Fig.1

Vagal injection of AAV-A53T induces gastrointestinal dysfunction and progressive neuron degeneration in the CNS. SD rats were subjected to vagal injection with AAVs containing empty vectors (AAV-EV) or A53T (AAV-A53T) and then evaluated with gastrointestinal autonomic function 4 weeks later. The control group was male SD rats without any treatment. A Colonic transit time changes over time. After 3 months of injection, colonic transit time (B), 12 h fecal pellet count (C) and total weight (D), and fecal water content (E) in rats. Representative images of Luxol fast blue staining of myelin in the left vagus nerve (F–I), immunohistochemical staining of ChAT in the medulla oblongata (J–M), and TH in the substantia nigra (N–Q) at 0, 3, 4, and 6 months after injection of AAV-A53T, respectively. Scale bars = 10 μm in F–I, 200 μm for the left column and 100 μm for the right column in J–M, 500 μm for the top row and 100 μm for the bottom row in N–Q. The number of ChAT positive neurons in the DMX (R) and TH positive neurons in the SNc (S). A–E: n = 12 per group; F–S: n = 6 per group. Data were presented as mean ± SEM. Statistical significance was analyzed using one-way ANOVA in A–E and two-way ANOVA in R and S, followed by Bonferroni’s multiple comparison test. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, ns, not significant; CNS, central nervous system; ChAT, choline acetyltransferase; TH, tyrosine hydroxylase; NST, nucleus of solitary tract; cc, central canal; L/RDMX, left/right dorsal motor nucleus of vagus nerve; L/RSNc, left/right substantia nigra pars compacta; VTA, ventral tegmental area; SNr, substantia nigra pars reticulata