Development of two morphological types of retinopetal fibers in chick embryos, as shown by the diffusion along axons of a carbocyanine dye in the fixed retina.

Détails

ID Serval
serval:BIB_0D883351B1BB
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Development of two morphological types of retinopetal fibers in chick embryos, as shown by the diffusion along axons of a carbocyanine dye in the fixed retina.
Périodique
Journal of Comparative Neurology
Auteur(s)
Fritzsch B., Crapon de Caprona M.D., Clarke P.G.H.
ISSN
0021-9967[print], 0021-9967[linking]
Statut éditorial
Publié
Date de publication
1990
Volume
300
Numéro
3
Pages
405-421
Langue
anglais
Notes
Comparative Study Journal Article Research Support, Non-U.S. Gov't --- Old month value: Oct 15
Résumé
Centrifugal fibers to the retinas of chick embryos and hatched chicks have been examined and traced following staining by diffusion along their axonal membranes of the carbocyanine dye DiI in fixed tissue. In the older embryos and hatched chicks, the report of Dogiel (Arch. Mikrosk. Anat. 44:622-648, 1895) has been confirmed that there are two very different morphological types of centrifugal fiber. The restricted type ends as a relatively thick fiber, lacking varicosities, that runs for a short distance in the most sclerad level of the inner plexiform layer before terminating in a pericellular nest overlying the flask-shaped body of a single amacrine cell. Thin filaments occasionally leave the pericellular net, apparently to terminate on adjacent cells. The widespread type also runs in the most sclerad level of the inner plexiform layer, but it is thin, varicose, and highly branched, and its terminal arbor may span more than 1 mm, remaining at the same level. Both types of terminal arbor issue from parent axons in the optic fiber layer of the retina. A single parent axon gives either a single terminal fiber of the restricted type or several terminals of the widespread type, but never a mixture of the two. It is argued that the restricted and widespread types originate respectively from the neurons of the contralateral isthmo-optic nucleus and from the "ectopic" neurons scattered outside the isthmo-optic nucleus. In development, the centrifugal fibers reach the retina between E9 and E10 and initially run radially in the optic fiber layer, parallel to the retinofugal fibers but avoiding the dorsal retina. They dive into the inner plexiform layer at about E12. By E13, the terminal arbors are forming, and the widespread and restricted types can already be distinguished. The widespread type continues to increase its territory until about E18, and then appears to remain stable, whereas the restricted type attains its maximum ramification between E13 and E15 and then contracts. Prior to the retraction, the terminal territories of the restricted type fibers overlap, which may provide the anatomical basis for the interaxonal competition that apparently contributes to neuronal death in the isthmo-optic nucleus between E13 and E16. Axons of ganglion cells exhibit transient side branches between E11 and E13; these never reach as deep as the level where the centrifugal fibers run.
Mots-clé
Animals, Axons/ultrastructure, Carbocyanines, Cell Survival, Chick Embryo, Coloring Agents, Dendrites/ultrastructure, Efferent Pathways, Kainic Acid, Nerve Endings/ultrastructure, Neurons, Efferent/ultrastructure, Retina/embryology, Retina/ultrastructure, Retinal Ganglion Cells/ultrastructure
Pubmed
Web of science
Création de la notice
20/01/2008 17:49
Dernière modification de la notice
20/08/2019 12:34
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