PSEN1 and Alzheimer disease: Noteworthy, the exuberant axonal sprouting observed in adult PS1 KImice selectively affects the hippocampal areas that are connected with entorhinal cortex/perforant path projections (Forster et al., 2006), which is reminiscent of the aberrant sprouting described in AD patients (Arendt, 2001; Geddes et al., 1985; Masliah et al., 1991; Rekart et al., 2004).