Figure 5.

Axon Outgrowth along the Nigrostriatal Pathway

(A) Quantification of TH+ axon growth along the nigrostriatal pathway shows a significant increase in the number of TH+ axons within the pathways of GDNF/GFRα1 (GG) and GDNF/netrin1 (GN) treatment groups compared to the control group injected with GFP. (B) Amphetamine-induced rotational tests for rats with different pathways with (+VM) and without (−VM) E14 VM transplants. Rats from the GDNF/netrin + VM (GN+VM) group showed significant recovery in rotational asymmetry at 8 and 10 weeks after transplantation (tp). Other rats did not display any significant rotational change for up to 10 weeks. (C) Correlation between the number of TH+ fiber growth along the pathways and the rotational change at 10 weeks after transplantation. There is a significant negative correlation between the number of TH+ fibers and the rotational change, indicating that the higher the number of TH+ fibers in the nigrostriatal pathway, the greater the decrease in rotational asymmetry, and the more functional recovery induced by the guidance pathway (Spearman rank correlation [r²] = 0.5061, p = 0.001). *p < 0.05; **p < 0.01; ***p < 0.001.