Send to

Choose Destination
Eur J Neurosci. 1992 Oct;4(11):1049-1058.

GABA Triggers a [Ca2+]i Increase in Murine Precursor Cells of the Oligodendrocyte Lineage.

Author information

Department of Neurobiology, University of Heidelberg, Im Neuenheimer Feld 345, 6900 Heidelberg, FRG.


The development of oligodendrocytes from their precursor cells can be studied in vitro by using a culture system in which cells can be identified at different developmental stages. We used this culture system to compare the effect of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) on intracellular Ca2+ concentration ([Ca2+]i) using fura-2 fluorescence systems. Application of GABA evoked transient [Ca2+]i increases in precursor cells. In contrast, [Ca2+]i levels were not affected in oligodendrocytes, which were identified by their positive labelling with the antibody O1. The precursor cells, identified by a lack of O1 staining, responded to GABA in the concentration range between 10-6 and 10-4 M. Since muscimol mimicked and bicuculline as well as picrotoxin blocked the GABA response, we conclude that the response is mediated by activation of GABAA receptors. The involvement of Ca2+ channels is inferred from the observation that the [Ca2+]i changes could be blocked by nifedipine or by omitting Ca2+ from the bath solution. Both GABAA receptors and Ca2+ channels have been previously identified on these precursor cells with the aid of the patch-clamp technique. We thus propose the following mechanism to explain our observations: the Cl- efflux via the GABA receptor depolarizes precursor cells, and this depolarization leads to activation of Ca2+ channels, resulting in an influx of Ca2+ and the observed rise in cytosolic [Ca2+]. Although its physiological importance is speculative, this event could serve as a signal from GABAergic neurons to glial precursor cells.


Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center