PRNP and infection: IHC analyses showed clear differences between the MV1 and MV2 infections with only diffuse-synaptic and perineuronal granular deposition of PrP in the MV1 infections compared with large PrPD plaques in the corpus callosum, smaller widespread plaques, coarse granular staining and a lesser amount of diffuse PrPD in the MV2 infections (Fig. 4).