TH and Parkinson disease: ICV delivering oxytocin also significantly protected striatum TH level reduction in the MPTP‐induced PD model (TH change in Oxt & MPTP group relative to SAL & MPTP group: 140.3 ± 14.46%, n = 9 and 10 mice for SAL & MPTP and Oxt & MPTP groups, p < 0.05, unpaired t‐test) (Figure 2L,M).