P2X7 receptors enhance glutamate release in hippocampal hilar neurons.
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.
Cho
Jin-Hwa
JH
Department of Pharmacology, School of Dentistry, Kyungpook National University, Jung-gu, Daegu, Republic of Korea.
Choi
In-Sun
IS
Jang
Il-Sung
IS
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D004594:Electrophysiology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism* / Q000502:physiology; D006624:Hippocampus / Q000378:metabolism*; D066298:In Vitro Techniques; D009474:Neurons / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D017729:Presynaptic Terminals / Q000187:drug effects; D058911:Purinergic P2X Receptor Agonists; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000187:drug effects; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects; D058486:Receptors, Purinergic P2X7 / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology; D013779:Tetrodotoxin / Q000494:pharmacology
D058911:Purinergic P2X Receptor Agonists; D011963:Receptors, GABA-A; D016194:Receptors, N-Methyl-D-Aspartate; D058486:Receptors, Purinergic P2X7; D018698:Glutamic Acid; D013779:Tetrodotoxin; C033901:3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate; D000255:Adenosine Triphosphate