Summary
A detailed study of the ultrastructure and RFamide immunoreactivity (RF-IR) in the flatwormsMicrostomum lineare andDiphyllobothrium dendriticum has been made with the immunogold technique. The present ultrastructural study confirms the localization of RF-IR cells observed by light microscopic immunocytochemistry. The RF-IR is demonstrated in small, electron-dense vesicles in neuronal cell bodies and processes. RF-IR is not detected in the rough endoplasmatic reticulum or the Golgi system of the nerve cells. The targets of RF positive fibres are nerve fibres, muscles and glands. Gold labelling occurs in classic synapses, which points to a role in neurotransmission. RF-IR is also observed in nerve terminals lacking the characteristics of synapses. These release sites occur close to muscle fibres in the intestine and body musculature ofM. lineare. Thus, an additional, paracrine action of the neuropeptide is suggested.
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Reuter, M., Gustafsson, M.K.S., Lang, J. et al. The release sites and targets of nerve cells immunoreactive to RFamide — an ultrastructural study ofMicrostomum lineare andDiphyllobothrium dendriticum (Plathelminthes). Zoomorphology 109, 303–308 (1990). https://doi.org/10.1007/BF00803570
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DOI: https://doi.org/10.1007/BF00803570