Fig. 4

Vagotomy prevents appearance of p-α-Syn pathology in the dmX after inoculation of α-Syn preformed fibrils. a FluoroGold labeling of the dmX. Left panel: Labeling appears in the dmX bilaterally 5 days after intraperitoneal injection of FluoroGold in unvagotomized mice. Right panel: FluoroGold labeling is absent in the right dmX when right (Rt.) vagotomy was performed prior to intraperitoneal injection of FluoroGold. AP, area postrema; cc, central canal. Scale bar 200 μm. b choline acetyltransferase (ChAT) and p-α-Syn immunohistochemistry in right-vagotomized mice 23 days and 45 days after α-Syn PFF inoculation. The number of ChAT-positive neurons in the right dmX decreased at 23 days and further decreased at 45 days (arrowheads). P-α-Syn–positive aggregates are present only in the left dmX at both time points (arrows). Scale bar 200 μm. c–e High-magnification images of p-α-Syn–positive cells. Scale bars 20 μm. f Number of ChAT-positive neurons in the dmX of untreated mice (Control) and right-vagotomized mice 23 days and 45 days after α-Syn PFF inoculation (n = 3–4). One-way ANOVA with Tukey’s multiple-comparisons test was performed; **p < 0.01, ***p < 0.001. g Number of p-α-Syn–positive neurons in the dmX of unvagotomised mice 45 days after α-Syn PFF inoculation and right-vagotomized mice 23 days and 45 days after α-Syn PFF inoculation (n = 4). Data are the mean ± SEM