Figure 2
GDNF administration leads to modest functional improvements in SOD1 rats. SOD1 rats administered AAV9-GDNF showed enhanced (a) forelimb but not (b) hindlimb grip strength over time relative to SOD1 AAV9(−)-injected controls (*P<0.05, two-way analysis of variance (ANOVA) error bars=s.e.m.). GDNF administration in WT rats did not lead to improved (c) forelimb or (d) hindlimb grip strength relative to saline- or (AAV9(−)-injected controls. (e) Forelimb and (f) hindlimb BBB scoring was performed to assess motor function deficits in SOD1 rats, and while there were no differences in hindlimb motor performance, (e, g) forelimb onset was significantly delayed after AAV9-GDNF administration relative to AAV9(−) controls (*P<0.05, Wilcoxon signed rank test). Differences in time of onset did not however translate into extended survival (h) as there was no difference between survival times in AAV9-GDNF- and AAV9(−)-injected SOD1 rats. Given that 70% of AAV9(−) and 60% of AAV9-GDNF rats showed onset in both limbs at the same time point or within 7 days of one another, and that each rat at end point exhibited a significant degree of both forelimb and hindlimb paralysis, rats were not further separated into groups based on fore- or hindlimb onset *P<0.05, two-way ANOVA error bars=s.e.m.
