PRNP and ischemia: However, because NMDA receptor hyperfunction contributes to cell death in ischemia (Lau and Tymianski, 2010; Lai et al., 2014), and since NMDA receptor desensitization is reduced in the absence of PrPC (You et al., 2012), enhanced NMDA receptor-mediated Ca2+ influx may very well contribute to the increased ischemia-induced cell death that is observed in PrPC-null mice.