What is "nociceptin"

n. (context biochemistry English) An neuralogically-active oligopeptide related to the opioids

Nociceptin/orphanin FQ (N/OFQ), a 17- amino acid neuropeptide, is the endogenous ligand for the nociceptin receptor (NOP, ORL-1), and initiates its function to act on numerous brain activities such as pain sensation and fear learning. It is derived from the prepronociceptin protein, as are a further 2 peptides, nocistatin & NocII, which inhibit the N/OFQ receptor function. Nociceptin itself acts as a potent anti-analgesic, effectively counteracting the effect of pain-relievers. The gene coding for prepronociceptin is located on Ch8p21 in humans. Nociceptin acts at the Nociceptin receptor (NOP receptor) formerly known as ORL1. Nociceptin is the first example of reverse pharmacology; the NOP receptor was discovered before the endogenous ligand which was discovered by two separate groups in 1995.