Fig. 4

PPA dysregulates fusion from autophagosome to autolysosome (a) Representative fluorescent images after transfection with RFP-GFP-LC3B in control hippocampal neurons and PPA-treated cells. Scale bar is 20 μm. b, c Quantification of number of GFP and YFP puncta (autophagosome) and RFP only puncta (autolysosome) from images in (A) (n = 5). d Black box shows representative TEM images in control hippocampal neurons and PPA-treated cells. Red box shows representative TEM high magnification images of autolysosome and autophagosome (black arrow indicates autophagosome and red arrow indicates autolysosome). Black scale bar is 500 μm. e, f Quantification of autophagosome and autolysosome number per area (n = 35). Bar graph showing mean ± SEM of the representative groups. g Top shows representative pyramidal neurons transfected with PLV-GFP and treated with bafilomycin A1 (2 nM) and PPA (100 μM) for 72 h. Bottom shows high magnification of representative secondary dendrites. Scale bar of top panel is 20 μm; scale bar of bottom panel is 1 μm. h Bar graph showing mean ± SEM for dendritic spine numbers of the representative groups (n = 50). *p < 0.05, ***p < 0.0005, ****p < 0.0001