Figure 4
Effects of whole-cell perfusion of dp-cofilin on dendritic spines.
(A) Fluorescence images of Alexa Flour 594- and PSD95-mGFP-labelled spines, which were induced to shrink using whole-cell perfusion of 10 μM recombinant human cofilin-1 protein. (B) Time course of the changes in spine volumes and PSD95-mGFP fluorescence intensities in cells injected with cofilin (76 spines, five cells) or with heat-inactivated (HI)-cofilin (78 spines, three cells). (C) Average reductions in spine volumes and PSD95-mGFP fluorescence intensities of cells perfused with cofilin at the proximal dendrite (40–130 μm from the soma, five cells, 76 spines), at the distal dendrite (230–430 μm, 38 spines), or perfused with HI-cofilin (at the proximal dendrite, 78 spines, three cells). The reductions in spine volumes and the fluorescence intensity of PSD95-mGFP were significant in the proximal dendrites (−27% ± 3.5%, ***p < 0.0001, Wilcoxon signed-rank test vs. zero and −26% ± 4.4%, ***p < 0.0001) but not in the distal dendrites [−3.5% ± 5.2% (p = 0.18) and −4.4% ± 6.6% (p = 0.24)) or HI-cofilin perfusion [4.8% ± 3.6% (p = 0.52) and 2.1% ± 2.8% (p = 0.68)]. Data represent the mean ± SEM.
