It was shown that a significant increase in microglial activation is marked by ionized calcium binding adaptor molecule-1 (Iba-1) (Rodriguez-Pallares et al., 2007), accompanied by a reduction in TH-ir neurons in PD model rats with saline treatment, while the vehicle group did not present any visible difference between the ipsilateral and the contralateral sides. This evidence concerns the gene AIF1 and Parkinson disease.