The effect of P 2X receptor activity on GABA A receptor-mediated inhibition in the gerbil hippocampus

Abstract

In the present study, to elucidate the effect of altered P 2X 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 2X 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 2X receptor did not affect GABA A receptor immunoreactivities, and P 2X 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 2X receptor may not be reciprocal, although GABA A receptor activity affects P 2X receptor functionality and its expression.