Neuritic p-tau pathology is modulated by the presence of α-syn. (A–E) P-tau staining 3 mpi in the hippocampus, auditory cortex, and entorhinal cortex (A) injected with either human AD-tau–enriched extracts alone or combined with α-syn mpffs (0.4 mg/ml) in WT and α-synKO mice, (B) mice injected with either human AD-tau–enriched extracts alone or combined with α-syn mpffs (0.4 mg/ml) as well as WT mice injected with human AD-tau–enriched extracts plus α-syn monomers (C), human AD-tau–enriched extracts, and α-syn mpffs injected after separate sonication (D), or human AD-tau–enriched extracts and a higher concentration of α-syn mpffs (2 mg/ml; E). Scale bar, 100 µm. All experimental data were verified in at least two independent experiments.