Extended Data Fig. 8. Functional consequences of TAM deletion in APP/PS1 mice.

(a) Quantification of the 3D colocalization of the excitatory pre- and post-synaptic markers vGlut1 and PSD95 in the 15mo hippocampus (CA1) (see Methods), as an index of synaptic connectivity. The previously documented decrease in co-localization of these markers in APP/PS1 mice is not altered by the combined mutation of Axl and Mertk. Stack size is 85 × 85 ×3 μm³ per image, averaged 3 images per CA1 section across 3–5 sections per mouse. Data points represent synaptic density index in n = 3 mice of the indicated genotypes. (b) Acquisition of association between a 30 s auditory tone and a subsequent co-terminal 2 s 0.5 mA foot shock, expressed as percent time immobile (% freezing) during the indicated intervals, over three successive trial intervals in 15 mo mice of the indicated genotypes (see Methods). (c) Data in b plotted for the indicated genotypes with the indicated statistical significance per interval. (d) Contextual fear memory as assayed by percent of a 3 minute interval in which mice of the indicated genotypes were immobile (% freezing) when returned to the same testing cage 24 h after the fear acquisition trials of h (see Methods). A cohort of group-housed male mice (n = 12–20/group) were used in the behavioral assay. Data points in h represent the mean % freezing of each group in the interval duration immediately prior to the point. Each data point in d is the % freezing of one animal in the duration of the testing period. Kruskal Wallis test followed by Dunn’s multiple comparison test (a) and Mann-Whitney test (c, d). Data are represented as mean ±1 STD.