The significance of the radial nerve cords in asteroids and echinoids

@article{Cobb2004TheSO,
  title={The significance of the radial nerve cords in asteroids and echinoids},
  author={James L. S. Cobb},
  journal={Zeitschrift f{\"u}r Zellforschung und Mikroskopische Anatomie},
  year={2004},
  volume={108},
  pages={457-474}
}
  • J. Cobb
  • Published 2004
  • Biology
  • Zeitschrift für Zellforschung und Mikroskopische Anatomie
SummaryThe radial nerve cords of a number of different species of echinoids and asteroids have been examined with the electron microscope. They have been shown to consist of tracts of small naked axons with discrete regions of neuropile. Synapses within these areas of neuropile have been described and their significance discussed. A careful examination has failed to reveal any connections between the ectoneural nerve and the mesodermal nerves and muscles. Synapses across the connective tissue… 
The giant neurone system in ophiuroids
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Immunocytochemical mapping of the novel echinoderm neuropeptide SALMFamide 1 (S1) in the starfish Asterias rubens
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An ultra-structural study of the gills of Echinus esculentus
TLDR
It is shown that the main function of the gills of Echinus esculentus is excretory and three apparent systems whereby excreteory products and necrotic coelomocytes are removed are described.
The giant neurone system in ophiuroids
TLDR
Degeneration studies confirmed the layout of the hyponeural motor axons and the juxtaligamental tissue is thought to be associated with changes in the structural properties of the collagenous ligaments of the arm during arm autotomy.
An ultrastructural study of the dermal papulae of the starfish, Asterias rubens, with special reference to innervation of the muscles
  • J. Cobb
  • Medicine, Biology
    Cell and Tissue Research
  • 2004
TLDR
It is proposed that there are ‘skeletal’ and ‘visceral’ types of smooth muscle in echinoderms and discusses this proposal at length.
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References

SHOWING 1-10 OF 26 REFERENCES
The podial pit — a new structure in the echinoidDiadema antillarum Philippi
TLDR
It is tentatively suggested that the remarkably superficial location of the fine nerve fibres may be correlated with the relatively high photosensitivity of this region.
The lantern of Echinus esculentus (L). II. Fine structure of hyponeural tissue and its connexions
  • J. Cobb, M. S. Laverack
  • Biology
    Proceedings of the Royal Society of London. Series B. Biological Sciences
  • 1966
TLDR
The innervation of the lantern muscles of Echinus is accomplished via ten discrete areas of nervous tissue, one on either side of each radial nerve cord, but associated with the circumoral ring, which has long been known as the hyponeural tissue.
VESICULATED AXONS IN HAEMAL VESSELS OF AN HOLOTHURIAN, CUCUMARIA FRONDOSA
Segments of the primitive haemal rete of the holothurian, Cucumaria, were fixed in glutaraldehyde and in osmic acid, embedded in epoxy resin, sectioned for electron microscopy and stained with uranyl
Ultrastructure of the tube foot wall of a regular echinoid,Diadema antillarum Philippi
  • R. Coleman
  • Biology
    Zeitschrift für Zellforschung und Mikroskopische Anatomie
  • 2004
SummaryAn ultrastructural study of the tube foot wall of a regular echinoid,Diadema antillarum, was made. Ciliated microvillous epithelial cells, their inclusions, amoebocytes, and the arrangement of
The innervation of the oesophagus of the sea-urchin Heliocidaris erythrogramma
  • J. Cobb
  • Biology
    Zeitschrift für Zellforschung und Mikroskopische Anatomie
  • 2004
TLDR
The fine structure of the oesophagus of the sea-urchin Heliocidaris erythrogramma is described and the presence of two vesicle types within separate axons may indicate dual innervation of the muscle cells.
Neurociliary Synapses in Pleurobrachia (Ctenophora)
TLDR
The question of the propagation of excitation between these axons, between the ciliated cells of a comb plate, and between comb plates, remains open, although regions where excitatory axons and ciliated Cells make contacts between themselves and with each other have some resemblance to electrically transmitting synapses.
COMPARATIVE ASPECTS OF SUPERFICIAL CONDUCTION SYSTEMS IN ECHINOIDS AND ASTEROIDS.
The spine-convergence response of sea urchins and the papula (deimal branchia) retraction response of starfish persist after removal of the central nervous system, but are blocked by scratching
The electrical activity of the radial nerve in Diadema antillarum Philippi and certain other echinoids.
TLDR
The response of Diadema has a double peak which is shown to represent responses of nerves differing in excitability and conduction velocity, which is related to inhibition of spine movements excited photically.
Über den Feinbau des hyponeuralen Nervensystems des Seesternes (Asterias rubens L.)
  • G. Hehn
  • Biology
    Zeitschrift für Zellforschung und Mikroskopische Anatomie
  • 2004
TLDR
The nerve of Lange, part of the starfish hyponeural nervous system, was investigated with the light-, fluorescence- and electron microscopes in Asterias rubens and cells have been found underneath the perikarya layer which are considered to be neurosecretory elements.
...
1
2
3
...