Summary
Distribution of (3H)GABA in the rat neural lobe was investigated 5 min after intracarotid administration using quantitative electron-microscopic autoradiography. Specificity of (3H)GABA-uptake was tested by pretreatment of control animals with nipecotic acid. It was concluded that, apart from a small fraction in the perivascular spaces, radioactivity was present exclusively in pituicytes. The results confirm and quantify earlier in-vitro observations; they are compared with recent immunocytochemical findings that reveal the presence of glutamate-decarboxylase-containing axons in the neural lobe. It is concluded that there may be GABAergic terminals that lack an uptake mechanism for exogenous transmitter. Nevertheless, (3H)GABA autoradiography is useful in demonstrating other functional components of GABAergic systems, i.e., glial cells.
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References
Balázs R, Machiyama Y, Patel AJ (1973) Compartmentation and the metabolism of γ-aminobutyrate. In: Balázs R, Cremer JE (eds) Metabolic compartmentation in the brain. Macmillan Press, London, pp 57–70
Beart PM, Kelly JS, Schon F (1974) γ-Aminobutyric acid in the rat peripheral nervous system, pineal and posterior pituitary. Biochem Soc Trans 2:266–268
Blackett NM, Parry DM (1977) A simplified method of “hypothetical grain” analysis of electron microscope autoradiographs. J Histochem Cytochem 25:206–214
Demarest KT, Moore KE (1979) Lack of a high affinity transport system for dopamine in the median eminence and posterior pituitary. Brain Res 171:545–551
Hamberger A, Norström A, Sandberg M, Svanberg U (1979) In vitro GABA transport in the neurohypophysis from rats with hereditary diabetes insipidus and after osmotic stimulation. Brain Res 174:341–344
Hertz L (1979) Functional interactions between neurons and astrocytes I. Turnover and metabolism of putative amino acid transmitters. Progr Neurobiol 13:277–301
Iversen LL, Kelly JS (1975) Uptake and metabolism of γ-aminobutyric acid by neurones and glial cells. Biochem Pharmacol 24:933–938
Iversen LL, Neal MJ (1968) The uptake of (3H)GABA by slices of rat cerebral cortex. J Neurochem 15:1141–1149
Kelly JS, Dick F (1977) GABA in glial cells of the peripheral and central nervous system. In: Schotteniels E, Franck G, Hertz L, Tower DB (eds) Dynamic properties of glia cells. Pergamon Press, Oxford New York Toronto Sydney Paris Frankfurt, pp 183–192
Larsson OM, Krogsgaard-Larsen P, Schousboe A (1980) Highaffinity uptake of (RS)-nipecotic acid in astrocytes cultured from mouse brain. Comparison with GABA transport. J Neurochem 34:970–977
Ockenfels H, Pilgrim Ch, Unsöld M (1981) In-vitro-Studien zur fixierungsbedingten Artefaktbildung in der elektronenmikroskopischen Autoradiographie. Acta Histochem Suppl 14:301–307
Oertel WH, Schmechel DE, Mugnaini E, Tappaz ML, Kopin IJ (1981) Immunocytochemical localization of glutamate decarboxylase in rat cerebellum with a new antiserum. Neuroscience 6:2715–2735
Oertel WH, Mugnaini E, Tappaz ML, Weise VK, Dahl A-L, Schmechel DE, Kopin IJ (1982) Central GABAergic innervation of neurointermediate pituitary lobe: Biochemical and immunocytochemical study in the rat. Proc Natl Acad Sci USA 79:675–679
Reisert I, Wagner H-J, Pilgrim Ch (1977) Incorporation of 3Hfucose into nerve and glial cells: Assessment by electron microscopic autoradiography. J Comp Neurol 176:453–466
Reisert I, Jirikowski G, Pilgrim Ch, Tappaz ML (1983) GABAergic neurons in dissociated cultures of rat hypothalamus, septum, and midbrain. Cell Tissue Res 229:685–694
Schon F, Iversen LL (1972) Selective accumulation of (3H)GABA by stellate cells in rat cerebellar cortex in vivo. Brain Res 42:503–507
Sotelo C (1975) Radioautography as a tool for the study of putative neurotransmitters in the nervous system. J Neural Transm Suppl 12:75–95
Tappaz M, Aguera M, Belin MF, Pujol JF (1980) Autoradiography of GABA in the rat hypothalamic median eminence. Brain Res 186:379–391
Tappaz ML, Wassef M, Oertel WH, Paut L, Pujol JF (1983) Lightand electron-microscopic immunocytochemistry of glutamic acid decarboxylase (GAD) in the basal hypothalamus: Morphological evidence for neuroendocrine γ-aminobutyrate (GABA). Neuroscience 9:271–287
Vincent SR, Hökfelt T, Wu J-Y (1982) GABA neuron system in hypothalamus and the pituitary gland: immunohistochemical demonstration using antibodies against glutamate decarboxylase. Neuroendocrinology 34:117–125
Zucker C, Yazulla S, Wu J-Y (1984) Non-correspondence of (3H)GABA uptake and GAD localization in goldfish amacrine cells. Brain Res 298:154–158
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Reisert, I., Wöhrle, M. & Pilgrim, C. Quantitative assessment of GABA-uptake sites in the neural lobe by electron-microscopic autoradiography. Cell Tissue Res. 241, 581–584 (1985). https://doi.org/10.1007/BF00214578
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DOI: https://doi.org/10.1007/BF00214578