Pathogenesis of Scrapie in the Mouse: the Role of the Spleen

Abstract

IN mice experimentally inoculated with scrapie agent, some sites for the early increase in titre lie within lympho reticular tissues, particularly the spleen^1,2. The time at which the agent can first be demonstrated to have increased in amount in the spleen depends on the host genotype² and also, probably, on other factors such as dose and strain of agent, which influence the overall time course of the disease^3,4. The incubation period after intracerebral inoculation of ME 7 scrapie agent prepared as a saline homogenate of infected brain is about two-thirds of that for an equivalent dose by the intraperitoneal route⁵. Further, after intracerebral inoculation, levels in the spleen rise marginally earlier than they do following intraperitoneal inoculation².