PSEN1 and Alzheimer disease: To explore whether the NPS/NPSR system is involved in the pathology of AD, we assessed the expression of NPSR in AD mice and found that there was a marked decrease of NPSR in APP/PS1 mice compared to WT mice (Figures 1A,B; two-sample Student’s t-test: t = 4.51, #p = 0.0107).