title: Ultrastructural localization of RFamide-like peptides in neuronal dense-cored vesicles in the peduncle of Hydra.
abstract: The presence of Arg-Phe-amide (RFamide)-like peptides in dense-cored vesicles in neurons of the peduncle of Hydra was demonstrated by immunogold electron microscopy. Thin sections of Lowicryl-embedded tissue labeled with antisera to RFamide and 5-nm gold-conjugated, secondary antibody and of Epon-Araldite-embedded tissue labeled with 15-nm gold particles revealed a concentration of RFamide-like immunoreactivity over the granular cores of vesicles in epidermal ganglion cells. Gold-labeled, dense-cored vesicles were present in the perikaryon, long thin neurites, and axon terminals of these neurons. The aggregation of labeled dense-cored vesicles in an axon terminal on the myoneme of an epitheliomuscular cell suggests a possible function of RFamide-like peptides in neuromuscular transmission. Gold staining of dense-cored vesicles completely disappeared when the RFamide antiserum was preabsorbed with 10 micrograms/ml RFamide. These results are the first demonstration that the dense-cored vesicles of Hydra neurons contain a neuropeptide.
authors.affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan 66506.
authors.forename: O
authors.initials: O
authors.lastname: Koizumi
authors.forename: J D
authors.initials: JD
authors.lastname: Wilson
authors.forename: C J
authors.initials: CJ
authors.lastname: Grimmelikhuijzen
authors.forename: J A
authors.initials: JA
authors.lastname: Westfall
mesh_terms: D000818:Animals; D006829:Hydra / Q000032:analysis* / Q000648:ultrastructure; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009479:Neuropeptides / Q000032:analysis*
chemical_list: D009479:Neuropeptides