CNR1 and Alzheimer disease: To better understand the ECS involvement in AD and support development of ECS-targeted therapies, this study aimed to investigate changes in CB1 and MAGL expression and availability in an aging transgenic mouse model of AD by PET imaging using [18F]FMPEP-d212 and [18F]MAGL-2102, 13, respectively, and validate results with autoradiography (ARG), immunofluorescence (IF), and western blotting.