Administered agents

Monomeric alpha-synuclein and pre-formed fibrils (PFFs). Mono and PFF synuclein were generously supplied by Dr. Kelvin Luk. Solutions for injection were prepared according to previously described protocols [30]. Briefly, monomeric mouse sequence αsyn (“mono”) or PFFs (endotoxin level 0.15 EU/mg protein) were diluted in PBS to 2μg/μl and sonicated prior to injection as previous described [33]. One animal was euthanized following this surgery due to recovery complications.

Antisense oligonucleotides. Mouse sequence αsyn-targeted and scrambled control antisense oligonucleotides (ASOs) were generously supplied by Ionis Pharmaceuticals. αsyn-targeted ASO was matched to the non A4 component of amyloid precursor component (#678363). Mouse αsyn ASO sequence: TTTAATTACTTCCACCA; control ASO sequence: CCTATAGGACTATCCAGGAA. ASOs were diluted in 1x PBS (without Ca^2 + or Mg^2 +) to 100 mg/ml stock solution. For injections, a working solution of 70 mg/ml was made and stored at 4°C. One animal was euthanized following this surgery due to recovery complications.