APP−/− mice were kindly provided by Dr. Hui Zheng (Zheng et al., 1995) and were backcrossed to C57BL/6 for more than 10 generations. The mice were kept as heterozyqous (APP+/−) or homozygous knock-out (APP−/−) background. All animal procedures were approved by the Institutional Animal Care and Use Committee at UCSD, and in accordance with the National Institutes of Health guidelines.
