Calcium Transient and Sodium-Calcium Exchange Current in Human versus Rabbit Sinoatrial Node Pacemaker Cells
Action potential and calcium transient recordings from rabbit (left) and human (right) SA nodal myocytes and associated numerical reconstructions of membrane currents. (a) Recorded membrane potential . (b) Recorded intracellular calcium concentration (). (c) Time derivative of (d). (d) Reconstructed hyperpolarization-activated inward current (). The noisy trace in gray is the net membrane current () computed from , where denotes membrane capacitance. (e) Reconstructed sodium-calcium exchange current (), with the net membrane current in gray.