PSEN1 and Alzheimer disease: By using 4-month old tgCRND8 and 18-month old APP/PS1 transgenic mice respectively, both glutamatergic and GABAergic presynaptic terminals were found elevated at early stage, but declined at late time point in the distinct AD mice models (Bell et al., 2003, 2006; Bell and Claudio Cuello, 2006; Marttinen et al., 2015).