S1PR1 and Alzheimer disease: Building upon our previous work with the S1PR1 targeting probe [18F]TZ4877, which was used to evaluate neuroinflammation in various physiological states and the effects of different therapeutic interventions,22, 23, 24 the present study aims to evaluate the effectiveness of EA therapy in APP/PS1 transgenic mice as an AD model; it also seeks to elucidate the mechanisms underlying EA therapy's ability in delaying the progression of AD, particularly regarding its impact on neuroinflammation.