Pathological PrP is abundant in sympathetic and sensory ganglia of hamsters fed with scrapie

Although the ultimate target of infection is the CNS, there is evidence tha t the peripheral nervous system (PNS) is involved in the pathogenesis of Tr ansmissible Spongiform Encephalopathies (TSEs). We used immunocytochemistry to identify the presence of pathological accumulations of a host protein, PrP, in the CNS and PNS (sensory and autonomic ganglia) of hamsters orally infected with 263K scrapie. All hamsters showed pathological deposition of PrP in most brain areas, along the length of the spinal cord, in nodose (NG ) and dorsal root (DRG) ganglia and in the coeliac mesenteric ganglion comp lex (CMGC). In one case, scant deposition was observed along a few axons of the vagus nerve. This finding suggests that, after oral challenge, TSE inf ectious agent uses neural pathways and ganglia of the peripheral nervous sy stem to reach target sites in the CNS. (C) 1999 Elsevier Science Ireland Lt d. All rights reserved.