Behavioral Actions of Neuropeptide W: More Evidence for a Role in the Stress Response

Neuropeptide W (NPW), an endogenous peptide ligand for GPR7 and GPR8, is produced in hypothalamic and brain stem regions important in the neuroendocrine, behavioral and autonomic responses to stress. Indeed, we demonstrated that central administration of NPW activated the hypothalamo‐pituitary adrenal axis (HPA). We then determined if NPW could alter locomotor activity or mean arterial pressure (MAP), two additional markers of the stress response. Lateral cerebroventricle (i.c.v.) cannulae were implanted in adult male rats 5 days before experimentation. In behavioral testing, basal activity was monitored for 1 hr prior to the administration of saline, 0.1, 0.3, 1, or 3 nmol NPW23 i.c.v. and behavior was monitored for 2 hr. For cardiovascular experiments, a cannula was implanted into the carotid artery. On the following day after recording baseline MAP, rats were injected with 1 nmol NPW23 i.c.v., and MAP was recorded for 1 hr. NPW treatment increased total locomotor activity in a dose‐related manner, and increased stereotypy and ambulatory activity, but did not significantly alter MAP, indicating NPW alters endocrine and behavioral responses to stress without inducing the cardiovascular effects.