Figure 6

IgG increases neurobehavioral recovery and axonal function. (A) Hind-limb functional recovery was assessed weekly for 6 weeks following SCI. Scores were assigned according to the Basso Beattie Bresnahan (BBB) Scale. Sham animals (n = 4) displayed no hind-limb functional deficits and were given a score of 21. IgG treatment was associated with significant improvement in hind-limb functional recovery (two-way ANOVA P <0.001). The differences in BBB scores between IgG- and saline-treated animals were statistically significant at weeks 2, 3, 5, and 6 (Bonferroni post-hoc test P <0.001, P = 0.015, P = 0.031, and P = 0.017, respectively). (B) The inclined plane test was used to assess functional recovery of the saline (n = 13) and IgG (n = 14) groups. The inclined plane test measures the hind- and forelimb strength and coordination necessary to maintain a horizontal position on an inclined plane. Larger inclined angles are associated with better functional recovery. At weeks 5 and 6, IgG-treated animals performed significantly better than saline-treated animals on the inclined plane test (two-way ANOVA P <0.001; Bonferroni post-hoc test week 5 P = 0.012 and week 6 P <0.001). (C) Motor-evoked potentials (MEPs) were recorded in injured spinal cords at 6 weeks following SCI. Conduction velocity in both the IgG and vehicle control group was significantly reduced compared to uninjured sham rats (one-way ANOVA P <0.05; Bonferroni post-hoc test P <0.01). IgG-treated animals demonstrated significantly faster conduction velocities compared to saline control animals (P = 0.03). (E) Schematic diagram showing how MEPs was recorded in the injured spinal cords at 6 weeks following SCI.