Fig. 6

Accumulation of pathological αS in enteric neurons of presymptomatic and sick αS Tg mice. Immunocolocalization with neuronal markers shows accumulation of αS toxic species only in enteric neurons, including dopaminergic and cholinergic types, in both the submucosal and myenteric plexi in Tg mice but not in controls. Distal colon frozen sections from presymptomatic (3 months old) (b, e, h) and sick αS Tgs (c, f, i) and nTg littermates (a, d, g) were stained with LB509 and β3-tubulin (a, b, c); ChAT and pser129-αS (d, e, f); Syn204 and TH (g, h, i). Sections were counterstained with DAPI. Notably, within the same section and concurrently with double labeled neurons (full arrow heads), we found healthy neurons without accumulation of toxic αS (empty arrow heads) or neurons with accumulation of toxic αS that belonged to other neuronal populations beyond the cholinergic or dopaminergic system (*), suggesting that different enteric neurons may be distinctively susceptible to αS spreading. Images were acquired with Leica microscope SP2 system, objective 63x. Scale bars = 40 μm