Fig. 3

Effects of other active zone proteins (Piccolo and Munc13–1) in huntingtin overexpressing hippocampal neurons. a Immunofluorescence showed a notable loss of Munc13–1 clusters and Munc13–1 containing mature synapses (a, arrowheads) induced by mutant huntingtin (69Q) overexpression. The quantitative analysis of Munc13–1 (b) and its synapses (c), n = 61–64 segments/group, N = 21–22 cells/group. d 69Q huntingtin overexpressing resulted in a dramatic decrease of presynaptic bouton marked by Piccolo, dendritic spine labeled by Actin-GFP and mature synapses (d, arrowheads) compared to 17Q condition, while 17Q overexpressing promoted numbers of Actin, Piccolo clusters and mature synapses when compare with control condition (Actin-GFP group). The statistics of Actin clusters (e) Piccolo clusters (f) and Piccolo containing mature synapses (g). n = 56–70 segments/group, N = 19–23 cells/group. All data obtained by at least triplicate individual experiments, one way ANOVA test, followed by a Tukey’s multiple comparisons post-test, *p < 0.05, **p < 0.01, ***p < 0.001 (Scale bar = 5 μm)