ABNORMAL FIBRILS FROM SCRAPIE-INFECTED BRAIN

Abnormal fibrillary structures, designated scrapie-associated fibrils (SAF), were observed using negative stain techniques in subfractions of brains from scrapie-affected animals (mice and hamsters). SAF were observed in all combinations of a strain of scrapie agent and a strain or species of host examined. The presence or absence of amyloid plaques is discussed. The histopathology of disease specimens is described. SAF consist of 2 or 4 filaments. They are morphologically dissimilar to the normal brain fibrils such as microtubules, neurofilaments, glial filaments and F actin. SAF bear a resemblance to amyloid.