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Item Type: | Article |
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Title: | Different mechanisms promote astrocyte Ca2+ waves and spreading depression in the mouse neocortex |
Creators Name: | Peters, O., Schipke, C.G., Hashimoto, Y. and Kettenmann, H. |
Abstract: | Cortical spreading depression (CSD) is thought to play an important role in different pathological conditions of the human brain. Here we investigated the interaction between CSD and Ca2+ waves within the astrocyte population in slices from mouse neocortex (postnatal days 10-14). After local KCl ejection as a trigger for CSD, we recorded the propagation of Ca2+ increases within a large population of identified astrocytes in synchrony with CSD measured as intrinsic optical signal (IOS) or negative DC-potential shift. The two events spread with 39.2 +/- 3.3 mum/sec until the IOS and negative DC-potential shift decayed after approximately 1 mm. However, the astrocyte Ca2+ wave continued to propagate for up to another 500 microm but with a reduced speed of 18.3 +/- 2.5 microm/sec that is also typical for glial Ca2+ waves in white matter or culture. While blocking CSD using MK-801 (40 microm), an NMDA-receptor antagonist, the astrocyte Ca2+ wave persisted with a reduced speed (13.2 +/- 1.5 microm/sec). The specific gap junction blocker carbenoxolon (100 microm) did not prevent CSD but decelerated the speed (2.9 +/- 0.9 microm/sec) of the astrocyte Ca2+ wave in the periphery of CSD. We also found that interfering with intracellular astrocytic Ca2+ signaling by depletion of internal Ca2+ stores does not affect the spread of the IOS. We conclude that CSD determines the velocity of an accompanying astrocytic Ca2+ response, but the astrocyte Ca2+ wave penetrates a larger territory and by this represents a self-reliant phenomenon with a different mechanism of propagation. |
Keywords: | Glia, Neocortex, Gap Junctions, Intrinsic Optical Signals, Migraine, Stroke, Animals, Mice |
Source: | Journal of Neuroscience |
ISSN: | 0270-6474 |
Publisher: | Society for Neuroscience |
Volume: | 23 |
Number: | 30 |
Page Range: | 9888-9896 |
Date: | 29 October 2003 |
Additional Information: | Copyright (c) 2003 by The Society for Neuroscience |
Official Publication: | http://www.jneurosci.org/cgi/content/abstract/23/30/9888 |
PubMed: | View item in PubMed |
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