Pain is a complex experience with sensory and emotional components. While acute pain is essential for survival, chronic pain is a debilitating disease accompanied by persistent unpleasant emotions. Efficient medications against chronic pain are lacking, and the absence of alternative to opioid analgesics has triggered the current Opioid Epidemic. Our lab studies how our nervous system generates pain perception, at the genetic, molecular, cellular, neural circuit, and behavioral levels. We also seek to understand how opioids alter activity in neural circuits to produce analgesia, but also side effects such as tolerance, addiction and respiratory depression. To this aim, we investigate the localization, trafficking and signaling properties of opioid receptors in neurons. These studies clarify pain and opioid mechanisms for identifying novel non-addictive drug targets to treat pain and strategies to dissociate opioid analgesia from deleterious effects.