maintained in standard housing conditions, survival of new astrocytes is compromised as well (Wen et al., 2004). Using PS1M146V knockin mice Wang and colleagues show that the number of newly formed cells and neurons in the hippocampus of these mice is decreased compared to wild type mice and that impaired neurogenesis correlates with deficient associative learning (Wang et al., 2004). In contrast, PS1KO mice rescued with PS1A246 exhibit increased proliferation of newly born cells in the dentate gyrus compared to mice rescued with PS1HWT, but no difference in extent of differentiation (Chevallier et al., 2005).
