Delta-opioid receptors are a type of protein found in the brain and other parts of the body. They belong to the opioid receptor family, which also includes mu-opioid receptors and kappa-opioid receptors. These receptors play a crucial role in modulating pain, mood, and emotional responses by interacting with natural and synthetic opioids. When activated by substances like endorphins or certain medications, delta-opioid receptors can produce effects such as pain relief and feelings of well-being. Research into these receptors is ongoing, as they may offer potential therapeutic targets for treating conditions like chronic pain and mood disorders without the side effects associated with other opioid receptors.