Our previously published studies are here reviewed detailing neuro-cnidocyte synapses, demonstrating putative neurotransmitter substances, and identifying complex neural pathways in sea anemones. Synapses were traced to their contacts on nematocytes and spirocytes by transmission electron microscopy of serial thin sections of tentacles. In five animals, cells containing microbasic p-mastigophores had synapses with clear vesicles, whereas cells containing basitrichous isorhizas had synapses with dense-cored vesicles, providing preliminary evidence for a selectivity of neurotransmitter types for different nematocysts. Either clear or dense-cored synaptic vesicles were also present at neuro-spirocyte contacts. Antho-RFamide immunoreactivity occurred in some anthozoan synaptic vesicles and immunogold labeling of serotonin was found at a neuro-spirocyte synapse. Neural pathways included direct innervation of spirocytes by sensory cells, sequential neuro-neuro-spirocyte and neuro-neuro-nematocyte synapses and reciprocal synapses involving axons of both sensory cells and ganglion cells. Such synaptic patterns resemble neuro-effector pathways found in higher animals and lay to rest the independent effector hypothesis for cnidocyte discharge in tentacles of sea anemones.
Key words: Aiptasia pallida, synapses, nematocytes, spirocytes, neurotransmitters
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2004 Kluwer Academic Publishers
About this paper
Cite this paper
Westfall, J.A. (2004). Neural pathways and innervation of cnidocytes in tentacles of sea anemones. In: Fautin, D.G., Westfall, J.A., Cartwrigh, P., Daly, M., Wyttenbach, C.R. (eds) Coelenterate Biology 2003. Developments in Hydrobiology, vol 178. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-2762-8_14
Download citation
DOI: https://doi.org/10.1007/978-1-4020-2762-8_14
Publisher Name: Springer, Dordrecht
Print ISBN: 978-1-4020-2761-1
Online ISBN: 978-1-4020-2762-8
eBook Packages: Springer Book Archive