Programme

Preliminary description:
Slow cardiac and neuronal pacemaking relies on spontaneous rhythmic activity in the low-frequency range, yet its core ionic mechanisms remain incompletely understood. This symposium will provide an overview of current knowledge and open questions regarding ionic pacemaking mechanisms in the heart and brain. It will highlight the identification of a novel ionic current with distinct functional and pharmacological properties that is essential for slow (1–5 Hz) spontaneous pacemaking in both sinoatrial node cells and midbrain dopamine neurons. This mechanism will be contrasted with ionic processes that support high-frequency (>10 Hz) pacemaking, which are restricted to neurons and involve specialized resurgent currents whose structural basis has recently been elucidated. Finally, recent evidence for plasticity of pacemaker frequency in dopamine neurons following partial lesions will be discussed, illustrating adaptive stabilization of firing patterns in vivo. Overall, the symposium offers a mechanistic update on fundamental principles of pacemaking in heart and brain.