Figure 5. α-syn overexpression-mediated forelimb motor impairments are duration-dependent.

A-C. Cylinder test; (A) 1.0 x 10¹³ vg/ml titer rAAV2/5-α-syn injected rats (■) displayed significant deficits in contralateral forepaw use at 8 weeks post vector injection compared to baseline (*, p = 0.045). 1.0 x 10¹⁴ vg/ml injected rats (☐), with equivalent SNpc THir neuron degeneration, displayed no significant deficits at 4 weeks post-vector injection (p > 0.05). B-C. Forelimb use was significantly correlated with TH expression in the lesioned striatum (B, r² = 0.84, p = 0.004), but not with surviving THir neuron numbers in the lesioned SNpc (C). D-F. Adjusting steps task; 1.0 x 10¹³ titer rAAV2/5-α-syn vector injected rats experienced significant reductions in contralateral forepaw use over 8 weeks (*p = 0.008, **p = 0.036) while 1.0 x 10¹⁴ titer injected rats did not (p > 0.05). E-F. Number of adjusting steps taken by the affected forepaw did not correlate with striatal THir expression or numbers of surviving THir nigral neurons. G-I. Bilateral tactile stimulation; no differences in time to contact the affected forepaw were observed in either titer group (p > 0.05) (G). H-I. The time to contact the affected forepaw was only moderately correlated to striatal THir expression (H, r² = 0.42) and numbers of surviving SNpc THir neurons (I, r² = 0.49).