Extracerebrospinal structures of the autonomous nervous system between intestinal tract and central nervous system as BSE-risk materials - Assessment of meat processing and meat deboning - 2. Nervus vagus [German]

摘要

On the basis of findings in studies about experimentally infected animals, the pathway of pathogenic prions is probably leading from the initial entrance in the gut wall directly via the vagus nerve to the obex region in the Medulla oblongata of the brain. Particularly in some studies, pathogenic prions were detected earlier in the dorsal motor nucleus of the vagus nerve than in thoracic segments of the spinal cord, the latter represents the infection's most frequent entrance into the central nervous system. Because the infection route to be covered is disminished through the by-pass of the spinal cord, it may metaphorically named a,short cut". The infection of the spinal cord as a frequent finding in BSE subsequently could occur in a descending way via the medulla oblongata and/or in an ascending way directly from the intestine via the sympathetic nervous system. In accordance with the working hypothesis that the membrane-bound prion protein is mainly expressed on neuronal surfaces, and consequently nerve cell bodies along neural pathways from intestinal tract to the central nervous system should be regarded as SRM, the whereabouts of the vagus nerve deserve attentiveness during slaughter and carving. The following modifications concerning the slaughter-processing including further processing are proposed: