Transmission electron microscopy

To observe the morphology of different fibrils, the Sup35 PFFs, α-syn PFFs, and S-α-syn PFFs were adsorbed to glow discharged 400 carbon-coated copper grids for 2 min, quickly washed twice with tris-HCl (50 mM, pH 7.4), and floated upon two drops of 0.75% uranyl formate for 30 s. The grids were allowed to dry before imaging on a Hitachi HT7800 transmission electron microscope operating at 80 kV. The images were captured and digitized with an ER-80 charge-coupled device (8 megapixels) by advanced microscopy techniques (53). The mitochondrial density and morphology were determined by electron microscopy as previously described (57). After deep anesthesia, animals were perfused with 2% glutaraldehyde. The striatum was dissected and postfixed at 4°C shielded from light until further preparation. After the standard procedure was performed, ultrathin sections were treated with 2% uranyl acetate and lead acetate and viewed at 100 kV under a transmission electron microscope.