P2X7 receptors enhance glutamate release in hippocampal hilar neurons

Neuroreport. 2010 Sep 15;21(13):865-70. doi: 10.1097/WNR.0b013e32833d9142.

Abstract

We examined the effect of 2'-3'-O-(4-benzoylbenzoyl)-adenosine-5'-triphosphate (Bz-ATP), a P2X7 receptor agonist, on action potential-independent glutamate release from nerve terminals attached to mechanically isolated immature hilar neurons. Bz-ATP increased spontaneous excitatory postsynaptic current (sEPSC) frequency, and this effect was blocked by Brilliant blue G, a P2X7 receptor antagonist, suggesting that P2X7 receptors mediate the facilitatory action of Bz-ATP on sEPSCs. In most of hilar neurons tested, the Bz-ATP-induced increase in sEPSC frequency was blocked by tetrodotoxin or Cd, suggesting that the activation of P2X7 receptors leads to a presynaptic depolarization. The P2X7 receptor-mediated facilitation of glutamate release would modulate the excitability of hilar neurons, and eventually have a broad impact on the pathophysiological functions mediated by the hippocampus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / analogs & derivatives
  • Adenosine Triphosphate / pharmacology
  • Animals
  • Electrophysiology
  • Excitatory Postsynaptic Potentials / physiology
  • Glutamic Acid / metabolism*
  • Glutamic Acid / physiology
  • Hippocampus / metabolism*
  • In Vitro Techniques
  • Neurons / metabolism*
  • Patch-Clamp Techniques
  • Presynaptic Terminals / drug effects
  • Purinergic P2X Receptor Agonists
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, GABA-A / drug effects
  • Receptors, N-Methyl-D-Aspartate / drug effects
  • Receptors, Purinergic P2X7 / physiology*
  • Synaptic Transmission / physiology
  • Tetrodotoxin / pharmacology

Substances

  • Purinergic P2X Receptor Agonists
  • Receptors, GABA-A
  • Receptors, N-Methyl-D-Aspartate
  • Receptors, Purinergic P2X7
  • Glutamic Acid
  • Tetrodotoxin
  • 3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate
  • Adenosine Triphosphate