Early accumulation of pathological PrP in the enteric nervous system and gut-associated lymphoid tissue of hamsters orally infected with scrapie

Infection of the central nervous system [CNS] is a defining feature of scra pie. Several findings suggest that scrapie agent invades the CNS via the sp lanchnic and vagus nerve after ingestion of infectivity. Here we address th e involvement of the enteric nervous system (ENS) and gut-associated lympho id tissue (GALT) in this pathogenetic process. Immunocytochemistry was used for the detection of pathological PrP in the duodenum and ileum of hamster s fed with 263K scrapie and sacrificed at different stages of incubation. T he experiments revealed early infection of various GALT components and of s ubmucosal and myenteric ENS ganglia. These results provide evidence for an important role of the ENS in scrapie neuroinvasion and for centripetal vaga l spread of infection from the gut to the brain after oral uptake of agent. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.