Commentary: Ion Channels, Fusion Pores and Exocytosis

The key function of adrenal chromaffin cells is to secrete catecholamines in response to stress. Under stress, chromaffin cells are stimulated by cholinergic synaptic inputs resulting in catecholamine release. This stimulus-secretion coupling is mediated by activation of Ca2+ signaling through ion channels followed by fusion pore formation and exocytosis, and subsequent endocytosis. Several sessions at this symposiumhighlighted advances in the understanding of the role of ion channels in exocytosis and endocytosis, the mechanics of fusion pore formation and the role of Ca2+ syntillas and gap junctional communication in modulating catecholamine release.