To determine whether p75NTR modulation could affect final common pathways of AD-related spine loss in vivo, effects of LM11A-31 were determined in an APP-mutant AD mouse model, APPL/S, which exhibit amyloid plaques starting at age 3–4 months43 and reduced spine densities by age 7.0–7.5 months (unpublished data, Longo Laboratory). The gene discussed is APP; the disease is Alzheimer disease.