GDNF and Parkinson disease: In summary, as we previously highlighted when testing the effect of the glial cell line-derived neurotrophic factor (GDNF) in the AAV-α-synuclein rat model [15, 17], Our results support the view that the preclinical α-synuclein-based models of PD may be more informative than neurotoxin-induced models for the assessment of novel experimental therapies and the re-evaluation of strategies already trialed in clinic.