Summary
The fine structure of adrenergic axon terminals was examined in the paraventricular nucleus of the thalamus (PNT) and in the hypothalamic arcuate nucleus-median eminence (ARC-ME) complex by use of phenylethanolamine-N-methyl transferase (PNMT) immunocytochemistry. In the PNT, immunoreactive terminals formed a dense and well-circumscribed plexus. In the ARC, labeled varicosities were less numerous and more evenly distributed. In the ME, they were scarce and confined to the inner zone. In all these areas, the diameter of immunoreactive varicosities ranged between 0.2 and 1.3 μm; in the ME and in the transitional zone between the ARC and the ME, a population of larger boutons (>2 μm) was also visible. All immunoreactive varicosities exhibited densely packed small, clear vesicles associated with a few large granular vesicles. In the PNT and the ARC, but not in the ME, they formed synaptic contacts with dendritic elements and were occasionally apposed to neuronal cell bodies. These axo-somatic appositions showed no junctional specializations. In the ME and transitional zone, immunoreactive terminals were frequently juxtaposed to, and occasionally established differentiated synaptic contacts with, tanycytes. These data support a transmitter role for adrenaline in the diencephalon and suggest that adrenaline plays a role in hypothalamo-hypophysiotropic regulation through interactions with neural and glial elements.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Armstrong DM, Ross CA, Pickel VM, Joh TH, Reis DJ (1982) Distribution of dopamine-, noradrenaline-, and adrenaline-containing cell bodies in the rat medulla oblongata: demonstrated by the immunocytochemical localization of catecholamine biosynthetic enzymes. J Comp Neurol 212:173–187
Bosler O, Beaudet A (1985) VIP neurons as prime synaptic targets for serotonin afferents in rat suprachiasmatic nucleus: a combined radioautographic and immunocytochemical study. J Neurocytol 14:749–763
Bosler O, Descarries L (1983) Uptake and retention of (3H)adrenaline by central monoaminergic neurons: A light and electron-microscope radioautographic study after intraventricular administration in the rat. Neuroscience 8:561–581
Bosler O, Bloch B, Bugnon C, Calas A (1982) Bases morphologiques des interactions monoamines-peptides dans l'hypothalamus neuroendocrine du rat. Données radioautographiques et immunocytochimiques. In Tixier-Vidal A and Richard P (eds) Régulations cellulaires multihormonales en neuroendocrinologie, Coll INSERM, vol 10, Paris, pp 17–36
Bouchaud C, Arluison M (1977) Serotoninergic innervation of ependymal cells in the rat subcommissural organ. A fluorescence, electron microscopic and radioautographic study. Biol Cell 1:65–72
Chamba G, Renaud B (1983) Distribution of tyrosine-hydroxylase, dopamine-β-hydroxylase and phenylethanolamine-N-methyl transferase activities in coronal sections of the rat lower brain stem. Brain Res 259:95–102
Chetverukhin VK, Belenky MA, Polenov AL (1979) Quantitative radioautographic light and electron microscopic analysis of the localization of monoamines in the median eminence of the rat. I. Catecholamines. Cell Tiss Res 203:469–485
Cimarusti DL, Saito K, Vaughn JE, Barber R, Roberts E, Thomas PE (1979) Immunocytochemical localization of dopamine-β-hydroxylase in rat locus coeruleus and hypothalamus. Brain Res 162:55–67
Cuello AC, Iversen LL (1973) Localization of tritiated dopamine in the median eminence of the rat hypothalamus by electron microscope autoradiography. Brain Res 63:474–478
Cuello AC, Weiner RI, Ganong WF (1973) Effect of lateral deafferentation on the morphology and catecholamine content of the mediobasal hypothalamus. Brain Res 59:191–200
Denoroy L (1979) Utilisation de la phényléthanolamine-N-méthyltransférase comme marqueur des structures adrénergiques. Application à l'étude de l'hypertension artérielle. Thèse Docteur-Ingénieur, Université Claude Bernard, Lyon
Gibbs DM (1985) Hypothalamic epinephrine is released into hypophysial portal blood during stress. Brain Res 335:360–364
Hökfelt T, Fuxe K, Goldstein M, Johansson O (1973) Evidence for adrenaline neurons in the rat brain. Acta Physiol Scand 89:286–288
Hökfelt T, Fuxe K, Goldstein M, Johansson O (1974) Immunohistochemical evidence for the existence of adrenaline neurons in the rat brain. Brain Res 66:235–251
Hökfelt T, Johansson O, Goldstein M (1984) Central catecholamine neurons as revealed by immunohistochemistry with special reference to adrenaline neurons. In: Björklund A and Hökfelt T (eds) Handbook of Chemical Neuroanatomy, vol 2: Classical Transmitters in the CNS, Part I, Elsevier, Amsterdam, pp 157–276
Holmes MC, Antoni FA, Aguilera G, Catt KJ (1986) Magnocellular axons in passage through the median eminence release vasopressin. Nature 319:326–329
Howe PRC, Costa M, Furness JB, Chalmers JP (1980) Simultaneous demonstration of phenylethanolamine-N-methyl transferase immunofluorescent and catecholamine fluorescent nerve cell bodies in the rat medulla oblongata. Neuroscience 5:2229–2238
Johnston CA, Gibbs DM, Negro-Vilar A (1983) High concentrations of epinephrine derived from a central source and of 5-hydroxyindole-3-acetic acid in hypophysial portal plasma. Endocrinology 113:819–821
Kalia M, Fuxe K, Goldstein M (1985a) Rat medulla oblongata. II. Dopaminergic, noradrenergic (A1 and A2) and adrenergic neurons, nerve fibers, and presumptive terminal processes. J Comp Neurol 233:308–332
Kalia M, Fuxe K, Goldstein M (1985b) Rat medulla oblongata. III. Adrenergic (C1 and C2) neurons, nerve fibers and presumptive terminal processes. J Comp Neurol 233:333–349
Kitahama K, Pearson J, Denoroy L, Kopp N, Ulrich J, Maeda T, Jouvet M (1985) Adrenergic neurons in human brain demonstrated by immunohistochemistry with antibodies to phenylethanolamine-N-methyl transferase (PNMT): discovery of a new group in the nucleus tractus solitarius. Neurosci Lett 53:303–308
Kobayashi H, Matsui T, Ishii S (1970) Functional electron microscopy of the hypothalamic median eminence. Int Rev Cytol 29:281–381
Lichtensteiger W, Richards JG (1975) Tuberal DA neurons and tanycytes: Response to electrical stimulation and nicotine. Experientia 31:742
Lichtensteiger W, Richards JG, Kopp HG (1978) Possible participation of non-neuronal elements of median eminence in neuroendocrine effects of dopaminergic and cholinergic systems. In: Scott DE, Kozlowski GP and Weindl A (eds), Brain Endocrine Interaction III. Neural hormones and reproduction, Karger, Basel, pp 251–262
Liposits Zs, Phelix C, Paull WK (1986) Electron microscopic analysis of tyrosine hydroxylase, dopamine-β-hydroxylase and phenylethanolamine-N-methyl-transferase immunoreactive innervation of the hypothalamic paraventricular nucleus in the rat. Histochemistry 84:105–120
Lundberg J, Bylock A, Goldstein M, Hansson HA, Dahlström A (1977) Ultrastructural localization of dopamine-β-hydroxylase in nerve terminals of the rat brain. Brain Res 120:549–552
Milner TA, Chan J, Massari VJ, Oertel WH, Park DH, Joh TH, Reis DJ, Pickel VM (1985) Ultrastructure and synaptic interactions of adrenergic and GABA-ergic neurons in the rat rostral ventro-lateral medulla. Soc Neurosci Abstr 11:570
Møllgård K, Wiklund L (1979) Serotoninergic synapses on ependymal and hypendymal cells of the rat subcommissural organ. J Neurocytol 8:445–467
Page RB, Dovey-Hartman BJ (1984) Neurohemal contact in the internal zone of the rabbit median eminence. J Comp Neurol 226:274–288
Pickel VM, Joh TH, Reis DJ (1976) Monoamine-synthesizing enzymes in central dopaminergic, noradrenergic and serotonergic neurons. Immunocytochemical localization by light and electron microscopy. J Histochem Cytochem 24:792–806
Piotte M, Beaudet A, Joh TH, Brawer JR (1985) The fine structural organization of tyrosine hydroxylase immunoreactive neurons in rat arcuate nucleus. J Comp Neurol 239:44–53
Robert O, Miachon S, Kopp N, Denoroy L, Tommasi M, Rollet D, Pujol JF (1984) Immunohistochemical study of the catecholaminergic systems in the lower brain stem of the human infant. Human Neurobiol 3:229–234
Ruggiero DA, Ross CA, Anwar M, Park DH, Joh TH, Reis DJ (1985) Distribution of neurons containing phenylethanolamine-N-methyltransferase in medulla and hypothalamus of rat. J Comp Neurol 239:127–154
Sladek JR, Sladek CD, Mc Neill TH, Wood JG (1978) New sites of monoamine localization in the endocrine hypothalamus as revealed by new methodological approaches. In: Scott DE, Kozlowski GP and Weindl A (eds) Brain-Endocrine Interaction III. Neural Hormones and Reproduction, Karger, Basel, pp 154–171
Vacca LL, Rosario SL, Zimmerman EA, Tomashefsky P, Ng PY, Hsu KC (1975) Application of immunoperoxidase techniques to localize horseradish peroxidase tracer in the central nervous system. J Histochem Cytochem 23:208–215
Wittkowsky W (1967) Zur Ultrastruktur der ependymalen Tanyzyten und Pituizyten sowie ihre synaptische Verknüpfung in der Neurohypophyse des Meerschweinchens. Acta Anat (Basel) 67:338–360
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bosler, O., Beaudet, A. & Denoroy, L. Electron-microscopic characterization of adrenergic axon terminals in the diencephalon of the rat. Cell Tissue Res. 248, 393–398 (1987). https://doi.org/10.1007/BF00218207
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00218207