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Development of tectal afferences and efferences in xenopus
Author(s) -
Chahoud B.H.,
Cordierpicouet M.J.,
Clairambault P.
Publication year - 1985
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/0736-5748(85)90157-1
Subject(s) - citation , library science , xenopus , computer science , biology , genetics , gene
NOT RECEIVED 81 SOME ASPECTS OF CERERELLAR DEVELOPMENT IN TRE CHICK EMBRYO UNDER NORMAL AND MODIFIED ENVIRONMENTAL CONDITIONS M. Bertossi, L. Mancini, B. Nice, D. Ribatzi, L. Roncali Institute of Human Anatomy and Histology & Embryology, University of Bari, Italy A microscopic and submicroscopic study of the cerebellum has been carried out in chick embryos and newborn chickens under normal and hypoxic conditions. I.Normal series. The cerebellum structure has been investigated from the 8th incubation day(i.d.) till the 30th day after hatching. At the 8th i-d. differentiating neuroblasts are already detectable in the deep cerebellar nuclei. The lamellae and the cortical layers commence to appear on the 10th i.d.. The Purkinje's cells have attained their distinctive features at the 14th i.d., and both the cortex stratification and the differentiation of its main cell types seem settled according to the definitive pattern by the 19th i.d.. II.Hypoxic series. The chick embryos were kept under a hypoxic condition obtained by covering a part of the egg shell surface with a layer of paraffin; after the hatching the chickens were exposed to the open air. In the embryo cerebellum the main histogenetic and vasculogenetic events seem to unfold normally up to the 15th i.d.. During the last week of incubation the neurocytes, in particular the Purkinje's cells, undergo progressive degenerative modifications. Indications of morphological changes in the vascular component can also be detected: however they seem reversible since the blood vessels gradually acquire again their normal features when, after hatching, the newborn chickens are exposed to the open air. 82 Development of Tectal Afferences and Efferences in Xenopus. B.H. CHAHOUD, M.J. CORDIER-PICOUET and P. CLAIRAMHAULT. Neuroembryoloqie Universite PARIS VII The developmental pattern of tectal afferences and efferences has been investigated with the aid of the Fink-Heimer technique and HRPinjections followed by the PAP immmunohistochemical procedure. Reciprocal connections: with the dorsal thalamus (bilateraly) and the isthmus (ipsilateraly) appear at stage 53; with the pretectum at stage 59 (but pretecto-tectal fibers emerge at stage 51). At the right end of metamorphosis, reciprocal connections are also established with: the dorsal tegmentum (bilateraly), the vestibular area (contralateraly) and the Vth nerve area (ipsilateraly); at the same period, the posterior tectum begins to receive ipsilateral afferences from the striatum, the ventral thalamus and the torus semi-circularis. Numerous bilateral efferences to the brain stem (whole teqmentum, area reticularis, vestibular area, fasciculus solitarius and oliva superior) appear as earlier as stages 51/53. Bilateral efferences to visual neuropils (area preoptica and Feniculate) emerge only at stage 59.