In the present study, we employed the PQ-induced Drosophila model of PD that was developed in our laboratory (Phom et al., 2014) and demonstrated that in PD brain DAergic neuronal number remains unaffected but the FI of the secondary antibody that targets the primary anti-TH antibody (TH is a rate-limiting enzyme in the dopamine synthesis and marker protein for DAergic neurons) decreased as compared with control suggesting the neurodegeneration. The gene discussed is TH; the disease is Parkinson disease.