Figure 7.

Effect of proinflammatory cytokines on neurotrophin and neuropeptide gene expression in nucleus pulposus cells. Histograms illustrating the relative gene expression of (a) nerve growth factor (NGF), (b) brain-derived neurotrophic factor (BDNF) and (c) substance P in nondegenerate and degenerate nucleus pulposus (NP) cells cultured with IL-1β and TNFα normalised to 18s and untreated controls. *Significance between IL-1β treatment and untreated control, **significance between IL-1β and TNFα treatments (P < 0.05). Data presented as the mean ± standard error of the mean.