«Opioids have both
analgesic and rewarding
effects and they have these
effects through mu opioid receptors and these receptors are expressed in pain terminals in the spinal cord and in areas of the brain that regulate pain but are also expressed in areas that regulate reward and a sense of pleasure,» Boyle said, referring to cells found in a person's central nervous system that bind to naturally occurring opioid compounds and reduce pain and make people feel much
better.