CNR1 and Alzheimer disease: We observed decreased CB1 availability on [18F]FMPEP-d2 imaging in female AppNL-G-F mice nearly brain-wide at 4-months (early-stage pathology) compared to male AppNL-G-F and female wt, which may be related to higher susceptibility of females to AD 15; though CB1 protein was decreased at 4-months in AppNL-G-F males and females.