18F-DPA-714 is a new PET ligand which labels microglial cells. The investigators aim to explore the topography and intensity of microglial activation in several different groups of PD patients: 1) de novo, drug-naïve subjects (n = 6); 2) non-fluctuating treated patients ("honeymoon") (n = 10); 3) advanced drug-responsive patients motor fluctuations (wearing-off or dyskinesia) (n = 6); 4) patients with LRRK2 gene mutation (n = 6); and 5) related to healthy patients carriers of the mutation LRRK2(n = 6). PET imaging will be performed with a new generation tomography having a very high resolution.