Optogenetics Fiber-Optic Laser (IMAGE) Washington University School of Medicine Caption New research at Washington University in St. Louis shows that it's possible to activate opioid receptors with light instead of pain-killing drugs. The discovery eventually may lead to new ways to relieve severe pain without the addictive properties and side effects posed by opiates. Credit Robert Boston 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.