PRRT2 and Cognitive impairment: To further confirm the neuroprotective effects of A1R signaling on cognitive impairment induced by CIH, we examined the levels of four downstream proteins—PKC, PKC-ζ, Gα(i), and syntaxin in the hippocampus after CIH (Okada et al., 2001; Di-Capua et al., 2003; Crawford et al., 2011; Rombo et al., 2016).