Figure 3.

Local and supraspinal axons regenerate into neurotrophin-secreting cell grafts in the lesioned primate spinal cord. A, Neurofilament-labeled axons extend into the cellular matrix spontaneously filling the lesion in a nongrafted injury site, 8 months after injury. B, C, Significantly greater numbers of neurofilament-labeled axons penetrate the lesion site in subjects that received grafts of autologous fibroblasts genetically modified to secrete BDNF and NT-3 (B), quantified in C (*p < 0.05). D–F, Raphespinal axons grow into control lesion site (D) but exhibit a 2.5-fold increase in growth into BDNF/NT-3-secreting grafts (E), quantified in F. G–I, Cerulospinal axons labeled by TH exhibit little growth into control lesion site (G), but growth is significantly increased in the presence of growth factors (H), quantified in I. Error bars indicate SEM. Scale bars: B (for A, B), E (for D, E), H (for G, H), 25 μm.