GLP1R and Alzheimer disease: The other GLP-1R agonist Exendin-4 also exhibited neuroprotective effects in a mouse model of AD (Li et al., 2010) and PD (Perry and Greig, 2005; Perry et al., 2007; Bertilsson et al., 2008; Harkavyi et al., 2008; Li et al., 2009; Eakin et al., 2013; Rachmany et al., 2013).