Intracerebroventricular administration of urotensin II promotes anxiogenic-like behaviors in rodents

We identified urotensin II (U-II) as the endogenous ligand for the orphan G-protein-coupled receptor GPR14 or SENR. Both U-II and GPR14 are expressed not only in peripheral tissues but also in the brain of rodents, suggesting that U-II plays a physiological role in the central nervous system. In the present study, we investigated the central effects of U-II in rodents. Intracerebroventricular administration of U-II induced anxiogenic-like behaviors in the elevated plus maze test and the hole-board test in mice in a dose-dependent manner, as did corticotropin releasing factor (CRF). The effective doses of U-II were 10-100-fold higher than these of CRF in these tests. Our results suggest that U-II is a candidate for the mediator of some aspect of stress or anxiety in the central nervous system.