Echigo-1: a panencephalopathic strain of creutzfeldt-jakob disease. I. neuropathological and immunohistochemical studies.

We demonstrate an unusually intensive accumulation of prion protein (PrP) on neuronal membranes in hamsters infected with the Echigo-1 panencephalopathic strain of Creutzfeldt-Jakob disease. This stands in strong contrast with the poor vacuolation in this model. Several distinct patterns of PrP(TSE) deposit were observed in the brain. The first type consisted of a fine granular "synaptic"/diffuse type of accumulation which, especially in the cerebral cortex, appeared laminar. Deposits frequently coalesced to form plaque-like structures. The second pattern consisted of perivascular plaque-like accumulations. When a vessel was cut longitudinally, these formed long linear arrays of plaques and smaller globules. The third, and most striking, consisted of perineuronal deposits. These formed small dots and coarser globules which were densely situated on the neuronal membrane on both cell bodies and their processes.