Figure 8.

Replenishment of drebrin A into AOD-treated neurons restores synaptic clustering of PSD-95. A, Two examples (A₁, A₂) of triple labeling of the neurons in AOD-treated cultures for GFP-drebrin A (green), PSD-95 (red), and synapsin I (blue). We injected GFP-tagged drebrin A expression vectors into AOD-treated neurons at 14 DIV using a microinjection method and immunostained the neurons for PSD-95 and synapsin I after 36 hr. GFP-drebrin A clusters are juxtaposed with synapsin I clusters. The PSD-95 clusters overlapping with GFP-drebrin A clusters (arrowheads) are larger and brighter than other PSD-95 clusters that do not overlap with GFP-drebrin A clusters (arrows). Scale bar, 2 μm. B, Quantitative analysis of averaged intensities of synaptic PSD-95 clusters in AOD-treated neurons expressing or not expressing GFP-drebrin A. The solid horizontal line shows 100% of control. PSD-95 clustering is enhanced by replenishment of GFP-drebrin A (n = 8 dendrites; ^*p < 0.0001; t test). Error bars indicate SEM. Histograms show means + SEM.