Which opioid receptor is associated with mediating euphoria?

The mu-1 opioid receptor is primarily associated with the modulation of euphoria. When opioids bind to these receptors in the brain, they can produce feelings of pleasure and well-being, which are part of what makes opioids effective for pain management as well as contributing to their potential for addiction. Activation of the mu-1 receptors influences the release of neurotransmitters that enhance mood and promote pleasurable sensations, making them significantly involved in the euphoric effects often reported by opioid users.

In contrast, while kappa and delta receptors can also have varying roles in pain and mood modulation, they typically do not mediate euphoria to the same extent as the mu-1 receptor. The mu-2 receptor, on the other hand, is more closely related to respiratory depression and sedation, rather than the euphoric effects seen with mu-1 activation.