PMCA seeding activity within the same M83 brain is higher in regions mostly targeted by the α-syn pathology. A) Comparison of PMCA seeding activities in different brain regions of 2 sick M83+/+ mice euthanized with typical clinical signs at the age of 573 (sick M83 #1) or 670 (sick M83 #2) days old. PMCA was performed using the C57Bl/6-WT brain substrate (10%, 144 cycles) after seeding with a 10−4 dilution of each of the following brain regions: olfactory bulb (OB), cerebral cortex (CTX), hippocampus (HIP), striatum (STR), midbrain (MB), cerebellum (CB), and brain stem (BS). Bars to the left of each panel indicate the ∼20-, 30-, 40-, 50-, and 60-kDa MW markers. B) ELISA detection of Ser129 phosphorylated α-syn in the same dissected brain regions from sick M83 #1 and #2 mice. Two quantities of brain homogenates were examined, including 0.2% [as described by Sargent et al. (11)] and 0.01% homogenates, this last concentration corresponding to the 10−4 dilution of seeds as examined by PMCA.