Neuronal autophagy in experimental scrapie.

In this study we report the formation of giant autophagic vacuoles (AV) in neurons in experimental scrapie in hamsters. Autophagy is an important step in the cellular turnover of proteins and organelles. It is known to occur in neurons under physiological as under pathological conditions. Giant AV, however, are seen very rarely only in pathological states. In our model AV are much more numerous after intracerebral (i.c.) transmission of the scrapie agent than after the transmission via the intraperitoneal route which points to a correlation between the intensity of the process and the period of incubation. As the appearance of the AV in our model is correlated chronologically with that of scrapie-associated fibrils, at least after i.c. transmission, the process may be related to a disturbance of cellular protein metabolism and, thus, to the processing of prion protein.