GRIN2A and Alzheimer disease: However, disease progression may involve changes in the number and structure of glutamate receptors and GluN2B subunits, because the expression of GluN2B and GluN2A subunits are selectively changed, especially related to the conversion of GluN2B subunit to GluN2A subunit (Sheng et al., 1994; Okabe et al., 1998; Bi and Sze, 2002; Hynd et al., 2004; Rodenas-Ruano et al., 2012; Bagasrawala et al., 2017), which may result in an overall decline in synaptic function and severe cognitive impairment in the later stage of AD and VaD (Cao et al., 2007).