Robert C. Coghill, PhD
Brain Mechanisms of Pain
Robert C. Coghill, PhD
The capacity to monitor the integrity of our bodies and to be made immediately aware of injury through the experience of pain is critical for our survival. Individuals who are born without this capacity frequently die at relatively young ages from injuries that they never felt.
In a reflection of the critical nature of this sensory experience, central nervous system mechanisms subserving the processing of pain are organized in a fashion that makes them highly resistant to disruption. Information processing is distributed across multiple brain regions and transmitted via parallel pathways. Thus, if any one pathway or region becomes damaged, other regions and other pathways are still available to contribute to this experience. This resiliency of pain processing mechanisms is clearly in evidence in many cases of chronic pain – pain which persists long after healing has occurred. Many forms of chronic pain, particularly those arising from damage to nerves, fail to respond to conventional treatments and cause an incalculable degree of both emotional and economic hardship.
The overall goal of this research is to better understand the functional organization of central nervous system mechanisms involved in the conscious experience of pain and to relate the implications of this organization to clinical pain states. Functional imaging methods, such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) in humans and autoradiography in animals, provide the major tools that allow us to peer inside the functioning nervous system to observe the responses of multiple brain regions simultaneously. Electrophysiological recordings of single neurons allow finer insights into the organization of pain processing mechanisms.
Pain, however, is very much an individual experience and is heavily influenced by environmental, emotional, and cognitive variables. Accordingly, psychological, experiential data is critical for the interpretation of neuroimaging data. Through these combined approaches, we hope to obtain a better basic understanding of central nervous system mechanisms engaged in the processing of pain, and lay the foundation for better diagnosis and treatment of clinical pain.
Coghill, R.C., McHaffie, J.G., Yen, Y. Neural correlates of inter-individual differences in the subjective experience of pain. Proc. Nat. Acad. Sci. (in press)
Koyama, T., McHaffie, J.G., Laurienti, P.J., Coghill, R.C. The single-epoch design: validation of a simplified paradigm for the collection of subjective ratings. NeuroImage (in press)
Grill, J.D., Coghill, R.C. Transient analgesia evoked by noxious stimulus offset. J. Neurophysiology 87:2205-8, 2002.
Coghill R.C., Gilron I., Iadarola M.J. Hemispheric lateralization of somatosensory processing. J. Neurophysiol. 85:2602-12, 2001.
Coghill, R.C., Sang, C.N., Maisog, J.M., Iadarola, M.J. Pain intensity processing within the human brain: A bilateral, distributed mechanism. J.Neurophysiology. 82:1934-43, 1999
Coghill, R.C., Sang, C.N., Berman, K.F., Bennett, G.J., Iadarola, M.J. Global cerebral blood flow decreases during pain. J. Cerebral Blood Flow and Metabolism 18:141-147, 1998
Coghill, R.C., Talbot, J.D., Meyer, E., Gjedde, A., Evans, A.C., Bushnell, M.C., and Duncan, G.H.. Distributed processing of pain and vibration in the human brain. J. Neuroscience 14:4095-4108, 1994.
Coghill, R.C., Mayer, D.J., and Price, D.D. The roles of spatial recruitment and discharge frequency in nociception in spinal cord coding of pain: A combined electrophysiological and imaging investigation. Pain 53:295-309, 1993.
Coghill, R.C., Mayer, D.J., and Price, D.D. Wide dynamic range but not nociceptive specific neurons encode multidimensional features of prolonged repetitive heat pain. J. Neurophysiol. 69:703-716, 1993.
Coghill, R.C., Price, D.D., Hayes, R.L. and Mayer, D.J. Spatial distribution of nociceptive processing in the rat spinal cord. J. Neurophysiol. 65:133-140, 1991