New research funded by the National Institute on Drug Abuse illuminates the crystal structure of the activated kappa opioid receptor (KOR). The breakthrough could facilitate the development of new medications to treat pain and addiction.
The KOR is activated by one of the body’s natural opioid molecules, called dynorphin. When activated, the receptor produces analgesia. It also suppresses the rewarding effects of addictive drugs, reducing the motivation to use them, but also contributes to withdrawal and stress responses that motivate addictive behavior.