Summary
The general ultrastructural features of the hypothalamo-neurohypophysial system in rats with hereditary hypothalamic diabetes insipidus (DI-rats, Brattleboro strain) are described. There is no decisively distinguishing difference between the neurons of the supraoptic and paraventricular nuclei. The neurons of both nuclei show signs of active protein synthesis. The perikarya of the neurons are markedly hypertrophic, the nuclei are large and the nucleoli prominent. In the cytoplasm there are numerous ribosomes, abundant rough-surfaced endoplasmic reticulum and extensive Golgi complexes. However, very few neurosecretory granules are to be seen. The axons of the hypothalamo-neurohypophysial tract are likewise enlarged and the paucity of neurosecretory granules is a striking feature also in the area of the tract. The majority of nerve endings in the posterior pituitary of DI-rats are devoid of neurosecretory granules. Microvesicles are abundant in the nerve endings and there are findings which suggest that microvesicles are involved either in endoor exocytosis. The signs of active protein synthesis and the concomitant paucity of neurosecretory granules are interpreted to imply transportation of the secretory proteins in an extragranular phase. The possible mode of release of the secretory proteins from the nerve endings and the role of microvesicles therein are discussed.
Similar content being viewed by others
References
Bissett, G. W., Clark, B. J., Errington, M. L.: The hypothalamic neurosecretory pathways for the release of oxytocin and vasopressin in the cat. J. Physiol. (Lond.) 217, 111–131 (1971).
Boudier, J. L., Boudier, J. A., Picard, D.: Ultrastructure du lobe postérieur de l'hypophyse du rat et ses modifications au cours de l'excrétion de vasopressine. Z. Zellforsch. 108, 357–380 (1970).
Cardell, R. R.: Ultrastructure of the salamander thyroidectomy cell. J. Ultrastruct. Res. 10, 515–527 (1964).
De Robertis, E. D. P.: Histophysiology of synapses and neurosecretion. Oxford: Pergamon Press 1964.
Diepen, R.: Der Hypothalamus. In: Handbuch der mikroskopischen Anatomie des Menschen, IV/7, S. 45–48. Berlin-Göttingen-Heidelberg: Springer 1962.
Dingemans, K. P.: On the origin of thyroidectomy cells. J. Ultrastruct. Res. 26, 480–500 (1969).
Dyball, R. E. J.: Oxytocin and ADH secretion in relation to electrical activity in antidromically identified supraoptic and paraventricular units. J. Physiol. (Lond.) 214, 245–256 (1971).
Eneström, S.: Nucleus supraopticus. A morphological and experimental study in the rat. Acta path. microbiol. scand., Suppl. 186, 1–99 (1967).
Friesen, H. G., Astwood, E. B.: Changes in neurohypophysial proteins induced by dehydration and ingestion of saline. Endocrinology 80, 278 (1967).
Jones, C. W., Pickering, B. T.: Comparison of the effects of water deprivation and sodium chloride imbibition on the hormone content of the neurohypophysis of the rat. J. Physiol. (Lond.) 203, 449–458 (1969).
Kalimo, H.: Ultrastructural studies on the hypothalamic neurosecretory neurones of the rat. I. The paraventricular neurones of the non-treated rat. Z. Zellforsch. 122, 283–300 (1971).
Krisch, B., Becker, K., Bargmann, W.: Exocytose im Hinterlappen der Hypophyse. Z. Zellforsch. 123, 47–54 (1972).
Kynčl, J., Jelínek, V., Rudinger, J.: The use of rats with lesion-induced or hereditary hypothalamic Diabetes insipidus for evaluating prolonged responses to antidiuretic hormone preparations. Acta endocr. (Kbh.) 60, 369–379 (1969).
Miller, M., Moses, A. M.: Radioimmunoassay of urinary antidiuretic hormone with application to study of the Brattleboro rat. Endocrinology 88, 1397–1396 (1971).
Moses, A. M., Miller, M.: Accumulation and release of pituitary vasopressin in rats heterozygous for hypothalamic Diabetes insipidus. Endocrinology 86, 34–42 (1970).
Nagasawa, J., Douglas, W. W., Schulz, R. A.: Micropinocytotic origin of coated and smooth microvesicles (“Synaptic Vesicles”) in neurosecretory terminals of posterior pituitary glands demonstrated by incorporation of horseradish peroxidase. Nature (Lond.) 232, 341–342 (1971).
Norström, A.: Axonal transport and turnover of neurohypophysial proteins in the rat. Thesis, University of Gothenburg, Sweden 1972.
Orkand, P. M., Palay, S. L.: Effects of treatment with exogenous vasopressin on the structural alterations in the hypothalamo-hypophysial system of rats with hereditary diabetes insipidus. Anat. Rec. 157, 295 (1967).
Pellegrino De Iraldi, A., De Robertis, E.: The neurotubular system of the axon and the origin of granulated and non-granulated vesicles in regenerating nerves. Z. Zellforsch. 87, 330–344 (1968).
Peters, A.: The fixation of the central nervous system and the analysis of electron micrographs of the neuropil with special reference to the cerebral cortex. In: Contemporary research methods in neuroanatomy (W. J. H. Nauta and S. O. E. Ebbesson, eds.), p. 56–76 Berlin-Heidelberg-New York: Springer 1970.
Pickering, B. T., Jones, C. W., Burford, G. D.: Biosynthesis and intraneuronal transport of neurosecretory products in the hypothalamo-neurohypophysial system. In: Neurohypophysial hormones, Ciba Foundation Study Group No. 39 (G. E. W. Wolstenholme and Joan Birch, eds.), p. 58–74. Edinburgh-London: Churchill Livingstone 1971.
Pilgrim, C.: Morphologische und funktionelle Untersuchungen zur Neurosekretbildung. Ergebn. Anat. Entwickl.-Gesch. 41, 1–79 (1969).
Rechardt, L.: Electron microscopic and histochemical observations on the supraoptic nucleus of normal and dehydrated rats. Acta physiol. scand., Suppl. 329, 1–79 (1969).
Redman, C. M.: Biosynthesis of serum proteins and ferritin by free and attached ribosomes of rat liver. J. Biol. Chem. 244, 4308–4314 (1969).
Reynolds, E. S.: The use of lead citrate as an electron dense stain in electron microscopy. J. Cell Biol. 17, 208–212 (1963).
Rinne, U. K.: Ultrastructure of the median eminence of the rat. Z. Zellforsch. 74, 98–122 (1966).
Rodriguez, E. M.: Ultrastructure of the neurohaemal region of the toad median eminence. Z. Zellforsch. 93, 182–212 (1969).
Rodriguez, E. M., Dellmann, H.-D.: Ultrastructure and hormonal content of the proximal stump of the transected hypothalamo-hypophysial tract of the frog (Rana pipiens). Z. Zellforsch. 104, 449–470 (1970).
Santolaya, R. C., Bridges, T. E., Lederis, K.: Elementary granules, small vesicles and exocytosis in the rat neurohypophysis after acute haemorrhage. Z. Zellforsch. 125, 277–288 (1972).
Scott, D. E.: Fine structural features of the neural lobe of the hypophysis of the rat with homozygous diabetes insipidus (Brattleboro strain). Neuroendocrinology 3, 156–176 (1968).
Sokol, H.: Evidence for oxytocin synthesis after electrolytic destruction of the paraventricular nucleus in rats with hereditary diabetes insipidus. Neuroendocrinology 6, 90–97 (1970).
Sokol, H., Valtin, H.: Morphology of the neurosecretory system of rats homozygous and heterozygous for hypothalamic diabetes insipidus (Brattleboro strain). Endocrinology 77, 692–700 (1965).
Sokol, H., Valtin, H.: Evidence for the synthesis of oxytocin and vasopressin in separate neurons. Nature (Lond.) 214, 314–315 (1967).
Streefkerk, J. G.: Functional changes in the morphological appearance of the hypothalamo-hypophyseal neurosecretory system, and catechnolaminergic neural system, and in the adenohypophysis of the rat. Thesis. Vrije Universiteit te Amsterdam. Amsterdam 1967.
Thorn, N. A.: Mechanism of release of neurohypophyseal hormones. In: Aspects of neuroendocrinology W. Bargmann and B. Scharrer, eds.), p. 140–152. Berlin-Heidelberg-New York: Springer 1970.
Valtin, H.: Hereditary hypothalamic diabetes insipidus in rats (Brattleboro strain). A useful experimental model. Amer. J. Med. 42, 814–827 (1967).
Valtin, H., Sawyer, W. H., Sokol, H. W.: Neurohypophysial principles in rats homozygous and heterozygous for hypothalamic diabetes insipidus (Brattleboro strain). Endocrinology 77, 701–706 (1965a).
Valtin, H., Schroeder, H. A.: Familial hypothalamic diabetes insipidus in rats (Brattleboro strain). Amer. J. Physiol. 425–430 (1964).
Valtin, H., Sokol, H. W., Sawyer, W. H., Harrington, A. R.: Possible synthesis of a “defective polypeptide” in a strain of rats with hereditary hypothalamic diabetes insipidus. Proc. of the 2nd International Congr. on Endocrinology, p. 1287. Amsterdam: Excerpta Medica Foundation 1965b.
Venable, J. H., Coggeshall, R.: A simplified lead citrate stain for use in electron microscopy. J. Cell Biol. 25, 407–408 (1965).
Watson, M. L.: Staining of tissue sections for electron microscopy with heavy metals. J. biophys. biochem. Cytol. 4, 475–478 (1958).
Whitaker, S., LaBella, F. S.: Ultrastructural localization of acid phosphatase in the posterior pituitary of the dehydrated rat. Z. Zellforsch. 125, 1–15 (1972).
Author information
Authors and Affiliations
Additional information
This study has been supported by grants from the Finnish Cultural Foundation and the Sigrid Jusélius Foundation. The collaboration of Professors Antti Arstila and Tapani Vanha-Perttula is gratefully acknowledged.
The Brattleboro-rats were kindly provided by Dr. Heinz Valtin, to whom we express our thanks.
Rights and permissions
About this article
Cite this article
Kalimo, H., Rinne, U.K. Ultrastructural studies on the hypothalamic neurosecretory neurons of the rat. Z.Zellforsch 134, 205–225 (1972). https://doi.org/10.1007/BF00307154
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00307154