During infancy respiratory patterns change with maturation. However, there is no documentation of the development of the neurons thought to be related to respiratory control. Relevant neurons in the medulla oblongata were examined using Golgi impregnation methods. Dendritic spines increased prenatally and decreased postnatally in the medullary respiratory centers (i.e., dorsal vagal nucleus, nucleus tractus solitarii and reticular formation). The prenatal neuronal maturation is earlier in the reticular formation than the vagal nucleus. These changes in neuronal dendrites may be related to the development of central respiratory control and the occurrence of primary apnea in prematurity and sleep apnea in sudden infant death syndrome.