GDNF and Parkinson disease: This suggests that in LC PD model GDNF levels are critical, as it has been shown that ectopic GDNF in high amounts (infused GDNF and AAV2-GDNF) is neuroprotective for SN dopaminergic neurons in lactacystin-treated mice (Du et al., 2008, 2013; d’Anglemont de Tassigny et al., 2015).