Summary
The distribution of monoamine oxidase (MAO) in the brain of Xenopus laevis tadpoles (stage 52–56) was studied histochemically with a modified Glenner's tryptamine-tetrazolium method. A moderate activity was observed in fibre regions of the striatum and septum (including the medial and lateral forebrain bundles), in the neuropil of the nucleus amygdalae, in the commissura anterior and commissura hippocampi, in the fibre regions of the diencephalon (including the optic chiasma), in the fibre regions of the tectum opticum and the tegmentum of the mesencephalon and in the white substance of the ventral half of the medulla oblongata. A greater MAO activity was found in the neuropil of the entire nucleus praeopticus. In the partes anterior and magnocellularis of this nucleus, MAO positive fibres are present in close contact with the perikarya, indicating a monoaminergic innervation of these neurons. The perikarya themselves did not show MAO activity. In the neurons of the nucleus praeopticus epichiasmaticus, the paraventricular organ (PVO) and nucleus infundibularis dorsalis (NID), only a slight MAO activity has been demonstrated in the perikarya, whereas a strong MAO positivity was found in the intraventricular protrusions and the neuropil. These data indicate the aminergic character of the neurons of these nuclei. From the postoptic fibre region a MAO positive tract was observed towards the developing median eminence and pars intermedia of the hypophysis. The pars nervosa and some cells of the pars distalis also contained MAO. Along the border of the aquaeduct of Silvius and the fourth ventricle, MAO positive liquor-containing neurons are also present.
The distribution of acetylcholinesterase (AChE) was investigated in the hypothalamohypophysial region. AChE activity was found in the neuropil of the nucleus praeopticus magnocellularis, in the fibres of the optic chiasma and in the postoptic fibre region. The neurons of the PVO and NID were AChE negative. An AChE positive tract could be traced from the postoptic fibre region to the developing median eminence and pars nervosa. The pars distalis did not show AChE activity. However, in tadpoles reaching the metamorphic climax, ChE activity appeared in certain cells of the pars distalis; this might be related to degenerative phenomena in the acidophilic cells. The absence of AChE activity in the pars intermedia indicates a regulation of MSH release by peptidergic nerves to be unlikely.
Similar content being viewed by others
References
Bartels, W.: Die Ontogenese der aminhaltigen Neuronensysteme im Gehirn von Rana temporaria. Z. Zellforsch. 116, 94–118 (1971).
Baumgarten, H. G., Björklund, A., Holstein, A. F., Nobin, A.: Organization and ultrastructural identification of the catecholamine nerve terminals in the neural lobe and pars intermedia of the rat pituitary. Z. Zellforsch. 126, 483–517 (1972).
Björklund, A.: Monoamine-containing fibres in the neuro-intermediate lobe of the pig and rat. Z. Zellforsch. 89, 573–589 (1968).
Björklund, A., Falck, B.: Histochemical characterization of a tryptamine-like substance stored cells of the mammalian adenohypophysis. Acta physiol. scand. 77, 475–489 (1969).
Braak, H.: Biogene Amine im Gehirn vom Frosch (Rana esculenta). Z. Zellforsch. 106, 269–308 (1970).
Cohen, A. G.: Observations of the pars intermedia of Xenopus laevis. Nature (Lond.) 215, 55–56 (1967).
Cottle, M. K. W., Silver, A.: Histochemical demonstration of acetylcholinesterase in the hypothalamus of the female guinea pig. Z. Zellforsch. 103, 570–588 (1970).
Doerr-Schott, J., Follenius, E.: Localisation des fibres aminergiques dans l'hypophyse de Rana esculenta. Etude autoradiographique au microscope électronique. C. R. Acad. Sci. (Paris) 269, 737–740 (1969).
Doerr-Schott, J., Follenius, E.: Innervation de l'hypophyse intermédiaire de Rana esculenta, et identification des fibres aminergiques par autoradiographie au microscope électronique. Z. Zellforsch. 106, 99–118 (1970).
Enemar, A., Falck, B.: On the presence of adrenergic nerves in the pars intermedia of the frog, Rana temporaria. Gen. comp. Endocr. 5, 577–583 (1965).
Enemar, A., Falck, B., Iturriza, F. C.: Adrenergic nerves in the pars intermedia of the pituitary in the toad, Bufo arenarum. Z. Zellforsch. 77, 325–330 (1967).
Follett, B. K., Kobayashi, H., Farner, D. S.: The distribution of monoamine oxidase and acetylcholinesterase in the hypothalamus and its relation to the hypothalamo-hypophysial neurosecretory system in the white-crowned sparrow, Zonotrichia leucophrys gambellii. Z. Zellforsch. 75, 57–65 (1966).
Glenner, G. G., Burtner, H. J., Brown, G. R.: The histochemical demonstration of monoamine oxidase activity by tetrazolium salts. J. Histochem. Cytochem. 5, 591–600 (1957).
Goos, H. J. Th.: Hypothalamic control of the pars intermedia in Xenopus laevis tadpoles. Z. Zellforsch. 97, 118–124 (1969).
Goos, H. J. Th., Halewijn, R. van: Biogenic amines in the hypothalamus of Xenopus laevis tadpoles. Naturwissenschaften 55, 393–394 (1968).
Haase, E., Farner, D. S.: Acetylcholinesterase in der Pars distalis von Zonotrichia leucophrys gambelii (Aves). Z. Zellforsch. 93, 356–368 (1969).
Haase, E., Farner, D. S.: Investigations of the butyrylcholinesterase-containing cells of the adenohypophysis of the white-crowned sparrow, Zonotrichia leucophrys gambelii. Z. Zellforsch. 118, 570–578 (1971).
Herrick, C. J.: The amphibian forebrain. VI. Necturus. J. comp. Neurol. 58, 1–289 (1933).
Hopkins, C. R.: Localization of adrenergic fibers in the amphibian pars intermedia by electron microscope autoradiography and their selective removal by 6-hydroxydopamine. Gen. comp. Endocr. 16, 112–120 (1971).
Iijima, K., Shantha, T. R., Bourne, G. H.: Enzyme-histochemical studies on the hypothalamus with special reference to the supraoptic and paraventricular nuclei of the squirrel monkey (Saimiri sciureus). Z. Zellforsch. 79, 76–91 (1967).
Imai, K.: Color change and pituitary function in Xenopus laevis. In: Biology of normal and abnormal melanocytes (eds. T. Kawamura, T. B. Fitzpatrick and M. Seiji), p. 17–30. Baltimore-London-Tokyo: University Park, Press 1971.
Ito, T.: Changes in skin color and fine structure of the intermediate pituitary gland of the frog, Rana nigromaculata, after extirpation of the median eminence. Neuroendocrinology 8, 180–197 (1971).
Iturriza, F. C.: Electronmicroscopic study of the pars intermedia of the pituitary of the toad, Bufo arenarum. Gen. comp. Endocr. 4, 492–502 (1964).
Jansen, W. F., West, R.: A cytochemical investigation of specific and non-specific cholinesterase activity in the saccus vasculosus of the rainbow trout. Proc. kon. ned. Akad. Wet., Series C 74, 344–351 (1971).
Kabawata, I.: Electron microscopy of the rat hypothalamic neurosecretory system. I. The supraoptic nuclei of normal and dehydrated rats. Gunma Symp. Endocr. 1, 51–58 (1964).
Karnovsky, M. J., Roots, L.: A “direct-coloring” thiocholine method for cholinesterases. J. Histochem. Cytochem. 12, 219–220 (1964).
Kerr, T.: The development of the pituitary in Xenopus laevis Daudin. Gen. comp. Endocr. 6, 303–311 (1966).
Kobayashi, H., Urano, A., Yokoyama, K.: Acetylcholinesterase (AChE) and monoamine oxidase (MAO) in the hypothalamic neurosecretory system. Proc. 3rd Intern. Congr. Histochem. Cytochem. p. 129–130 (1968).
Konstantinova, M.: The effect of adrenaline and acetylcholine on the hypothalamo-hypophysial neurosecretion in the rat. Z. Zellforsch. 83, 549–567 (1967).
Matsui, T., Kobayashi, H.: Histochemical demonstration of monoamine oxidase in the hypothalamo-hypophysial system of the tree sparrow and the rat. Z. Zellforsch. 68, 172–182 (1965).
Murakami, M.: Elektronenmikroskopische Untersuchung der neurosekretorischen Zellen im Hypothalamus der Maus. Z. Zellforsch. 56, 277–299 (1962).
Nakai, Y.: Electron microscopic observations on synapse-like contacts between pituicytes and different types of nerve fibers in the anuran pars nervosa. Z. Zellforsch. 110, 27–39 (1970).
Nakai, Y., Gorbman, A.: Evidence for a double innervated secretory unit in the anuran pars intermedia. II. Electron microscopic studies. Gen. comp. Endocr. 13, 108–116 (1969).
Nieuwkoop, P. D., Faber, J.: Normal table of Xenopus laevis Daudin. Amsterdam: North-Holland Publishing Co. 1956.
Novikoff, A. B., Shin, W. Y., Drucker, J.: Cold acetone fixation for enzyme localization in frozen sections. J. Histochem. Cytochem. 8, 37–40 (1960).
Olsson, K.: Effects on water diuresis of infusions of transmitter substances into the 3rd ventricle. Acta physiol. scand. 79, 133–135 (1970).
Oordt, P. G. W. J. van, Goos, H. J. Th., Peute, J., Terlou, M.: Hypothalamo-hypophysial relations in amphibian larvae. Gen. comp. Endocr., Suppl. 3, 41–50 (1972).
Pehlemann, F. W.: Ultrastructure and innervation of the pars intermedia of the pituitary of Xenopus laevis. Gen. comp. Endocr. 9, 481 (1967).
Peterson, R. P.: Synapses in the rat supraoptic nucleus. Anat. Rec. 151, 399 (1965).
Peute, J.: Fine structure of the paraventricular organ of Xenopus laevis tadpoles. Z. Zellforsch. 97, 564–575 (1969).
Peute, J.: Ultrastructural aspects of the nucleus infundibularis dorsalis in the hypothalamus of Xenopus laevis. Z. Zellforsch. 137, 513–520 (1973).
Peute, J., Goos, H. J. Th.: Biogenic amines in the tuber cinereum of Xenopus laevis. Electron and fluorescence microscopical observations. Aspects of neuroendocrinology (eds. W. Bargmann, B. Scharrer) p. 111–117. Berlin-Heidelberg-New York: Springer 1970.
Polenov, A L., Senchik, J. I.: Synapses on neurosecretory cells of the supraoptic nucleus in white mice. Nature (Lond.) 211, 1423–1424 (1966).
Saland, L. C.: Ultrastructure of the frog pars intermedia in the relation to hypothalamic control of hormone release. Neuroendocrinology 3, 72–88 (1968).
Terlou, M., Ploemacher, R. E.: The distribution of monomamine in the tel-, di- and mesencephalon of Xenopus laevis tadpoles, with special reference to the hypothalamo-hypophysial system. Z. Zellforsch. 137, 521–540 (1973).
Uemura, H.: Cholinesterases in the hypothalamo-hypophysial system of the bird, Zosterops palpebrosa japonica. Zool. Mag. (Japan) 73, 118–126 (1964).
Uemura, H.: Histochemical studies on the distribution of cholinesterase and alkaline phosphatase in the vertebrate neurosecretory system. Annot. Zool. Jap. 38, 79–96 (1965).
Urano, A.: Monoamine oxidase in the hypothalamic neurosecretory system and the adenohypophysis of the Japanese quail and the mouse. J. Fac. Univ. Tokyo Section IV, 11, 437–451 (1968).
Urano, A.: Monoamine oxidase in the hypothalamo-hypophysial region of the brown smooth dogfish, Triakis scyllia. Endocr. jap. 18, 37–46 (1971a).
Urano, A.: Monoamine oxidase in the hypothalamo-hypophysial region of the teleosts, Anguilla japonica and Oryzias latipes. Z. Zellforsch. 114, 83–94 (1971b).
Urano, A.: Monoamine oxidase in the neurohypophysis of the newt (Cynops pyrrhogaster pyrrhogaster), the toad (Bufo bufo japonicus) and the tortoise (Clemmys japonica). Z. Zellforsch. 126, 454–465 (1972).
Vigh, B.: The paraventricular organ, its structure and function. In: Zirkumventrikuläre Organe und Liquor. Symposium Reinhardsbrunn (Hrsg. G. Sterba), S. 148–150. Jena: Fischer 1969.
Vigh, B.: Das Paraventrikularorgan und das Zirkumventrikuläre System. Studia Biologica Hungarica, Bd. 10, Budapest: Akadémiai Kiadó 1971.
Vigh-Teichmann, I., Vigh, B., Aros, B.: Enzymhistochemische Studien am Nervensystem. IV. Acetylcholinesteraseaktivität im Liquorkontakt — Neuronensystem verschiedener Vertebraten. Histochemie 21, 322–337 (1970).
Author information
Authors and Affiliations
Additional information
The stimulating interest and helpful advice of Prof. Dr. P. G. W. J. van Oordt is gratefully acknowledged. Thanks are also due to Mr. H. van Kooten and his co-workers for making the photographs.
Rights and permissions
About this article
Cite this article
Terlou, M., Stroband, H.W.J. The distribution of monoamine oxidase and acetylcholinesterase in the brain of Xenopus laevis tadpoles. Z.Zellforsch 140, 261–275 (1973). https://doi.org/10.1007/BF00306698
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00306698