P2X7 receptor differentially modulates astroglial apoptosis and clasmatodendrosis in the rat brain following status epilepticus

Abstract

Recently, it has been reported that astroglial loss/dysfunction plays a role in epileptogenesis. In addition, astroglial loss is accompanied by up-regulation of P2X7 receptor expression in microglia. Therefore, we investigated whether P2X7 receptor is involved in astroglial damages induced by status epilepticus (SE). In the present study, astroglial loss showed the regional-specific manner and the differential responses to P2X7 receptor functions. Both OxATP and brilliant blue G (P2X7 receptor antagonists) infusion prevented apoptotic astroglial loss in the molecular layer of the dentate gyrus and the frontoparietal cortex, while it promoted clasmatodendrosis in the CA1 region as compared to saline treatment. In contrast, BzATP (a P2X7 receptor agonist) treatment exacerbated apoptotic astroglial loss in the molecular layer of the dentate gyrus and the frontoparietal cortex, but alleviated SE-induced astroglial swelling in the CA1 region. Astroglial loss in the piriform cortex was not affected by P2X7 receptor agonist- or antagonist-infusion. These findings suggest that P2X7 receptor function differently modulates SE-induced astroglial loss in distinct brain regions.