Similarly, in the 6-OHDA rat model of PD, chronic (10 days) infusion of platelet-derived growth factor (PDGF-BB) and brain-derived neurotrophic factor (BDNF) results in the generation of newly-formed cells in the striatum and SN, but these cells do not demonstrate the expression pattern of striatal mature projection neurons or dopaminergic neurons in SN [247]. The gene discussed is BDNF; the disease is Parkinson disease.