Fig. 1

a Example of the of electrically evoked C-fiber responses in the dorsal horn neurons at baseline i.e., before and 180 min after the application of nucleus pulposus (NP) onto the dorsal nerve roots. b The time course of electrically evoked C-fiber responses expressed as the percent of baseline following the application of NP (black) and control (Ctrl, white); within subjects effects rmANOVA, p = 0.003. c Fold expression of IL-6 in NP tissue frozen directly (native) or 180 min after NP application onto the dorsal nerve roots (exposed) after harvesting. Students t test **p < 0.01. Data are given as the mean ± SEM