Cells positive for brain-derived neurotrophic factor localization. Mean percentages of cells positive for brain-derived neurotrophic factor (BDNF) localization are shown here for the outer annulus (OA, n = 22), the inner annulus (IA, n = 6), and the nucleus (nuc, n = 4). The mean percentage in the OA is significantly greater than that present in IA or in nuc (P ≤ 0.01). Data presented as the mean ± standard error of the mean.
Gruber et al. Arthritis Research & Therapy 2008 10:R82 doi:10.1186/ar2456