PSEN1 and Alzheimer disease: Exaggerated BB-induced intracellular calcium release hasbeen demonstrated in fibroblasts and neurons from genetically modified mice bearinga mutation in the presenilin-1 (PS-1) mutation.18 These transgenic mice have been developed as a usefulanimal model since mutations in the presenilin-1 (PS1) gene on chromosome 14 arecausally linked to many cases of early-onset inherited AD.18,19Importantly, the alterations in BB-induced enhancement of calcium signaling observedin this mouse model resemble those described in patients with AD.