P2X7 receptors mediate ATP release and amplification of astrocytic intercellular Ca2+ signaling

Sylvia O. Suadicani, Celia F. Brosnan, Eliana Scemes

Research output: Contribution to journalArticle

378 Citations (Scopus)

Abstract

Modulation of synaptic transmission and brain microcirculation are new roles ascribed to astrocytes in CNS function. A mechanism by which astrocytes modify neuronal activity in the healthy brain depends on fluctuations of cytosolic Ca2+ levels, which regulate the release of "gliotransmitters" via an exocytic pathway. Under pathological conditions, however, the participation of other pathways, including connexin hemichannels and the pore-forming P2X7R, have been proposed but remain controversial. Through the use of genetically modified 1321N1 human astrocytoma cells and of spinal cord astrocytes derived from neonatal Cx43- and P2X7R-null mice, we provide strong evidence that P2X7Rs, but not Cx43 hemichannels, are sites of ATP release that promote the amplification of Ca2+ signal transmission within the astrocytic network after exposure to low divalent cation solution. Moreover, our results showing that gap junction channel blockers (heptanol, octanol, carbenoxolone, flufenamic acid, and mefloquine) are antagonists of the P2X7R indicate the inadequacy of using these compounds as evidence for the participation of connexin hemichannels as sites of gliotransmitter release.

Original languageEnglish (US)
Pages (from-to)1378-1385
Number of pages8
JournalJournal of Neuroscience
Volume26
Issue number5
DOIs
StatePublished - Feb 1 2006

Fingerprint

Purinergic P2X7 Receptors
Astrocytes
Connexin 43
Connexins
Adenosine Triphosphate
Heptanol
Flufenamic Acid
Carbenoxolone
Mefloquine
Octanols
Gap Junctions
Divalent Cations
Astrocytoma
Brain
Microcirculation
Synaptic Transmission
Spinal Cord

Keywords

  • Astrocyte
  • ATP release
  • Ca waves
  • Connexin hemichannels
  • Gap junction blockers
  • Glia

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

P2X7 receptors mediate ATP release and amplification of astrocytic intercellular Ca2+ signaling. / Suadicani, Sylvia O.; Brosnan, Celia F.; Scemes, Eliana.

In: Journal of Neuroscience, Vol. 26, No. 5, 01.02.2006, p. 1378-1385.

Research output: Contribution to journalArticle

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