We find that oxytocin signals are disturbed together with striatal TH level in the 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐induced PD model, modulating brain oxytocin level will change the MPTP‐induced neurotoxicity for nigrostriatal DA signals, and direct knocking out substantia nigra (SN) oxytocin receptors will induce the time‐dependent degeneration of SNc DA neurons via increasing DA excitotoxicity. The gene discussed is TH; the disease is Parkinson disease.