MAPT and Cognitive impairment: However, many basic studies and some clinical studies have found that anesthetic drugs can cause significant phosphorylation of tau protein, accompanied by cognitive impairment (Weingarten et al., 1975; Planel et al., 2007; Run et al., 2009; Tan et al., 2010; Tang et al., 2011; Le Freche et al., 2012).