Address all correspondence and requests for reprints to: Stephen G. Waxman, MD, PhD, Department of Neurology, LCI 707, Yale Medical School, 333 Cedar Street, New Haven, CT 06510; email: stephen. waxman@ yale. edu. by changes in physiological properties that contribute to hyperexcitability in these cells. Sodium channel expression is also altered in experimental models of inflammatory pain. The multiplicity of sodium channels, and the dynamic nature of their expression, makes them important targets for pharmacologic manipulation in the search for new therapies for pain.