FIGURE 6. Reduced inhibitory microenvironment leads to enhanced caudal axonal densities and promotes functional recovery after SCI.

(a) A schematic diagram illustrating the transplantation of MP-scaffold in a mouse T8 hemisection model. (b) Proposed mechanism for MP-scaffold-enhanced functional recovery by suppressed inflammation, reduced fibrotic scarring and enhanced axonal growth. (c) Timeline of the long-term in vivo experiments. (d) Representative immunostaining images of the spinal cord from the control (SCI with scaffold implantation) and experimental (SCI with MP-scaffold implantation) conditions illustrating the overall serotonergic (5-HT) axonal density 28 days after the injury (left panel). Magnified views of the immunohistochemical staining images are shown in the middle and right panels, demonstrating the presence of axonal growth caudal to the lesion site (arrows indicate 5-HT labeled axons). (e) Quantification of the distance-dependent distribution of axonal numbers (per section) 1-month post-injury show higher axonal density in the MP-scaffold-treated animal groups. Error bar represents standard deviation around the mean. *p<0.05 by Student’s t-test, n=7 animals for both groups. 4-5 tissue sections were analyzed and then averaged for each animal. (f) BMS scores of the control and experimental conditions indicating an accelerated functional recovery from the experimental condition compared to the control. Whereas most animals in the control group only achieved scores at dorsal stepping, the experimental group present significantly higher functional scores. n=12 and 11 animals for the experimental group and control group, respectively. Error bar represents standard error around the mean. *p<0.05 by student’s t-test.