Distributions of prostaglandin EP3 and EP4 receptor mRNA in the rat parabrachial nucleus

By using in situ hybridization, the distribution of mRNA for the PGE(2) receptors EP3 and EP4 was examined in the rat parabrachial nucleus (PB), a major brain stem relay for autonomic and nociceptive processing. EP3 receptor mRNA was present in most subnuclei, with the densest labeling in the external lateral, dorsal lateral, superior lateral, central lateral and Kolliker-Fuse nuclei. EP4 receptor mRNA expressing cells had a more restricted distribution, largely being confined to the superior lateral and adjacent parts of the dorsal and central lateral nuclei in a pattern complementary to that for EP3 receptor mRNA. These findings suggest that EP3 and EP4 receptors in PB have distinct functional roles that include nociceptive processing, blood pressure regulation and feeding behavior. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.