Journal: JACC. Clinical electrophysiology
Article Title: The Heart’s Pacemaker Mimics Brain Cytoarchitecture and Function
Figure Lengend Snippet: 2-Dimensional Images of a Whole-Mount Preparation of SAN Tissue With Triple Immunolabeling for S100B, HCN4, and TH or VAChT (A to C) Two-dimensional images of SAN tissue with triple immunolabeling for S100B + cells (cyan) , HCN4-immunoreactive pacemaker cells (red) , and TH + adrenergic fibers (green) illustrate anatomical interactions between pacemaker cells, adrenergic nerves, and interstitial cells. (D to F) Two-dimensional images of SAN tissue with triple immunolabeling for S100B + cells (cyan) , HCN4 immunoreactive pacemaker cells (red) , and VAChT + cholinergic fibers (green) illustrate anatomical relations between pacemaker cells, adrenergic nerves, and interstitial cells. Pink stars in any panel indicate the nuclei of peripheral glial cells. S100B + spicula extended from “octopus”-like cells in A, C, and E ended on TH + varicosities (A and C) or on VAChT + varicosities (E) . Yellow arrows indicate the S100B + “endfeet.” An adrenergic neurite on A , indicated by a white star , overlaps with the spiculum of an “octopus”-like S100Bþ cell. An amoeboid-like S100B + cell in the upper right corner of C receives adrenergic innervation. Images on C (adrenergic nerves) and D (cholinergic nerves) illustrate uneven innervation of S100B + cells. (F) Composite point of contact between 3 cells: one S100B-immunoreactive cell, an HCN4-immunoreactive cell, and fibers from the neuronal plexus. A white arrow indicates the region where cellular extensions from an intertwined couple of S100B + cells, an HCN4 + pacemaker cell, and a cholinergic neurite co-localize within 1 μm of each other. A white star indicates the point of contact between an S100B + cell and a cholinergic nerve, whereas a white triangle marks the point of contact between a cholinergic nerve and an HCN4 + pacemaker cell. Abbreviations as in Figures 1 , 3 , and 4 .
Article Snippet: HCN4+ cells were identified by rabbit polyclonal antibodies for cyclic nucleotide-gate cation channels HCN4 (1:300; Alomone Labs).