title: Electron immunogold labeling of regulatory peptide immunoreactivity in the nervous system of Moniezia expansa (Cestoda: Cyclophyllidea).
abstract: An electron immunogold-labeling technique was used in conjunction with a post-embedding procedure to demonstrate for the first time the ultrastructural distribution of the parasitic platyhelminth neuropeptide, neuropeptide F (NPF), in the nervous system of the cestode Moniezia expansa. Two axon types, distinguished by their populations of different-sized electron-dense vesicles, were identified. Immunogold labeling demonstrated an apparent homogeneity of PP, FMRFamide and NPF (M. expansa) antigenic sites throughout the larger dense-cored vesicles within the central nervous system. Triple labeling clearly demonstrated the co-localisation of immunoreactivities (IR) for NPF, PP and FMRFamide within the same dense-cored vesicles. The presence of NPF-IR within the vesicles occupying the perikaryon of the neuronal cell body indicated that the peptides had undergone post-translational C-terminal amidation prior to entering the axon. Antigen pre-absorption experiments using NPF prevented labeling with either PP or FMRFamide antisera, and the failure of these antisera to block NPF-IR supports the view that some, if not all, of the PP/FMRFamide-IR is due to NPF-like peptides.
authors.affiliation: Comparative Neuroendocrinology Research Group, School of Biology and Biochemistry, Queen's University, Belfast, Northern Ireland, UK.
authors.forename: G P
authors.initials: GP
authors.lastname: Brennan
authors.forename: D W
authors.initials: DW
authors.lastname: Halton
authors.forename: A G
authors.initials: AG
authors.lastname: Maule
authors.forename: C
authors.initials: C
authors.lastname: Shaw
mesh_terms: D000818:Animals; D002589:Cestoda / Q000737:chemistry* / Q000648:ultrastructure; D019835:FMRFamide; D015801:Helminth Proteins / Q000032:analysis*; D007150:Immunohistochemistry; D016253:Microscopy, Immunoelectron; D009420:Nervous System / Q000737:chemistry* / Q000648:ultrastructure; D009479:Neuropeptides / Q000032:analysis*; D010191:Pancreatic Polypeptide / Q000032:analysis
chemical_list: D015801:Helminth Proteins; D009479:Neuropeptides; C076101:neuropeptide F; D010191:Pancreatic Polypeptide; D019835:FMRFamide