Figure 3. Correlative STED microscopy of SiR-actin with synchrotron PCI and XRF in spines.

(a) Confocal imaging of a primary rat hippocampal neuron labeled with SiR-actin showing F-actin-rich protrusions along dendrites. (b) STED imaging of SiR-actin of the dendrite region framed in white in a. (c) Zoom on the STED SiR-actin of a F-actin-rich protrusion framed in (b). (d) Synchrotron radiation X-ray PCI of the dendrite region framed in white in a. (e) Zoom on the PCI region of a F-actin-rich protrusion framed in (d). (f-i) SXRF element maps (P, S, Cu, Zn) from the region of interest framed in (b) and (d). (j) Line scans for F-actin (red) and copper (blue) normalized distributions along the red line plotted in (h). Scale bar: 200 nm, except for (a) 10 µm, (b) and (d) 1 µm. Color scales: min-max values in ng.mm⁻².

Figure 3—figure supplement 1. Element distributions in dendrites and spines.

(A) Confocal image of SiR-tubulin (green) and SiR700-actin (red) in dendrites. (B) STED image of SiR-tubulin in the same zone as in (A). (C) Confocal large image including the region shown in (A) with SiR-tubulin (green) and SiR700-actin (red). (D–G) SXRF element maps (P, S, Cu, Zn) from the same region as (A). (H) Overlay image of STED SiR-tubulin (green) and zinc (red). (I) Overlay image of sulfur (green) and zinc (red). (J) Overlay image of phosphorus (green) and zinc (red). (K) Overlay image of copper (green) and zinc (red). Scale bar: 1 µm except for (C) 10 µm. Color scales: min-max values in ng.mm⁻².