Figure 1From: Expression and regulation of neurotrophins in the nondegenerate and degenerate human intervertebral discNerve growth factor expression in human intervertebral disc tissue. Nerve growth factor (NGF) protein expression was identified in (a), (c) the chondrocyte-like cells of human nucleus pulposus and inner annulus fibrosus tissue, and (e) the fibroblast-like cells of the outer annulus fibrosus. (b), (d), (f) IgG controls were negative. Scale bar = 50 μm.Back to article page