Propagation of Action Potentials and the Structure of the Nexus in Cardiac Muscle

摘要: The hypothesis that the nexus is a specialized structure allowing current flow between cell interiors corroborated by concomitant structural changes of and electrical coupling cells due to soaking in solutions abnormal tonicity. Fusiform frog atrial fibers are interconnected nexuses. nexuses, desmosomes, regions myofibrillar attachment this muscle not associated manner similar intercalated discs guinea pig cardiac muscle. Indeed, nexuses occur wherever membranes closely apposed. Action potentials bundles detected extracellularly across sucrose gap change from monophasic diphasic when shunted resistor. This indicates action transmitted sufficient excitatory allowed gap. When solution made hypertonic, propagation past blocked resistance increases. Electron micrographs demonstrate atrium ventricle ruptured hypertonic solutions.