Figure 2
Properties of spine enlargement in vivo. (A) Ratio of head volume (ΔVH) change >30% in enlarged spines and enlargement durability. The left stacked bar represents the ratio of enlarged (22%) to remaining spines (78%) across all examined dendrites (20). The right stacked bar represents the distribution of enlargement durations. Numbers in the histograms indicate the number of spines. (B) The average increase in spine volume (109% ± 24%) across 16 stimulated spines (median = 62%, interquartile range [IQR] = 45%:153%) and neighboring spines located <3 µm away from stimulation site (2.2% ± 4.6%; median = 1.9%, IQR = −10%:21%; 15 spines) and 3–10 µm away from stimulation site(2.0% ± 6.0%; median = 6.0%, IQR = −4.4%:12%; 8 spines). **p < 0.01, based on Wilcoxon signed-rank test (versus zero). Error bars represent standard error of the mean. (C) A scatter plot of average spine enlargement (10–30 min after stimulation [i.e., ΔVH]) among stimulated spines compared to the distance between the most enlarged spines and other stimulated spines on each dendrite. (D) A scatter plot depicting average spine enlargement among stimulated spines compared to relative pre-stimulation spine head volume. Enlarged spines (ΔVH >30%) are indicated by red circles. Pearson’s product-moment correlation coefficients and linear regression lines for all samples (gray) or for enlarged spines (red) are calculated for each scatter plot.
