BDNF and Parkinson disease: Fontanesi et al. (80) found that 4 weeks of comprehensive rehabilitation training (combined functional, aerobic, and goal-directed training) improved motor and non-motor symptoms in patients with PD at clinical stage 2–3, and significantly upregulated brain derived neurotrophic factor-TrkB signal transduction; further analysis showed that the Unified Parkinson’s Disease Rating Scale scores of patients with PD were significantly positively correlated with upregulation of the TrkB protein, suggesting that exercise may slow disease progression by this mechanism.