Fig. 2. Structures associated with TeNT H_C binding and internalization. (A-D) Distribution of TeNT H_C observed by EM in MNs after incubation with TeNT H_C at 4°C followed by 10 nm gold-conjugated antibody. Gold (arrows) is found along neurite surfaces (a) and in forming coated pits (B). TeNT H_C is also observed at synaptic sites (C) and neurite contacts (D). (E-H) MNs were treated as in AD, washed and then warmed to 37°C for 5 (E and F) or 20 minutes (G and H). TeNT H_C is found in coated pits (E) and coated vesicles (F), whereas at later internalization timepoints gold particles are observed in tubular (G) and round organelles (H). Control samples where TeNT H_C was omitted showed negligible gold labelling. Bars, 0.2 µm.