Figure 1.

Alzheimer's pathology accelerates prion disease in mice models. A, To assess the effect of AD neuropathology in the onset of prion disease, we inoculated intraperitoneally Tg2576 mice with RML prions at 365 (orange line) and 45 (green line) days of age. As control, age-matched WT mice (nontransgenic littermates) were inoculated with the same stock and quantity of the infectious agent (black line). WT animals infected at 45 or 365 d of age developed prion disease at very similar times, and thus the data for these two groups are presented together in the graph. Clinical signs were assessed as described in Materials and Methods. When animals were definitively diagnosed with prion disease, they were killed to avoid additional pain. The data show that both groups of Tg2576-inoculated mice develop prion disease in a shorter time compared with age-matched WT controls. In addition, we performed a second infectivity passage in WT mice by inoculating infectious material from the brain of a sick Tg2576 animal injected at 365 d of age (blue line). B, Average of incubation periods of the different groups shown in A, including the statistical comparison between each experimental group with the WT control mice. The statistical analysis was done using the Student t test.