Evidence for P2X 3 receptors in the developing rat brain

Abstract

P2X receptor-mediated responses to the ATP analogue, α,β-methylene ATP, in rat brain [1, 6, 10–12, 14, 15, 17, 23, 24]cannot be accounted for by the receptor proteins known to be present. [9, 16, 26]Such experiments are often performed on cells from neonates [1, 10, 12, 17, 24]and, since differential developmental regulation of P2X 1 and P2X 2 receptor messenger RNAs has already been demonstrated, [18]this is likely to be the case for other P2X receptors. This study was designed to address the possible existence of α,β-methylene ATP-sensitive P2X 3 receptors in rat brains of various ages using a P2X 3 receptor-selective antibody. P2X 3 receptor protein was found in discrete regions of the embryonic (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 differential expression of these receptors in neonates may account for some reported electrophysiological responses to α,β-methylene ATP.