Creation of PS1M146V-KIN, InsP3R1Opt+/− (M146V/Opt) and 3xTg, InsP3R1Opt+/− (3xTg/Opt) mice. A, Immunofluorescence analysis of hippocampal slices from 5-week-old mice using an InsP3R1-specific antibody. B, Reverse transcriptase RT-PCR on hippocampal RNA from 3-month-old animals for PS1 expression. Unpaired two-tailed t test, n = 3 mice each, no significant differences observed. C, D, A C57BL/6 mouse carrying the Opt allele was crossed to a C57BL/6 mouse homozygote for the PS1M146V-KIN mutation. First-generation M146V+/−/Opt+/− mice were crossed to M146V+/− littermates without the Opt allele to isolate the Opt allele on the WT background and to generate the M146V/Opt line. E, F, A C57BL/6 mouse carrying the Opt allele was crossed to a C57BL/6/129S6 3xTg mouse (containing the PS1M146V-KIN mutation and the human APPSWE and tauP301L transgenes). E, First-generation 3xTg+/−/Opt+/− mice were backcrossed to parental 3xTg mice to restore the PS1M146V-KIN mutation to homozygosity and the APPSWE and tauP301L transgene copy number. Bar graph presents data from RT-PCR conducted on genomic DNA for APPSWE and tauP301L transgenes after six backcrosses to the 3xTg line. F, First-generation 3xTg+/−/Opt+/− mice were crossed to littermates without the Opt allele to generate the control lines. Error bars show mean and SEM.