Summary
By combining the Golgi and the electronmicroscope techniques it has been possible to identify accurately the system of centrifugal fibers which arborizes in the lamina of muscoid flies forming the so-called nervous bags. Each of them originates from a single fiber entering the lamina at the site in which the second order and the long visual fibers leave it. This single fiber represents the peripheral portion of a T-shaped trunk stemming from a small neuronal body located in the external region of the medulla. The central branch terminates within the first synaptic field of this visual center.
After entering the lamina the centrifugal fiber ramifies profusely and its branches can be seen climbing and synapsing on the surface of the photoreceptor axon endings. The synaptic loci show characteristic synaptic ribbons located within the nervous bag fibers. This fact suggests that direction of conduction is from the medulla to the lamina. This study has also revealed that the intramedullar terminals of the centrifugal fibers establish intimate contacts with one of the two second order fiber endings.
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References
Blackstad, T. W.: Mapping of experimental axon degeneration by electronmicroscopy of Golgi preparations. Z. Zellforsch. 67, 819–834 (1965).
Cajal, S. R.: Textura del sistema nervioso del nombre y de los vertebrados, tomo II. Madrid: 1904. Nicolás Noya
—: Nota sobre la estructura de la retina de la mosca (M. vomitoria L.) Trab. Lab. Invest. Biol. Univ. Madrid 7, 217–257 (1909).
— Sánchez, D.: Contributión al conocimiento de los centros nerviosos de los insectos. Trab. Lab. Invest. Biol. Univ. Madrid 13, 11–164 (1915).
Hillman, D. E.: Morphological organization of the frog cerebellar cortex: A light and electronmicroscopic study. J. Neurophysiol. 32, 818–846 (1969).
Horridge, G. A., Meinertzhagen, I. A.: The accuracy of the patterns of first- and second-order neurons of the visual system of Calliphora. Proc. roy. Soc. B 175, 69–82 (1970).
Melamed, J., Trujillo-Cenóz, O.: The fine structure of the central cells in the ommatidia of Dipterans. J. Ultrastruct. Res. 21, 313–334 (1968).
Pease, D. C.: Paper presented at Southern California Society for Electron microscopy meeting. University of California, Los Angeles, p. 1–21 (1961).
Sjöstrand, F. S.: Ultrastructure of retinal rod synapses of the guinea-pig eye as revealed by three-dimensional reconstructions from serial sections. J. Ultrastruct. Res. 2, 122–170 (1958).
Trujillo-Cenóz, O.: Some aspects of the structural organization of the intermediate retina of Dipterans. J. Ultrastruct. Res. 13, 1–33 (1965).
—: Some aspects of the structural organization of the medulla in muscoid flies. J. Ultrastruct. Res. 27, 533–553 (1969).
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This work was supported by Grant No. 618–67 (Mod No. 67–0618) of the Office of Aerospace Research, United States Air Force and by NIH grant NSO 866901.
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Trujillo-Cenóz, O., Melamed, J. Light and electronmicroscope study of one of the systems of centrifugal fibers found in the lamina of muscoid flies. Z. Zellforsch. 110, 336–349 (1970). https://doi.org/10.1007/BF00321146
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DOI: https://doi.org/10.1007/BF00321146