Notably, the absence or reduction of receptors like signal regulatory protein α (SIRPα) and cannabinoid receptor 1 (CB1) on microglia, as well as the receptor CD2000 on neurons, can lead to an increased loss of synapses and cognitive impairment mediated by microglia and phagocytosis (291–294). This evidence concerns the gene CNR1 and Cognitive impairment.