Fig. 4

α-Syn pathology spreading pattern depends on the strain injected: exhaustive analysis. Heatmap representing the severity of α-syn pathology (pser129 inclusions) in numerous brain regions, ipsilateral (a) (legend in blue) and contralateral (b) (legend in red) to the injection site, 3- and 6-months post injections of different strains (exhaustive representation) or of human α-syn preformed fibrils (huPFFs; from the laboratory of V.M-Y Lee). Data for the huPFFs were obtained from previous experiments, published in [54, 56]. The colors code for the mean score of each group per designated brain region and the scoring was performed on a scale from 0 to 4 in 3–6 animals per group (3 MPI: monomers, n = 4; Fibrils, n = 5; Ribbons, n = 5; F-65, n = 5; F-91, n = 5; F-110, n = 5; huPFFs, n = 4; 6 MPI: monomers, n = 3; Fibrils, n = 5; Ribbons, n = 5; F-65, n = 4; F-91, n = 5; F-110, n = 5; huPFFs, n = 4). A list of brain structures abbreviations is provided as Additional file 4. * The huPFFs were injected at a higher concentration (5 μg/μL) than the strains (fibrils, ribbons, F-65, F-91 and F-110) and the control (monomers) used in this work (2 μg/μL); the volume injected remained the same (0.8 μL, 4 μg of huPFFs versus 1.6 μg of each strain per OB)