Neuropeptide S: A New Player in the Modulation of Arousal and Anxiety

NPS modulates vigilance states. Effect of central administration of 0.1 and 1 nmole NPS or vehicle on vigilance states in rats during the first hour post injection. EEG and EMG recordings were scored for different stages of vigilance, indicating either wakefulness, slow wave sleep stage 2 (SWS2), or paradoxical sleep (REMS), and total time spent in each vigilance state was calculated. NPS (0.1 and 1 nmole) significantly increases wakefulness and reduces SWS2 and REMS. N=8 animals per group; ** significantly different from saline-injected animals, p < 0.01. [Note: Scores for SWS1 were omitted from the graph due to the small contribution of SWS1 to total sleep time, averaging less than 5%. NPS also reduced SWS1 significantly; see (23).]