P2X receptors are expressed on neurons containing luteinizing hormone-releasing hormone in the mouse hypothalamus

Expression of P2X1, P2X2, P2X3, P2X4, P2X5 and P2X6 receptors, members of a family of ATP-gated cation channels, on neurons containing luteinizing hormone-releasing hormone (LHRH) in the mouse hypothalamus was studied with double-labeling fluorescence immunohistochemistry. This study demonstrated that different combinations of P2X receptor subunits were expressed on the perikarya and axon terminals of LHRH-producing neurons. It was shown for the first time that P2X2, P2X4, P2X5 and P2X6 receptor subunits were expressed on the perikarya of LHRH-producing neurons and P2X2 and P2X6 on their axon terminals. These results suggest that activation of P2X receptors by ATP via different homomeric or heteromeric P2X receptors at both presynaptic and postsynaptic sites could be involved in the regulation of LHRH secretion at the forebrain level.