expression of this Aβ degrading enzyme (Belyaev et al., 2009; Pardossi-Piquard et al., 2005). Recent studies have revealed that Aβ42 enhances the survival and differentiation of progenitor cells (Lopez-Toledano and Shelanski, 2004) or compromise these processes (Haughey et al., 2002a; Calafiore et al., 2006; Mazur-Kolecka et al., 2006; Millet et al., 2005). This controversy may be the result of the use of variable Aβ preparations in vitro, exhibiting differential conformations.
