Author/Editor		Palygin, Oleg; Lalo, Ulyana; Verkhratsky, Alexei; Pankratov, Yuri
Title		Ionotropic NMDA and P2X[sub]1/5 receptors mediate synaptically induced Ca[sup]2+ signalling in cortical astrocytes
Type		članek
Vol. and No.		Letnik 48, št. 4
Publication year		2010
Volume		str. 225-231
ISSN		0143-4160 - Cell calcium
Language		eng
Abstract		Local, global and propagating calcium (Ca(2+)) signals provide the substrate for glial excitability. Here we analyse Ca(2+) permeability of NMDA and P2X(1/5) receptors expressed in cortical astrocytes and provide evidence that activation of these receptors trigger astroglial Ca(2+) signals when stimulated by either endogenous agonists or by synaptic release of neurotransmitters. The Ca(2+) permeability of the ionotropic receptors was determined by reversal potential shift analysis; the permeability ratio P(Ca)/P(K) was 3.1 for NMDA receptors and 2.2 for P2X(1/5) receptors. Selective stimulation of ionotropic receptors (with NMDA and alpha, beta-methyleneATP) in freshly isolated cortical astrocytes induced ion currents associated with transient increases in cytosolic Ca(2+) concentration ([Ca(2+)](i)). Stimulation of neuronal afferents in cortical slices triggered glial synaptic currents and [Ca(2+)](i) responses, which were partially blocked by selective antagonists of NMDA (D-AP5 and UBP141) and P2X(1/5) (NF449) receptors. We conclude that ionotropic receptors contribute to astroglial Ca(2+) signalling and may provide a specific mechanism for fast neuronal-glial signalling at the synaptic level.
Keywords		NMDA receptors P2X receptors astroglia receptorji NMDA P2X receptorji astroglia