These cartoons summarize the PrPres distribution and the pattern of deposition in the brains of BvPrP-Tg407 mice inoculated with FFI-BH (left), FFI-BH_PMCA (central), and FFI-OM_PMCA (right). Synaptic and diffuse PrPres deposition pattern is represented with solid purple color while plaque-like deposits with purple dots. Animals inoculated with FFI-BH showed mixed synaptic-diffuse and plaque-like patterns of PrPres deposition mainly affecting the striatum, thalamus, and deep layers of the frontal cortex. No PrPres immunoreactivity was detectable in mice numbers #5 and #6. In the brain of animals inoculated with FFI-BH_PMCA, the deposition was characterized by focal plaque-like deposits of PrPres affecting the thalamus, striatum, and frontal cortex. A similar pattern of deposition was observed in the brain of animal number #2 inoculated with FFI-OM_PMCA. Surprisingly, animal number #1 of the same group did not show any detectable PrPres by immunohistochemistry (even if a PrPres signal was clearly detectable by western blot). All AD-BH, AD-BH_PMCA, and AD-OM_PMCA-inoculated animals did not show any PrPres signal. FFI: Fatal Familial Insomnia; PMCA: Protein Misfolding Cyclic Amplification; OM: olfactory mucosa; BH: brain homogenate.