Examples of the brain PrPdprofile types encountered in different transmission groups. A: recipient AAS1: type A profile in cerebral cortex (note similarities with Figure 2a); inset, recipient AAS10 (type A) illustrating the absence of intracellular PrPd in deep cerebellar nuclei despite the presence of abundant extracellular aggregates. B: recipient AAS17: type A’ profile in corpus striatum: peri-vascular PrPd in capsula interna and abundant extracellular (peri-neuronal, linear and particulate) PrPd in neuropil but inconspicuous intraneuronal PrPd in deep cerebellar nuclei (inset, same recipient). C: recipient VVC11 (type M’) showing co-occurrence of extracellular (linear, perineurinal, particulate and coalescing) and intraneuronal PrPd in corpus striatum; inset: recipient VVC12 showing the same co-occurrence of intra- and extra-cellular PrPd in deep cerebellar nuclei (type M'). D: recipient VVC1: type M profile with almost complete absence of extracellular glia-associated PrPd and some neuropil-associated and intracellular aggregates in deep cerebral cortex layers; inset, same recipient showing abundant intraneuronal PrPd in deep cerebellar nuclei. E: recipient VVC13 (type P profile) showing abundant extracellular PrPd in the neuropil of the thalamus and prominent non-vascular, Kuru-type plaques (detail in inset). F: recipient VVC14 (type CH profile) showing conspicuous intracellular PrPd deposits in Purkinje cells and in neurons and glial cells within the red nucleus (inset). IHC with R145 PrP monoclonal antibody and haematoxylin counterstaining. Original magnifications: large images × 4 (except F, ×10); insets × 60.