Nat. Rev. Cardiol. doi:10.1038/nrcardio.2015.193 Figure 2 Evidence for a multichannel Ca2+-release function in Purkinje cells Figure 2 | Evidence for a multichannel Ca2+-release function in Purkinje cells. a | Optical section of a canine Purkinje cell labelled with a ryanodine receptor (RyR) antibody that probes all RyR isoforms showing a uniform staining of the cell. b | Labelling of canine Purkinje cells with the inositol trisphosphate receptor (IP3R1) antibody (green) and the RyR2-specific antibody (red) shows there is a gap in IP3R1 and RyR2 staining (arrow). c | The gap shown by the IP3R1 and RyR2 antibody staining is filled by the RyR3 antibody. d | Transverse profiles of the cells with the averaged fluorescence intensity for IP3R1, RyR2, and RyR3 antibodies obtained from pixel-to-pixel averaged arrays of 30 lines. e | Representation of the fluorescence intensity of IP3R1 (green), RyR2 (red), and RyR3 (blue) antibodies relative to the cellular distribution along transverse profiles in canine Purkinje cells (0 μm is the fluorescence boundary of the cell). IP3R1 is found exclusively under the cell membrane, whereas RyR2 has a uniform striated distribution except in the peripheral region, where a gap in RyR2 and IP3R1 staining was consistently detected (arrow). This gap was filled by the RyR3 antibody. Permission obtained from Walters Kluwer Health © Stuyvers, B. et al. Ca2+ sparks and waves in canine Purkinje cells: a triple layered system of Ca2+ activation. Circ. Res. 97, 35–43 (2005). Permission obtained from Walters Kluwer Health © Stuyvers, B. et al. Ca2+ sparks and waves in canine Purkinje cells: a triple layered system of Ca2+ activation. Circ. Res. 97, 35–43 (2005) Haissaguerre, M. et al. (2016) Ventricular arrhythmias and the His–Purkinje system Nat. Rev. Cardiol. doi:10.1038/nrcardio.2015.193