LRRK2 and Parkinson disease: We assessed whether PET imaging of [18F]FDOPA and [18F]fallypride could identify changes to respectively presynaptic function or dopamine receptor levels, using the Waxholm atlas (Fig. 1A), and compared susceptible dorsal versus spared ventral striatum (Fig. 1B), in LRRK2-R1441C and LRRK2-G2019S transgenic rat models of early PD, and assessed corresponding D2-receptor immunolabelling (Table 1).