Glutamate receptor-linked changes in membrane potential and intracellular Ca2+ in primary rat astrocytes
Article first published online: 12 OCT 2004
Copyright © 1989 Alan R. Liss, Inc.
Volume 2, Issue 6, pages 397–402, 1989
How to Cite
Enkvist, M.O. K., Holopainen, I. and Åkerman, K. E.O. (1989), Glutamate receptor-linked changes in membrane potential and intracellular Ca2+ in primary rat astrocytes. Glia, 2: 397–402. doi: 10.1002/glia.440020602
- Issue published online: 12 OCT 2004
- Article first published online: 12 OCT 2004
- Manuscript Accepted: 6 JUN 1989
- Manuscript Received: 30 MAR 1989
Kainate-, quisqualate- and glutamate-induced depolarization and mobilization of intracellular Ca2+ was determined in primary cultured astrocytes using the fluorescent probes DiBa-C4-(3) and fura-2, respectively. All three receptor agonists depolarized the cells in a Na+-dependent manner and increased the intracellular Ca2+ concentration. The glutamate- and quisqualate-induced increase in cytosolic Ca2+ was only partially inhibited by removal of extracellular Ca2+, whereas the response to kainate was totally dependent on extracellular Ca2+. The mechanisms for depolarization and increases in cytosolic Ca2+ appeared to be independent of each other, as extracellular Ca2+ removal or intracellular Ca2+ buffering with entrapped BAPTA did not affect the depolarization. Removal of extracellular Na+ did not affect the agonist-induced increase in Ca2+. If quisqualate was added after kainate, the cells were hyperpolarized in a Ca2+- and K+-dependent manner. This could be due to effects on a Ca2+-dependent K+ channel, the effects of which are normally hidden by the greater effect on Na+ channels as a response to quisqualate.