Nociceptin and the nociceptin receptor in learning and memory.

There are many processes in which the neuropeptide nociceptin/orphanin FQ (N/OFQ or nociceptin) is involved in the brain. The role of nociceptin in learning and memory holds promise in modulating these processes in health and disease in the human brain. This review summarizes the body of research focused on N/OFQ and its specific receptor, the nociceptin receptor (NOP receptor), in learning and memory, and its potential mechanisms of action, in which acetylcholine, NMDA receptor, and noradrenaline may be critical. Finally, the association between NOP receptor and posttraumatic stress disorder (PTSD), a psychiatric disorder with altered fear learning, is examined as one of the potential outcomes resulting from pathological consequences of dysregulation of N/OFQ-NOP receptor in the brain.