Abstract
We have studied the architecture of giant neuropile glial cells of the medicinal leech Hirudo medicinalis L. using confocal laser scanning microscopy. We also measured changes in the intracellular Ca2+ concentration ([Ca2+]i) induced by activation of glutamate receptors or voltage-gated Ca2+ channels in different glial cell compartments. Glial cells of isolated segmental ganglia were filled iontophoretically with the Ca2+ indicator dye Fluo-3. The three-dimensional structure, calculated from serial sections, showed that numerous fine glial branches extend within the whole neuropile, where most of the synapses between neurones are established. Activation of glial glutamate receptors by glutamate or kainate, or depolarizing the cell membrane by elevating the external K+ concentration resulted in a transient increase in [Ca2+]i, as measured by Fluo-3 fluorescence. The comparison of [Ca2+]i changes in glial cell branches with changes in the cell body demonstrated that transients in the branches were 2–3 times larger than those in the cell body. The results suggest that glutamate receptors and voltage-gated Ca2+ channels are located in the membrane not only of the glial cell body but also of the cellular branches, which may extend close to synaptic domains.
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References
Coggeshall, R.E. (1974) Gap junctions between identified glial cells in the leech. J. Neurobiol. 5: 463–467
Coggeshall, R.E., Fawcett, D.W. (1964) The fine structure of the central nervous system of the leech, Hirudo medicinalis. J. Neurophysiol. 27: 229–289
Deitmer, J.W., Munsch, T. (1992) Kainate/glutamate-induced changes in intracellular calcium and pH in leech glial cells. NeuroReport 3: 693–696
Deitmer, J.W., Munsch, T. (1994) Neurone-glia dialogue in the leech central nervous system: glial cell responses to glutamate and kainate. Verh. Dtsch. Zool. Ges. 87: 185–194
Deitmer, J.W., Schneider, H.-P. (1997) Intracellular acidification of the leech giant glial cell evoked by glutamate and aspartate. Glia 19: 111–122
Eilers, J., Augustine, G.J., Konnerth, A. (1995) Subthreshold synaptic Cat+ signalling in fine dendrites and spines of cerebellar Purkinje neurones. Nature 373: 155–158
Grynkiewicz, G., Poenie, M., Tsien, R.Y. (1985) A new generation of Ca2+ indicators with greatly improved fluorescence properties. J. Biol. Chem. 260: 3440–3450
Kuffler, S.W., Potter, D.D. (1964) Glia in the leech central nervous system: physiological properties and neurone-glia relationship. J. Neurophysiol. 27: 290–320
Lohr, C., Nett, W., Deitmer, J.W. (1996a) Glutamate-mediated signalling in the giant leech glial cell. Verh. Dtsch. Zool. Ges. 89: 67
Lohr, C., Rose, C.R., Deitmer, J.W. (1996b) Extracellular Ca2+ changes during transmitter application in the leech central nervous system. Neurosci. Lett. 205: 57–60
Munsch, T., Deitmer, J.W. (1992) Calcium transients in identified leech glial cells in situ evoked by high potassium concentrations and 5-hydroxytryptamine. J. Exp. Biol. 167: 251–265
Munsch, T., Deitmer, J.W. (1995) Maintenance of fura-2 fluorescence in glial cells and neurones of the leech central nervous system. J. Neurosci. Methods 57: 195–204
Munsch, T., Deitmer, J.W. (1997) Intracellular Ca2+, Na+ and H+ transients evoked by kainate in the leech giant glial cells in situ. Neurosci. Res. 27: 45–56
Payton, B. (1981) Structure of the leech nervous system. In: Muller, K.J., Nicholls, J. G., Stent, G.S. (eds) Neurobiology of the leech. Cold Spring Harbor Laboratory, New York, pp. 35–50
Pfeiffer, F. (1992) Farbstoffmarkierung zur Identifizierung von Nerven-und Gliazellen in Ganglien des Blutegels Hirudo medicinalis. Diplomarbeit der Universität Kaiserslautern.
Retzius, G. (1891) Zur Kenntniss des centralen Nervensystems der Würmer. Biol Unters. Neue Folge 11: 1–28
Rose, C.R., Lohr, C., Deitmer, J.W. (1995) Activity-induced Ca2+ transients in nerve and glial cells in the leech CNS. NeuroReport 6: 642–644
White, N.S., Errington, R.J., Fricker, M.D., Wood, J.L. (1996) Aberration control in quantitative imaging of botanical specimens by multidimensional fluorescence microscopy. J. Microsc. 181: 99–116
Wuttke, W.A. (1990) Mechanism of potassium uptake in neuropile glial cells in the central nervous system of the leech. J. Neurophysiol. 63: 1089–1097
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Lohr, C., Deitmer, J.W. (1998). Structural and physiological properties of leech giant glial cells as studied by confocal microscopy. In: EBO — Experimental Biology Online Annual 1996/97. EBO — Experimental Biology Online Annual, vol 1996/1997. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-00932-1_18
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DOI: https://doi.org/10.1007/978-3-662-00932-1_18
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