“…Nonhuman primates treated with MPTP develop motor defects that closely resemble the behaviors in PD, including bradykinesia, rigidity and postural abnormalities, as well as other pathophysiological changes observed in PD patients, so the MPTP-treated monkey has been recognized as the gold standard model of PD ( Masilamoni and Smith, 2017 ). Common marmosets were subcutaneously administrated with MPTP (2.0 mg/kg) once daily for 5 days and exhibited significant and stable motor deficits, including a marked reduction in basal locomotor activity, poor coordination of movement, abnormal or rigid posture, reduced alertness, and head-checking movements ( Lincoln et al., 2016 ). The adult male cynomolgus monkeys, intravenously injected with MPTP (0.4 mg/kg) twice a week for more than 12 weeks, displayed stable parkinsonian symptoms, such as tremor, bradykinesia, and impaired balance ( Kikuchi et al., 2017 ).…”