P2RX7 and Alzheimer disease: It has been reported that Aβ1-42 can activate microglia through the P2X7 pathway, probably by binding directly to the P2X7 receptor.378 Mounting evidence has shown that there is an enrichment of P2X7-positive microglia around the senile plaques in human AD postmortem brain samples and AD mouse model.379,380 In vitro culturing of human microglia with amyloidogenic Aβ1-42 significantly improved the expression of P2X7.