Anatomical evidence for ileal Peyer's patches innervation by enteric nervous system: A potential route for prion neuroinvasion?

Abstract

We have examined the innervation of the gut-associated lymphoid system of the sheep ileum, with a view to identifying potential sites for neuroinvasion by pathogens, such as prions (PrPSc). Special attention has been paid to the follicles of Peyer's patches (PPs), which are major sites of PrP Sc accumulation during infection. Evidence exists that the enteric nervous system, together with the parasympathetic and sympathetic pathways projecting to the intestine, are important for PrPSc entry into the central nervous system. Thus, PrPSc might move from PPs to the neurons and nerve fibres that innervate them. We investigated, by immunohistochemistry and retrograde tracing (DiI) from the follicle..