The Orphanin FQ/Nociceptin (OFQ/N) System.- Orexins and Orexin Receptors: From Molecules to Integrative Physiology.- Prolactin-Releasing Peptide.- Structure and Function of Ghrelin.- GPR54 and Kisspeptins.- Neuropeptide S: Anatomy, Pharmacology, Genetics and Physiological Functions.- The Melanin-Concentrating Hormone System and Its Physiological Functions.- Biological Function of Prokineticins.- Neuromedin S: Discovery and Functions.- Relaxin-3, INSL5, and Their Receptors.- The NPB/NPW Neuropeptide System and Its Role in Regulating Energy Homeostasis, Pain, and Emotion.