Activity-dependent ATP-waves in the mouse neocortex are independent from astrocytic calcium waves.
In the corpus callosum, astrocytic calcium waves propagate via a mechanism involving ATP-release but not gap junctional coupling. In the present study, we report for the neocortex that calcium wave propagation depends on functional astrocytic gap junctions but is still accompanied by ATP-release. In acute slices obtained from the neocortex of mice deficient for astrocytic expression of connexin43, the calcium wave did not propagate. In contrast, in the corpus callosum and hippocampus of these mice, the wave propagated as in control animals. In addition to calcium wave propagation in astrocytes, ATP-release was recorded as a calcium signal from 'sniffer cells', a cell line expressing high-affinity purinergic receptors placed on the surface of the slice. The astrocyte calcium wave in the neocortex was accompanied by calcium signals in the 'sniffer cell' population. In the connexin43-deficient mice we recorded calcium signals from sniffer cells also in the absence of an astrocytic calcium wave. Our findings indicate that astrocytes propagate calcium signals by two separate mechanisms depending on the brain region and that ATP release can propagate within the neocortex independent from calcium waves.
Haas
Brigitte
B
Cellular Neuroscience, Max-Delbrück-Center for Molecular Medicine, and Institute of Genetics, Division of Molecular Genetics, University of Bonn, 53117 Bonn, Germany Eschenallee 3, 14050 Berlin, Germany.
Schipke
Carola G
CG
Peters
Oliver
O
Söhl
Goran
G
Willecke
Klaus
K
Kettenmann
Helmut
H
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001253:Astrocytes / Q000502:physiology*; D001683:Biological Clocks / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology*; D018031:Connexin 43 / Q000172:deficiency; D017629:Gap Junctions / Q000502:physiology*; D066298:In Vitro Techniques; D051379:Mice; D008805:Mice, Inbred A; D019579:Neocortex / Q000502:physiology*; D013223:Statistics as Topic; D009435:Synaptic Transmission / Q000502:physiology*
D018031:Connexin 43; D000255:Adenosine Triphosphate