Figure 5

Effect of α-SYN over-expression on dopaminergic neurodegeneration in wild-type and FcγR-/- mice. A-D) The SN of wild-type and FcγR-/- mice expressing α-SYN or GFP was stained for tyrosine hydroxylase 24 weeks after treatment. The images depict a representative sample of the injected side of the SN of the four treatment groups. E) Counts of TH positive neurons using unbiased stereology. The wild-type mice treated with AAV2-SYN revealed a significant reduction in dopamine neuron count in the injected side compared to the un-injected side. No significant loss of dopamine neurons was observed in wild-type mice treated with AAV2-GFP and FcγR-/- mice expressing GFP/SYN. *p < 0.05, one-tailed t test, ipsilateral vs contralateral in WT SYN mice. F-K) Representative neurite samples of WT AAV2-SYN and FcγR-/- AAV2-SYN mice. The α-SYN(green)-expressing neuron in WT mice has little TH (red) staining in the beaded degenerating neurite, while FcγR-/- mice are protected from neuritic change. Panel H and K are high-magnification images of the neurites in the square of panel G and J respectively. Scale bars: panels A, B, C, D bar = 200 μm; panels F, G, I, J bar = 25 μm; panels H, K bar = 6 um.