Increased mortality in IL1raKO mice during Aβ infusion. Alzet pumps containing Aβ1–42 or vehicle were surgically implanted in IL1raKO and WT littermate mice (n = 10–12 mice per Aβ-infused group; n = 5 mice per vehicle-infused group), and post-operative survival was monitored for 42 days. Kaplan-Meier survival curves show that WT mice infused with vehicle or Aβ, and IL1raKO mice infused with vehicle experienced no mortality during the time period. In contrast, Aβ-infused IL1raKO mice experienced a 50% mortality rate (6 of the 12 animals died before 42 days). This mortality was significantly different from the other experimental and control groups (error bars = SEM; p < 0.05).