Figure 5.

Spatial dynamics of dendritic calcium during iLTP and LTD

(A) Representative epifluorescence image of a Homer1c-GFP expressing neuron (left) loaded with Rhod-2 through the patch pipette (gold, right). Scale bar, 5 μm.

(B) Relative Rhod-2 fluorescence intensity quantified during different protocols: LFS (black), LFS paired with glutamate uncaging (blue), and glutamate uncaging alone (pink), in two 4-μm-long dendritic portions of the same neuron. The arrow indicates the beginning of the protocol.

(C) Left: Magnifications of the dendritic portions framed in A, stimulated with LFS (top) or LFS + glutamate uncaging (bottom). The yellow arrowhead indicates the stimulated spine. Scale bar, 1 μm. Right: Gold pseudocolor representation of Rhod-2 fluorescence intensity changes at plateau (5 s) of the stimulating protocols (i.e., LFS, top, and LFS paired with glutamate uncaging, bottom) with respect to baseline values (F_5s–F_baseline).

(D) Fluorescence line scans along the lines in C, normalized to the average fluorescence detected along the line scan in LFS.

(E) Changes in the relative dendritic Rhod-2 fluorescence intensity (as measured in Figure 5D) as a function of the distance from a reference or stimulated spine (see STAR Methods). The gray area indicates the range of ± 3μm from the potentiated spine (LFS: n = 23 neurons, LFS + glu uncaging: n = 22 neurons, F_1,265 = 22.1, p < 0.001, two-way ANOVA followed by Bonferroni's multiple comparison test). Statistical significance for each data point is shown. Values are expressed as mean ± SEM. ^∗p < 0.05, ^∗∗p < 0.01, ns = not significant. See also Figure S3.