Given that the SS4 insertion of presynaptic NRX1 increases postsynaptic NMDAR responses and thereby enhances NMDAR-dependent LTP at the hippocampal CA1-subiculum synapses (Dai et al., 2019), it is likely that the AβO binding to NRX1 SS4 site could impact NMDAR-dependent LTP, which is impaired by AβO treatment and in AD model mouse lines with Aβ overproduction (Wang et al., 2004; Hwang et al., 2017; Liu et al., 2019). Here, ABO is linked to Alzheimer disease.