endogenous opioid

a substance produced in the body that has the analgesic and euphoric effects of morphine. Three families of endogenous opioids are well known: the enkephalins, endorphins, and dynorphins. All are neuropeptides that bind to opioid receptors in the central nervous system; they are mostly inhibitory, acting like opiates to block pain. They bind relatively nonselectively to opioid receptors, although enkephalins bind preferentially to the delta opioid receptors and dynorphins to kappa opioid receptors. Three other endogenous opioid peptides have been identified: nociceptin/orphanin FQ (N/OFQ) and endomorphins 1 and 2. Also called opioid neurotransmitter.

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Psychology term of the day

July 27th 2024

primary insomnia

in DSM–IV–TR, a sleep disorder characterized by difficulty in initiating or maintaining a restorative sleep to a degree in which the severity and persistence of the sleep disturbance causes clinically significant distress, impairment in a significant area of functioning, or both. The disorder is not caused by a general medical condition or the effects of a substance and is not exclusively an aspect of another sleep disorder or mental disorder. It is termed insomnia disorder in DSM–5. See dyssomnia. Compare primary hypersomnia.