EVIDENCE FOR P2X(3) RECEPTORS IN THE DEVELOPING RAT-BRAIN

P2X receptor-mediated responses to the ATP analogue, alpha,beta-methyl ene ATP, in rat brain(1,6,10-12,14,15,17,23,24) cannot be accounted fo r bg the receptor proteins known to be present.(9,16,26) Such experime nts are often performed on cells from neonates(1,10,12,17,24) and, sin ce differential developmental regulation of P2X, and P2X(2) receptor m essenger RNAs has already been demonstrated,(18) this is likely to be the case for other P2X receptors, This study was designed to address t he possible existence of alpha,beta-methylene ATP-sensitive P2X, recep tors in rat brains of various ages using a P2X, receptor-selective ant ibody. P2X, receptor protein was found in discrete regions of the embr yonic (E16) and neonatal rat brain (P7 and P14) but was not detectable in adult animals. This is the first demonstration of the presence of these receptors in brains from various ages of rat and the differentia l expression of these receptors in neonates may account for some repor ted electrophysiological responses to alpha,beta-methylene ATP. (C) 19 98 IBRO, Published by Elsevier Science Ltd.