidisciplinary University of Maryland Organized Research Center in the thematic area of persistent pain has been formed to facilitate the mission of the Group.
Major advances have been made in our understanding of some of the basic mechanisms of persistent pain, including the identification and cloning of peripheral receptors and their changes in excitability associated with injury, the central nervous system changes that result from the persistent neuronal barrage arising from sites of injury, and the role of descending modulatory mechanisms in engaging the attentional, motivational and cognitive substrates that influence how we perceive pain. Nevertheless, important gaps in our knowledge remain. Research programs at the University of Maryland have utilized the latest advances in biomedical technology to extend our knowledge about the functional properties of peripheral nociceptors located in the skin, muscle and viscera and their biophysical properties. Nociceptors in the skin have a special class of sodium channels in their membrane which appears to enhance their ability to respond to tissue-damaging stimulation. We know much less about the peripheral and central nervous system characteristics of visceral nociceptive pathways in the nervous system, and researchers are learning about sodium channels in visceral nociceptors, how the spinal cord processes visceral information, and how this information is modulated by descending pathways in the brain. Other studies have shown that tissue damage and inflammation leads to dynamic changes in descending pain modulatory circuitry that has important implications for our understanding of diffuse pain conditions arising from deep tissues such as fibromyalgia, irritable bowel syndrome and low back pain. Tissue injury leads to increases in neuronal excitability at the spinal cord level and in descending pain modulatory circuits originating from the brain stem. These changes involve alterations in the phosphorylation of glutamate receptor subunits, changes in their gene expression, as well as changes in the functional properties of the neurons.
Another important finding being investigated is the new knowledge that neonatal tissue injury in animals and children can lead to changes in the development of pain circuitry in peripheral and ascending and descending pain pathways in the brain. These changes often increase our response to painful stimulation as adults. New research is investigating noninvasive approaches that will provide protection against these developmental changes in newborn infants and preterm neonates. Other important research is examining how higher centers in the brain process information about pain using modern imaging techniques in patients and human subjects. These techniques are helping research scientists at the University of Maryland better understand how the sensory, attentional, cognitive and emotional components of the pain experience are encoded and how they can be modified. Related studies examine gender related differences in higher center pain processing and changes associated with chronic and debilitating pain conditions. Researchers are also interested in the etiology and treatment of temporomandibular disorders, low back pain and fibromyalgia. Acupuncture studies are underway to determine their usefulness in the management of various pain conditions. In summary, this group of scientists brings multidisciplinary expertise to study all aspects of pain and its management and the University of Maryland Center to Advance Chronic Pain Research is recognized for its leadership role in this field.