For over 40 years a major strategy in characterizing dorsal horn encoding mechanisms of pain has been to apply noxious stimuli to receptive fields of wide dynamic range (WDR) and more selectively nociceptive (ie, nociceptive specific) NS dorsal horn neurons and then compare their responses to those obtained in psychophysical studies that utilize these same types of stimuli ( and references therein]. Stimuli that apply noxious temperatures to the skin (eg, 43–51°C) optimally compare neuronal and psychophysical responses because spatial and temporal features of these stimuli can be precisely controlled. This approach has helped explain the roles of spatial and temporal summation as well as population coding in both normal and pathophysiological pain. However, this approach not only helps explain pain mechanisms but also quantitative sensory tests (QSTs) used to implicate enhanced or diminished neural responses in chronic pain conditions and predict clinical pain intensity.
Posted on July 31, 2013