Effects of Neutralizing Antibodies to Tumor Necrosis Factor-Alpha on Nucleus Pulposus–Induced Abnormal Nociresponses in Rat Dorsal Horn Neurons

STUDY DESIGN: The effect of an anti-tumor necrosis factor alpha (anti-TNFalpha) antibody on abnormal discharges caused by application of nucleus pulposus to the nerve root was investigated in an electrophysiologic study. OBJECTIVES: To assess whether inhibition of TNFalpha can reduce nucleus pulposus-induced abnormal discharges. SUMMARY OF BACKGROUND DATA: It has been shown that TNFalpha, a proinflammatory cytokine, is a key pathogenic factor in the development of nucleus pulposus-induced abnormal discharges as a pain sensation. However, the electrophysiologic mechanisms involved in sciatica after disc herniation still have not been elucidated. METHODS: Extracellular activities of wide-dynamic-range neurons were assessed in 21 rats. Autologous nucleus pulposus harvested from the tail was applied to the L5 nerve root. The animals were simultaneously treated with…