Figure 6: 3D ultrastructure of the ID and comparative NaV1.5 cluster dimensions.
From: Nanoscale visualization of functional adhesion/excitability nodes at the intercalated disc
(a–g) FIB-SEM and segmentation of a complete ID from adult ventricular tissue. (a) Three-dimensional cube of tissue (∼30 × 28 × 12 μm3; see Methods). (b,c) 3D-rendered models of structures visible after image segmentation: a complete ID (light pink), blood vessels and red blood cells (solid and transparent red), a portion of a second ID (transparent blue) and lateral membranes of up to six cells (different tones of green, white, blue, orange and violet) are visible. (d,e): 3D-rendered model of complete ID overlaid on two virtual tissue sections at different depths (2.5 μm apart from each other in the z-axis). Scale bar, 5 μm. (f) Complete three-dimensional view of the ID at two orientations (180° rotation). Plicate region marked with asterisk shown in more detail in g from three different angles. Scale bar, 2 μm. A NaV1.5 cluster (green), and the modelled NaV1.5 molecules within it (blue) are depicted in the same scale. An enlarged view of the NaV1.5 cluster is shown on the right. (h) SICM image of the cell end of an isolated ventricular myocyte. Histograms in i,j compare the peak-to-peak next neighbour distances measured in the plicate region of the FIB-SEM-resolved image and those measured by SICM, demonstrating similar periodicity in the surface foldings. N=166 and 48 for i,j, respectively.
