NPS and Anxiety: The neuropeptide S (NPS) system, consisting of the 20-amino acid peptide NPS and its G-protein coupled receptor (NPSR), has been shown to be involved in processes of anxiety, fear-extinction, and fear memory consolidation (Xu et al., 2004; Okamura and Reinscheid, 2007; Jüngling et al., 2008; Okamura et al., 2011).