Breathing is generated by a neuronal network located within the caudal brainstem. One area of particular significance for respiratory rhythm generation is the pre-Bötzinger (preBotC) complex in the ventrolateral medulla. An important step towards understanding the cellular and network basis by which neurons within this region generate the respiratory rhythm was made in a recent study by Koshiya and Smith.(1) Using simultaneous image analysis and electrophysiological techniques these authors identified a discrete population of synaptically-coupled pacemaker neurons within the preBotC. They postulated that these neurons constitute the minimal essential network component (kernel) for generating the respiratory rhythm. BioEssays 22:6-9, 2000.