Modulation of Central Synapses by Astrocyte-Released ATP and Postsynaptic P2X Receptors.

Eric Boué-Grabot,Yuriy Pankratov

doi:10.1155/2017/9454275

Abstract

Communication between neuronal and glial cells is important for neural plasticity. P2X receptors are ATP-gated cation channels widely expressed in the brain where they mediate action of extracellular ATP released by neurons and/or glia. Recent data show that postsynaptic P2X receptors underlie slow neuromodulatory actions rather than fast synaptic transmission at brain synapses. Here, we review these findings with a particular focus on the release of ATP by astrocytes and the diversity of postsynaptic P2X-mediated modulation of synaptic strength and plasticity in the CNS.

Highlights

Adenosine 5′-triphosphate (ATP) is arguably one of the most abundant molecules in living cells serving as universal energy “currency.” So, it is of no surprise that ATP is widely utilized as an extracellular signaling molecule [1]
P2 receptors are classified into several subtypes of ligand-gated ion channels (P2X1–P2X7 subunits) and eight distinct G protein-coupled receptors (P2Y) which are both characterized by a variety of distinct properties and a broad range of ATP sensitivities ranging from nanomolar (P2Y receptor) to tenth micromolar (P2X) or millimolar for P2X7 [1, 11,12,13,14]
No change of the fast excitatory synaptic transmission between P2X4 knockout and wild-type mice confirmed the absence of contribution of P2X4 in synaptic transmission, and the results suggested that P2X4 receptors regulated NR2B content within synaptic NMDAR [81]

Summary

Introduction

Adenosine 5′-triphosphate (ATP) is arguably one of the most abundant molecules in living cells serving as universal energy “currency.” So, it is of no surprise that ATP is widely utilized as an extracellular signaling molecule [1]. Presynaptic P2 receptors play a critical role in the regulation of neurotransmitter release [10, 11] by contributing to the intracellular Ca2+ signaling [11, 13] by virtue of the high Ca2+ permeability (P2X) and ability to stimulate IP3-dependent Ca2+ release from endoplasmic reticulum (P2Y). These properties can underlie an important role for postsynaptic P2X. The recent knowledge on the role of postsynaptic P2X receptors focused on glianeuron interactions is summarized

Release of ATP by Glial Cells

Neuromodulatory Action of Postsynaptic P2X Receptors in the CNS

Modulation of Glutamatergic Excitatory Synapse by P2X Receptors

Modulation of GABAergic Inhibitory Synapse

Concluding Remarks