High-Dose Neural Stem/Progenitor Cell Transplantation Increases Engraftment and Neuronal Distribution and Promotes Functional Recovery in Rats after Acutely Severe Spinal Cord Injury

Figure 3

Abundant NF-positive neuronal fibers regenerated at the injury site in the high-dose group. (a–c) Representative images for longitudinal tissue section from the injury site with NF immunostaining showing NF-positive fibers regenerating in the high-dose, low-dose, and SCI group at 8 weeks postsurgery. Scale bars: 1 mm. (A1, B1, and C1) High magnification images from (a–c) showing NF-positive fibers in the center of injury areas (the white dotted lines indicated the boundary between the host spinal cord and the lesion area). Scale bars: 200 μm. (D-1, D-2, D-3, and D-4) Confocal images with z-stack revealing grafted GFP-expressing NSPC-derived NF-positive fibers in the high-dose group. Scale bars: 20 μm. (e) 8 weeks after surgery, quantitative analyses of the number of NF-positive fibers in the rostral, center, and caudal to the lesion area. Note that more NF-positive fibers appear to penetrate and occupy the entire area of the injury site in the high-dose group than the low-dose and SCI group, especially the central area of the injury site (A1), while seldom appear in the corresponding region in the low-dose group (B1) and even almost no in the corresponding region in the SCI group (C1). Besides, the number of NF-positive fibers at the central of the injury site in the low-dose group is higher than the SCI group (, , . NS: not significant, animals per group).

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