Summary
The SFO of the chicken is divided in half by a large central blood sinus; ventrally it is covered by a thin layer of ependyma (including tanycytes, dendrites, and axons) which connects the two lateral halves and protrudes as a midsagittal crest into the lumen of the third ventricle. The ependyma consists predominantly of tanycytes with long basal processes which terminate upon perivascular spaces. These cells have an extensive Golgi apparatus and abundant lysosomes; their cellular apices containing polyribosomes and a few vesicles frequently protrude into the ventricle. In addition to astrocytes, oligodendrocytes, and microglial cells, there is another glial cell population that is distinguished by the presence of parallel stacks or spherical to ovoid conglomerates of rough ER and their unique location, i.e., limited to areas ventral and ventral-lateral to the large blood sinus. Two types of neurons are present: neurons in which there is a paucity of granulated vesicles and occasional vacuoles in both the cytoplasm and nuclei, the second type of neuron elaborates many granulated vesicles. Numerous puncta adhaerentia are observed between adjacent neuronal perikarya and between glial processes and neuronal perikarya.
Diverse axon types are found within the chicken SFO. Axo-dendritic and axo-somatic axon terminals and presynaptic axon dilations contain assorted combinations of electron-lucent and granulated vesicles of different maximal diameters. Based on the morphology of these axons, cholinergic, peptidergic, and serotoninergic fibers are described. There are two additional groups of axons whose classification awaits further investigation.
The chicken SFO differs from the mammalian SFO in several respects: it possesses an ependyma with secretory and/or absorptive tanycytes predominating; it is divided midsagittally by a central blood sinus; its lateral and dorsal limits are nebulous; a previously undescribed peculiar type of glial cell is found in a limited portion of the organ; supraependymal neurons are lacking.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bruni, J.E., Montemurro, D.G., Clattenburg, R.E.: Morphology of the ependymal lining of the rat third ventricle following intraventricular administration of synthetic luteinizing hormone-releasing hormone (LH-RH): A scanning electron microscopic investigation. Am. J. Anat. 150, 411–426 (1977)
Dellmann, H.-D.: Scanning and transmission electron microscopy of the subfornical organ of the grass frog (Rana pipiens). Anat. Rec. 189, 540 (1977) (abstr.)
Dellmann, H.-D.: Scanning and transmission electron microscopy of the subfornical organ of the grass frog (Rana pipiens). Cell Tissue Res. 186, 361–374 (1978)
Dellmann, H.-D., Linner, J.G.: Correlative light, scanning and transmission electron microscopy of the ventricular surface of the rat subfornical organ with special emphasis on supraependymal cells. Anat. Rec. 187, 565 (1977) (abstr.)
Dellmann, H.-D., Pearson, C.B.: Better epoxy resin embedding for electron microscopy at low relative humidity. Stain Technol. 52, 5–8 (1977)
Dellmann, H.-D., Simpson, J.B.: Comparative ultrastructure and function of the subfornical organ. In: Brain endocrine interaction II. The ventricular system in neuroendocrine mechanisms (K. Knigge, D. Scott, H. Kobayashi and S. Ishii, eds.), pp. 166–189. Basel: Karger 1975
Dellmann, H.-D., Simpson, J.B.: The subfornical organ. Int. Rev. Cytol., in press (1979)
Joseph, S.A., Scott, D.E., Vaala, S.S., Knigge, E.M., Krobisch Dudley, G.: Localization and content of thyrotrophin releasing factor (TRF) in median eminence of the hypothalamus. Acta Endocrinol. (Kbh.) 74, 214–255 (1973)
Legait, H.: Les voies efférentes des noyaux neurosécrétoires hypothalamiques chez les oiseaux. C. R. Soc. Biol. 150, 996–998 (1956)
Legait, H., Legait, E.: Paraphyse et organe subfornical chez les oiseaux. C. R. Soc. Biol. 151, 365–367 (1957)
Legait, H., Legait, E., Grignon, G.: Existe-t-il chez les oiseaux l'homologue de l'organe subfornical du troisième ventricule des mammifères? Bull. Assoc. Anat. 95, 509–513 (1957)
Leonhardt, H., Lindemann, B.: Surface morphology of the subfornical organ in the rabbit's brain. Z. Zellforsch. 146, 243–260 (1973)
Mikami, S., Asari, M.: Ultrastructure of the subfornical organ of the Japanese quail (Coturnix coturnix). Cell Tissue Res. 188, 19–34 (1978)
Paull, W.K., Martin, H., Scott, D.E.: Third ventricular floor surface alteration following intraventricular administration of dopamine. Scanning Electron Microscopy 1978, Vol. II, 817–822 (1978)
Peters, A., Palay, S.L., Webster, H.deF.: The fine structure of nervous system. The neurons and supporting cells. Philadelphia-London-Toronto: Saunders 1976
Phillips, M.I., Deshmuckh, P.P., Larsen, W.: Morphological comparisons of the ventricular wall of subfornical organ and organum vasculosum of the lamina terminalis. Scanning Electron Microscopy 1978, Vol. II, 349–356 (1978)
Scott, D.E., Krobisch Dudley, G., Knigge, K.M.: The ventricular system in neuroendocrine mechanisms. II. In vivo monoamine transport by ependyma of the median eminence. Cell Tissue Res. 154, 1–16 (1974a)
Scott, D.E., Paull, W.K., Kozlowski, G.P., Krobisch Dudley, G., Knigge, K.M.: Cellular localization of thyrotropic releasing factor (TRF) after intraventricular administration. In: Neurosecretion — The final neuroendocrine pathway (F. Knowles, L. Vollrath, eds.), pp. 165–169. New York-Heidelberg-Berlin: Springer 1974b
Simpson, J.B., Mangiapane, M.L., Dellmann, H.-D.: Central receptor sites for angiotensin-induced drinking: A critical review. Fed. Proc., in press (1978)
Takei, Y.: The role of the subfornical organ in drinking induced by angiotensin in the Japanese quail, Coturnix coturnix japonica. Cell Tissue Res. 185, 175–191 (1977)
Takei, Y., Tsuneki, K., Kobayashi, H.: Surface fine structure of the subfornical organ of the Japanese quail, Coturnix coturnix japonica. Cell Tissue Res. 191, 389–404 (1978)
Tsuneki, K., Takei, Y., Kobayashi, H.: Parenchymal fine structure of the subfornical organ of the Japanese quail, Coturnix coturnix japonica. Cell Tissue Res. 191, 405–419 (1978)
Author information
Authors and Affiliations
Additional information
Dedicated to Prof. H. Grau at the occasion of his 80th birthday
We gratefully acknowledge the technical help of Susan Woroch and secretarial assistance of Diana Hapes and Debbie Harrison
Rights and permissions
About this article
Cite this article
Dellmann, HD., Linner, J.G. Ultrastructure of the subfornical organ of the chicken (Gallus domesticus). Cell Tissue Res. 197, 137–153 (1979). https://doi.org/10.1007/BF00233559
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00233559