Ultrastructural localization of RFamide-like peptides in neuronal dense-cored vesicles in the peduncle of Hydra.
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.
Koizumi
O
O
Department of Anatomy and Physiology, Kansas State University, Manhattan 66506.
Wilson
J D
JD
Grimmelikhuijzen
C J
CJ
Westfall
J A
JA
D000818:Animals; D006829:Hydra / Q000032:analysis* / Q000648:ultrastructure; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009479:Neuropeptides / Q000032:analysis*
D009479:Neuropeptides