Abstract
This paper reviews aspects of the origin and fate of synaptic vesicles and of the related catecholamine-containing secretion granules of the adrenal medulla. Most attention is given to evidence concerning the proposal that the membrane surrounding synaptic vesicles can originate from axonal agranular reticulum, participate in exocytosis and endocytosis and eventually undergo degradation in lysosomes of axons and perikarya. A number of relevant details of the roles of several organelles in neurons and other cells of the nervous system are discussed. The paper centers around microscopic and cytochemical work on a few experimental systems.