Old APPPS1 tissue was cultured alone (old alone, white bars) or incubated with conditioned media (CM) collected from young WT slices (old alone + young CM, gray bars). Analysis included co‐culture of old APPPS1 and young WT brain slices (old co‐culture, black bars) as a positive control and old APPPS1 tissue incubated with conditioned media collected from old APPPS1 slices (old alone + old CM, white squared bars) as a negative control. Quantitative analysis at 7, 11, and 14 DIV reveals increased numbers of core‐only plaques upon incubation of the old APPPS1 tissue with conditioned media collected from young WT slices, fully recapitulating core‐only plaque numbers observed in the co‐culture. The values are expressed as percentages of core‐only plaques from the total number of amyloid plaques and represent mean ± SEM from three independent experiments, each experiment including at least two independent slice culture dishes (n.s. = not significant, **P < 0.01, ***P < 0.001; unpaired two‐tailed Student's t‐test).
Old APPPS1 tissue was incubated with conditioned media collected from young WT slices previously treated with clodronate (old alone + young CM + Clo, gray bars) and vehicle control (old alone + young CM + Ctr, white bars). Quantitative analysis at 7, 11, and 14 DIV reveals decreased numbers of core‐only plaques upon incubation of the old APPPS1 tissue with conditioned media collected from young WT slices pre‐treated with Clo. The values are expressed as percentages of core‐only plaques from the total number of amyloid plaques and represent mean ± SEM from three independent experiments, each experiment including at least two independent slice culture dishes (n.s. = not significant, ***P < 0.001; unpaired two‐tailed Student's t‐test).
Old APPPS1 tissue was incubated with conditioned media collected from cultured WT primary microglial cells (old alone + MG CM, gray bar) or with unconditioned slice culture media as a control (old alone + Ctr, white bar). Quantitative analysis of core‐only plaques at 14 DIV reveals enhanced amyloid plaque clearance upon incubation of the old APPPS1 tissue with conditioned media collected from cultured primary microglia. The values are expressed as percentages of core‐only plaques from the total number of amyloid plaques and represent mean ± SEM from three independent experiments, each experiment including two independent slice culture dishes (*P < 0.05; unpaired two‐tailed Student's t‐test).