SNCA and nervous system disorder: Whereas none of the PBS-inoculated mice developed disease throughout the course of the experiment (420 days), four of five mice inoculated intraperitoneally with α-synuclein fibrils developed neurologic disease, with marked signs of paralysis, kyphosis, and reduced activity, within 229 ± 17 days (mean ± standard deviation [SD]) after inoculation (Fig. 1B; see Movie S1 in the supplemental material).