Neuromedin U (NMU) is a hypothalamic peptide that has been recently found to 
reduce food intake, but few is known about its other functions in the central 
nervous system. We here studied behavioral activities induced by an 
intracerebroventricular (ICV) administration of NMU in rats and mice. NMU 
increased gross locomotor activity, face washing behavior, and grooming. 
NMU-induced stress response was significantly abolished by pretreatment with an 
antagonist of corticotropin-releasing hormone (CRH), alpha-helical CRH (9-41) 
(alpha-hCRH), or anti-CRH IgG. NMU did not induce locomotor activity in CRH 
knockout mice. NMU that interacts anatomically and/or functionally with the CRH 
system is a novel physiological regulator of stress response.