FIGURE 2.

Improved visualisation and analysis of clustered RyR organisation in peripheral couplons of rat ventricular myocytes with dSTORM super-resolution. (A) RyR labelling near the surface of a myocyte in diffraction-limited view of RyR clusters, many of which are oblong or elongated in shape. (B) The dSTORM image corresponding to the region shown in (A). (C,D) Magnified views of matching diffraction-limited and dSTORM images from a few peripheral couplons. Note the small clusters and likely unitary RyRs [indicated in (A–D) by arrowheads] are undetectable in the diffraction-limited data. (E) To quantify cluster sizes (in RyRs/cluster), quasi-crystalline 30 × 30 nm assembly of RyRs in the regions of labelling was assumed. (F-i) Macquaide et al. (2015) compared deconvolved STED images of RyR labelling of healthy sheep atrial myocytes (control) with (G-i) RyR labelling in atrial myocytes of a sheep model of atrial fibrillation (AF). Compared to control (F-ii), the AF myocytes (G-ii) consisted of a higher frequency of smaller RyR cluster (arrows) and a smaller inter-cluster spacings, as illustrated by the magnified views of the clusters outlined in (F,G-i). Scale bars, (A,B): 1 μm, (C–E): 150 nm, (F,G-i): 500 nm, (F,G-ii): 200 nm. (F,G) Adapted with permission from Macquaide et al. (2015).