Kappa Opioid Receptor (IMAGE) University of North Carolina Health Care Caption This is an illustration of the active state kappa opioid receptor bound to a morphine derivative (purple). Credit Tao Che and Daniel Wacker, Roth Lab, UNC School of Medicine Usage Restrictions credit properly License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.