R-Type Voltage-Gated Ca²⁺ Channels in Cardiac and Neuronal Rhythmogenesis

During the past decades, an increasing number of ion channel and transporter types have been identified acting together to produce cardiac and neuronal pacemaker action potentials. The basis of pacemaker activity was understood in more detail by using single-microelectrode recordings on cells isolated from pacemaker regions. Meanwhile, this powerful technique was complemented by computer modeling and recombinant technologies, including gene inactivation of ion channels and transporters, which may be involved in the generation of the electrical activity of pacemaker cells. Several genes of the voltage-gated Ca(2+) channel (VGCC) family have been ablated, and their role in cardiac and neuronal pacemaking is compared in the present summary, focusing on the role of murine R-type voltage-gated Ca(2+) channels encoded by cacna1e and expressing the ion conducting subunit Cav2.3.