Cover picture: The calyx of Held is a giant nerve terminal in the auditory brainstem that is involved in sound localization. A photograph of a calyx of Held from an adult cat, revealed by immunostaining for PEP-19 (peptide protein 19), a Ca-binding protein, is shown. Superimposed on the photograph is a three-dimensional rendering of the same calyx showing that it has several ~finger~ and emerges from a thick axon. The preterminal axonal region bare of myelin is called the heminode, and it contains a high density of channels. We thank Dr. Albert Berrebi (West Virginia University School of Medicine, Morgantown, WV) for his expertise in immunolabeling using this antiserum. For details, see the article by Leo et al. in this issue (pages 3724–3738).