Cannabinoid Receptor (IMAGE) NIH/National Institute on Drug Abuse Caption Superimposed on the shadow of a marijuana leaf and artistic smoke, the molecular structure of the cannabinoid receptor CB1 is shown as a yellow ribbon with the bound stabilizing antagonist AM6538 as orange sticks. The active ingredient in marijuana, THC, is show as yellow sticks among the smoke Credit Yekaterina Kadyshevskaya, The Stevens Laboratory, University of Southern California Usage Restrictions None 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.