The effect of P2X receptor activity on GABAA receptor-mediated inhibition in the gerbil hippocampus.
In the present study, to elucidate the effect of altered P(2)X receptor transmission on GABA(A) receptor expression and its transmission, we studied the morphological and electrophysiological responses of GABA(A) receptor in the gerbil hippocampus following P(2)X receptor antagonist/agonist treatment. Suramin or pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS) treatment did not affect GABA(A) receptor immunoreactivities and paired-pulse responses in the gerbil hippocampus. In addition, ATP treatment did not significantly affect population spike amplitude ratios and EPSP slope ratios in the gerbil dentate gyrus. Co-application, but not pretreatment, of PPADS or suramin enhanced the effect of muscimol on paired-pulse inhibition in the dentate gyrus. In contrast, co-application of ATP reduced the effect of muscimol in the dentate gyrus. These findings indicate that the blockade of P(2)X receptor did not affect GABA(A) receptor immunoreactivities, and P(2)X receptor may modulate GABA(A) receptor-mediated inhibition when in co-activation with GABA(A) receptor. Therefore, our findings suggest that the relationship between GABA(A) receptor and P(2)X receptor may not be reciprocal, although GABA(A) receptor activity affects P(2)X receptor functionality and its expression.
Kim
Duk-Soo
DS
Department of Anatomy, College of Medicine, Hallym University, Chunchon, Kangwon-Do 200-702, South Korea.
Kwak
Sung-Eun
SE
Kim
Ji-Eun
JE
Won
Moo Ho
MH
Suh
Jun-Gyo
JG
Oh
Yang-Seok
YS
Kang
Tae-Cheon
TC
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D005071:Evoked Potentials / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D018755:GABA Agonists / Q000494:pharmacology; D005849:Gerbillinae; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D009118:Muscimol / Q000494:pharmacology; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology*; D018048:Receptors, Purinergic P2 / Q000187:drug effects / Q000502:physiology*; D058469:Receptors, Purinergic P2X; D013498:Suramin / Q000494:pharmacology; D009435:Synaptic Transmission / Q000502:physiology
D018755:GABA Agonists; D011963:Receptors, GABA-A; D018048:Receptors, Purinergic P2; D058469:Receptors, Purinergic P2X; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; D009118:Muscimol; D011732:Pyridoxal Phosphate; D013498:Suramin; D000255:Adenosine Triphosphate