Summary
A well developed system of ependymal glial cells with long basilar processes stretching to the surface of the brain (tanycytes, Horstmann, 1954) has been described in the basal hypothalamus of Coturnix quail. The tanycytes both in the median eminence and the ventro-lateral hypothalamus form a link between the third ventricle and the hypophysial circulation. The processes of the ventro-lateral tanycytes terminate in the region of the infundibular sulcus in apposition to a loose network of vessels which are continuous with the primary plexus of the hypophysial portal system.
Within the median eminence, the subependymal capillary network connects the vasculature of the contra-lateral sides of hypothalamus. There are no direct connections with the hypophysial portal vessels.
With the aid of the light and electron microscope the ventricular ependyma was divided into a dorsal “typical” region and two “glandular” regions (ventro-lateral and ventral). Each region contains different forms of tanycyte. One of the two forms of tanycyte (designated type 3) associated with the ventro-lateral glandular ependyma has no contact with the third ventricle.
Ultrastructural studies on the “glandular” ependyma failed to show any obvious differences between castrated, oestrogen or testosterone implanted, and sexually mature or immature quail.
The possibility that the tanycyte-vascular system may have a neuroendocrine role is discussed.
Zusammenfassung
Im basalen Hypothalamus der Wachtel Coturnix wurde ein gut entwickeltes System von ependymalen Gliazellen mit langen Fortsätzen beobachtet. Diese Ependymzellen (Tanycyten, Horstmann, 1954) reichen bis an die Oberfläche des Gehirns. Die Tanycyten der Eminentia mediana und des ventro-lateralen Hypothalamus bilden eine Verbindung zwischen dem III. Ventrikel und dem portalen Hypophysenkreislauf. Die Fortsätze der ventro-lateralen Tanycyten enden in der Region des Sulcus infundibularis an einem lockeren Gefäßnetz, das sich in das primäre Kapillarnetz des portalen Gefäßsystems der Hypophyse fortsetzt.
Das subependymale Kapillarnetz der Eminentia mediana verbindet die Gefäßsysteme der kontralateralen Hypothalamushälften. Hier gibt es keine direkten Verbindungen mit dem portalen Gefäßapparat.
Aufgrund von licht- und elektronenmikroskopischen Studien wird das Ventrikelependym von Coturnix in eine dorsale „typische“ Region und in zwei „glanduläre“ Regionen (ventrolateral und ventral) gegliedert. Jedes dieser Gebiete zeigt unterschiedliche Tanycytenformen. Einer der beiden „glandulären“ Tanycytentypen (Typ 3), der im Verein mit dem ventrolateralen „glandulären“ Ependym auftritt, hat keinen Kontakt mit dem III. Ventrikel.
Ultrastrukturstudien am „glandulären“ Ependym ergaben keine sicheren Unterschiede zwischen kastrierten und mit Oestrogen oder Testosteron behandelten, sowie zwischen geschlechtsreifen und nicht geschlechtsreifen Wachteln.
Die Möglichkeit einer neuroendokrinen Funktion des Tanycyten-Gefäß-Systems wird diskutiert.
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References
Anand Kumar, T. C., Knowles, Sir F.: A system linking the third ventricle with the pars tuberalis of the rhesus monkey. Nature (Lond.) 215, 54 (1967).
Bern, H. A., Nishioka, R. S.: Fine structure of the median eminence of some passerine birds. Proc. Zool. Soc. Bengal 18, 107–119 (1965).
Crosby, E. C., Showers, M. J.: Comparative anatomy of the preoptic and hypothalamic areas. In: The hypothalamus, p. 61–134. Springfield, Ill. C. Thomas 1969.
Diepen, R.: Der Hypothalamus. In: Handbuch der mikroskopischen Anatomie des Menschen (W. Bargmann, Ed.), Bd IV/7. Berlin-Göttingen-Heidelberg: Springer 1962.
Dodd, J. M., Follett, B. K., Sharp, P. J.: Hypothalamic control of pituitary function in submammalian vertebrates. In: Comparative physiology and biochemistry (Lowenstein, O.E., ed.), vol. 4, p. 114–200. New York-London: Academic Press 1971.
Duvernoy, H., Gainet, F., Koritké, J. G.: Sur la vascularisation de l'hypophyse des Oiseaux. J. Neuro-Visc. Rel. 31, 109–127 (1969).
Follett, B. K.: Gonadotrophin-releasing activity in the quail hypothalamus. Gen. comp. Endocr. 15, 165–179 (1970).
— Farner, D. S.: The effects of the daily photoperiod on gonadal growth, neurohypophysial hormone content, and neurosecretion in the hypothalamo-hypophysial system of the Japanese quail (Coturnix coturnix japonica). Gen. comp. Endocr. 7, 111–124 (1966).
— Sharp, P. J.: Circadian rhythmicity in photoperiodically induced gonadotrophin release and gonadal growth in the quail. Nature (Lond.) 223, 968–971 (1969).
-- -- Photo-induced gonadal growth in Coturnix quail. In preparation (1972).
Gallyas, F.: Silver staining of fibrous neuroglia by means of physical development. Acta neuropath. (Berl.) 16, 39–43 (1970).
Green, J. D.: The comparative anatomy of the hypophysis with special reference to its blood supply and innervation. Amer. J. Anat. 88, 225–311 (1951).
Hagedoorn, J.: Seasonal changes in the ependyma of the third ventricle of the skunk, Mephitis mephitis nigra. Anat. Rec. 151, 453 Abst. (1965).
Holmes, R. L.: The vascular pattern of the median eminence of the hypophysis in the macaque. Folia primatol. 7, 216–230 (1967).
Horstmann, E.: Die Faserglia des Selachiergehirns. Z. Zellforsch. 39, 588–617 (1954).
Jazdowska, B., Dobrowolski, W.: Vascularization of the hypophysis in sheep. Endokr. pol. 16, 269–282 (1965).
Klinkerfuss, G. H.: An electron microscopic study of the ependyma and subependymal glia of the lateral ventricle of the cat. Amer. J. Anat. 115, 71–100 (1964).
Knowles, Sir F.: Ependymal secretion, especially in the hypothalamic region. J. Neuro-Visc. Rel., Suppl. IX 97–110 (1969).
— Anand Kumar, T. C.: Structural changes, related to reproduction, in the hypothalamus and in the pars tuberalis of the rhesus monkey. Part I. The hypothalamus. Part II. The pars tuberalis. Phil. Trans. B 256, 357–375 (1969).
Kobayashi, H., Matsui: Synapses in the rat and pigeon median eminence. Endocr. jap. 14, 279–283 (1967).
— Fine structure of the median eminence and its functional significance. In: Frontiers in neuroendocrinology, p. 3–46. New York: Oxford University Press 1969.
— Ishii, S.: Functional electron microscopy of the hypothalamic median eminence. Int. Rev. Cytol. 29, 281–381 (1970).
Kuhlenbeck, H.: The central nervous system of vertebrates, vol. 3, part 1: Structural elements: Biology of nervous tissue. Basel-München-New York: Karger 1969.
Leonhardt, H.: Über ependymale Tanycyten des III. Ventrikels beim Kaninchen in elektronenmikroskopischer Betrachtung. Z. Zellforsch. 74, 1–11 (1966).
— Lindner, E.: Marklose Nervenfasern im III. und IV. Ventrikel des Kaninchen- und Katzengehirns. Z. Zellforsch. 78, 1–18 (1967).
Leveque, T. F.: In: Advances in neuroendocrinology. (Nalbandov, A., Ed.), p. 314–328. Illinois: University Press 1963.
— Hofkin, G. A.: Demonstration of an alcohol-chloroform insoluble periodic acid-Schiff reactive substance in the hypothalamus of the rat. Z. Zellforsch. 53, 185–191 (1961).
— Stutinsky, F., Porte, A., Stoeckel, M.-E.: Morphologie fine d'une différenciation glandulaire du recessus infundibulaire chez le rat. Z. Zellforsch. 69, 381–394 (1966).
Löfgren, F.: The infundibular recess, a component in the hypothalamo-adenohypophysial system. Acta morph. neerl.-scand. 6, 55–78 (1960).
Matsui, T., Kobayashi, H.: Surface protrusions from the ependymal cells of the median eminence. Arch. Anat. micr. Morph. exp. 51, 431–436 (1968).
Motta, M., Fraschini, F., Martini, L.: “Short” feedback mechanisms in the control of anterior pituitary function. In: Frontiers in neuroendocrinology, p. 211–253. New York: Oxford University Press 1969.
Oehmke, H.-J.: Regionale Strukturunterschiede im Nucleus infundibularis der Vögel (Passeriformes). Z. Zellforsch. 92, 406–421 (1968).
Oksche, A.: Histologische Untersuchungen über die Bedeutung des Ependyms, der Glia und der Plexus chorioidei für den Kohlenhydratstoffwechsel des ZNS. Z. Zellforsch. 48, 74–129 (1958).
Pearse, A. G. E.: Histochemistry, 2nd. ed. London: Churchill 1960.
Ramón y Cajal, S.: Histologie du système nerveux de l'homme et des vertébrés, vol. 1. Trans. Azoulay. Paris: Maloine 1909.
Schachenmayr, W.: Über die Entwicklung von Ependym und Plexus chorioideus der Ratte. Z. Zellforsch. 77, 25–63 (1967).
Scharrer, E.: The final common path in neuroendocrine integration. Arch. Anat. micr. 54, 359–370 (1965).
Sharp, P. J., Follett, B. K.: The distribution of monoamines in the hypothalamus of the Japanese quail, Coturnix coturnix japonica. Z. Zellforsch. 90, 245–262 (1968).
— The blood supply to the pituitary and basal hypothalamus in the Japanese quail (Coturnix coturnix japonica). J. Anat. (Lond.) 104, 227–232 (1969a).
— The effect of hypothalamic lesions on gonadotrophin release in Japanese quail (Coturnix coturnix japonica). Neuroendocrinology 5, 205–218 (1969b).
Stensaas, L. J., Stensaas, S. S.: Light microscopy of glial cells in turtles and birds. Z. Zellforsch. 91, 315–340 (1968).
Tienhoven, A. van, Juhász, L. P.: The chicken telencephalon, diencephalon and mesencephalon in stereotaxic coordinates. J. comp. Neurol 118, 185–197 (1960).
Török, B.: Structure of the vascular connections of the hypothalamo-hypophysial region. Acta anat. (Basel) 59, 84–89 (1964).
Vigh, B.: Ependymosécrétion, sécrétion Gomori-positive de l'épendyme dans l'hypothalamus. Ann. Endocr. (Paris) 25 Suppl., 140–141 (1964).
— Aros, B., Wenger, T., Koritsánszky, S., Ceglédi, G.: Ependymosecretion (ependymal neurosecretion). IV. The Gomori-positive secretion of the hypothalamic ependyma of various vertebrates and its relation to the anterior pituitary. Acta biol. Acad. Sci. hung. 13, 407–419 (1963).
Wingstrand, K. G.: The structure of the avian pituitary. Lund: Gleerup 1951.
Wittkowski, W.: Zur Ultrastruktur der ependymalen Tanyzyten und Pituizyten sowie ihre synaptische Verknüpfung in der Neurohypophyse des Meerschweinchens. Acta anat. (Basel) 67, 338–360 (1967).
— Ependymokrinie und Rezeptoren in der Wand des Recessus infundibularis der Maus und ihre Beziehung zum kleinzelligen Hypothalamus. Z. Zellforsch. 93, 530–546 (1969).
Ziesmer, C.: Eine Verbesserung der Silber-Imprägnierung nach Bodian. Z. wiss. Mikrosk. 60, 57–59 (1951).
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Supported by Grant AB 18/1 from the Agricultural Research Council to Professor J.M. Dodd and Dr. B.K. Follett.
I am indebted to Professor A. Oksche, Dept. of Anatomy, University of Giessen for providing research facilities and to The Royal Society for additional financial support.
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Sharp, P.J. Tanycyte and vascular patterns in the basal hypothalamus of Coturnix quail with reference to their possible neuroendocrine significance. Z.Zellforsch 127, 552–569 (1972). https://doi.org/10.1007/BF00306871
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DOI: https://doi.org/10.1007/BF00306871