AMPA-TYPE GLUTAMATE RECEPTORS IN GLIAL PRECURSOR CELLS OF THE RAT CORPUS-CALLOSUM - IONIC AND PHARMACOLOGICAL PROPERTIES

被引：33

作者：

BERGER, T ^{[1
]}

机构：

[1] UNIV FREIBURG, INST ANAT, D-79104 FREIBURG, GERMANY

来源：

GLIA | 1995年 / 14卷 / 02期

关键词：

GLUTAMATE; KAINATE; CYCLOTHIAZIDE; CALCIUM PERMEABILITY; PATCH-CLAMP IN SITU;

D O I：

10.1002/glia.440140205

中图分类号：

Q189 [神经科学];

学科分类号：

071006 ;

摘要：

Glial cells in fiber tracts express various functional transmitter receptors, e.g., for glutamate. However, little is known about their biophysical and pharmacological profile. Using the in situ patch-clamp technique, kainate- and AMPA-induced conductance changes of glial precursor cells in the rat corpus callosum were investigated to study these aspects. Precursor cells were identified by their voltage-gated currents and were easily discernable from astrocytes and oligodendrocytes. Kainate induced two overlying effects in these cells: the activation of a cationic current and the block of potassium conductances. Cesium in the pipette solution blocked potassium conductances nearly completely and the ionic profile of the kainate-induced cationic current could be studied in detail. Full replacement of the sodium in the bath by calcium resulted only in a small kainate-induced (calcium) inward current flow, but the kainate-induced outward current carried by Cs+ was less affected reflecting a weak calcium permeability. The kainate response could be blocked by 6,7-dinitroquinoxaline-2,3-dione (DNQX) and millimolar zinc concentrations. Go-application of micromolar concentrations of zinc slightly enhanced the kainate-induced current, while Evans Blue was without any significant effect. Cyclothiazide increased the kainate response by a factor of x6 while concanavalin A did not enlarge it. The AMPA-induced current was amplified by a factor of x39 by cyclothiazide. The present data suggested the expression of weakly calcium-permeable AMPA receptors on glial precursor cells in the rat corpus callosum. Only a small fraction of the agonist-induced current could be seen without the appropriate blockers of receptor desensitization. An additional expression of kainate-preferring glutamate receptors could not be shown. (C) 1995 Wiley-Liss, Inc.

引用

页码：101 / 114

页数：14

共 59 条

[1] Attwell D., Barbour B., Szatkowski M., Nonvesicular release of neurotransmitter, Neuron, 11, pp. 401-407, (1993)
[2] Backus K.H., Berger T., (1995)
[3] Berger T., Backus K.H., (1995)
[4] Berger T., Schnitzer J., Kettenmann H., Developmental changes in the membrane current pattern, K+ buffer capacity and morphology of glial cells in the corpus callosum slice, J. Neurosci., 11, pp. 3008-3024, (1991)
[5] Berger T., Walz W., Schnitzer J., Kettenmann H., GABA and glutamate‐activated currents in glial cells in the corpus callosum slice, J. Neurosci. Res., 31, pp. 21-27, (1992)
[6] Bochet P., Audinat E., Lambolez P., Crepel F., Rossier J., Lino M., Tsuzuki K., Ozawa S., Subunit composition at the single‐cell level explains functional properties of a glutamate‐gated channel, Neuron, 12, pp. 383-388, (1994)
[7] Borges K., Ohlemeyer C., Trotter J., Kettenmann H., AMPA/kainate receptor activation in murine oligodendrocyte precursor cells leads to activation of a cationic conductance, calcium influx and blockade of delayed rectifying K+ channels, Neuroscience, 63, pp. 135-149, (1994)
[8] Burnashev N., Khodorova A., Jonas P., Helm P.J., Wisden W., Monyer H., Seeburg P.H., Sakmann B., Calcium‐permeable AMPA‐kainate receptors in fusiform cerebellar glial ceils, Science, 256, pp. 1566-1570, (1992)
[9] Burnashev N., Monyer H., Seeburg P.H., Sakmann B., Divalent ion permeability of AMPA receptor channels is dominated by the edited form of a single subunit, Neuron, 8, pp. 189-198, (1992)
[10] Chiu S.Y., Wilson G.F., The role of K+ channels in Schwann cell proliferation in Wallerian degeneration of explant rabbit sciatic nerves, J. Physiol. (Lond.), 408, pp. 199-222, (1989)

← 1 2 3 4 5 6 →