Fig. 1.

PFF-induced pathology at 18- and 23-month post-injection is mild (a) α-Syn pathology detected by an antibody against pser129 is present in brain regions ipsilateral (legend in blue) and contralateral (legend in red) to the injection site. Diagrams illustrating the anatomical location of α-syn pathology (assessed by antibody against pser129) in the brain on coronal sections at 18-month post-injection of mPFFs (b), of HuPFFs (c) and at 23-month post-injection of HuPFFs (d). The green star indicates the injection site. Severity of pathology is represented by different colours, from no pathology-to-severe pathology and is based on a scoring method. The sections were immunostained in three independent histochemical experiments. Histochemical analysis was performed on all animals at 18-month post-injection of mPFFs, and at 23-month post-injection of HuPFFs, mMs and PBS as well as in 21- and 26-month-old non-injected animals (age-matched; PBS-injected and non-injected mice not shown) (mPFFs 18 months: n = 3; HuPFFs 18 months: n = 5, HuPFFs 23 months: n = 4, mMs 18 months and 23 months: n = 4 for each time point; PBS 18 months: n = 3); non-injected mice 18-month post-injection time (age: 21 months): n = 3; 23-month post-injection time (age: 26 months): n = 3. The data presented here are from representative animals. Scale bar: 20 μm. All the images with a purple scale bar were acquired at ×60; all the other images were acquired at ×40 and match the black scale bars. A list of brain structure abbreviations is available in Online Resource 4