Figure 1. Progression of Clinical Scores in MPTP treated monkeys.

Weekly clinical measures (mean ± SEM) for all monkeys aligned on MPTP treatment cessation (MPTP-Off). The shaded area corresponds to the symptomatic stage. During chronic low dose MPTP intoxication (MPTP) and prior to attaining the clinical threshold of 5, monkeys are considered as presymptomatic. After MPTP-Off, 3 monkeys spontaneously recovered to a non-symptomatic stage within 1–4 weeks while 1 monkey remained in a mild-symptomatic stage. Arrowheads in red indicate the time of MPTP onset for each animal.