Fig. 4.

TH and VMAT-2 down-regulation. (A–C) Representative photographs of triple-stained sections from the combined α-SYN + FIB group, showing marked down-regulation of TH (green) and VMAT-2 (red) in neurons containing dense p-Syn⁺ aggregates (white) at 10 d after PFF injection (examples marked by arrowheads). Arrows in C–C′′ mark cells where TH is down-regulated and the expression of VMAT-2 is retained. (D and E) Colabeling with the panneuronal marker Hu confirmed that part of the surviving neurons in SNc had lost their TH expression (arrowheads). In the animals treated with AAV vector alone (α-SYN ONLY), pSyn was more diffusely distributed in the cytoplasm (F) and the expression of TH and VMAT-2 was mostly retained (F′ and F′′, arrowheads). (Scale bars: A, A′, and A′′, 100 μm; B, B′, and B′′, 50 μm; C, C′, and C′′, 50 μm; D, 200 μm; E and E′, 50 μm; F, F′, and F′′, 50 μm.)