MAPT and Cognitive impairment: Several lines of evidence suggest that abnormal phosphorylation of soluble tau causes synapse loss, impaired synaptic function, disrupted axonal transport, and cognitive deficits (DeKosky and Scheff, 1990; Callahan and Coleman, 1995; Mandelkow et al., 2003; Thies and Mandelkow, 2007; Hoover et al., 2010).