CNR1 and Alzheimer disease: Consistent with the human findings, CB1R expression was also reduced in the cortex of 5xFAD mice and in the hippocampus of Tg4-42 mice.<h4>Conclusions</h4>Our data demonstrate a region-specific downregulation of CB1R in both human AD brains and transgenic mouse models, which correlates with key neuropathological hallmarks of the disease.