The role of electrical signalling in the control of endocrine secretions by the brain has been clear for many years. Recently, the influences of hormones on synthetic events in neuroendocrine cells have raised new questions concerning the peptides released from such neurons. This volume concentrates on the relation between these two fields and asks how electrical action potentials facilitate secretion of substances from nerve cells which control endocrine events. While stimulus-secretion coupling has been studied extensively in other physiological contexts, this is the first treatment of the phenomenon in an exclusively neuroendocrine setting.