PRNP and scrapie: We show here that different light microscopic types of abnormal PrP (PrPd) accumulation found in each of 10 sheep scrapie cases correspond ultrastructurally with abnormal endocytosis, increased endo‐lysosomes, microfolding of plasma membranes, extracellular PrPd release and intercellular PrPd transfer of neurons and/or glia.