Heterogeneity in the membrane current pattern of identified glial cells in the hippocampal slice: a combined patch-clamp and ultrastructural study

Item Type:	Article
Title:	Heterogeneity in the membrane current pattern of identified glial cells in the hippocampal slice: a combined patch-clamp and ultrastructural study
Creators Name:	Steinhaeuser, C. and Berger, T. and Frotscher, M. and Kettenmann, H.
Abstract:	Glial cells, acutely isolated or in tissue culture, have previously been shown to express a variety of voltage-gated channels. To resolve the question whether such channels are also expressed by glial cells in their normal cellular environment, we have applied the patch-clamp technique to study glial cells in hippocampal slices of 10 - 12-day-old mice. Based on the membrane current pattern, we distinguished four glial cell types. One was characterized by passive, symmetrical K+ currents activated in depolarizing and hyperpolarizing directions. A second population showed a similar current pattern, but with a marked decay of the current during the 50-ms voltage jumps. In a third population, the decaying passive currents were superimposed with a delayed rectifier outward current and, in some cases, with a slow inward current activated by depolarization. The fourth population expressed delayed rectifying outward currents, an inward rectifier K+ current and fast inward currents activated by depolarization. To unequivocally identify the glial cells we combined electrophysiological and ultrastructural characterizations. Therefore, cells were filled with the fluorescent dye lucifer yellow during characterization of their membrane currents, the fluorescence of the dye was used to convert diaminobenzidine to an electron-dense material, and subsequently slices were inspected in the electron microscope. Recordings were obtained from cells in the stratum radiatum and were identified as glial by their size, the characteristic chromatin distribution, and the lack of synaptic membrane specializations.
Keywords:	Glial Cells, Ion Channels, Neuron-Glia Interaction, Electron Microscopy, Patch Clamp, Brain Slice, Animals, Mouse
Source:	European Journal of Neuroscience
ISSN:	0953-816X
Publisher:	Blackwell Publishing
Volume:	4
Number:	6
Page Range:	472-484
Date:	1 January 1992
Official Publication:	https://doi.org/10.1111/j.1460-9568.1992.tb00897.x
PubMed:	View item in PubMed

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