Thus, reduced expression of p75NTR, which has been shown to slow down cognitive decline in an animal model of Alzheimer’s disease (Qian et al., 2018), not only inhibits the loss of hippocampal spines that we have previously described (Bachis et al., 2016b) but also precludes the impairment in memory observed in 8–10mo gp120tg mice. The gene discussed is NGFR; the disease is Alzheimer disease.