Figure 7.

The effect of the non-coding AAV2/6 injection on the levels of tyrosine hydroxylase (TH) in the striatum and substantia nigra pars compacta (SNc) by immunohistochemistry. (A) Quantification of TH immunoreactivity in DAB-stained striatal slices. Microinjections of the non-coding AAV2/6 vector at the dose of 2×10⁷ TUs induced mild decreases in striatal TH immunoreactivity in both saline- and METH-treated rats (−13% and −21%, respectively). Data was analyzed by one-way ANOVA followed by the Student-Newman-Keuls post-hoc test (F(5,22) =10.739, p<0.001). ***p<0.001, **p<0.01, ^*p<0.05, significant difference between saline and METH; #p<0.05, ^tp=0.051, significant difference or a trend between injected and non-injected; mean ± SEM, n=4-6. (B) Representative images of TH and DAPI immunolabeling in the SNc injected with 2×10⁷ TUs of the non-coding AAV2/6. AAV2/6-injected SNc had slightly lower TH levels than contralateral non-injected SNc. Bar: 1000 μm. (C) Evaluation of nigral DA cell death. Quantification of DAPI-positive (blue) nuclei in TH-positive (red) nigral cells resulted in the same number of nuclei/area in AAV2/6-injected as in non-injected SNc (p>0.05, unpaired two-tailed, Student’s t-test, t=0.3926, df=10, n=6). Abbreviations: AAV vector, adeno-associated viral vector; METH, methamphetamine.