Reward Processing by the Opioid System in the Brain

The opioid system consists of three receptors, mu, delta, and kappa, which are activated by endogenous opioid peptides processed from three protein precursors, proopiomelanocortin, proenkephalin, and prodynorphin. Opioid receptors are recruited in response to natural rewarding stimuli and drugs of abuse, and both endogenous opioids and their receptors are modified as addiction develops. Mechanisms whereby aberrant activation and modifications of the opioid system contribute to drug craving and relapse remain to be clarified. This review summarizes our present knowledge on brain sites where the endogenous opioid system controls hedonic responses and is modified in response to drugs of abuse in the rodent brain.…

• EC
  European Commission
• UD
  Université de Strasbourg
• CN
  Centre National de la Recherche Scientifique
• NI
  National Institutes of Health
• NI
  National Institute on Alcohol Abuse and Alcoholism
• NI
  National Institute on Drug Abuse